WO2018116915A1 - 感活性光線性又は感放射線性樹脂組成物、感活性光線性又は感放射線性膜、パターン形成方法、及び、電子デバイスの製造方法 - Google Patents
感活性光線性又は感放射線性樹脂組成物、感活性光線性又は感放射線性膜、パターン形成方法、及び、電子デバイスの製造方法 Download PDFInfo
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/0045—Photosensitive materials with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists
- G03F7/0392—Macromolecular compounds which are photodegradable, e.g. positive electron resists the macromolecular compound being present in a chemically amplified positive photoresist composition
- G03F7/0397—Macromolecular compounds which are photodegradable, e.g. positive electron resists the macromolecular compound being present in a chemically amplified positive photoresist composition the macromolecular compound having an alicyclic moiety in a side chain
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/20—Exposure; Apparatus therefor
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/26—Processing photosensitive materials; Apparatus therefor
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/20—Exposure; Apparatus therefor
- G03F7/2051—Exposure without an original mask, e.g. using a programmed deflection of a point source, by scanning, by drawing with a light beam, using an addressed light or corpuscular source
- G03F7/2053—Exposure without an original mask, e.g. using a programmed deflection of a point source, by scanning, by drawing with a light beam, using an addressed light or corpuscular source using a laser
Definitions
- the present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition, an actinic ray-sensitive or radiation-sensitive film, a pattern forming method, and an electronic device manufacturing method.
- An actinic ray-sensitive or radiation-sensitive resin composition generates an acid in an exposed area by irradiation with radiation such as far ultraviolet light, and develops an active radiation irradiated area and a non-irradiated area by a reaction using this acid as a catalyst. It is a pattern forming material that changes the solubility in a liquid and forms a pattern on a substrate.
- a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component.
- a pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.
- a further short wavelength light source for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't. For this reason, for example, an ArF excimer laser resist containing a resin having an alicyclic hydrocarbon structure has been developed.
- the photoacid generator that is a main component of the actinic ray-sensitive or radiation-sensitive resin composition is a compound that absorbs light and generates an acid.
- sulfonium salts composed of a sulfonium cation and a counter anion (X ⁇ ) are widely used as a photoacid generator (see, for example, Patent Document 1).
- the present invention has a very high roughness performance, exposure latitude, and focus margin especially in the formation of ultrafine patterns (for example, contact hole patterns with a hole diameter of 45 nm or less, and line and space patterns with a line width of 45 nm or less).
- the present invention has the following configuration, whereby the above object of the present invention is achieved.
- EL An actinic ray-sensitive or radiation-sensitive resin composition that satisfies the relationship represented by the following formula (1) when the exposure latitude is EL and the aerial image intensity logarithmic gradient is NILS.
- EL is calculated by the following formula.
- EL (%) ⁇ [(exposure amount at which line width of line pattern is + 10% of 75 nm) ⁇ (exposure amount at which line width of line pattern is ⁇ 10% of 75 nm)] / (line width of line pattern is Exposure amount to be 75 nm) ⁇ ⁇ 100
- NILS is an aerial image intensity logarithmic gradient in an optical image having a line width of 75 nm.
- the actinic ray-sensitive or radiation-sensitive resin composition comprises (A) a photoacid generator that generates an acid having a pKa of ⁇ 1.40 or more upon irradiation with an actinic ray or radiation, and (B) an acid-decomposable group.
- the acid generated from the photoacid generator (A) upon irradiation with actinic rays or radiation is a sulfonic acid represented by any one of the following general formulas (a), (b) and (I) to (V).
- Rf 1 represents a fluorine atom or an alkyl group containing a fluorine atom.
- R 1 represents a monovalent organic group.
- Rf 2 and Rf 3 each independently represent a fluorine atom or an alkyl group containing a fluorine atom.
- R 2 represents a monovalent organic group.
- R 11 and R 12 each independently represent a monovalent organic group.
- R 13 represents a hydrogen atom or a monovalent organic group.
- L 1 represents a group represented by —CO—O—, —CO—, —O—, —S—, —O—CO—, —S—CO— or —CO—S—. Two of R 11 , R 12 and R 13 may be bonded to each other to form a ring.
- R 21 and R 22 each independently represent a monovalent organic group.
- R 23 represents a hydrogen atom or a monovalent organic group.
- L 2 represents a group represented by —CO—, —O—, —S—, —O—CO—, —S—CO— or —CO—S—.
- R 31 and R 33 each independently represents a hydrogen atom or a monovalent organic group.
- R 31 and R 33 may be bonded to each other to form a ring.
- R 41 and R 43 each independently represent a hydrogen atom or a monovalent organic group.
- R 41 and R 43 may be bonded to each other to form a ring.
- R 51 , R 52 and R 53 each independently represent a hydrogen atom or a monovalent organic group. Two of R 51 , R 52 and R 53 may be bonded to each other to form a ring.
- R 4A , R 5A and R 6A each independently represent a monovalent organic group.
- W A represents a -CO- or a divalent aromatic ring group.
- R 7A represents a hydrogen atom, a methyl group or a trifluoromethyl group.
- R 5A and R 6A may combine with each other to form a ring.
- R 4B , R 5B and R 6B each independently represent a hydrogen atom or a monovalent organic group.
- R 5B and R 6B may be bonded to each other to form a ring.
- W B represents —CO— or a divalent aromatic ring group.
- R 7B represents a hydrogen atom, a methyl group or a trifluoromethyl group.
- Composition [8] An actinic ray-sensitive or radiation-sensitive film formed from the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [7].
- the roughness performance, the exposure latitude, and the focus margin are extremely improved particularly in the formation of ultrafine patterns (for example, contact hole patterns with a hole diameter of 45 nm or less, and line and space patterns with a line width of 45 nm or less).
- ultrafine patterns for example, contact hole patterns with a hole diameter of 45 nm or less, and line and space patterns with a line width of 45 nm or less.
- the present invention will be described in detail.
- the description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
- the notation which does not describe substitution and non-substitution includes the thing which has a substituent with the thing which does not have a substituent.
- the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
- Actinic rays” or “radiation” in the present specification refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer laser, extreme ultraviolet rays (EUV light), X-rays, electron beams (EB), etc. Means.
- light means actinic rays or radiation.
- exposure in the present specification is not limited to exposure with a far ultraviolet ray, an extreme ultraviolet ray, an X-ray, an EUV light or the like represented by a mercury lamp or an excimer laser, but an electron beam, and In addition, drawing with a particle beam such as an ion beam is included in the exposure.
- “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
- (meth) acrylate represents acrylate and methacrylate
- (meth) acryl represents acryl and methacryl
- the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (Mw / Mn) of the resin are measured by GPC (solvent) using a GPC (Gel Permeation Chromatography) apparatus (HLC-8120GPC manufactured by Tosoh Corporation).
- the actinic ray-sensitive or radiation-sensitive resin composition of the present invention has an exposure latitude (EL) of EL and an aerial image intensity logarithmic gradient of NILS (Normalized Image Log Slope; NILS). And an actinic ray-sensitive or radiation-sensitive resin composition satisfying the relationship represented by the following formula (1).
- EL is calculated by the following formula.
- NILS is an aerial image intensity logarithmic gradient in an optical image having a line width of 75 nm.
- EL is measured by the following method.
- An antireflective film ARC29A manufactured by Nissan Chemical Industries, Ltd.
- the actinic ray-sensitive or radiation-sensitive resin composition is applied on the antireflection film so as to have a film thickness of 90 nm and baked (PB) at 100 ° C. for 60 seconds to obtain actinic ray-sensitive or radiation-sensitive material. Create a sex membrane.
- the exposed actinic ray-sensitive or radiation-sensitive film is baked (PEB) at 85 ° C. for 60 seconds, and then developed using butyl acetate as a developer.
- PEB baked
- butyl acetate as a developer.
- S-9380II scanning electron microscope
- the line portion was measured for the line pattern (line and space pattern) obtained as described above, and the line width of the line pattern was The exposure amount at which 75 nm is obtained is defined as Eop.
- the obtained line and space pattern is applied to the following formula to calculate EL.
- EL (%) ⁇ [(exposure amount at which line width of line pattern is + 10% of 75 nm) ⁇ (exposure amount at which line width of line pattern is ⁇ 10% of 75 nm)] / (line width of line pattern is Exposure amount to be 75 nm (Eop)) ⁇ ⁇ 100
- NILS is measured by the following method.
- the exposure conditions described in (3) above in the software Prolith made by KLA-Tencor (1: 1 line and space mask (6% halftone mask) with a pitch of 150 nm and a light shielding part of 75 nm), ArF exposure, NA 0.75 , Dipole illumination, outer sigma 0.89, inner sigma 0.65) were input, and an aerial image intensity logarithmic gradient in an optical image having a line width of 75 nm was calculated from the optical intensity distribution.
- the present invention has the above-described configuration, in particular, in the formation of ultrafine patterns (for example, contact hole patterns having a hole diameter of 45 nm or less or line and space patterns having a line width of 45 nm or less), roughness performance, exposure latitude, and focus margin are provided.
- ultrafine patterns for example, contact hole patterns having a hole diameter of 45 nm or less or line and space patterns having a line width of 45 nm or less
- roughness performance, exposure latitude, and focus margin are provided.
- the degree can be made very good. The reason is not clear, but is presumed as follows.
- EL / NILS is preferably 13.0 or more, and more preferably 14.0 or more.
- EL / NILS is generally 15.0 or less.
- the actinic ray-sensitive or radiation-sensitive resin composition according to the present invention is not particularly limited as long as it satisfies the above formula (1), that is, “EL / NILS> 12.0”.
- a photoacid generator that generates an acid having a pKa of ⁇ 1.40 or more upon irradiation hereinafter, also simply referred to as “photoacid generator (A)”
- photoacid generator (A) also simply referred to as “photoacid generator (A)”
- B) an Eth sensitivity of 5.64 or less.
- It is preferably an actinic ray-sensitive or radiation-sensitive resin composition containing a resin having a repeating unit having an acid-decomposable group, whereby the above formula (1) can be suitably achieved.
- the resin (B) has a repeating unit having an acid-decomposable group having an Eth sensitivity of 5.64 or less.
- the “acid-decomposable group having an Eth sensitivity of 5.64 or less” is an acid-decomposable group that easily decomposes and leaves by the action of an acid, as will be described in detail later. Therefore, in the exposed portion of the actinic ray-sensitive or radiation-sensitive film, the acid-decomposable group can be sufficiently decomposed by an acid that cannot be said to be a strong acid.
- the present inventors generate an acid that cannot be said to be a strong acid, as an acid generator, an acid having a pKa of ⁇ 1.40 or more by irradiation with actinic rays or radiation.
- an acid generator an acid having a pKa of ⁇ 1.40 or more by irradiation with actinic rays or radiation.
- the acid decomposition reaction of the acid-decomposable group proceeds in the exposed area, and the detachment from the acid-decomposable group is sufficiently generated.
- the dissolution contrast of the exposed portion and the unexposed portion with respect to the developing solution is very large, because of the fact that is easily diffused into the unexposed portion of the actinic ray-sensitive or radiation-sensitive film.
- the actinic ray-sensitive or radiation-sensitive resin composition described above it is considered that “EL / NILS> 12.0” can be achieved.
- the actinic ray-sensitive or radiation-sensitive resin composition of the present invention is preferably a resist composition, and may be a negative resist composition or a positive resist composition.
- the actinic ray-sensitive or radiation-sensitive resin composition of the present invention may be a resist composition for organic solvent development or a resist composition for alkali development.
- the resist composition of the present invention is typically a chemically amplified resist composition.
- the composition of the present invention will be described. To do.
- Photoacid generator that generates an acid having a pKa of ⁇ 1.40 or more upon irradiation with actinic rays or radiation>
- the pKa of the acid generated from the photoacid generator by irradiation with actinic rays or radiation is less than ⁇ 1.40, the diffusion of the leaving product from the acid-decomposable group to the unexposed area tends to be insufficient, As a result, since it becomes difficult to satisfy the above formula (1), in the above ultrafine pattern formation, there is a tendency for the roughness performance, exposure latitude performance, and focus margin to decrease. Further, the pKa of the acid is preferably 3.00 or less, whereby the acid strength of the acid does not become too low, and in the above ultrafine pattern formation, roughness performance, exposure latitude performance, and The focus margin tends to be improved.
- the pKa of the acid generated from the photoacid generator (A) upon irradiation with actinic rays or radiation is preferably ⁇ 1.40 or more and 3.00 or less, and is ⁇ 1.00 or more and 2.50 or less. More preferably, it is more preferably ⁇ 0.80 or more and 2.00 or less.
- the acid dissociation constant pKa represents the acid dissociation constant pKa in an aqueous solution.
- Chemical Handbook (II) (4th revised edition, 1993, edited by the Chemical Society of Japan, Maruzen Co., Ltd.) The lower the value, the higher the acid strength.
- the acid dissociation constant pKa in an aqueous solution can be measured by measuring an acid dissociation constant at 25 ° C. using an infinitely diluted aqueous solution, and using the following software package 1, Hammett
- the values based on the substituent constants and the database of known literature values can also be obtained by calculation.
- the values of pKa described in this specification all indicate values obtained by calculation using this software package.
- the photoacid generator (B) is preferably a compound that does not contain an aromatic ring in the anionic structure (substantially an ionic compound). Since such a photoacid generator (B) is particularly highly transparent to ArF light, it is sufficient to reach the bottom of the actinic ray-sensitive or radiation-sensitive film even when exposed to ArF light. Therefore, the effect of the present invention tends to be expressed more easily.
- the acid having a pKa of ⁇ 1.40 or more generated from the photoacid generator upon irradiation with actinic rays or radiation is preferably a sulfonic acid.
- the sulfonic acid is preferably an alkyl sulfonic acid in which one fluorine atom is bonded to the carbon atom at the ⁇ -position of the sulfonic acid group.
- “one fluorine atom is bonded to the ⁇ -position carbon atom of the sulfonic acid group” means that two or more fluorine atoms are not bonded to the ⁇ -position carbon atom of the sulfonic acid group.
- the alkyl group in this alkylsulfonic acid may have a substituent.
- R 1 and R in the following general formulas (a), (b) and (I) to (V): 2 , R 11 , R 12 , R 21 , R 22 , R 23 , R 33 , R 43, and R 53 may be exemplified by substituents that the monovalent organic group may have.
- the sulfonic acid generated from the photoacid generator (A) upon irradiation with actinic rays or radiation is specifically represented by any of the following general formulas (a), (b) and (I) to (V).
- a sulfonic acid is preferable.
- the photoacid generator (A) generates a sulfonic acid represented by any one of the following general formulas (a), (b) and (I) to (V) upon irradiation with actinic rays or radiation.
- An acid generator is preferred.
- Rf 1 represents a fluorine atom or an alkyl group containing a fluorine atom.
- R 1 represents a monovalent organic group.
- Rf 2 and Rf 3 are each independently a fluorine atom or an alkyl group containing a fluorine atom.
- R 2 represents a monovalent organic group.
- R 11 and R 12 each independently represent a monovalent organic group.
- R 13 represents a hydrogen atom or a monovalent organic group.
- L 1 represents a group represented by —CO—O—, —CO—, —O—, —S—, —O—CO—, —S—CO— or —CO—S—.
- R 21 and R 22 each independently represent a monovalent organic group.
- R 23 represents a hydrogen atom or a monovalent organic group.
- L 2 represents a group represented by —CO—, —O—, —S—, —O—CO—, —S—CO— or —CO—S—.
- Two of R 21 , R 22 and R 23 may be bonded to each other to form a ring.
- R 31 and R 33 each independently represents a hydrogen atom or a monovalent organic group. R 31 and R 33 may be bonded to each other to form a ring.
- R 41 and R 43 each independently represent a hydrogen atom or a monovalent organic group. R 41 and R 43 may be bonded to each other to form a ring.
- R 51 , R 52 and R 53 each independently represent a hydrogen atom or a monovalent organic group. Two of R 51 , R 52 and R 53 may be bonded to each other to form a ring.
- the monovalent organic group as the general formulas (a) and (b) preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, still more preferably 1 to 10 carbon atoms,
- an alkyl group, a cycloalkyl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, and the like can be given. These groups may further have a substituent.
- the monovalent organic group as 53 preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, still more preferably 1 to 10 carbon atoms, and examples thereof include alkyl groups and cycloalkyl groups. , Aryl group, aralkyl group, alkenyl group and the like. These groups may further have a substituent.
- substituents examples include a halogen atom, an alkyl group (which may be linear or branched, preferably having 1 to 12 carbon atoms), and a cycloalkyl group (monocyclic, polycyclic or spiro ring). And preferably has 3 to 20 carbon atoms), aryl group (preferably 6 to 14 carbon atoms), hydroxy group, carbonyl group, ether group, cyano group, alkoxy group, ester group, amide group, urethane group, ureido group , A thioether group, a sulfonamide group, a sulfonic acid ester group, and a group formed by combining two or more selected from these atoms and groups.
- a halogen atom an alkyl group (which may be linear or branched, preferably having 1 to 12 carbon atoms), and a cycloalkyl group (monocyclic, polycyclic or spiro ring). And preferably has 3 to
- the alkyl group containing a fluorine atom as Rf 1 , Rf 2 and Rf 3 in the general formulas (a) and (b) represents an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the carbon of the alkyl group
- the number is preferably 1 to 6, and more preferably 1 to 3.
- the alkyl group containing a fluorine atom is preferably a perfluoroalkyl group, more preferably a trifluoromethyl group.
- the photoacid generator (A) of the present invention is preferably a compound represented by the following general formula (A).
- Y - it is the general formula (a), represents a sulfonate anion corresponding to the acid represented by any one of (b) and (I) ⁇ (V).
- X + represents a cation.
- Cation as X + is not particularly limited, as a preferred embodiment, for example, described below general formula (ZI), (ZII) or (ZIII) in cation - include (Z portions other than).
- R 201 , R 202 and R 203 each independently represents an organic group.
- the organic group as R 201 , R 202 and R 203 generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
- Two of R 201 to R 203 may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.
- Examples of the group formed by combining two members out of R 201 to R 203 include an alkylene group (eg, butylene group, pentylene group).
- Z ⁇ represents a sulfonate anion corresponding to the sulfonate represented by any one of the above general formulas (a), (b) and (I) to (V).
- Examples of the organic group represented by R 201 , R 202 and R 203 include the corresponding groups in the compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) described later. Can be mentioned.
- the compound which has two or more structures represented by general formula (ZI) may be sufficient.
- at least one of R 201 to R 203 of the compound represented by the general formula (ZI) is a single bond or at least one of R 201 to R 203 of the other compound represented by the general formula (ZI). It may be a compound having a structure bonded through a linking group.
- More preferred (ZI) components include compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) described below.
- the compound (ZI-1) is at least one of aryl group R 201 ⁇ R 203 of formula (ZI), arylsulfonium compounds, namely, compounds containing an arylsulfonium as a cation.
- arylsulfonium compound all of R 201 to R 203 may be an aryl group, or a part of R 201 to R 203 may be an aryl group and the rest may be an alkyl group or a cycloalkyl group.
- arylsulfonium compound examples include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.
- the aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group.
- the aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a benzothiophene residue.
- the two or more aryl groups may be the same or different.
- the alkyl group or cycloalkyl group optionally possessed by the arylsulfonium compound is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
- the aryl group, alkyl group, and cycloalkyl group of R 201 to R 203 are an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms).
- An alkoxy group for example, having 1 to 15 carbon atoms
- a halogen atom for example, a hydroxyl group, and a phenylthio group may be substituted.
- Compound (ZI-2) is a compound in which R 201 to R 203 in formula (ZI) each independently represents an organic group having no aromatic ring.
- the aromatic ring includes an aromatic ring containing a hetero atom.
- the organic group containing no aromatic ring as R 201 to R 203 generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
- R 201 to R 203 are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group.
- a carbonylmethyl group particularly preferably a linear or branched 2-oxoalkyl group.
- the alkyl group and cycloalkyl group of R 201 ⁇ R 203 preferably a linear or branched alkyl group (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group) having 1 to 10 carbon atoms, carbon Examples thereof include cycloalkyl groups having a number of 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).
- R 201 to R 203 may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
- the compound (ZI-3) is a compound represented by the following general formula (ZI-3), which is a compound having a phenacylsulfonium salt structure.
- R 1c to R 5c are each independently a hydrogen atom, alkyl group, cycloalkyl group, aryl group, alkoxy group, aryloxy group, alkoxycarbonyl group, alkylcarbonyloxy group, cycloalkylcarbonyloxy group, halogen atom, hydroxyl group Represents a nitro group, an alkylthio group or an arylthio group.
- R 6c and R 7c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group.
- R x and R y each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.
- R 1c to R 5c , R 5c and R 6c , R 6c and R 7c , R 5c and R x , and R x and R y may be bonded to form a ring structure.
- this ring structure may contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
- the ring structure include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocycle, or a polycyclic fused ring formed by combining two or more of these rings.
- Examples of the ring structure include 3- to 10-membered rings, preferably 4- to 8-membered rings, more preferably 5- or 6-membered rings.
- Examples of the group formed by combining any two or more of R 1c to R 5c , R 6c and R 7c , and R x and R y include a butylene group and a pentylene group.
- the group formed by combining R 5c and R 6c and R 5c and R x is preferably a single bond or an alkylene group, and examples of the alkylene group include a methylene group and an ethylene group.
- Zc - is the general formula (a), represents a sulfonate anion corresponding to the acid represented by any one of (b) and (I) ⁇ (V).
- alkoxy group in the alkoxycarbonyl group as R 1c ⁇ R 5c are the same as specific examples of the alkoxy group as the R 1c ⁇ R 5c.
- Specific examples of the alkyl group in the alkylcarbonyloxy group and alkylthio group as R 1c ⁇ R 5c are the same as specific examples of the alkyl group of the R 1c ⁇ R 5c.
- Specific examples of the cycloalkyl groups in the cycloalkyl carbonyl group as R 1c ⁇ R 5c are the same as specific examples of cycloalkyl groups as the R 1c ⁇ R 5c.
- Specific examples of the aryl group in the aryloxy group and arylthio group as R 1c ⁇ R 5c are the same as specific examples of the aryl group of the R 1c ⁇ R 5c.
- Examples of the cation in the compound (ZI-2) or (ZI-3) in the present invention include cations described in paragraph [0036] and thereafter of US Patent Application Publication No. 2012/0076996.
- the compound (ZI-4) is represented by the following general formula (ZI-4).
- R 13 represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a cycloalkyl group. These groups may have a substituent.
- R 14 is independently a group having a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a cycloalkyl group, when a plurality of R 14 are present.
- R 15 each independently represents an alkyl group, a cycloalkyl group or a naphthyl group. These groups may have a substituent.
- Two R 15 may be bonded to each other to form a ring.
- the ring skeleton may contain a hetero atom such as an oxygen atom or a nitrogen atom.
- it is preferred that two R 15 are alkylene groups and are bonded to each other to form a ring structure.
- l represents an integer of 0-2.
- r represents an integer of 0 to 8.
- Z ⁇ represents a sulfonate anion corresponding to the sulfonate represented by any one of the above general formulas (a), (b) and (I) to (V).
- the alkyl group of R 13 , R 14 and R 15 is linear or branched and preferably has 1 to 10 carbon atoms, and is preferably a methyl group, an ethyl group, n -Butyl group, t-butyl group and the like are preferable.
- Examples of the cation of the compound represented by the general formula (ZI-4) in the present invention include paragraphs [0121], [0123], [0124] of JP2010-256842A, and JP2011-76056A. The cations described in paragraphs [0127], [0129], and [0130] of the above.
- R 204 to R 207 each independently represents an aryl group, an alkyl group, or a cycloalkyl group.
- the aryl group of R 204 to R 207 is preferably a phenyl group or a naphthyl group, more preferably a phenyl group.
- the aryl group of R 204 to R 207 may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like.
- Examples of the skeleton of the aryl group having a heterocyclic structure include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
- the alkyl group and cycloalkyl group in R 204 to R 207 are preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups having a number of 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).
- the aryl group, alkyl group, and cycloalkyl group of R 204 to R 207 may have a substituent.
- substituents that the aryl group, alkyl group, and cycloalkyl group of R 204 to R 207 may have include an alkyl group (eg, having 1 to 15 carbon atoms) and a cycloalkyl group (eg, having 3 to 15 carbon atoms). ), Aryl groups (for example, having 6 to 15 carbon atoms), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups, and the like.
- Z ⁇ represents a sulfonate anion corresponding to the sulfonate represented by any one of the above general formulas (a), (b) and (I) to (V).
- the photoacid generator (A) of the present invention may be in the form of a low molecular compound or may be incorporated in a part of the polymer. Moreover, you may use together the form incorporated in a part of polymer and the form of a low molecular compound. In the present invention, the photoacid generator (A) is preferably in the form of a low molecular compound.
- the molecular weight is preferably 3000 or less, more preferably 2000 or less, and even more preferably 1000 or less.
- the photoacid generator (A) of the present invention When the photoacid generator (A) of the present invention is in a form incorporated in a part of the polymer, it may be incorporated in a part of the resin (B) described later, and is a resin different from the resin (B). It may be incorporated into.
- the photoacid generator (A) of the present invention can be synthesized by a known method, for example, according to the method described in JP-A No. 2007-161707.
- the photo-acid generator (A) of this invention can be used individually by 1 type or in combination of 2 or more types.
- the content of the photoacid generator (A) of the present invention in the composition (when there are a plurality of types) is preferably 0.1 to 30% by mass, based on the total solid content of the composition, Preferably, the content is 0.5 to 25% by mass, more preferably 3 to 20% by mass, and particularly preferably 3 to 15% by mass.
- the photoacid generator (A) of the present invention contains a compound represented by the above general formula (ZI-3) or (ZI-4)
- the content of the acid generator contained in the composition (multiple types)
- the total if present) is preferably 5 to 35% by mass, more preferably 7 to 30% by mass, based on the total solid content of the composition.
- the actinic ray-sensitive or radiation-sensitive resin composition of the present invention may or may not contain a photoacid generator different from the photoacid generator (A), but by irradiation with actinic rays or radiation. It is preferable not to contain a photoacid generator that generates an acid having a pKa of less than -1.40.
- the resin (B) is a resin having a repeating unit having an acid-decomposable group (hereinafter also referred to as “acid-decomposable resin” or “resin (B)”).
- the Eth sensitivity of the repeating unit having an acid-decomposable group in the resin (B) is 5.64 or less.
- the Eth sensitivity is an index corresponding to “exposure amount necessary for forming a pattern”, and the smaller the value, the more the acid-decomposable group is decomposed by the acid at a low exposure amount (typically, acid exposure).
- the protecting group in the decomposable group is eliminated).
- the Eth sensitivity of the repeating unit having an acid-decomposable group (hereinafter, also simply referred to as “acid-decomposable repeating unit”) is 5.64 or less because the upper limit of the Eth sensitivity is suppressed. This means that the repeating unit having a functional group has high acid decomposition reactivity.
- a resist composition (actinic ray-sensitive or radiation-sensitive resin composition) is prepared.
- the acid-decomposable resin in the resist composition has the following lactone group-containing repeating unit a and an acid-decomposable repeating unit which is a measurement target of Eth sensitivity at a molar ratio of 40:60, and has a weight average molecular weight ( Mw) is an acid-decomposable resin having a 10,000.
- ARC29A Organic antireflection film-forming ARC29A (Nissan Chemical Co., Ltd.) is applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm.
- the resist composition prepared above is applied and baked at 100 ° C. for 60 seconds (PB: Prebake) to form a resist film having a thickness of 100 nm.
- the film thickness after PEB and after development is measured using VM-3110 (manufactured by Dainippon Screening) to obtain an exposure dose-film thickness curve, and the Eth sensitivity is obtained.
- the post-development film thickness when the exposure amount is E [mJ / cm 2 ] is T E [nm]
- the exposure amount when ⁇ E represented by the following formula (1) becomes the maximum value ⁇ max is
- the Eth sensitivity is expressed by the following equation (2).
- (1 ⁇ Xmax / ⁇ max / 100) means “1 ⁇ Xmax ⁇ ⁇ max ⁇ 100”, that is, ⁇ 1 ⁇ (Xmax / ⁇ max / 100) ⁇ .
- Xmax is expressed by the following formula (3).
- the method for calculating the Eth sensitivity of the acid-decomposable repeating unit has been described above.
- the acid-decomposable resin used in the above ⁇ (A) Preparation of resist composition> is typically obtained by the following method. Can do.
- the lactone group-containing repeating unit a and the lactone group-containing repeating unit a having a molar ratio of 40:60 are included in the lactone group-containing repeating unit a and the acid-decomposable repeating unit whose Eth sensitivity is measured.
- the corresponding monomer and the monomer corresponding to the acid-decomposable repeating unit whose Eth sensitivity is to be measured are 2,2 ′ in an amount such that the weight-average molecular weight (Mw) of the acid-decomposable resin to be polymerized is 10,000.
- -Dimethyl azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] (polymerization initiator) is dissolved in cyclohexanone (monomer concentration is 25% by mass) and polymerized at 80 ° C under a nitrogen stream.
- a cyclohexanone mixed solution containing a polymerization initiator and a monomer separately prepared for cyclohexanone accommodated in a flask at 80 ° C. the mass of cyclohexanone in this mixed solution is four times the mass of cyclohexanone in the flask Is added dropwise over 4 hours, followed by further stirring at 80 ° C. for 2 hours.
- reprecipitation treatment is performed with a large amount of methanol / water (mass ratio 9: 1), and the precipitate is filtered.
- the obtained solid is vacuum-dried to obtain an acid-decomposable resin, which is used for obtaining the Eth sensitivity (acid-decomposition reactivity) of the acid-decomposable repeating unit.
- the acid-decomposable resin is used in the pattern forming method of the present invention, typically, when an organic developer is used as the developer, a negative pattern is suitably formed. When an alkali developer is used as the developer, a positive pattern is preferably formed.
- the acid-decomposable group is a group that is decomposed by the action of an acid and increases in polarity, and preferably has a structure in which the polar group is protected by a group that decomposes and leaves by the action of an acid (leaving group). Since the Eth sensitivity of the acid-decomposable repeating unit tends to change depending on the type of the leaving group, the Eth sensitivity of the acid-decomposable repeating unit is set to 5.64 or less by selecting the structure of the leaving group. be able to.
- polar groups include phenolic hydroxyl groups, carboxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkyl Sulfonyl) (alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris Acidic groups such as (alkylsulfonyl) methylene groups (groups dissociated in a 2.38 mass% tetramethylammonium hydroxide aqueous solution conventionally used as a resist developing solution), alcoholic phosphat
- the alcoholic hydroxyl group is a hydroxyl group bonded to a hydrocarbon group and means a hydroxyl group other than a hydroxyl group directly bonded on an aromatic ring (phenolic hydroxyl group).
- An aliphatic alcohol substituted with a functional group for example, a fluorinated alcohol group (such as a hexafluoroisopropanol group)) is excluded.
- the alcoholic hydroxyl group is preferably a hydroxyl group having a pKa (acid dissociation constant) of 12 or more and 20 or less.
- Preferred polar groups include carboxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), and sulfonic acid groups.
- a preferable group as the acid-decomposable group is a group in which the hydrogen atom of these groups is substituted with a group capable of leaving with an acid.
- Examples of the group capable of leaving with an acid (leaving group) include —C (R 36 ) (R 37 ) (R 38 ), —C (R 36 ) (R 37 ) (OR 39 ), —C (R 01) (R 02) (can be exemplified OR 39) or the like.
- R 36 to R 39 each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
- R 36 and R 37 may be bonded to each other to form a ring.
- R 01 and R 02 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
- the alkyl group of R 36 to R 39 , R 01 and R 02 is preferably an alkyl group having 1 to 8 carbon atoms, for example, methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl Group, octyl group and the like.
- the cycloalkyl group of R 36 to R 39 , R 01 and R 02 may be monocyclic or polycyclic.
- the monocyclic type is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.
- the polycyclic type is preferably a cycloalkyl group having 6 to 20 carbon atoms. For example, an adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, ⁇ -pinel group, tricyclodecanyl group, tetracyclododecyl group. Group, androstanyl group and the like.
- the aryl group of R 36 to R 39 , R 01 and R 02 is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
- the aralkyl group of R 36 to R 39 , R 01 and R 02 is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group and a naphthylmethyl group.
- the alkenyl group of R 36 to R 39 , R 01 and R 02 is preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group.
- the ring formed by combining R 36 and R 37 is preferably a cycloalkyl group (monocyclic or polycyclic).
- the cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group or an adamantyl group.
- a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferable, and a monocyclic cycloalkyl group having 5 carbon atoms is particularly preferable.
- the acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.
- Resin (B) is a repeating unit having an acid-decomposable group, and preferably has a repeating unit represented by the following general formula (AI) assuming that the Eth sensitivity satisfies 5.64 or less.
- Xa 1 represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.
- T represents a single bond or a divalent linking group.
- Rx 1 to Rx 3 each independently represents an alkyl group or a cycloalkyl group. Two of Rx 1 to Rx 3 may combine to form a ring structure.
- Examples of the divalent linking group for T include an alkylene group, —COO—Rt— group, —O—Rt— group, phenylene group and the like.
- Rt represents an alkylene group or a cycloalkylene group.
- T is preferably a single bond or a —COO—Rt— group.
- Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a —CH 2 — group, — (CH 2 ) 2 — group, or — (CH 2 ) 3 — group. More preferably, T is a single bond.
- the alkyl group of Xa1 may have a substituent, and examples of the substituent include a hydroxyl group and a halogen atom (preferably a fluorine atom).
- the alkyl group for X a1 preferably has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a trifluoromethyl group, and a methyl group is preferable.
- X a1 is preferably a hydrogen atom or a methyl group.
- the alkyl group of Rx 1 , Rx 2 and Rx 3 may be linear or branched, and is a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl. Group, t-butyl group and the like are preferable.
- the number of carbon atoms of the alkyl group is preferably 1 to 10, and more preferably 1 to 5.
- Examples of the cycloalkyl group of Rx 1 , Rx 2 and Rx 3 include polycyclic rings such as a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group and an adamantyl group. Are preferred.
- the ring structure formed by combining two of Rx 1 , Rx 2 and Rx 3 includes a monocyclic cycloalkane ring such as cyclopentyl ring and cyclohexyl ring, norbornane ring, tetracyclodecane ring, tetracyclododecane ring, adamantane ring
- a polycyclic cycloalkyl group such as is preferable.
- a monocyclic cycloalkane ring having 5 or 6 carbon atoms is particularly preferable.
- Rx 1 , Rx 2 and Rx 3 are preferably each independently an alkyl group, more preferably a linear or branched alkyl group having 1 to 4 carbon atoms.
- Each of the above groups may have a substituent, and examples of the substituent include an alkyl group (1 to 4 carbon atoms), a cycloalkyl group (3 to 8 carbon atoms), a halogen atom, an alkoxy group (carbon 1 to 4), a carboxyl group, an alkoxycarbonyl group (2 to 6 carbon atoms), and the like, and 8 or less carbon atoms are preferable.
- a substituent having no hetero atom such as an oxygen atom, a nitrogen atom, or a sulfur atom is more preferable (for example, More preferably, it is not an alkyl group substituted with a hydroxyl group, etc.), more preferably a group consisting of only a hydrogen atom and a carbon atom, and particularly preferably a linear or branched alkyl group or a cycloalkyl group. .
- Rx 1 to Rx 3 are each independently an alkyl group, and it is preferable that two of Rx 1 to Rx 3 are not bonded to form a ring structure.
- an increase in the volume of the group represented by —C (Rx 1 ) (Rx 2 ) (Rx 3 ) as a group capable of decomposing and leaving by the action of an acid can be suppressed, and after the exposure step and the exposure step In the post-exposure heating step that may be performed, the volume shrinkage of the exposed portion tends to be suppressed.
- Resin (B) is a repeating unit having an acid-decomposable group, and has a repeating unit represented by the following general formula (A) or (B), assuming that the Eth sensitivity satisfies 5.64 or less. It is preferable.
- R 4A , R 5A and R 6A each independently represent a monovalent organic group.
- W A represents a -CO- or a divalent aromatic ring group.
- R 7A represents a hydrogen atom, a methyl group or a trifluoromethyl group.
- R 5A and R 6A may combine with each other to form a ring.
- R 4B , R 5B and R 6B each independently represent a hydrogen atom or a monovalent organic group.
- R 5B and R 6B may be bonded to each other to form a ring.
- W B represents —CO— or a divalent aromatic ring group.
- R 7B represents a hydrogen atom, a methyl group or a trifluoromethyl group.
- the monovalent organic group as R 4A , R 5A , R 6A , R 4B , R 5B and R 6B preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, still more preferably.
- Examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkylcarbonyl group, a cycloalkylcarbonyl group, and an alkyloxycarbonyl group. These groups may further have a substituent.
- substituents examples include a halogen atom, an alkyl group (which may be linear or branched, and preferably 1 to 12 carbon atoms), and a cycloalkyl group (monocyclic, polycyclic or spirocyclic).
- a halogen atom an alkyl group (which may be linear or branched, and preferably 1 to 12 carbon atoms), and a cycloalkyl group (monocyclic, polycyclic or spirocyclic).
- aryl group preferably having 6 to 14 carbon atoms
- hydroxy group carbonyl group
- ether group preferably having 6 to 14 carbon atoms
- hydroxy group carbonyl group
- ether group preferably having 6 to 14 carbon atoms
- hydroxy group carbonyl group
- ether group preferably having 6 to 14 carbon atoms
- hydroxy group carbonyl group
- ether group preferably having 6 to 14 carbon atoms
- hydroxy group carbonyl group
- ether group
- the divalent aromatic ring group as W A and W B, phenylene group, naphthylene group, and, the like can be illustrated anthranylene group is preferably a phenylene group.
- the divalent aromatic ring group may further have a substituent, and specific examples thereof include monovalent organic groups as R 4A , R 5A , R 6A , R 4B , R 5B and R 6B. It is the same as that given as a specific example of the substituent which may have.
- repeating unit represented by the general formula (A) or (B) having an Eth sensitivity of 5.64 or less include specific examples of the repeating unit represented by the general formula (AI). Although the repeating unit mentioned and the following repeating unit are mentioned, this invention is not limited to these specific examples.
- Resin (B) is a repeating unit described in paragraphs [0057] to [0071] of JP-A-2014-202969 as a repeating unit having an acid-decomposable group, and has an Eth sensitivity of 5.64 or less. It is also preferable to have what satisfies the above.
- Resin (B) is a repeating unit that generates an alcoholic hydroxyl group described in paragraphs [0072] to [0073] of JP-A-2014-202969 as a repeating unit having an acid-decomposable group, and has an Eth sensitivity. May satisfy 5.64 or less.
- the Eth sensitivity of the acid-decomposable repeating unit of the resin (B) is usually 5.20 or more.
- the Eth sensitivity of the acid-decomposable repeating unit is preferably 5.20 or more and 5.64 or less, more preferably 5.20 or more and 5.55 or less, and more preferably 5.20 or more and 5.50 or less. Is more preferable.
- Resin (B) may have one type of repeating unit having an acid-decomposable group or two or more types.
- the resin (B) may have a repeating unit with an Eth sensitivity exceeding 5.64 as an acid-decomposable repeating unit.
- the Eth sensitivity of an acid-decomposable repeating unit having an Eth sensitivity exceeding 5.64 is usually 8.00 or less.
- repeating units with an Eth sensitivity exceeding 5.64 include the following units.
- the acid in the resin (B) may have an Eth sensitivity exceeding 5.64.
- the Eth sensitivity of the decomposable repeating unit is a weighted average of the Eth sensitivities of each acid-decomposable repeating unit, weighted by the number of moles of each acid-decomposable repeating unit, in other words, the Eth sensitivity of each acid-decomposable repeating unit.
- the Eth sensitivity of the acid-decomposable repeating units calculated by the weighted average is 5.64 or less, and the Eth sensitivity is The same applies to the preferable range.
- the resin (B) has a repeating unit with an Eth sensitivity exceeding 5.64 in addition to an acid-decomposable repeating unit with an Eth sensitivity of 5.64 or less, the acid decomposition with an Eth sensitivity of 5.64 or less.
- the content of the ionic repeating unit is preferably 50 mol% or more based on the total acid-decomposable repeating unit.
- the content of the repeating unit having an acid-decomposable group contained in the resin (B) is based on the total repeating units of the resin (B), It is preferably 20 to 90 mol%, more preferably 40 to 80 mol%.
- the resin (B) has a repeating unit represented by the above general formula (AI), and the content of the repeating unit represented by the above general formula (AI) with respect to all the repeating units of the resin (B) is 40 mol. % Or more is preferable.
- Resin (B) also preferably has a repeating unit having at least one selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure.
- Any lactone structure or sultone structure can be used as long as it has a lactone structure or sultone structure, but a 5- to 7-membered ring lactone structure or a 5- to 7-membered ring sultone structure is preferable.
- Other ring structures are condensed in a form that forms a bicyclo structure or spiro structure in a membered lactone structure, or other rings that form a bicyclo structure or a spiro structure in a 5- to 7-membered ring sultone structure Those having a condensed ring structure are more preferable.
- Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), (LC1-17), especially A preferred lactone structure is (LC1-4).
- the lactone structure portion or the sultone structure portion may or may not have a substituent (Rb 2 ).
- Preferred substituents (Rb 2 ) include alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 2 to 8 carbon atoms, and carboxyl groups. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. More preferred are an alkyl group having 1 to 4 carbon atoms, a cyano group, and an acid-decomposable group.
- n 2 represents an integer of 0 to 4. When n 2 is 2 or more, the plurality of substituents (Rb 2 ) may be the same or different. A plurality of substituents (Rb 2 ) may be bonded to form a ring.
- the repeating unit having a lactone structure or a sultone structure usually has an optical isomer, but any optical isomer may be used.
- One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used.
- the optical purity (ee) thereof is preferably 90% or more, more preferably 95% or more.
- the repeating unit having a lactone structure or a sultone structure is preferably a repeating unit represented by the following general formula (III).
- A represents an ester bond (a group represented by —COO—) or an amide bond (a group represented by —CONH—).
- R 0 represents an alkylene group, a cycloalkylene group, or a combination thereof independently when there are a plurality of R 0 .
- Z is independently a single bond, an ether bond, an ester bond, an amide bond, or a urethane bond when there are a plurality of Zs.
- each R independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group.
- R 8 represents a monovalent organic group having a lactone structure or a sultone structure.
- n is the number of repetitions of the structure represented by —R 0 —Z—, and represents an integer of 0 to 5, preferably 0 or 1, and more preferably 0. When n is 0, —R 0 —Z— does not exist and becomes a single bond.
- R 7 represents a hydrogen atom, a halogen atom or an alkyl group.
- the alkylene group and cycloalkylene group represented by R 0 may have a substituent.
- Z is preferably an ether bond or an ester bond, and particularly preferably an ester bond.
- the alkyl group for R 7 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
- the alkylene group of R 0 , the cycloalkylene group, and the alkyl group in R 7 may each be substituted.
- substituents examples include a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom, a mercapto group, a hydroxyl group, Examples thereof include alkoxy groups such as methoxy group, ethoxy group, isopropoxy group, t-butoxy group and benzyloxy group, and acyloxy groups such as acetyloxy group and propionyloxy group.
- R 7 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
- the preferred chain alkylene group for R 0 is preferably a chain alkylene having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and examples thereof include a methylene group, an ethylene group, and a propylene group.
- a preferred cycloalkylene group is a cycloalkylene group having 3 to 20 carbon atoms, and examples thereof include a cyclohexylene group, a cyclopentylene group, a norbornylene group, and an adamantylene group.
- a chain alkylene group is more preferable, and a methylene group is particularly preferable.
- the monovalent organic group having a lactone structure or a sultone structure represented by R 8 is not limited as long as it has a lactone structure or a sultone structure. Specific examples include those represented by the general formulas (LC1-1) to ( LC1-21) and a lactone structure or a sultone structure represented by any of (SL1-1) to (SL1-3), among which the structure represented by (LC1-4) is particularly preferable. Further, n 2 in (LC1-1) to (LC1-21) is more preferably 2 or less.
- R 8 is preferably a monovalent organic group having an unsubstituted lactone structure or sultone structure, or a monovalent organic group having a lactone structure or sultone structure having a methyl group, a cyano group or an alkoxycarbonyl group as a substituent.
- a monovalent organic group having a lactone structure (cyanolactone) having a cyano group as a substituent is more preferable.
- repeating unit having a group having a lactone structure or a sultone structure are shown below, but the present invention is not limited thereto.
- the content of the repeating unit having a lactone structure or a sultone structure is 5 to 60 mol% with respect to all the repeating units of the resin (B). More preferably, it is 5 to 55 mol%, still more preferably 10 to 50 mol%.
- the resin (B) may have a repeating unit having a carbonate structure.
- the carbonate structure is preferably a cyclic carbonate structure.
- the repeating unit having a cyclic carbonate structure is preferably a hydrophilic repeating unit. Thereby, swelling during development is suppressed.
- the repeating unit having a cyclic carbonate structure is preferably a repeating unit represented by the following general formula (A-1).
- R A 1 represents a hydrogen atom or an alkyl group.
- R A 2 each independently represents a substituent when n is 2 or more.
- A represents a single bond or a divalent linking group.
- Z represents an atomic group that forms a monocyclic or polycyclic structure together with a group represented by —O—C ( ⁇ O) —O— in the formula.
- n represents an integer of 0 or more.
- the alkyl group represented by R A 1 may have a substituent such as a fluorine atom.
- R A 1 preferably represents a hydrogen atom, a methyl group or a trifluoromethyl group, and more preferably represents a methyl group.
- the substituent represented by R A 2 is, for example, an alkyl group, a cycloalkyl group, a hydroxyl group, an alkoxy group, an amino group, or an alkoxycarbonylamino group.
- an alkyl group having 1 to 5 carbon atoms for example, a linear alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group; an isopropyl group, an isobutyl group or a t-butyl group.
- Examples thereof include branched alkyl groups having 3 to 5 carbon atoms such as
- the alkyl group may have a substituent such as a hydroxyl group.
- n is an integer of 0 or more representing the number of substituents. n is, for example, preferably 0 to 4, more preferably 0.
- Examples of the divalent linking group represented by A include an alkylene group, a cycloalkylene group, an ester bond, an amide bond, an ether bond, a urethane bond, a urea bond, or a combination thereof.
- the alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and examples thereof include a methylene group, an ethylene group, and a propylene group.
- A is preferably a single bond or an alkylene group.
- Examples of the polycycle including —O—C ( ⁇ O) —O— represented by Z include, for example, a cyclic carbonate represented by the following general formula (a) together with one or more other ring structures: Examples include a structure forming a condensed ring and a structure forming a spiro ring.
- the “other ring structure” that can form a condensed ring or a spiro ring may be an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic ring. .
- Monomers corresponding to the repeating units represented by the general formula (A-1) are, for example, Tetrahedron Letters, Vol. 27, no. 32 p. 3741 (1986), Organic Letters, Vol. 4, no. 15p. 2561 (2002) and the like, and can be synthesized by a conventionally known method.
- one type of repeating units represented by the general formula (A-1) may be contained alone, or two or more types may be contained.
- the content of the repeating unit having a cyclic carbonate structure (preferably, the repeating unit represented by the general formula (A-1)) is based on the total repeating units constituting the resin (B). It is preferably 3 to 80 mol%, more preferably 3 to 60 mol%, particularly preferably 3 to 30 mol%, and most preferably 10 to 15 mol%.
- R A 1 in the following specific examples are the same meaning as R A 1 in the general formula (A-1).
- Resin (B) may have a repeating unit having a hydroxyl group or a cyano group.
- Examples of such a repeating unit include the repeating units described in paragraphs [0081] to [0084] of JP-A No. 2014-098921.
- the resin (B) may have a repeating unit having an acid group.
- the acid group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bissulfonylimide group, and an aliphatic alcohol (for example, hexafluoroisopropanol group) in which the ⁇ -position is substituted with an electron withdrawing group.
- the repeating unit having an acid group include the repeating units described in paragraphs [0085] to [0086] of JP-A-2014-089921.
- the resin (B) can further have a repeating unit that has an alicyclic hydrocarbon structure having no polar group (for example, an acid group, a hydroxyl group, a cyano group, etc.) and does not exhibit acid decomposability.
- a repeating unit that has an alicyclic hydrocarbon structure having no polar group (for example, an acid group, a hydroxyl group, a cyano group, etc.) and does not exhibit acid decomposability.
- a repeating unit include the repeating units described in paragraphs [0114] to [0123] of JP-A-2014-106299.
- the resin (B) may contain, for example, repeating units described in paragraphs [0045] to [0065] of JP-A-2009-258586.
- Resin (B) used in the method of the present invention in addition to the above repeating structural unit, dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and further, resolving power which is a general necessary characteristic of resist,
- Various repeating structural units can be included for the purpose of adjusting heat resistance, sensitivity, and the like. Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.
- a monomer for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.
- any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.
- the content molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and the general required performance of the resist, resolving power, heat resistance, sensitivity. It is set appropriately in order to adjust etc.
- the resin (B) preferably has substantially no aromatic group from the viewpoint of transparency to ArF light. More specifically, the repeating unit having an aromatic group in the entire repeating unit of the resin (B) is preferably 5 mol% or less, more preferably 3 mol% or less, and ideally 0 More preferably, it does not have a repeating unit having mol%, that is, an aromatic group.
- the resin (B) preferably has a monocyclic or polycyclic alicyclic hydrocarbon structure.
- the resin (B) is preferably one in which all of the repeating units are composed of (meth) acrylate-based repeating units.
- all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are methacrylate repeating units and acrylate repeating units.
- the acrylate-based repeating unit is preferably 50 mol% or less of the total repeating units.
- the resin (B) preferably has an aromatic group.
- the resin (B) contains a repeating unit containing a phenolic hydroxyl group
- examples of the repeating unit containing a phenolic hydroxyl group include a hydroxystyrene repeating unit and a hydroxystyrene (meth) acrylate repeating unit.
- the resin (B) may be any of a random polymer, a block polymer, or a graft polymer.
- the resin (B) can be synthesized according to a conventional method (for example, radical polymerization).
- a conventional method for example, radical polymerization.
- a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours.
- the dropping polymerization method is added, and the dropping polymerization method is preferable.
- a part of the monomer species may be previously charged in the polymerization vessel.
- a copolymer having a uniform composition ratio from the start of polymerization to the completion of polymerization can be obtained, and the solubility in the developer is made uniform.
- reaction solvent examples include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt
- the polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon.
- a polymerization initiator a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization.
- azo initiator an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable.
- Preferable initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like.
- an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery.
- the solid content concentration in the reaction solution is 5 to 50% by mass, preferably 10 to 30% by mass.
- the reaction temperature is usually 10 ° C. to 150 ° C., preferably 30 ° C. to 120 ° C., more preferably 60 to 100 ° C.
- the weight average molecular weight of the resin (B) is preferably 1,000 to 200,000, more preferably 2,000 to 20,000, still more preferably 3,000 to 15,000, particularly preferably 3, 000 to 11,000.
- the degree of dispersion is usually 1.0 to 3.0, preferably 1.0 to 2.6, more preferably 1.0 to 2.0, and particularly preferably 1.1 to 2.0. Those in the range are used. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the side wall of the resist pattern, the better the roughness.
- the resin (B) may be used alone or in combination.
- the Eth sensitivity of the acid-decomposable repeating unit in the resin (B) is the Eth sensitivity of the acid-decomposable repeating unit of each acid-decomposable resin with the weight of each acid-decomposable resin as a weight. This is a weighted average of sensitivity. In other words, the sum of the sensitivity of the acid-decomposable repeating unit of each acid-decomposable resin multiplied by the mass fraction of each acid-decomposable resin with respect to the total mass of the acid-decomposable resin. It is a thing.
- an acid-decomposable resin whose acid decomposable repeating unit has an Eth sensitivity of 5.64 or less and an acid-decomposable repeating unit whose Eth sensitivity is 5.64 or more as the resin (B).
- the content of the acid-decomposable resin having an Eth-decomposable repeating unit with an Eth sensitivity of 5.64 or less relative to the total amount of the acid-decomposable resin is less than the total amount of the acid-decomposable resin. It is preferable that the Eth sensitivity is higher than the content of the acid-decomposable resin exceeding 5.64.
- Content of resin (B) in the total solid of the composition of this invention is 20 mass% or more.
- the upper limit is not particularly limited, but is preferably 99% by mass or less, more preferably 97% by mass or less, and still more preferably 95% by mass or less.
- the composition of the present invention may contain a hydrophobic resin (hereinafter also referred to as “hydrophobic resin (D)” or simply “resin (D)”).
- the hydrophobic resin (D) is preferably different from the acid-decomposable resin.
- the hydrophobic resin (D) is preferably designed to be unevenly distributed at the interface.
- unlike the surfactant it is not always necessary to have a hydrophilic group in the molecule, and the polar / nonpolar substance is mixed uniformly. You don't have to contribute to Examples of the effects of adding the hydrophobic resin include control of the static / dynamic contact angle of the resist film surface with respect to water, improvement of immersion liquid followability, and suppression of outgas.
- the hydrophobic resin (D) is selected from any one of “fluorine atom”, “silicon atom”, and “CH 3 partial structure contained in the side chain portion of the resin” from the viewpoint of uneven distribution in the film surface layer. It is preferable to have the above, and it is more preferable to have two or more.
- the hydrophobic resin (D) contains a fluorine atom and / or a silicon atom
- the fluorine atom and / or silicon atom in the hydrophobic resin (D) may be contained in the main chain of the resin. , May be contained in the side chain.
- the hydrophobic resin (D) contains a fluorine atom
- it is a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a partial structure having a fluorine atom.
- the alkyl group having a fluorine atom preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms
- a cycloalkyl group having a fluorine atom and an aryl group having a fluorine atom are a cycloalkyl group in which one hydrogen atom is substituted with a fluorine atom and an aryl group having a fluorine atom, respectively, and further a substituent other than a fluorine atom is substituted. You may have.
- alkyl group having a fluorine atom examples include groups represented by the following general formulas (F2) to (F4).
- the invention is not limited to this.
- R 57 to R 68 each independently represents a hydrogen atom, a fluorine atom or an alkyl group (straight or branched).
- R 57 to R 61 , at least one of R 62 to R 64 , and at least one of R 65 to R 68 are each independently a fluorine atom or at least one hydrogen atom is a fluorine atom. It represents a substituted alkyl group (preferably having 1 to 4 carbon atoms). All of R 57 to R 61 and R 65 to R 67 are preferably fluorine atoms.
- R 62 , R 63 and R 68 are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Further preferred. R 62 and R 63 may be connected to each other to form a ring.
- the hydrophobic resin (D) may contain a silicon atom.
- the partial structure having a silicon atom is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure.
- Examples of the repeating unit having a fluorine atom or a silicon atom include those exemplified in US2012 / 0251948A1 [0519].
- the hydrophobic resin (D) it is also preferred to include CH 3 partial structure side chain moiety.
- CH 3 partial structure contained in the side chain moiety in the hydrophobic resin (D) (hereinafter, simply referred to as "side chain CH 3 partial structure")
- The, CH 3 partial structure an ethyl group, and a propyl group having Is included.
- a methyl group directly bonded to the main chain of the hydrophobic resin (D) (for example, an ⁇ -methyl group of a repeating unit having a methacrylic acid structure) is caused by the influence of the main chain on the surface of the hydrophobic resin (D). Since the contribution to uneven distribution is small, it is not included in the CH 3 partial structure in the present invention.
- the hydrophobic resin (D) is a repeating unit derived from a monomer having a polymerizable moiety having a carbon-carbon double bond, such as a repeating unit represented by the following general formula (M).
- R 11 to R 14 are CH 3 “as is”, the CH 3 is not included in the CH 3 partial structure of the side chain moiety in the present invention.
- CH 3 partial structure exists through some atoms from C-C backbone, and those falling under CH 3 partial structures in the present invention.
- R 11 is an ethyl group (CH 2 CH 3 )
- R 11 to R 14 each independently represents a side chain portion.
- R 11 to R 14 in the side chain portion include a hydrogen atom and a monovalent organic group.
- the monovalent organic group for R 11 to R 14 include an alkyl group, a cycloalkyl group, an aryl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, and a cycloalkylaminocarbonyl.
- Group, an arylaminocarbonyl group, and the like, and these groups may further have a substituent.
- the hydrophobic resin (D) is preferably a resin having a repeating unit having a CH 3 partial structure in the side chain portion, and as such a repeating unit, a repeating unit represented by the following general formula (II), and It is more preferable to have at least one repeating unit (x) among repeating units represented by the following general formula (III).
- X b1 represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom
- R 2 has one or more CH 3 partial structure represents a stable organic radical to acid.
- the organic group that is stable to acid is more preferably an organic group that does not have the “acid-decomposable group” described in the resin (A).
- the alkyl group of Xb1 preferably has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a trifluoromethyl group, and a methyl group is preferable.
- X b1 is preferably a hydrogen atom or a methyl group.
- R 2 include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, and an aralkyl group having one or more CH 3 partial structures.
- R 2 is preferably an alkyl group or an alkyl-substituted cycloalkyl group having one or more CH 3 partial structures.
- the acid-stable organic group having one or more CH 3 partial structures as R 2 preferably has 2 or more and 10 or less CH 3 partial structures, and more preferably 2 or more and 8 or less.
- Preferred specific examples of the repeating unit represented by the general formula (II) are shown below. Note that the present invention is not limited to this.
- the repeating unit represented by the general formula (II) is preferably an acid-stable (non-acid-decomposable) repeating unit, and specifically, a group that decomposes by the action of an acid to generate a polar group. It is preferable that it is a repeating unit which does not have.
- the repeating unit represented by formula (III) will be described in detail.
- X b2 represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom
- R 3 represents an acid-stable organic group having one or more CH 3 partial structures
- n represents an integer of 1 to 5.
- the alkyl group of Xb2 is preferably an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a trifluoromethyl group, and a hydrogen atom is preferable.
- X b2 is preferably a hydrogen atom. Since R 3 is an organic group that is stable against acid, more specifically, R 3 is preferably an organic group that does not have the “acid-decomposable group” described in the resin P.
- R 3 includes an alkyl group having one or more CH 3 partial structures.
- the acid-stable organic group having one or more CH 3 partial structures as R 3 preferably has 1 or more and 10 or less CH 3 partial structures, more preferably 1 or more and 8 or less, More preferably, it is 1 or more and 4 or less.
- n represents an integer of 1 to 5, more preferably an integer of 1 to 3, and still more preferably 1 or 2.
- the repeating unit represented by the general formula (III) is preferably an acid-stable (non-acid-decomposable) repeating unit, and specifically, a group that decomposes by the action of an acid to generate a polar group. It is preferable that it is a repeating unit which does not have.
- the repeating unit represented by the general formula (II) contains a CH 3 partial structure in the side chain portion, and particularly when it does not have a fluorine atom and a silicon atom
- the repeating unit represented by the general formula (II) contains a CH 3 partial structure in the side chain portion, and particularly when it does not have a fluorine atom and a silicon atom
- the content of at least one repeating unit (x) among the repeating units represented by the general formula (III) is preferably 90 mol% or more based on all repeating units of the hydrophobic resin (D). More preferably, it is 95 mol% or more. Content is 100 mol% or less normally with respect to all the repeating units of hydrophobic resin (D).
- the hydrophobic resin (D) comprises at least one repeating unit (x) among the repeating unit represented by the general formula (II) and the repeating unit represented by the general formula (III). ),
- the surface free energy of the hydrophobic resin (D) increases.
- the hydrophobic resin (D) is less likely to be unevenly distributed on the surface of the resist film, and the static / dynamic contact angle of the resist film with respect to water can be reliably improved and the immersion liquid followability can be improved. it can.
- the hydrophobic resin (D) includes the following (x) to (z) regardless of whether (i) a fluorine atom and / or a silicon atom is included or (ii) a CH 3 partial structure is included in the side chain portion. ) May have at least one group selected from the group of (X) an acid group, (Y) a group having a lactone structure, an acid anhydride group, or an acid imide group, (Z) a group decomposable by the action of an acid
- Examples of the acid group (x) include a phenolic hydroxyl group, a carboxylic acid group, a fluorinated alcohol group, a sulfonic acid group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl) (alkylcarbonyl) methylene group, and an (alkylsulfonyl) (alkyl Carbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) A methylene group etc. are mentioned.
- Preferred acid groups include fluorinated alcohol groups (preferably hexafluoroisopropanol), sulfonimide groups, and
- the repeating unit having an acid group (x) includes a repeating unit in which an acid group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a resin having a linking group. Examples include a repeating unit in which an acid group is bonded to the main chain, and a polymerization initiator or chain transfer agent having an acid group can be introduced at the end of the polymer chain at the time of polymerization. preferable.
- the repeating unit having an acid group (x) may have at least one of a fluorine atom and a silicon atom.
- the content of the repeating unit having an acid group (x) is preferably from 1 to 50 mol%, more preferably from 3 to 35 mol%, still more preferably from 5 to 5%, based on all repeating units in the hydrophobic resin (D). 20 mol%.
- Specific examples of the repeating unit having an acid group (x) are shown below, but the present invention is not limited thereto.
- Rx represents a hydrogen atom, CH 3 , CF 3 , or CH 2 OH.
- the group having a lactone structure As the group having a lactone structure, the acid anhydride group, or the acid imide group (y), a group having a lactone structure is particularly preferable.
- the repeating unit containing these groups is a repeating unit in which this group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid ester and methacrylic acid ester.
- this repeating unit may be a repeating unit in which this group is bonded to the main chain of the resin via a linking group.
- this repeating unit may be introduce
- Examples of the repeating unit having a group having a lactone structure include those similar to the repeating unit having a lactone structure described above in the section of the resin (A).
- the content of the repeating unit having a group having a lactone structure, an acid anhydride group, or an acid imide group is preferably 1 to 100 mol% based on all repeating units in the hydrophobic resin (D), The content is more preferably 3 to 98 mol%, further preferably 5 to 95 mol%.
- examples of the repeating unit having a group (z) capable of decomposing by the action of an acid are the same as the repeating unit having an acid-decomposable group exemplified in the resin (A).
- the repeating unit having a group (z) that decomposes by the action of an acid may have at least one of a fluorine atom and a silicon atom.
- the content of the repeating unit having a group (z) that is decomposed by the action of an acid is preferably 1 to 80 mol% with respect to all the repeating units in the resin (D). The amount is preferably 10 to 80 mol%, more preferably 20 to 60 mol%.
- the hydrophobic resin (D) may further have a repeating unit different from the above-described repeating unit.
- the repeating unit containing a fluorine atom is preferably 10 to 100 mol%, more preferably 30 to 100 mol%, based on all repeating units contained in the hydrophobic resin (D). Further, the repeating unit containing a silicon atom is preferably 10 to 100 mol%, more preferably 20 to 100 mol% in all repeating units contained in the hydrophobic resin (D).
- hydrophobic resin (D) contains a CH 3 partial structure in the side chain portion
- a mode in which the hydrophobic resin (D) does not substantially contain a fluorine atom and a silicon atom is also preferable.
- hydrophobic resin (D) is substantially comprised only by the repeating unit comprised only by the atom chosen from a carbon atom, an oxygen atom, a hydrogen atom, a nitrogen atom, and a sulfur atom.
- the standard polystyrene equivalent weight average molecular weight of the hydrophobic resin (D) is preferably 1,000 to 100,000, more preferably 1,000 to 50,000.
- the hydrophobic resin (D) may be used alone or in combination.
- the content of the hydrophobic resin (D) in the composition is preferably 0.01 to 10% by mass, more preferably 0.05 to 8% by mass, based on the total solid content in the composition of the present invention.
- the residual monomer and oligomer components are preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass.
- the molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably in the range of 1 to 5, more preferably in the range of 1 to 3.
- hydrophobic resin (D) various commercially available products can be used, and the hydrophobic resin (D) can be synthesized according to a conventional method (for example, radical polymerization).
- the composition of the present invention preferably contains an acid diffusion controller.
- the acid diffusion controller acts as a quencher that traps the acid generated from the photoacid generator or the like during exposure and suppresses the reaction of the acid-decomposable resin in the unexposed area due to excess generated acid.
- Examples of the acid diffusion controller include a basic compound, a low molecular compound having a nitrogen atom and a group capable of leaving by the action of an acid, a basic compound whose basicity is reduced or disappeared by irradiation with actinic rays or radiation, or An onium salt that is a weak acid relative to the photoacid generator can be used.
- Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).
- R 200 , R 201 and R 202 may be the same or different and are a hydrogen atom, an alkyl group (preferably having a carbon number of 1 to 20), a cycloalkyl group (preferably having a carbon number of 3 to 20) or an aryl group (having a carbon number). 6-20), wherein R 201 and R 202 may combine with each other to form a ring.
- R 203 , R 204 , R 205 and R 206 may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.
- the alkyl group having a substituent is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms.
- the alkyl groups in the general formulas (A) and (E) are more preferably unsubstituted.
- Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine and the like, and more preferred compounds include imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate Examples thereof include a compound having a structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond. Specific examples of preferred compounds include those exemplified in US2012 / 0219913A1 [0379].
- Preferred examples of the basic compound further include an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group.
- These basic compounds may be used individually by 1 type, and may be used in combination of 2 or more types.
- the composition of the present invention may or may not contain a basic compound.
- the content of the basic compound is usually 0.001 to 10 mass based on the solid content of the composition. %, Preferably 0.01 to 5% by mass.
- a low molecular weight compound having a nitrogen atom and having a group capable of leaving by the action of an acid is an amine derivative having a group on the nitrogen atom that is leaving by the action of an acid. It is preferable that As the group capable of leaving by the action of an acid, an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, and a hemiaminal ether group are preferable, and a carbamate group and a hemiaminal ether group are particularly preferable. .
- the molecular weight of the compound (C) is preferably 100 to 1000, more preferably 100 to 700, and particularly preferably 100 to 500.
- Compound (C) may have a carbamate group having a protecting group on the nitrogen atom.
- the protecting group constituting the carbamate group can be represented by the following general formula (d-1).
- Rb each independently represents a hydrogen atom, an alkyl group (preferably 1 to 10 carbon atoms), a cycloalkyl group (preferably 3 to 30 carbon atoms), an aryl group (preferably 3 to 30 carbon atoms), an aralkyl group ( Preferably, it represents 1 to 10 carbon atoms) or an alkoxyalkyl group (preferably 1 to 10 carbon atoms).
- Rb may be connected to each other to form a ring.
- the alkyl group, cycloalkyl group, aryl group, and aralkyl group represented by Rb are substituted with a functional group such as hydroxyl group, cyano group, amino group, pyrrolidino group, piperidino group, morpholino group, oxo group, alkoxy group, or halogen atom. It may be. The same applies to the alkoxyalkyl group represented by Rb.
- Rb is preferably a linear or branched alkyl group, cycloalkyl group, or aryl group. More preferably, it is a linear or branched alkyl group or cycloalkyl group.
- Examples of the ring formed by connecting two Rb to each other include an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic hydrocarbon group, or a derivative thereof.
- Specific examples of the group represented by the general formula (d-1) include, but are not limited to, the structures disclosed in US2012 / 0135348 A1 [0466].
- the compound (C) has a structure represented by the following general formula (6).
- Ra represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group.
- l 2
- two Ras may be the same or different, and two Ras may be connected to each other to form a heterocyclic ring together with the nitrogen atom in the formula.
- the heterocyclic ring may contain a hetero atom other than the nitrogen atom in the formula.
- Rb has the same meaning as Rb in formula (d-1), and preferred examples are also the same.
- l represents an integer of 0 to 2
- the alkyl group, cycloalkyl group, aryl group and aralkyl group as Ra are described above as the groups in which the alkyl group, cycloalkyl group, aryl group and aralkyl group as Rb may be substituted. It may be substituted with a group similar to the group.
- Ra alkyl group, cycloalkyl group, aryl group, and aralkyl group examples include: The same group as the specific example mentioned above about Rb is mentioned.
- Specific examples of the particularly preferable compound (C) in the present invention include compounds disclosed in US2012 / 0135348 A1 [0475], but are not limited thereto.
- the compound represented by the general formula (6) can be synthesized based on JP2007-298869A, JP2009-199021A, and the like.
- the low molecular compound (C) having a group capable of leaving by the action of an acid on the nitrogen atom can be used singly or in combination of two or more.
- the content of the compound (C) in the composition of the present invention is preferably 0.001 to 20% by mass, more preferably 0.001 to 10% by mass, further based on the total solid content of the composition.
- the content is 0.01 to 5% by mass.
- a basic compound whose basicity decreases or disappears upon irradiation with actinic rays or radiation (hereinafter also referred to as “compound (PA)”) has a proton acceptor functional group and is irradiated with actinic rays or radiation. Is a compound whose proton acceptor properties are degraded, disappeared, or changed from proton acceptor properties to acidic properties.
- the proton acceptor functional group is a group that can interact electrostatically with a proton or a functional group having an electron.
- a functional group having a macrocyclic structure such as a cyclic polyether or a ⁇ -conjugated group. It means a functional group having a nitrogen atom with an unshared electron pair that does not contribute.
- the nitrogen atom having an unshared electron pair that does not contribute to ⁇ conjugation is, for example, a nitrogen atom having a partial structure represented by the following formula.
- Examples of a preferable partial structure of the proton acceptor functional group include a crown ether, an azacrown ether, a primary to tertiary amine, a pyridine, an imidazole, and a pyrazine structure.
- the compound (PA) is decomposed by irradiation with an actinic ray or radiation to generate a compound in which the proton acceptor property is lowered, disappeared, or changed from proton acceptor property to acidity.
- the decrease or disappearance of the proton acceptor property or the change from the proton acceptor property to the acid is a change in the proton acceptor property caused by the addition of a proton to the proton acceptor functional group.
- the acid dissociation constant pKa of the compound generated by decomposition of the compound (PA) upon irradiation with actinic rays or radiation preferably satisfies pKa ⁇ 1, more preferably ⁇ 13 ⁇ pKa ⁇ 1. More preferably, ⁇ 13 ⁇ pKa ⁇ 3.
- the compound (PA) generates, for example, a compound represented by the following general formula (PA-1) as the proton adduct generated by decomposition upon irradiation with actinic rays or radiation. Since the compound represented by the general formula (PA-1) has an acidic group together with the proton acceptor functional group, the proton acceptor property is reduced or disappeared compared to the compound (PA), or the proton acceptor property is reduced. It is a compound that has changed to acidic.
- PA-1 a compound represented by the following general formula (PA-1) as the proton adduct generated by decomposition upon irradiation with actinic rays or radiation. Since the compound represented by the general formula (PA-1) has an acidic group together with the proton acceptor functional group, the proton acceptor property is reduced or disappeared compared to the compound (PA), or the proton acceptor property is reduced. It is a compound that has changed to acidic.
- Q represents —SO 3 H, —CO 2 H, or —W 1 NHW 2 R f .
- R f represents an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 6 to 30 carbon atoms), and W 1 and W 2 each independently represents —SO 2 — or —CO—.
- A represents a single bond or a divalent linking group.
- X represents —SO 2 — or —CO—.
- n represents 0 or 1.
- B represents a single bond, an oxygen atom, or —N (R x ) R y —.
- R x represents a hydrogen atom or a monovalent organic group
- R y represents a single bond or a divalent organic group.
- R x may be bonded to R y to form a ring, or R x may be bonded to R to form a ring.
- R represents a monovalent organic group having a proton acceptor functional group.
- the compound (PA) is preferably an ionic compound.
- the proton acceptor functional group may be contained in either the anion portion or the cation portion, but is preferably contained in the anion portion.
- a compound (PA) other than the compound that generates the compound represented by the general formula (PA-1) can be appropriately selected.
- an ionic compound that has a proton acceptor moiety in the cation moiety may be used.
- a compound represented by the following general formula (7) is exemplified.
- A represents a sulfur atom or an iodine atom.
- m represents 1 or 2
- n represents 1 or 2.
- R represents an aryl group.
- R N represents an aryl group substituted with a proton acceptor functional group.
- X ⁇ represents a counter anion.
- X - include specific examples of, for example, and the like anions described in paragraphs JP 2016-42199 [0149] - [0183].
- Specific examples of the aryl group of R and R N is a phenyl group are preferably exemplified.
- proton acceptor functional group R N are the same as those of the proton acceptor functional group described in the foregoing formula (PA-1).
- Specific examples of the ionic compound having a proton acceptor site in the cation moiety include compounds exemplified in US2011 / 0269072A1 [0291]. Such a compound can be synthesized with reference to methods described in, for example, JP-A-2007-230913 and JP-A-2009-122623.
- a compound (PA) may be used individually by 1 type, and may be used in combination of 2 or more type.
- the content of the compound (PA) is preferably 0.1 to 10% by mass, more preferably 1 to 8% by mass, based on the total solid content of the composition.
- an onium salt that becomes a weak acid relative to the photoacid generator can be used as an acid diffusion control agent.
- the photoacid generator is irradiated with actinic rays or radiation.
- the generated acid collides with an onium salt having an unreacted weak acid anion, a weak acid is released by salt exchange to produce an onium salt having a strong acid anion.
- the strong acid is exchanged with a weak acid having a lower catalytic ability, so that the acid is apparently deactivated and the acid diffusion can be controlled.
- the onium salt that is a weak acid relative to the photoacid generator is preferably a compound represented by the following general formulas (d1-1) to (d1-3).
- R 51 represents a hydrocarbon group which may have a substituent
- Z 2c represents a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (however, a carbon adjacent to S).
- R 52 is an organic group
- Y 3 is a linear, branched or cyclic alkylene group or an arylene group
- Rf is a fluorine atom.
- Each of the M + is independently a sulfonium or iodonium cation.
- sulfonium cation or iodonium cation represented by M + include a sulfonium cation exemplified by the general formula (ZI) and an iodonium cation exemplified by the general formula (ZII).
- Preferable examples of the anion moiety of the compound represented by the general formula (d1-1) include the structures exemplified in paragraph [0198] of JP2012-242799A.
- Preferable examples of the anion moiety of the compound represented by the general formula (d1-2) include the structures exemplified in paragraph [0201] of JP2012-242799A.
- Preferable examples of the anion moiety of the compound represented by the general formula (d1-3) include structures exemplified in paragraphs [0209] and [0210] of JP2012-242799A.
- An onium salt that is a weak acid relative to the photoacid generator is (C) a compound having a cation moiety and an anion moiety in the same molecule, and the cation moiety and the anion moiety being linked by a covalent bond (Hereinafter also referred to as “compound (CA)”).
- the compound (CA) is preferably a compound represented by any one of the following general formulas (C-1) to (C-3).
- R 1 , R 2 and R 3 represent a substituent having 1 or more carbon atoms.
- L 1 represents a divalent linking group or a single bond linking the cation moiety and the anion moiety.
- -X - it is, -COO -, -SO 3 - represents an anion portion selected from -R 4 -, -SO 2 -, -N.
- R 4 is a group having a carbonyl group: —C ( ⁇ O) —, a sulfonyl group: —S ( ⁇ O) 2 —, and a sulfinyl group: —S ( ⁇ O) — at the site of connection with the adjacent N atom.
- R 1 , R 2 , R 3 , R 4 and L 1 may be bonded to each other to form a ring structure.
- R 1 to R 3 may be combined to form a double bond with the N atom.
- Examples of the substituent having 1 or more carbon atoms in R 1 to R 3 include alkyl group, cycloalkyl group, aryl group, alkyloxycarbonyl group, cycloalkyloxycarbonyl group, aryloxycarbonyl group, alkylaminocarbonyl group, cycloalkylamino A carbonyl group, an arylaminocarbonyl group, etc. are mentioned. Preferably, they are an alkyl group, a cycloalkyl group, and an aryl group.
- L 1 as the divalent linking group is a linear or branched alkylene group, cycloalkylene group, arylene group, carbonyl group, ether bond, ester bond, amide bond, urethane bond, urea bond, and two types thereof. Examples include groups formed by combining the above. L 1 is more preferably an alkylene group, an arylene group, an ether bond, an ester bond, or a group formed by combining two or more of these.
- Preferable examples of the compound represented by the general formula (C-1) include paragraphs [0037] to [0039] of JP2013-6827A and paragraphs [0027] to [0029] of JP2013-8020A. ] Can be mentioned.
- Preferable examples of the compound represented by the general formula (C-2) include compounds exemplified in paragraphs [0012] to [0013] of JP2012-189977A.
- Preferable examples of the compound represented by the general formula (C-3) include the compounds exemplified in paragraphs [0029] to [0031] of JP 2012-252124 A.
- the content of the onium salt that is a weak acid relative to the photoacid generator is preferably 0.5 to 10.0% by mass, based on the solid content of the composition, and preferably 0.5 to 8.0.
- the content is more preferably mass%, and further preferably 1.0 to 8.0 mass%.
- the composition of the present invention usually contains a solvent.
- Solvents that can be used in preparing the composition include, for example, alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactate esters, alkyl alkoxypropionates, cyclic lactones (preferably having 4 to 4 carbon atoms). 10), an organic solvent such as a monoketone compound (preferably having 4 to 10 carbon atoms) which may have a ring, alkylene carbonate, alkyl alkoxyacetate, alkyl pyruvate and the like. Specific examples of these solvents include those described in US Patent Application Publication No. 2008/0187860 [0441] to [0455].
- the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group the above-mentioned exemplary compounds can be selected as appropriate.
- the solvent containing a hydroxyl group alkylene glycol monoalkyl ether, alkyl lactate and the like are preferable, and propylene glycol monomethyl ether ( PGME, also known as 1-methoxy-2-propanol), ethyl lactate, and methyl 2-hydroxyisobutyrate are more preferred.
- alkylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, monoketone compound which may contain a ring, cyclic lactone, alkyl acetate and the like are preferable, and among these, propylene glycol monomethyl ether Acetate (PGMEA, also known as 1-methoxy-2-acetoxypropane), ethyl ethoxypropionate, 2-heptanone, ⁇ -butyrolactone, cyclohexanone, butyl acetate are particularly preferred, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2 -Heptanone is most preferred.
- PGMEA propylene glycol monomethyl ether Acetate
- ethyl ethoxypropionate 2-heptanone
- ⁇ -butyrolactone cyclohexanone
- the mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. .
- a mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.
- the solvent preferably contains propylene glycol monomethyl ether acetate, and is preferably a propylene glycol monomethyl ether acetate single solvent or a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.
- the composition of the present invention may or may not further contain a surfactant.
- the fluorine-based and / or silicon-based surfactant fluorine-based surfactant, silicon-based surfactant, fluorine atom
- composition of the present invention contains a surfactant
- a surfactant when using an exposure light source of 250 nm or less, particularly 220 nm or less, it is possible to provide a resist pattern with less adhesion and development defects with good sensitivity and resolution.
- the fluorine-based and / or silicon-based surfactant include surfactants described in paragraph [0276] of US Patent Application Publication No. 2008/0248425.
- surfactants other than the fluorine-based and / or silicon-based surfactants described in paragraph [0280] of US Patent Application Publication No. 2008/0248425 may be used.
- the amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.0005 to 1%, based on the total solid content of the composition. % By mass.
- the addition amount of the surfactant 10 ppm or less with respect to the total amount of the composition (excluding the solvent) the surface unevenness of the hydrophobic resin is increased, thereby making the resist film surface more hydrophobic. It is possible to improve water followability at the time of immersion exposure.
- the composition of the present invention may or may not contain a carboxylic acid onium salt.
- carboxylic acid onium salts include those described in US Patent Application Publication No. 2008/0187860 [0605] to [0606]. These carboxylic acid onium salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide and carboxylic acid with silver oxide in a suitable solvent.
- the content thereof is generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, based on the total solid content of the composition. More preferably, it is 1 to 7% by mass.
- the composition of the present invention may further include an acid proliferator, a dye, a plasticizer, a photosensitizer, a light absorber, an alkali-soluble resin, a dissolution inhibitor, and a compound that promotes solubility in a developer ( For example, a phenol compound having a molecular weight of 1000 or less, an alicyclic compound having a carboxyl group, or an aliphatic compound) can be contained.
- Such phenol compounds having a molecular weight of 1000 or less can be obtained by referring to the methods described in, for example, JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. Can be easily synthesized by those skilled in the art.
- alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.
- the solid content concentration of the composition of the present invention is usually 1.0 to 10% by mass, preferably 2.0 to 5.7% by mass, more preferably 2.0 to 5.3% by mass.
- the resist solution can be uniformly applied on the substrate, and further, a resist pattern having excellent line width roughness can be formed.
- the reason for this is not clear, but perhaps the solid content concentration is 10% by mass or less, preferably 5.7% by mass or less, which suppresses aggregation of the material in the resist solution, particularly the photoacid generator. As a result, it is considered that a uniform resist film was formed.
- the solid content concentration is a weight percentage of the weight of other resist components excluding the solvent with respect to the total weight of the composition.
- the method for preparing the composition of the present invention is not particularly limited, but it is preferable to dissolve each of the above-described components in a predetermined organic solvent, preferably the above mixed solvent, and filter.
- the pore size of the filter used for filter filtration is preferably 0.1 ⁇ m or less, more preferably 0.05 ⁇ m or less, and still more preferably 0.03 ⁇ m or less made of polytetrafluoroethylene, polyethylene, or nylon.
- filter filtration for example, as in JP-A-2002-62667, circulation filtration may be performed, or filtration may be performed by connecting a plurality of types of filters in series or in parallel.
- the composition may be filtered multiple times. Furthermore, you may perform a deaeration process etc. with respect to a composition before and behind filter filtration.
- the present invention also relates to a pattern forming method using the actinic ray-sensitive or radiation-sensitive resin composition.
- the pattern formation method of this invention is demonstrated.
- the actinic ray-sensitive or radiation-sensitive film (typically a resist film) of the present invention will also be described.
- the pattern forming method of the present invention comprises: (I) a step of forming an actinic ray-sensitive or radiation-sensitive film with the above-mentioned actinic ray-sensitive or radiation-sensitive resin composition (film forming step); (Ii) a step of exposing the actinic ray-sensitive or radiation-sensitive film to an actinic ray or radiation (exposure step); and (Iii) a step of developing the actinic ray-sensitive or radiation-sensitive film irradiated with actinic rays or radiation using a developer.
- the pattern forming method of the present invention is not particularly limited as long as it includes the steps (i) to (iii), and may further include the following steps.
- the exposure method in the exposure step is preferably immersion exposure.
- the pattern forming method of the present invention preferably includes (iv) a preheating step before (ii) the exposure step.
- the pattern forming method of the present invention preferably includes (v) a post-exposure heating step after (ii) the exposure step.
- the pattern forming method of the present invention may include (ii) an exposure step a plurality of times.
- the pattern forming method of the present invention may include (iv) a preheating step a plurality of times.
- the pattern forming method of the present invention may include (v) a post-exposure heating step a plurality of times.
- the actinic ray-sensitive or radiation-sensitive film in the present invention is a film formed from the actinic ray-sensitive or radiation-sensitive resin composition described above, and more specifically, the composition is applied onto a substrate. It is preferable that it is a film
- the above-mentioned (i) actinic ray-sensitive or radiation-sensitive film formation step, (ii) exposure step, and (iii) development step are performed by generally known methods. Can do.
- an antireflection film may be formed between the actinic ray-sensitive or radiation-sensitive film and the substrate.
- the antireflection film a known organic or inorganic antireflection film can be appropriately used.
- the substrate is not particularly limited, and is generally used in a manufacturing process of a semiconductor such as an IC, a manufacturing process of a circuit board such as a liquid crystal or a thermal head, and other photo-fabrication lithography processes.
- a substrate can be used, and specific examples thereof include an inorganic substrate such as silicon, SiO 2 , or SiN, or a coated inorganic substrate such as SOG (Spin On Glass).
- the pattern forming method of the present invention includes (i) an actinic ray-sensitive or radiation-sensitive film forming step, (ii) before an exposure step, and (iv) a preheating step (PB; Prebake). It is also preferable. It is also preferable to include (v) a post-exposure heating step (PEB; Post Exposure Bake) after (ii) the exposure step and before (iii) the development step.
- PEB Post Exposure Bake
- the heating temperature is preferably 70 to 130 ° C., more preferably 80 to 120 ° C. for both PB and PEB.
- the heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, and still more preferably 30 to 90 seconds for both PB and PEB.
- the heating can be performed by means provided in a normal exposure machine and developing machine, and may be performed using a hot plate or the like.
- the light source wavelength used for exposure apparatus Infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, an electron beam, etc. can be mentioned, Preferably it is 250 nm or less, More Far ultraviolet light with a wavelength of preferably 220 nm or less, more preferably 1 to 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F 2 excimer laser (157 nm), X-ray, EUV ( 13 nm), or an electron beam, and KrF excimer laser, ArF excimer laser, EUV or electron beam is preferable, and ArF excimer laser is more preferable.
- an immersion exposure method can be applied to the exposure step.
- the immersion exposure method can be combined with a super-resolution technique such as a phase shift method or a modified illumination method.
- the immersion exposure can be performed, for example, according to the method described in paragraphs [0594] to [0601] of JP2013-242397A.
- a developer containing an organic solvent hereinafter also referred to as an organic developer
- an organic developer is preferably used.
- alkali developer a quaternary ammonium salt typified by tetramethylammonium hydroxide is usually used.
- an alkaline aqueous solution such as an inorganic alkali, a primary to tertiary amine, an alcohol amine, or a cyclic amine is also used.
- examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; first amines such as ethylamine and n-propylamine.
- the alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
- the pH of the alkali developer is usually from 10.0 to 15.0.
- the development time using an alkali developer is usually 10 to 300 seconds. The alkali concentration (and pH) and development time of the alkali developer can be appropriately adjusted according to the pattern to be formed.
- a polar solvent such as a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, or an ether solvent, or a hydrocarbon solvent can be used.
- ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, Examples include cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetylalcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, or propylene carbonate.
- ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl.
- Examples include butyl, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.
- the alcohol solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol or alcohols such as n-decanol; glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol; or ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether , Diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, or Butoxy glycol ether-based solvents such as methyl butanol; and the like.
- ether solvent examples include dioxane, tetrahydrofuran and the like in addition to the glycol ether solvent.
- amide solvent examples include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, or 1,3-dimethyl-2-imidazolidinone. Can be used.
- hydrocarbon solvent examples include aromatic hydrocarbon solvents such as toluene and xylene; or aliphatic hydrocarbon solvents such as pentane, hexane, octane and decane.
- the aliphatic hydrocarbon solvent that is a hydrocarbon solvent may be a mixture of compounds having the same number of carbon atoms and different structures.
- decane is used as the aliphatic hydrocarbon solvent
- 2-methylnonane, 2,2-dimethyloctane, 4-ethyloctane, and isooctane which are compounds having the same carbon number and different structures
- the compounds having the same number of carbon atoms and different structures may include only one kind or plural kinds as described above.
- a plurality of the above solvents may be mixed, or a solvent other than the above or water may be mixed and used.
- the water content of the developer as a whole is preferably less than 10% by mass, and more preferably substantially free of moisture. That is, the amount of the organic solvent used relative to the organic developer is preferably 90% by mass or more and 100% by mass or less, and more preferably 95% by mass or more and 100% by mass or less with respect to the total amount of the developer. .
- the organic developer is a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. preferable.
- the vapor pressure of the organic developer at 20 ° C. is preferably 5 kPa or less, more preferably 3 kPa or less, and even more preferably 2 kPa or less.
- a surfactant can be added to the organic developer as required.
- an ionic or nonionic fluorine type and / or silicon type surfactant etc. can be used.
- fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, US Pat. No.
- the amount of the surfactant used is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the developer.
- the organic developer may contain a basic compound.
- the basic compound include amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.
- amine compounds amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.
- a development method for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle) Method), a method of spraying the developer on the substrate surface (spray method), or a method of continuously discharging the developer while scanning the developer discharge nozzle on the substrate rotating at a constant speed (dynamic dispensing). Law) etc.
- the preferred range of the discharge pressure of the discharged developer and the method for adjusting the discharge pressure of the developer are not particularly limited. For example, paragraphs [0631] to [0631] to [0631] 0636] can be used.
- a step of developing using a developer containing an organic solvent (organic solvent developing step) and a step of developing using an alkaline aqueous solution (alkali developing step) are used in combination. Also good. Thereby, a finer pattern can be formed.
- organic solvent developing step organic solvent developing step
- alkali developing step alkaline aqueous solution
- a portion with low exposure intensity is removed by the organic solvent development step, but a portion with high exposure strength is also removed by further performing the alkali development step.
- a pattern can be formed without dissolving only the intermediate exposure intensity region, so that a finer pattern than usual can be formed (Japanese Patent Laid-Open No. 2008-292975 [0077]. ] And the same mechanism).
- a step of rinsing with a rinsing liquid may be included. preferable.
- rinsing solution used in the rinsing step after the step of developing with an alkali developer pure water can be used, and an appropriate amount of a surfactant can be added.
- a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.
- a heat treatment can be performed to remove moisture remaining in the pattern.
- the rinsing solution used in the rinsing step after the step of developing with a developer containing an organic solvent is not particularly limited as long as the resist pattern is not dissolved, and a solution containing a general organic solvent can be used.
- a rinsing liquid a rinsing liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. It is more preferable. Specific examples of the hydrocarbon solvent, ketone solvent, ester solvent, alcohol solvent, amide solvent, and ether solvent are the same as those described in the developer containing an organic solvent.
- a step of washing with a rinsing liquid containing various organic solvents is performed, more preferably a step of washing with a rinsing liquid containing an alcohol solvent or an ester solvent, and particularly preferably a monohydric alcohol.
- the washing step is performed using a rinse solution containing, and most preferably, the washing step is performed using a rinse solution containing a monohydric alcohol having 5 or more carbon atoms.
- examples of the monohydric alcohol used in the rinsing step include linear, branched, or cyclic monohydric alcohols.
- Examples of the monohydric alcohol having 5 or more carbon atoms include 1-hexanol, 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, 3-methyl-1-butanol, and methyl isobutyl carbinol. .
- a hydrocarbon compound having 6 to 30 carbon atoms is preferable, a hydrocarbon compound having 8 to 30 carbon atoms is more preferable, and a hydrocarbon compound having 8 to 30 carbon atoms is more preferable.
- a hydrocarbon compound having 10 to 30 carbon atoms is particularly preferred. Among these, pattern collapse can be suppressed by using a rinse liquid containing decane and / or undecane.
- a glycol ether solvent may be used in addition to the ester solvent (one or more).
- ester solvent preferably butyl acetate
- glycol ether solvent preferably propylene glycol monomethyl ether (PGME)
- a plurality of each component may be mixed, or may be used by mixing with an organic solvent other than the above.
- the water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 3% by mass or less. By setting the water content to 10% by mass or less, good development characteristics can be obtained.
- the vapor pressure of the rinsing solution used after the step of developing with a developer containing an organic solvent is preferably 0.05 kPa or more and 5 kPa or less, more preferably 0.1 kPa or more and 5 kPa or less at 20 ° C. 12 kPa or more and 3 kPa or less are more preferable.
- the wafer that has been developed using the developer containing the organic solvent is cleaned using the rinse solution containing the organic solvent.
- the method of the cleaning process is not particularly limited. For example, a method of continuing to discharge the rinse liquid onto the substrate rotating at a constant speed (rotary coating method), and immersing the substrate in a bath filled with the rinse liquid for a certain period of time. A method (dip method), a method of spraying a rinsing liquid onto the substrate surface (spray method), or the like can be applied.
- a cleaning process by a spin coating method, and after the cleaning, rotate the substrate at a rotational speed of 2000 rpm to 4000 rpm to remove the rinse liquid from the substrate.
- a heating step Post Bake
- the developing solution and the rinsing solution remaining between the patterns and inside the patterns are removed by baking.
- the heating step after the rinsing step is usually performed at 40 to 160 ° C., preferably 70 to 95 ° C., usually 10 seconds to 3 minutes, preferably 30 seconds to 90 seconds.
- the actinic ray-sensitive or radiation-sensitive resin composition of the present invention and various materials used in the pattern forming method of the present invention for example, a resist solvent, a developer, a rinse solution, an antireflection film-forming composition, or It is preferable that the topcoat-forming composition or the like does not contain impurities such as metals.
- the content of impurities contained in these materials is preferably 1 ppm or less, more preferably 100 ppt or less, still more preferably 10 ppt or less, and particularly preferably (not more than the detection limit of the measuring device). Examples of a method for removing impurities such as metals from the various materials include filtration using a filter.
- the pore size of the filter is preferably 10 nm or less, more preferably 5 nm or less, and still more preferably 3 nm or less.
- the filter material is preferably a polytetrafluoroethylene, polyethylene, or nylon filter.
- a filter that has been washed in advance with an organic solvent may be used.
- a plurality of types of filters may be connected in series or in parallel. When a plurality of types of filters are used, filters having different pore diameters and / or materials may be used in combination. Moreover, various materials may be filtered a plurality of times, and the step of filtering a plurality of times may be a circulating filtration step.
- a raw material having a low metal content is selected as a raw material constituting the various materials, and filter filtration is performed on the raw materials constituting the various materials.
- a method of performing distillation under a condition in which contamination is suppressed as much as possible by lining the inside of the apparatus with Teflon (registered trademark) or the like can be mentioned.
- the preferable conditions for filter filtration performed on the raw materials constituting the various materials are the same as those described above.
- impurities may be removed with an adsorbent, or a combination of filter filtration and adsorbent may be used.
- the adsorbent a known adsorbent can be used.
- an inorganic adsorbent such as silica gel or zeolite, or an organic adsorbent such as activated carbon can be used.
- a method for improving the surface roughness of the pattern may be applied to the pattern formed by the pattern forming method of the present invention.
- a method for improving the surface roughness of the pattern for example, a method of treating a resist pattern with a plasma of a hydrogen-containing gas disclosed in International Publication No. 2014/002808 can be mentioned.
- JP 2004-235468 A, US Patent Application Publication No. 2010/0020297, JP 2009-19969 A, Proc. of SPIE Vol. 8328 83280N-1 “EUV Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement” may be applied.
- the pattern forming method of the present invention can also be used for guide pattern formation in DSA (Directed Self-Assembly) (see, for example, ACS Nano Vol. 4 No. 8 Pages 4815-4823). Further, the resist pattern formed by the above method can be used as a core material (core) of a spacer process disclosed in, for example, JP-A-3-270227 and JP-A-2013-164509.
- DSA Directed Self-Assembly
- the resist pattern formed by the above method can be used as a core material (core) of a spacer process disclosed in, for example, JP-A-3-270227 and JP-A-2013-164509.
- the present invention also relates to a method for manufacturing an electronic device including the pattern forming method of the present invention described above.
- the electronic device manufactured by the method for manufacturing an electronic device of the present invention is suitable for electrical and electronic equipment (for example, home appliances, OA (Office Automation) related equipment, media related equipment, optical equipment, communication equipment, etc.). It is to be installed.
- electrical and electronic equipment for example, home appliances, OA (Office Automation) related equipment, media related equipment, optical equipment, communication equipment, etc.
- ARC29SR organic antireflection film-forming composition
- PB Prebake
- the obtained wafer was used with an ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA 1.20, C-Quad, outer sigma 0.900, inner sigma 0.812, XY deflection) 1: Exposure was through a 6% halftone mask with a one line and space pattern. Ultra pure water was used as the immersion liquid. Then, it heated at 105 degreeC for 60 second (PEB: Post Exposure Bake). Next, it was developed by paddle with an organic developer (butyl acetate) for 30 seconds, and rinsed by paddle with a rinse solution [methyl isobutyl carbinol (MIBC)] for 30 seconds. Subsequently, the wafer was rotated at a rotational speed of 4000 rpm for 30 seconds to form a 1: 1 line and space pattern having a line width of 44 nm.
- an ArF excimer laser immersion scanner manufactured by ASML; XT1700i, NA 1.20, C-Quad, outer
- ⁇ Focus margin evaluation method DOF: Depth of Focus
- Eopt Depth of Focus
- exposure and development are performed by changing the exposure focus conditions in increments of 10 nm in the focus direction, and the space line width (CD) of each pattern obtained is expressed as a line.
- the focus corresponding to the minimum value or the maximum value of the curve obtained by plotting each CD is measured with a width measurement scanning electron microscope SEM (Hitachi, Ltd. S-9380) as the best focus. did.
- SEM width measurement scanning electron microscope
- Resins (acid-decomposable resins), photoacid generators, acid diffusion control agents, hydrophobic resins, surfactants, and solvents in Table 2 are as follows.
- SL-1 Propylene glycol monomethyl ether acetate (PGMEA: 1-methoxy-2-acetoxypropane)
- SL-2 Propylene glycol monomethyl ether (PGME: 1-methoxy-2-propanol)
- SL-3 Cyclohexanone
- SL-4 ⁇ -Butyrolactone
- the roughness performance, the exposure latitude, and the focus margin are extremely improved particularly in the formation of ultrafine patterns (for example, contact hole patterns with a hole diameter of 45 nm or less, and line and space patterns with a line width of 45 nm or less).
- ultrafine patterns for example, contact hole patterns with a hole diameter of 45 nm or less, and line and space patterns with a line width of 45 nm or less.
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Abstract
Description
KrFエキシマレーザーを露光光源とする場合には、主として248nm領域での吸収の小さい、ポリ(ヒドロキシスチレン)を基本骨格とする樹脂を主成分に使用するため、高感度、高解像度で、且つ良好なパターンを形成し、従来のナフトキノンジアジド/ノボラック樹脂系に比べて良好な系となっている。
一方、更なる短波長の光源、例えばArFエキシマレーザー(193nm)を露光光源として使用する場合は、芳香族基を有する化合物が本質的に193nm領域に大きな吸収を示すため、上記化学増幅系でも十分ではなかった。このため、例えば、脂環炭化水素構造を有する樹脂を含有するArFエキシマレーザー用レジストが開発されている。
そこで、本発明は、特に、超微細のパターン(例えば、孔径45nm以下のコンタクトホールパターンや、線幅45nm以下のラインアンドスペースパターン)の形成において、ラフネス性能と露光ラチチュードとフォーカス余裕度とを非常に優れたものとできる、感活性光線性又は感放射線性樹脂組成物、並びに、これを用いた感活性光線性又は感放射線性膜、パターン形成方法、及び、電子デバイスの製造方法を提供することを目的とする。
露光ラチチュードをELとし、空中像強度対数勾配をNILSとした場合に、下記式(1)で表わされる関係を満たす感活性光線性又は感放射線性樹脂組成物。
EL/NILS>12.0 ・・・(1)
上記式(1)において、ELは下記式により算出される。
EL(%)={[(ラインパターンの線幅が75nmの+10%となる露光量)-(ラインパターンの線幅が75nmの-10%となる露光量)]/(ラインパターンの線幅が75nmとなる露光量)}×100
NILSは、線幅75nmの光学像における空中像強度対数勾配である。
〔2〕
上記感活性光線性又は感放射線性樹脂組成物が、(A)活性光線又は放射線の照射によりpKaが-1.40以上の酸を発生する光酸発生剤、及び、(B)酸分解性基を有する繰り返し単位を有する樹脂を含有し、上記酸分解性基を有する繰り返し単位のEth感度が5.64以下である、〔1〕に記載の感活性光線性又は感放射線性樹脂組成物。
〔3〕
上記pKaが-1.40以上の酸がスルホン酸である、〔2〕に記載の感活性光線性又は感放射線性樹脂組成物。
〔4〕
上記スルホン酸が、スルホン酸基のα位の炭素原子に1つのフッ素原子が結合するアルキルスルホン酸である、〔3〕に記載の感活性光線性又は感放射線性樹脂組成物。
〔5〕
活性光線又は放射線の照射により上記光酸発生剤(A)が発生する酸が、下記一般式(a)、(b)及び(I)~(V)のいずれかで表されるスルホン酸である、〔3〕に記載の感活性光線性又は感放射線性樹脂組成物。
上記一般式(a)中、Rf1は、フッ素原子、又は、フッ素原子を含むアルキル基を表す。R1は、1価の有機基を表す。
上記一般式(b)中、Rf2及びRf3は、各々独立して、フッ素原子、又は、フッ素原子を含むアルキル基を表す。R2は、1価の有機基を表す。
上記一般式(I)中、R11及びR12は、各々独立して、1価の有機基を表す。R13は、水素原子又は1価の有機基を表す。L1は、-CO-O-、-CO-、-O-、-S-、-O-CO-、-S-CO-又は-CO-S-で表される基を表す。R11、R12及びR13の2つは互いに結合して環を形成しても良い。
上記一般式(II)中、R21及びR22は、各々独立して、1価の有機基を表す。R23は、水素原子又は1価の有機基を表す。L2は、-CO-、-O-、-S-、-O-CO-、-S-CO-又は-CO-S-で表される基を表す。R21、R22及びR23の2つは互いに結合して環を形成しても良い。
上記一般式(III)中、R31及びR33は、各々独立して、水素原子又は1価の有機基を表す。R31とR33とは互いに結合して環を形成しても良い。
上記一般式(IV)中、R41及びR43は、各々独立して、水素原子又は1価の有機基を表す。R41とR43とは互いに結合して環を形成しても良い。
上記一般式(V)中、R51、R52及びR53は、各々独立して、水素原子又は1価の有機基を表す。R51、R52及びR53の2つは互いに結合して環を形成しても良い。
〔6〕
上記樹脂(B)が、上記酸分解性基を有する繰り返し単位として、下記一般式(A)又は(B)で表される繰り返し単位を有する樹脂である、〔2〕~〔5〕のいずれか1項に記載の感活性光線性又は感放射線性樹脂組成物。
上記一般式(A)中、R4A、R5A及びR6Aは、それぞれ独立して、1価の有機基を表す。WAは、-CO-又は二価の芳香環基を表す。R7Aは、水素原子、メチル基又はトリフルオロメチル基を表す。R5A及びR6Aは、互いに結合して環を形成しても良い。
上記一般式(B)中、R4B、R5B及びR6Bは、それぞれ独立して、水素原子、又は、1価の有機基を表す。R5B及びR6Bは、互いに結合して環を形成しても良い。WBは、-CO-又は二価の芳香環基を表す。R7Bは、水素原子、メチル基又はトリフルオロメチル基を表す。
〔7〕
活性光線又は放射線の照射によりpKa-1.40未満の酸を発生する光酸発生剤を含まない、〔2〕~〔6〕のいずれか1項に記載の感活性光線性又は感放射線性樹脂組成物。
〔8〕
〔1〕~〔7〕のいずれか1項に記載の感活性光線性又は感放射線性樹脂組成物により形成された感活性光線性又は感放射線性膜。
〔9〕
〔1〕~〔7〕のいずれか1項に記載の感活性光線性又は感放射線性樹脂組成物によって感活性光線性又は感放射線性膜を形成する工程と、
上記感活性光線性又は感放射線性膜に活性光線又は放射線を照射する工程と、
活性光線又は放射線が照射された感活性光線性又は感放射線性膜を、現像する工程と、を備えるパターン形成方法。
〔10〕
〔9〕に記載のパターン形成方法を含む、電子デバイスの製造方法。
以下に記載する構成要件の説明は、本発明の代表的な実施態様に基づいてなされることがあるが、本発明はそのような実施態様に限定されるものではない。
本明細書に於ける基(原子団)の表記に於いて、置換及び無置換を記していない表記は、置換基を有さないものと共に置換基を有するものをも包含するものである。例えば、「アルキル基」とは、置換基を有さないアルキル基(無置換アルキル基)のみならず、置換基を有するアルキル基(置換アルキル基)をも包含するものである。
本明細書中における「活性光線」又は「放射線」とは、例えば、水銀灯の輝線スペクトル、エキシマレーザーに代表される遠紫外線、極紫外線(EUV光)、X線、及び、電子線(EB)等を意味する。また、本発明において光とは、活性光線又は放射線を意味する。
また、本明細書中における「露光」とは、特に断らない限り、水銀灯、エキシマレーザーに代表される遠紫外線、極紫外線、X線、及び、EUV光等による露光のみならず、電子線、及び、イオンビーム等の粒子線による描画も露光に含める。
本願明細書において「~」とはその前後に記載される数値を下限値及び上限値として含む意味で使用される。
本明細書において、樹脂の重量平均分子量(Mw)、数平均分子量(Mn)、及び分散度(Mw/Mn)は、GPC(Gel Permeation Chromatography)装置(東ソー製HLC-8120GPC)によるGPC測定(溶媒:テトラヒドロフラン、流量(サンプル注入量):10μl、カラム:東ソー社製TSK gel Multipore HXL-M(×4本)、カラム温度:40℃、流速:1.0mL/分、検出器:示差屈折率(RI)検出器)によるポリスチレン換算値として定義される。
次に、本発明の感活性光線性又は感放射線性樹脂組成物について説明する。
EL/NILS>12.0 ・・・(1)
上記式(1)において、ELは下記式により算出される。
EL(%)={[(ラインパターンの線幅が75nmの+10%となる露光量)-(ラインパターンの線幅が75nmの-10%となる露光量)]/(ラインパターンの線幅が75nmとなる露光量)}×100
NILSは、線幅75nmの光学像における空中像強度対数勾配である。
(1)シリコンウェハ上に反射防止膜ARC29A(日産化学社製)を86nm塗布し、205℃60秒間のベークを行う。
(2)感活性光線性又は感放射線性樹脂組成物を反射防止膜上に90nmの膜厚になるように塗布し、100℃60秒間のベーク(PB)を行い、感活性光線性又は感放射線性膜を作成する。
(3)感活性光線性又は感放射線性膜にArFスキャナ(PAS5500/1100)を用いて、ピッチ150nm、遮光部75nmの1:1のラインアンドスペースのマスク(6%ハーフトーンマスク)を介して露光(NA0.75、Dipole照明、アウターシグマ0.89、インナーシグマ0.65)する。なお、上記式(1)におけるELの測定は、上記条件によるArF露光によって行うものだが、これは、感活性光線性又は感放射線性樹脂組成物が上記条件によるArF露光用以外の用途に使用されることを否定するものではなく、例えば、KrF露光用、EB露光用、EUV露光用等の用途に使用されても良い。
(4)露光された感活性光線性又は感放射線性膜を85℃60秒間ベーク(PEB)した後、現像液としての酢酸ブチルを用いて、現像を実施する。
(5)上記により得られたラインパターン(ラインアンドスペースパターン)を走査電子顕微鏡(S-9380II;日立ハイテクノロジーズ社製)を用いて、ライン部の測長を実施し、ラインパターンの線幅が75nmとなる露光量をEopとして定義する。
(6)得られたラインアンドスペースパターンを下記の計算式に当てはめ、ELを算出する。
EL(%)={[(ラインパターンの線幅が75nmの+10%となる露光量)-(ラインパターンの線幅が75nmの-10%となる露光量)]/(ラインパターンの線幅が75nmとなる露光量(Eop))}×100
KLA-Tencor社製のソフトウエアProlithに上記(3)に記載の露光条件(ピッチ150nm、遮光部75nmの1:1のラインアンドスペースのマスク(6%ハーフトーンマスク)、ArF露光、NA0.75、Dipole照明、アウターシグマ0.89、インナーシグマ0.65)を入力し、光学強度分布より、線幅75nmの光学像における空中像強度対数勾配を算出した。
その理由は明らかではないが、以下の通りと推測される。
また、詳細な理由は不明であるが、ELの値がNILSの12.0倍を超過することにより、露光部と未露光部との現像液に対する溶解コントラストが非常に大きくなり、その結果、高いELに加えて、ラフネス性能とフォーカス余裕度とを非常に優れたものにすることができたものと考えられる。
また、詳細な理由は不明であるが、本発明者らは、酸発生剤として、活性光線又は放射線の照射によりpKaが-1.40以上を示す酸という、強酸とは言えない酸を発生する光酸発生剤を用いた場合には、露光部内で、酸分解性基の酸分解反応が進行して、酸分解性基からの脱離物が充分に発生することに加え、この脱離物が感活性光線性又は感放射性膜の未露光部に拡散しやすいせいか、露光部と未露光部との現像液に対する溶解コントラストが非常に大きくなっていることを見出した。その結果、上記の感活性光線性又は感放射性樹脂組成物によれば、「EL/NILS>12.0」を達成することができるものと考えられる。
本発明のレジスト組成物は、典型的には、化学増幅型のレジスト組成物である。
また、上記酸のpKaは、3.00以下であることが好ましく、これにより、酸の酸強度が低くなりすぎず、上記の超微細のパターン形成においては、ラフネス性能、露光ラチチュード性能、及び、フォーカス余裕度がより良化する傾向となる。
また、上記スルホン酸は、スルホン酸基のα位の炭素原子に1つのフッ素原子が結合するアルキルスルホン酸であることが好ましい。ここで、「スルホン酸基のα位の炭素原子に1つのフッ素原子が結合する」とは、スルホン酸基のα位の炭素原子に2個以上のフッ素原子が結合しないことを意味する。このアルキルスルホン酸におけるアルキル基は、置換基を有していても良く、その具体例としては、例えば、下記一般式(a)、(b)及び(I)~(V)におけるR1、R2、R11、R12、R21、R22、R23、R33、R43及びR53としての1価の有機基が有していても良い置換基の例を挙げることができる。
換言すれば、光酸発生剤(A)は、活性光線又は放射線の照射により下記一般式(a)、(b)及び(I)~(V)のいずれかで表されるスルホン酸を発生する酸発生剤であることが好ましい。
上記一般式(b)中、Rf2及びRf3は、各々独立して、フッ素原子、又は、フッ素原子を含むアルキル基を表す。R2は、1価の有機基を表す。
上記一般式(I)中、R11及びR12は、各々独立して、1価の有機基を表す。R13は、水素原子又は1価の有機基を表す。L1は、-CO-O-、-CO-、-O-、-S-、-O-CO-、-S-CO-又は-CO-S-で表される基を表す。R11、R12及びR13の2つは互いに結合して環を形成しても良い。
上記一般式(II)中、R21及びR22は、各々独立して、1価の有機基を表す。R23は、水素原子又は1価の有機基を表す。L2は、-CO-、-O-、-S-、-O-CO-、-S-CO-又は-CO-S-で表される基を表す。R21、R22及びR23の2つは互いに結合して環を形成しても良い。
L1及びL2としての上記した2価の連結基に関し、左側の結合手が、スルホン酸基(-SO3H)が結合する炭素原子に結合し、右側の結合手が、R12及びR22に結合する。
上記一般式(III)中、R31及びR33は、各々独立して、水素原子又は1価の有機基を表す。R31とR33とは互いに結合して環を形成しても良い。
上記一般式(IV)中、R41及びR43は、各々独立して、水素原子又は1価の有機基を表す。R41とR43とは互いに結合して環を形成しても良い。
上記一般式(V)中、R51、R52及びR53は、各々独立して、水素原子又は1価の有機基を表す。R51、R52及びR53の2つは互いに結合して環を形成しても良い。
一般式(I)~(V)におけるR1、R2、R11、R12、R21、R22、R23、R31、R33、R41、R43、R51、R52及びR53としての1価の有機基は、好ましくは炭素数1~30であり、より好ましくは炭素数1~20であり、更に好ましくは炭素数1~10であり、例えば、アルキル基、シクロアルキル基、アリール基、アラルキル基、アルケニル基などを挙げることができる。これらの基は更に置換基を有していてもよい。
上記置換基としては、ハロゲン原子、アルキル基(直鎖、分岐のいずれであっても良く、炭素数1~12が好ましい)、シクロアルキル基(単環、多環、スピロ環のいずれであっても良く、炭素数3~20が好ましい)、アリール基(炭素数6~14が好ましい)、ヒドロキシ基、カルボニル基、エーテル基、シアノ基、アルコキシ基、エステル基、アミド基、ウレタン基、ウレイド基、チオエーテル基、スルホンアミド基、スルホン酸エステル基、及び、これらの原子及び基から選択される2種以上が組み合わされてなる基等が挙げられる。
また、フッ素原子を含むアルキル基は、パーフルオロアルキル基であることが好ましく、トリフルオロメチル基であることがより好ましい。
X+は、カチオンを表す。
R201、R202及びR203は、各々独立に、有機基を表す。
R201、R202及びR203としての有機基の炭素数は、一般的に1~30、好ましくは1~20である。
また、R201~R203のうち2つが結合して環構造を形成してもよく、環内に酸素原子、硫黄原子、エステル結合、アミド結合、カルボニル基を含んでいてもよい。R201~R203の内の2つが結合して形成する基としては、アルキレン基(例えば、ブチレン基、ペンチレン基)を挙げることができる。
Z-は、上記一般式(a)、(b)及び(I)~(V)のいずれかで表されるスルホン酸に対応するスルホン酸アニオンを表す。
なお、一般式(ZI)で表される構造を複数有する化合物であってもよい。例えば、一般式(ZI)で表される化合物のR201~R203の少なくとも1つが、一般式(ZI)で表されるもうひとつの化合物のR201~R203の少なくとも一つと、単結合又は連結基を介して結合した構造を有する化合物であってもよい。
化合物(ZI-1)は、上記一般式(ZI)のR201~R203の少なくとも1つがアリール基である、アリールスルホニウム化合物、即ち、アリールスルホニウムをカチオンとする化合物である。
アリールスルホニウム化合物は、R201~R203の全てがアリール基でもよいし、R201~R203の一部がアリール基で、残りがアルキル基又はシクロアルキル基でもよい。
アリールスルホニウム化合物としては、例えば、トリアリールスルホニウム化合物、ジアリールアルキルスルホニウム化合物、アリールジアルキルスルホニウム化合物、ジアリールシクロアルキルスルホニウム化合物、アリールジシクロアルキルスルホニウム化合物を挙げることができる。
アリールスルホニウム化合物が必要に応じて有しているアルキル基又はシクロアルキル基は、炭素数1~15の直鎖又は分岐アルキル基及び炭素数3~15のシクロアルキル基が好ましく、例えば、メチル基、エチル基、プロピル基、n-ブチル基、sec-ブチル基、t-ブチル基、シクロプロピル基、シクロブチル基、シクロヘキシル基等を挙げることができる。
化合物(ZI-2)は、式(ZI)におけるR201~R203が、各々独立に、芳香環を有さない有機基を表す化合物である。ここで芳香環とは、ヘテロ原子を含有する芳香族環も包含するものである。
R201~R203としての芳香環を含有しない有機基は、一般的に炭素数1~30、好ましくは炭素数1~20である。
R201~R203は、各々独立に、好ましくはアルキル基、シクロアルキル基、アリル基、ビニル基であり、更に好ましくは直鎖又は分岐の2-オキソアルキル基、2-オキソシクロアルキル基、アルコキシカルボニルメチル基、特に好ましくは直鎖又は分岐2-オキソアルキル基である。
R201~R203は、ハロゲン原子、アルコキシ基(例えば炭素数1~5)、水酸基、シアノ基、ニトロ基によって更に置換されていてもよい。
化合物(ZI-3)とは、以下の一般式(ZI-3)で表される化合物であり、フェナシルスルフォニウム塩構造を有する化合物である。
R1c~R5cは、各々独立に、水素原子、アルキル基、シクロアルキル基、アリール基、アルコキシ基、アリールオキシ基、アルコキシカルボニル基、アルキルカルボニルオキシ基、シクロアルキルカルボニルオキシ基、ハロゲン原子、水酸基、ニトロ基、アルキルチオ基又はアリールチオ基を表す。
R6c及びR7cは、各々独立に、水素原子、アルキル基、シクロアルキル基、ハロゲン原子、シアノ基又はアリール基を表す。
Rx及びRyは、各々独立に、アルキル基、シクロアルキル基、2-オキソアルキル基、2-オキソシクロアルキル基、アルコキシカルボニルアルキル基、アリル基又はビニル基を表す。
上記環構造としては、芳香族若しくは非芳香族の炭化水素環、芳香族若しくは非芳香族の複素環、又は、これらの環が2つ以上組み合わされてなる多環縮合環を挙げることができる。環構造としては、3~10員環を挙げることができ、4~8員環であることが好ましく、5又は6員環であることがより好ましい。
R5cとR6c、及び、R5cとRxが結合して形成する基としては、単結合又はアルキレン基であることが好ましく、アルキレン基としては、メチレン基、エチレン基等を挙げることができる。
Zc-は、上記一般式(a)、(b)及び(I)~(V)のいずれかで表されるスルホン酸に対応するスルホン酸アニオンを表す。
R1c~R5cとしてのアルキルカルボニルオキシ基及びアルキルチオ基におけるアルキル基の具体例は、上記R1c~R5cとしてのアルキル基の具体例と同様である。
R1c~R5cとしてのシクロアルキルカルボニルオキシ基におけるシクロアルキル基の具体例は、上記R1c~R5cとしてのシクロアルキル基の具体例と同様である。
R1c~R5cとしてのアリールオキシ基及びアリールチオ基におけるアリール基の具体例は、上記R1c~R5cとしてのアリール基の具体例と同様である。
化合物(ZI-4)は、下記一般式(ZI-4)で表される。
R13は水素原子、フッ素原子、水酸基、アルキル基、シクロアルキル基、アルコキシ基、アルコキシカルボニル基、又はシクロアルキル基を有する基を表す。これらの基は置換基を有してもよい。
R14は、複数存在する場合は各々独立して、水酸基、アルキル基、シクロアルキル基、アルコキシ基、アルコキシカルボニル基、アルキルカルボニル基、アルキルスルホニル基、シクロアルキルスルホニル基、又はシクロアルキル基を有する基を表す。これらの基は置換基を有してもよい。
R15は各々独立して、アルキル基、シクロアルキル基又はナフチル基を表す。これらの基は置換基を有してもよい。2個のR15が互いに結合して環を形成してもよい。2個のR15が互いに結合して環を形成するとき、環骨格内に、酸素原子、窒素原子などのヘテロ原子を含んでもよい。一態様において、2個のR15がアルキレン基であり、互いに結合して環構造を形成することが好ましい。
lは0~2の整数を表す。
rは0~8の整数を表す。
Z-は、上記一般式(a)、(b)及び(I)~(V)のいずれかで表されるスルホン酸に対応するスルホン酸アニオンを表す。
本発明における一般式(ZI-4)で表される化合物のカチオンとしては、特開2010-256842号公報の段落[0121]、[0123]、[0124]、及び、特開2011-76056号公報の段落[0127]、[0129]、[0130]等に記載のカチオンを挙げることができる。
一般式(ZII)、(ZIII)中、R204~R207は、各々独立に、アリール基、アルキル基又はシクロアルキル基を表す。
R204~R207のアリール基としてはフェニル基、ナフチル基が好ましく、更に好ましくはフェニル基である。R204~R207のアリール基は、酸素原子、窒素原子、硫黄原子等を有する複素環構造を有するアリール基であってもよい。複素環構造を有するアリール基の骨格としては、例えば、ピロール、フラン、チオフェン、インドール、ベンゾフラン、ベンゾチオフェン等を挙げることができる。
R204~R207におけるアルキル基及びシクロアルキル基としては、好ましくは、炭素数1~10の直鎖又は分岐アルキル基(例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基)、炭素数3~10のシクロアルキル基(シクロペンチル基、シクロヘキシル基、ノルボニル基)を挙げることができる。
Z-は、上記一般式(a)、(b)及び(I)~(V)のいずれかで表されるスルホン酸に対応するスルホン酸アニオンを表す。
本発明において、光酸発生剤(A)は、低分子化合物の形態であることが好ましい。
本発明の光酸発生剤(A)が、低分子化合物の形態である場合、分子量は3000以下が好ましく、2000以下がより好ましく、1000以下が更に好ましい。
本発明の光酸発生剤(A)が、重合体の一部に組み込まれた形態である場合、後述する樹脂(B)の一部に組み込まれてもよく、樹脂(B)とは異なる樹脂に組み込まれてもよい。
本発明の光酸発生剤(A)は、公知の方法で合成することができ、例えば、特開2007-161707号公報に記載の方法に準じて合成することができる。
本発明の光酸発生剤(A)は、1種類単独又は2種類以上を組み合わせて使用することができる。
本発明の光酸発生剤(A)の組成物中の含有量(複数種存在する場合はその合計)は、組成物の全固形分を基準として、0.1~30質量%が好ましく、より好ましくは0.5~25質量%、更に好ましくは3~20質量%、特に好ましくは3~15質量%である。
本発明の光酸発生剤(A)として、上記一般式(ZI-3)又は(ZI-4)により表される化合物を含む場合、組成物中に含まれる酸発生剤の含有量(複数種存在する場合はその合計)は、組成物の全固形分を基準として、5~35質量%が好ましく、7~30質量%がより好ましい。
なお、本発明の感活性光線性又は感放射線性樹脂組成物は、光酸発生剤(A)とは異なる光酸発生剤を含有してもしなくても良いが、活性光線又は放射線の照射によりpKaが-1.40未満の酸を発生する光酸発生剤を含有しないことが好ましい。
樹脂(B)は、酸分解性基を有する繰り返し単位を有する樹脂(以下、「酸分解性樹脂」又は「樹脂(B)」ともいう)である。ここで、樹脂(B)における酸分解性基を有する繰り返し単位のEth感度は、5.64以下である。
ここで、レジスト組成物中の酸分解性樹脂は、下記ラクトン基含有繰り返し単位aと、Eth感度の測定対象である酸分解性繰り返し単位とをモル比40:60で有し、重量平均分子量(Mw)が10,000の酸分解性樹脂である。
シリコンウエハ上に有機反射防止膜形成用のARC29A(日産化学社製)を塗布し、205℃で60秒間ベークを行ない、膜厚86nmの反射防止膜を形成する。その上に、先に調製したレジスト組成物を塗布し、100℃で60秒間ベーク(PB:Prebake)し、膜厚100nmのレジスト膜を形成する。
得られたレジスト膜に対し、ArFエキシマレーザースキャナー(ASML社製 PAS5500/1100、NA0.75、アウターシグマ0.89)を用い、1.0~25.9mJ/cm2の範囲で露光量をそれぞれ変えて全面露光を行う。なお、本発明の組成物がArF露光用以外(例えば、KrF露光用、EB露光用、EUV露光用等)である場合でも、Eth感度の評価は上記条件によるArF露光によって行なうものとする。
次に、85℃で60秒間加熱(PEB:Post Exposure Bake)後、酢酸ブチルで30秒間パドル現像した後に、2000回転(rpm)で20秒間高速回転して乾燥させる。この際、PEB後、および現像後の膜厚をVM-3110(大日本スクリーニング社製)を用いて測定して露光量-膜厚曲線を得、Eth感度を求める。
露光量E[mJ/cm2]のときの現像後膜厚をTE[nm]としたとき、以下の式(1)で表されるγEが最大値γmaxとなるときの露光量をEmax、現像後膜厚をTEmaxとすると、Eth感度は以下の式(2)で表される。
また、Xmaxは、下記式(3)で表される。
重合される酸分解性樹脂においてラクトン基含有繰り返し単位aとEth感度の測定対象である酸分解性繰り返し単位とがモル比40:60となるようなモノマー量比の、ラクトン基含有繰り返し単位aに対応するモノマーと、Eth感度の測定対象である酸分解性繰り返し単位に対応するモノマーとを、重合される酸分解性樹脂の重量平均分子量(Mw)が10,000となる量の2,2’-アゾビスイソ酪酸ジメチル〔V-601、和光純薬工業(株)製〕(重合開始剤)と共に、シクロヘキサノンに溶解させ(モノマー濃度は25質量%)、窒素気流下80℃で重合する。
例えば、フラスコ内に80℃にて収容されたシクロヘキサノンに向けて、別途用意した重合開始剤とモノマーを含有するシクロヘキサノン混合溶液(この混合溶液におけるシクロヘキサノンの質量は、フラスコ内のシクロヘキサノンの質量の4倍とされている)を4時間かけて滴下した後、80℃で更に2時間攪拌する。反応液を放冷後、多量のメタノール/水(質量比9:1)により再沈殿処理を行い、沈殿物をろ過する。得られた固体を真空乾燥することで、酸分解性樹脂を得て、これを酸分解性繰り返し単位のEth感度(酸分解反応性)を求めるために用いる。
酸分解性繰り返し単位のEth感度は、脱離基の種類によって変化しやすい傾向があるため、脱離基の構造を選択することにより、酸分解性繰り返し単位のEth感度を5.64以下とすることができる。
酸で脱離する基(脱離基)としては、例えば、-C(R36)(R37)(R38)、-C(R36)(R37)(OR39)、-C(R01)(R02)(OR39)等を挙げることができる。
式中、R36~R39は、各々独立に、アルキル基、シクロアルキル基、アリール基、アラルキル基又はアルケニル基を表す。R36とR37とは、互いに結合して環を形成してもよい。
R01及びR02は、各々独立に、水素原子、アルキル基、シクロアルキル基、アリール基、アラルキル基又はアルケニル基を表す。
R36~R39、R01及びR02のシクロアルキル基は、単環型でも、多環型でもよい。単環型としては、炭素数3~8のシクロアルキル基が好ましく、例えば、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロへキシル基、シクロオクチル基等を挙げることができる。多環型としては、炭素数6~20のシクロアルキル基が好ましく、例えば、アダマンチル基、ノルボルニル基、イソボロニル基、カンファニル基、ジシクロペンチル基、α-ピネル基、トリシクロデカニル基、テトラシクロドデシル基、アンドロスタニル基等を挙げることができる。なお、シクロアルキル基中の少なくとも1つの炭素原子が酸素原子等のヘテロ原子によって置換されていてもよい。
R36~R39、R01及びR02のアリール基は、炭素数6~10のアリール基が好ましく、例えば、フェニル基、ナフチル基、アントリル基等を挙げることができる。
R36~R39、R01及びR02のアラルキル基は、炭素数7~12のアラルキル基が好ましく、例えば、ベンジル基、フェネチル基、ナフチルメチル基等を挙げることができる。
R36~R39、R01及びR02のアルケニル基は、炭素数2~8のアルケニル基が好ましく、例えば、ビニル基、アリル基、ブテニル基、シクロへキセニル基等を挙げることができる。
R36とR37とが結合して形成される環としては、シクロアルキル基(単環若しくは多環)であることが好ましい。シクロアルキル基としては、シクロペンチル基、シクロヘキシル基などの単環のシクロアルキル基、ノルボルニル基、テトラシクロデカニル基、テトラシクロドデカニル基、アダマンチル基などの多環のシクロアルキル基が好ましい。炭素数5~6の単環のシクロアルキル基がより好ましく、炭素数5の単環のシクロアルキル基が特に好ましい。
Xa1は、水素原子、アルキル基、シアノ基又はハロゲン原子を表す。
Tは、単結合又は2価の連結基を表す。
Rx1~Rx3は、それぞれ独立に、アルキル基又はシクロアルキル基を表す。
Rx1~Rx3の2つが結合して環構造を形成してもよい。
Tは、単結合又は-COO-Rt-基が好ましい。Rtは、炭素数1~5のアルキレン基が好ましく、-CH2-基、-(CH2)2-基、-(CH2)3-基がより好ましい。Tは、単結合であることがより好ましい。
Xa1のアルキル基は、炭素数1~4のものが好ましく、メチル基、エチル基、プロピル基、ヒドロキシメチル基又はトリフルオロメチル基等が挙げられるが、メチル基であることが好ましい。
Xa1は、水素原子又はメチル基であることが好ましい。
Rx1、Rx2及びRx3のシクロアルキル基としては、シクロペンチル基、シクロヘキシル基などの単環のシクロアルキル基、ノルボルニル基、テトラシクロデカニル基、テトラシクロドデカニル基、アダマンチル基などの多環のシクロアルキル基が好ましい。
上記一般式(B)中、R4B、R5B及びR6Bは、それぞれ独立して、水素原子、又は、1価の有機基を表す。R5B及びR6Bは、互いに結合して環を形成しても良い。WBは、-CO-又は二価の芳香環基を表す。R7Bは、水素原子、メチル基又はトリフルオロメチル基を表す。
置換基としては、ハロゲン原子、アルキル基(直鎖、分岐のいずれであっても良く、炭素数1~12が好ましい)、シクロアルキル基(単環、多環、スピロ環のいずれであっても良く、炭素数3~20が好ましい)、アリール基(炭素数6~14が好ましい)、ヒドロキシ基、カルボニル基、エーテル基、シアノ基、アルコキシ基、エステル基、アミド基、ウレタン基、ウレイド基、チオエーテル基、スルホンアミド基、スルホン酸エステル基、及び、これらの原子及び基から選択される2種以上が組み合わされてなる基等が挙げられる。
二価の芳香環基は、更に置換基を有していても良く、その具体例としては、R4A、R5A、R6A、R4B、R5B及びR6Bとしての1価の有機基が有していても良い置換基の具体例として挙げたものと同様である。
よって、樹脂(B)が酸分解性繰り返し単位を複数種類有している場合は、上記加重平均により算出される酸分解性繰り返し単位のEth感度が5.64以下とされており、上記Eth感度の好ましい範囲についても同様である。
Aは、エステル結合(-COO-で表される基)又はアミド結合(-CONH-で表される基)を表す。
R0は、複数個ある場合にはそれぞれ独立にアルキレン基、シクロアルキレン基、又はその組み合わせを表す。
Zは、複数個ある場合にはそれぞれ独立に、単結合、エーテル結合、エステル結合、アミド結合、ウレタン結合
R8は、ラクトン構造又はスルトン構造を有する1価の有機基を表す。
nは、-R0-Z-で表される構造の繰り返し数であり、0~5の整数を表し、0又は1であることが好ましく、0であることがより好ましい。nが0である場合、-R0-Z-は存在せず、単結合となる。
R7は、水素原子、ハロゲン原子又はアルキル基を表す。
Zは好ましくは、エーテル結合、エステル結合であり、特に好ましくはエステル結合である。
R0のアルキレン基、シクロアルキレン基、R7におけるアルキル基は、各々置換されていてもよく、置換基としては、例えば、フッ素原子、塩素原子、臭素原子等のハロゲン原子やメルカプト基、水酸基、メトキシ基、エトキシ基、イソプロポキシ基、t-ブトキシ基、ベンジルオキシ基等のアルコキシ基、アセチルオキシ基、プロピオニルオキシ基等のアシルオキシ基が挙げられる。
R7は、水素原子、メチル基、トリフルオロメチル基、ヒドロキシメチル基が好ましい。
また、R8は無置換のラクトン構造又はスルトン構造を有する1価の有機基、或いはメチル基、シアノ基又はアルコキシカルボニル基を置換基として有するラクトン構造又はスルトン構造を有する1価の有機基が好ましく、シアノ基を置換基として有するラクトン構造(シアノラクトン)を有する1価の有機基がより好ましい。
環状炭酸エステル構造を有する繰り返し単位は、下記一般式(A-1)で表される繰り返し単位であることが好ましい。
RA 2は、nが2以上の場合は各々独立して、置換基を表す。
Aは、単結合、又は2価の連結基を表す。
Zは、式中の-O-C(=O)-O-で表される基と共に単環又は多環構造を形成する原子団を表す。
nは0以上の整数を表す。
RA 1で表されるアルキル基は、フッ素原子等の置換基を有していてもよい。RA 1は、水素原子、メチル基又はトリフルオロメチル基を表すことが好ましく、メチル基を表すことがより好ましい。
RA 2で表される置換基は、例えば、アルキル基、シクロアルキル基、ヒドロキシル基、アルコキシ基、アミノ基、アルコキシカルボニルアミノ基である。好ましくは炭素数1~5のアルキル基であり、例えば、メチル基、エチル基、プロピル基、ブチル基等の炭素数1~5の直鎖状アルキル基;イソプロピル基、イソブチル基、t-ブチル基等の炭素数3~5の分岐状アルキル基等を挙げることができる。アルキル基はヒドロキシル基等の置換基を有していてもよい。
nは置換基数を表す0以上の整数である。nは、例えば、好ましくは0~4であり、より好ましくは0である。
本発明の一形態において、Aは、単結合、アルキレン基であることが好ましい。
Zにより表される、-O-C(=O)-O-を含む多環としては、例えば、下記一般式 (a)で表される環状炭酸エステルが1又は2以上の他の環構造と共に縮合環を形成している構造や、スピロ環を形成している構造が挙げられる。縮合環又はスピロ環を形成し得る「他の環構造」としては、脂環式炭化水素基であってもよいし、芳香族炭化水素基であってもよいし、複素環であってもよい。
樹脂(B)において、環状炭酸エステル構造を有する繰り返し単位(好ましくは、一般式(A-1)で表される繰り返し単位)の含有率は、樹脂(B)を構成する全繰り返し単位に対して、3~80モル%であることが好ましく、3~60モル%であることが更に好ましく、3~30モル%であることが特に好ましく、10~15モル%であることが最も好ましい。このような含有率とすることによって、レジストとしての現像性、低欠陥性、低LWR(Line Width Roughness)、低PEB(Post Exposure Bake)温度依存性、プロファイル等を向上させることができる。
なお、以下の具体例中のRA 1は、一般式(A-1)におけるRA 1と同義である。
これにより、本発明の方法に用いられる樹脂(B)に要求される性能、特に、(1)塗布溶剤に対する溶解性、(2)製膜性(ガラス転移点)、(3)アルカリ現像性、(4)膜べり(親疎水性、アルカリ可溶性基選択)、(5)未露光部の基板への密着性、(6)ドライエッチング耐性、等の微調整が可能となる。
その他にも、上記種々の繰り返し構造単位に相当する単量体と共重合可能である付加重合性の不飽和化合物であれば、共重合されていてもよい。
樹脂(B)において、各繰り返し構造単位の含有モル比はレジストのドライエッチング耐性や標準現像液適性、基板密着性、レジストプロファイル、更にはレジストの一般的な必要性能である解像力、耐熱性、感度等を調節するために適宜設定される。
本発明の組成物が、KrF露光用、EB露光用又はEUV露光用であるとき、樹脂(B)は芳香族基を有することが好ましい。樹脂(B)がフェノール性水酸基を含む繰り返し単位を含むことがより好ましく、フェノール性水酸基を含む繰り返し単位としては、ヒドロキシスチレン繰り返し単位やヒドロキシスチレン(メタ)アクリレート繰り返し単位を挙げることができる。
樹脂(B)は、常法に従って(例えばラジカル重合)合成することができる。例えば、一般的合成方法としては、モノマー種及び開始剤を溶剤に溶解させ、加熱することにより重合を行う一括重合法、加熱溶剤にモノマー種と開始剤の溶液を1~10時間かけて滴下して加える滴下重合法などが挙げられ、滴下重合法が好ましい。滴下重合法においては、モノマー種の一部を予め重合容器内に仕込んでおいても良い。こうすることにより、重合開始から重合完了まで均一な組成比を有する共重合体を得ることができ、現像液への溶解性が均一化される。例えば、本発明においては、Si原子を有するモノマー及び酸分解性基を有するモノマーの少なくとも一方を予め重合容器に仕込んだ状態で滴下重合を行なうことが好ましい。反応溶媒としては、例えばテトラヒドロフラン、1,4-ジオキサン、ジイソプロピルエーテルなどのエーテル類やメチルエチルケトン、メチルイソブチルケトンのようなケトン類、酢酸エチルのようなエステル溶媒、ジメチルホルムアミド、ジメチルアセトアミドなどのアミド溶剤、更には後述のプロピレングリコールモノメチルエーテルアセテート、プロピレングリコールモノメチルエーテル、シクロヘキサノンのような本発明の組成物を溶解する溶媒が挙げられる。より好ましくは本発明の組成物に用いられる溶剤と同一の溶剤を用いて重合することが好ましい。これにより保存時のパーティクルの発生が抑制できる。
重合反応は窒素やアルゴンなど不活性ガス雰囲気下で行われることが好ましい。重合開始剤としては市販のラジカル開始剤(アゾ系開始剤、パーオキサイドなど)を用いて重合を開始させる。ラジカル開始剤としてはアゾ系開始剤が好ましく、エステル基、シアノ基、カルボキシル基を有するアゾ系開始剤が好ましい。好ましい開始剤としては、アゾビスイソブチロニトリル、アゾビスジメチルバレロニトリル、ジメチル2,2’-アゾビス(2-メチルプロピオネート)などが挙げられる。所望により開始剤を追加、あるいは分割で添加し、反応終了後、溶剤に投入して粉体あるいは固形回収等の方法で所望のポリマーを回収する。反応溶液中の固形分濃度は5~50質量%であり、好ましくは10~30質量%である。反応温度は、通常10℃~150℃であり、好ましくは30℃~120℃、更に好ましくは60~100℃である。
分散度(分子量分布)は、通常1.0~3.0であり、好ましくは1.0~2.6、更に好ましくは1.0~2.0、特に好ましくは1.1~2.0の範囲のものが使用される。分子量分布の小さいものほど、解像度、レジスト形状が優れ、且つレジストパターンの側壁がスムーズであり、ラフネス性に優れる。
樹脂(B)を複数併用する場合、樹脂(B)における酸分解性繰り返し単位のEth感度は、各酸分解性樹脂の質量を重みとした、各酸分解性樹脂の酸分解性繰り返し単位のEth感度の加重平均であり、換言すれば、各酸分解性樹脂の酸分解性繰り返し単位のEth感度に、酸分解性樹脂の全質量に対する各酸分解性樹脂の質量分率を乗じたものを総和したものである。
本発明の組成物が、樹脂(B)として、酸分解性繰り返し単位のEth感度が5.64以下の酸分解性樹脂と、酸分解性繰り返し単位のEth感度が5.64超過の酸分解性樹脂を含有する場合、酸分解性樹脂の全量に対する、酸分解性繰り返し単位のEth感度が5.64以下の酸分解性樹脂の含有率が、酸分解性樹脂の全量に対する、酸分解性繰り返し単位のEth感度が5.64超過の酸分解性樹脂の含有率よりも多いことが好ましい。
本発明の組成物の全固形分中の樹脂(B)の含有量は、20質量%以上である。なかでも、40質量%以上であることが好ましく、60質量%以上であることより好ましく、80質量%以上であることがさらに好ましい。上限は特に制限されないが、99質量%以下であることが好ましく、97質量%以下であることがより好ましく、95質量%以下であることが更に好ましい。
本発明の組成物は、疎水性樹脂(以下、「疎水性樹脂(D)」又は単に「樹脂(D)」ともいう)を含有してもよい。なお、疎水性樹脂(D)は酸分解性樹脂とは異なることが好ましい。
疎水性樹脂(D)は、界面に偏在するように設計されることが好ましいが、界面活性剤とは異なり、必ずしも分子内に親水基を有する必要はなく、極性/非極性物質を均一に混合することに寄与しなくてもよい。
疎水性樹脂を添加することの効果として、水に対するレジスト膜表面の静的/動的な接触角の制御、液浸液追随性の向上、アウトガスの抑制などを挙げることができる。
疎水性樹脂(D)が、フッ素原子及び/又は珪素原子を含む場合、疎水性樹脂(D)に於ける上記フッ素原子及び/又は珪素原子は、樹脂の主鎖中に含まれていてもよく、側鎖中に含まれていてもよい。
フッ素原子を有するアルキル基(好ましくは炭素数1~10、より好ましくは炭素数1~4)は、少なくとも1つの水素原子がフッ素原子で置換された直鎖又は分岐アルキル基であり、更にフッ素原子以外の置換基を有していてもよい。
フッ素原子を有するシクロアルキル基及びフッ素原子を有するアリール基は、それぞれ、1つの水素原子がフッ素原子で置換されたシクロアルキル基及びフッ素原子を有するアリール基であり、更にフッ素原子以外の置換基を有していてもよい。
R57~R68は、各々独立に、水素原子、フッ素原子又はアルキル基(直鎖若しくは分岐)を表す。但し、R57~R61の少なくとも1つ、R62~R64の少なくとも1つ、及びR65~R68の少なくとも1つは、各々独立に、フッ素原子又は少なくとも1つの水素原子がフッ素原子で置換されたアルキル基(好ましくは炭素数1~4)を表す。
R57~R61及びR65~R67は、全てがフッ素原子であることが好ましい。R62、R63及びR68は、少なくとも1つの水素原子がフッ素原子で置換されたアルキル基(好ましくは炭素数1~4)が好ましく、炭素数1~4のパーフルオロアルキル基であることが更に好ましい。R62とR63は、互いに連結して環を形成してもよい。
フッ素原子又は珪素原子を有する繰り返し単位の例としては、US2012/0251948A1〔0519〕に例示されたものを挙げることが出来る。
ここで、疎水性樹脂(D)中の側鎖部分が有するCH3部分構造(以下、単に「側鎖CH3部分構造」ともいう)には、エチル基、プロピル基等が有するCH3部分構造を包含するものである。
一方、疎水性樹脂(D)の主鎖に直接結合しているメチル基(例えば、メタクリル酸構造を有する繰り返し単位のα-メチル基)は、主鎖の影響により疎水性樹脂(D)の表面偏在化への寄与が小さいため、本発明におけるCH3部分構造に包含されないものとする。
一方、C-C主鎖から何らかの原子を介して存在するCH3部分構造は、本発明におけるCH3部分構造に該当するものとする。例えば、R11がエチル基(CH2CH3)である場合、本発明におけるCH3部分構造を「1つ」有するものとする。
R11~R14は、各々独立に、側鎖部分を表す。
側鎖部分のR11~R14としては、水素原子、1価の有機基などが挙げられる。
R11~R14についての1価の有機基としては、アルキル基、シクロアルキル基、アリール基、アルキルオキシカルボニル基、シクロアルキルオキシカルボニル基、アリールオキシカルボニル基、アルキルアミノカルボニル基、シクロアルキルアミノカルボニル基、アリールアミノカルボニル基などが挙げられ、これらの基は、更に置換基を有していてもよい。
Xb1は、水素原子又はメチル基であることが好ましい。
R2としては、1つ以上のCH3部分構造を有する、アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基、アリール基、及び、アラルキル基が挙げられる。上記のシクロアルキル基、アルケニル基、シクロアルケニル基、アリール基、及び、アラルキル基は、更に、置換基としてアルキル基を有していてもよい。
R2は、1つ以上のCH3部分構造を有する、アルキル基又はアルキル置換シクロアルキル基が好ましい。
R2としての1つ以上のCH3部分構造を有する酸に安定な有機基は、CH3部分構造を2個以上10個以下有することが好ましく、2個以上8個以下有することがより好ましい。
一般式(II)で表される繰り返し単位の好ましい具体例を以下に挙げる。なお、本発明はこれに限定されるものではない。
以下、一般式(III)で表される繰り返し単位について詳細に説明する。
Xb2のアルキル基は、炭素数1~4のものが好ましく、メチル基、エチル基、プロピル基、ヒドロキシメチル基又はトリフルオロメチル基等が挙げられるが、水素原子である事が好ましい。
Xb2は、水素原子であることが好ましい。
R3は、酸に対して安定な有機基であるため、より具体的には、上記樹脂Pにおいて説明した“酸分解性基”を有さない有機基であることが好ましい。
R3としての1つ以上のCH3部分構造を有する酸に安定な有機基は、CH3部分構造を1個以上10個以下有することが好ましく、1個以上8個以下有することがより好ましく、1個以上4個以下有することが更に好ましい。
nは1から5の整数を表し、1~3の整数を表すことがより好ましく、1又は2を表すことが更に好ましい。
(x)酸基、
(y)ラクトン構造を有する基、酸無水物基、又は酸イミド基、
(z)酸の作用により分解する基
好ましい酸基としては、フッ素化アルコール基(好ましくはヘキサフルオロイソプロパノール)、スルホンイミド基、ビス(アルキルカルボニル)メチレン基が挙げられる。
酸基(x)を有する繰り返し単位の含有量は、疎水性樹脂(D)中の全繰り返し単位に対し、1~50モル%が好ましく、より好ましくは3~35モル%、更に好ましくは5~20モル%である。
酸基(x)を有する繰り返し単位の具体例を以下に示すが、本発明は、これに限定されるものではない。式中、Rxは水素原子、CH3、CF3、又は、CH2OHを表す。
これらの基を含んだ繰り返し単位は、例えば、アクリル酸エステル及びメタクリル酸エステルによる繰り返し単位等の、樹脂の主鎖に直接この基が結合している繰り返し単位である。或いは、この繰り返し単位は、この基が連結基を介して樹脂の主鎖に結合している繰り返し単位であってもよい。或いは、この繰り返し単位は、この基を有する重合開始剤又は連鎖移動剤を重合時に用いて、樹脂の末端に導入されていてもよい。
ラクトン構造を有する基を有する繰り返し単位としては、例えば、先に樹脂(A)の項で説明したラクトン構造を有する繰り返し単位と同様のものが挙げられる。
疎水性樹脂(D)は、更に、上述した繰り返し単位とは別の繰り返し単位を有していてもよい。
また、疎水性樹脂(D)は、1種で使用してもよいし、複数併用してもよい。
疎水性樹脂(D)の組成物中の含有量は、本発明の組成物中の全固形分に対し、0.01~10質量%が好ましく、0.05~8質量%がより好ましい。
本発明の組成物は、酸拡散制御剤を含有することが好ましい。酸拡散制御剤は、露光時に光酸発生剤等から発生する酸をトラップし、余分な発生酸による、未露光部における酸分解性樹脂の反応を抑制するクエンチャーとして作用するものである。酸拡散制御剤としては、塩基性化合物、窒素原子を有し、酸の作用により脱離する基を有する低分子化合物、活性光線又は放射線の照射により塩基性が低下又は消失する塩基性化合物、又は、光酸発生剤に対して相対的に弱酸となるオニウム塩を使用することができる。
R200、R201及びR202は、同一でも異なってもよく、水素原子、アルキル基(好ましくは炭素数1~20)、シクロアルキル基(好ましくは炭素数3~20)又はアリール基(炭素数6~20)を表し、ここで、R201とR202は、互いに結合して環を形成してもよい。
R203、R204、R205及びR206は、同一でも異なってもよく、炭素数1~20個のアルキル基を表す。
これら一般式(A)及び(E)中のアルキル基は、無置換であることがより好ましい。
好ましい化合物の具体例としては、US2012/0219913A1 [0379]に例示された化合物を挙げることができる。
好ましい塩基性化合物として、更に、フェノキシ基を有するアミン化合物、フェノキシ基を有するアンモニウム塩化合物、スルホン酸エステル基を有するアミン化合物及びスルホン酸エステル基を有するアンモニウム塩化合物を挙げることができる。
これらの塩基性化合物は、1種類を単独で用いてもよく、2種類以上を組み合わせて用いてもよい。
光酸発生剤と塩基性化合物の組成物中の使用割合は、光酸発生剤/塩基性化合物(モル比)=2.5~300が好ましく、より好ましくは5.0~200、更に好ましくは7.0~150である。
酸の作用により脱離する基として、アセタール基、カルボネート基、カルバメート基、3級エステル基、3級水酸基、ヘミアミナールエーテル基が好ましく、カルバメート基、ヘミアミナールエーテル基であることが特に好ましい。
化合物(C)の分子量は、100~1000が好ましく、100~700がより好ましく、100~500が特に好ましい。
化合物(C)は、窒素原子上に保護基を有するカルバメート基を有してもよい。カルバメート基を構成する保護基としては、下記一般式(d-1)で表すことができる。
Rbは、各々独立に、水素原子、アルキル基(好ましくは炭素数1~10)、シクロアルキル基(好ましくは炭素数3~30)、アリール基(好ましくは炭素数3~30)、アラルキル基(好ましくは炭素数1~10)、又はアルコキシアルキル基(好ましくは炭素数1~10)を表す。Rbは相互に連結して環を形成していてもよい。
Rbが示すアルキル基、シクロアルキル基、アリール基、アラルキル基は、ヒドロキシル基、シアノ基、アミノ基、ピロリジノ基、ピペリジノ基、モルホリノ基、オキソ基等の官能基、アルコキシ基、ハロゲン原子で置換されていてもよい。Rbが示すアルコキシアルキル基についても同様である。
2つのRbが相互に連結して形成する環としては、脂環式炭化水素基、芳香族炭化水素基、複素環式炭化水素基若しくはその誘導体等が挙げられる。
一般式(d-1)で表される基の具体的な構造としては、US2012/0135348 A1 [0466]に開示された構造を挙げることができるが、これに限定されるものではない。
Rbは、上記一般式(d-1)におけるRbと同義であり、好ましい例も同様である。
lは0~2の整数を表し、mは1~3の整数を表し、l+m=3を満たす。
一般式(6)において、Raとしてのアルキル基、シクロアルキル基、アリール基、アラルキル基は、Rbとしてのアルキル基、シクロアルキル基、アリール基、アラルキル基が置換されていてもよい基として前述した基と同様な基で置換されていてもよい。
本発明における特に好ましい化合物(C)の具体的としては、US2012/0135348 A1 [0475]に開示された化合物を挙げることができるが、これに限定されるものではない。
本発明において、酸の作用により脱離する基を窒素原子上に有する低分子化合物(C)は、一種単独でも又は2種以上を混合しても使用することができる。
本発明の組成物における化合物(C)の含有量は、組成物の全固形分を基準として、0.001~20質量%であることが好ましく、より好ましくは0.001~10質量%、更に好ましくは0.01~5質量%である。
プロトンアクセプター性は、pH測定を行うことによって確認することができる。
Qは、-SO3H、-CO2H、又は-W1NHW2Rfを表す。ここで、Rfは、アルキル基(好ましくは炭素数1~20)、シクロアルキル基(好ましくは炭素数3~20)又はアリール基(好ましくは炭素数6~30)を表し、W1及びW2は、各々独立に、-SO2-又は-CO-を表す。
Aは、単結合又は2価の連結基を表す。
Xは、-SO2-又は-CO-を表す。
nは、0又は1を表す。
Bは、単結合、酸素原子、又は-N(Rx)Ry-を表す。ここで、Rxは水素原子又は1価の有機基を表し、Ryは単結合又は2価の有機基を表す。Rxは、Ryと結合して環を形成していてもよく、Rと結合して環を形成していてもよい。
Rは、プロトンアクセプター性官能基を有する1価の有機基を表す。
mは1又は2を表し、nは1又は2を表す。但し、Aが硫黄原子の時、m+n=3、Aがヨウ素原子の時、m+n=2である。
Rは、アリール基を表す。
RNは、プロトンアクセプター性官能基で置換されたアリール基を表す。X-は、対アニオンを表す。
X-の具体例としては、例えば、特開2016-42199号公報の段落〔0149〕~〔0183〕に記載のアニオンなどを挙げることができる。
R及びRNのアリール基の具体例としては、フェニル基が好ましく挙げられる。
以下に、カチオン部にプロトンアクセプター部位を有するイオン性化合物の具体例としては、US2011/0269072A1[0291]に例示された化合物を挙げることが出来る。
なお、このような化合物は、例えば、特開2007―230913号公報及び特開2009―122623号公報などに記載の方法を参考にして合成できる。
化合物(PA)の含有量は、組成物の全固形分を基準として、0.1~10質量%が好ましく、1~8質量%がより好ましい。
光酸発生剤と、光酸発生剤から生じた酸に対して相対的に弱酸である酸を発生するオニウム塩を混合して用いた場合、活性光線性又は放射線の照射により光酸発生剤から生じた酸が未反応の弱酸アニオンを有するオニウム塩と衝突すると、塩交換により弱酸を放出して強酸アニオンを有するオニウム塩を生じる。この過程で強酸がより触媒能の低い弱酸に交換されるため、見かけ上、酸が失活して酸拡散の制御を行うことができる。
一般式(d1-2)で表される化合物のアニオン部の好ましい例としては、特開2012-242799号公報の段落〔0201〕に例示された構造を挙げることが出来る。
一般式(d1-3)で表される化合物のアニオン部の好ましい例としては、特開2012-242799号公報の段落〔0209〕及び〔0210〕に例示された構造を挙げることが出来る。
化合物(CA)としては、下記一般式(C-1)~(C-3)のいずれかで表される化合物であることが好ましい。
R1、R2、R3は、炭素数1以上の置換基を表す。
L1は、カチオン部位とアニオン部位を連結する2価の連結基又は単結合を表す。
-X-は、-COO-、-SO3 -、-SO2 -、-N--R4から選択されるアニオン部位を表す。R4は、隣接するN原子との連結部位に、カルボニル基:-C(=O)-、スルホニル基:-S(=O)2-、スルフィニル基:-S(=O)-を有する1価の置換基を表す。
R1、R2、R3、R4、L1は互いに結合して環構造を形成してもよい。また、(C-3)において、R1~R3のうち2つを合わせて、N原子と2重結合を形成してもよい。
一般式(C-1)で表される化合物の好ましい例としては、特開2013-6827号公報の段落〔0037〕~〔0039〕及び特開2013-8020号公報の段落〔0027〕~〔0029〕に例示された化合物を挙げることが出来る。
一般式(C-2)で表される化合物の好ましい例としては、特開2012-189977号公報の段落〔0012〕~〔0013〕に例示された化合物を挙げることが出来る。
一般式(C-3)で表される化合物の好ましい例としては、特開2012-252124号公報の段落〔0029〕~〔0031〕に例示された化合物を挙げることが出来る。
本発明の組成物は、通常、溶剤を含有する。
組成物を調製する際に使用することができる溶剤としては、例えば、アルキレングリコールモノアルキルエーテルカルボキシレート、アルキレングリコールモノアルキルエーテル、乳酸アルキルエステル、アルコキシプロピオン酸アルキル、環状ラクトン(好ましくは炭素数4~10)、環を有してもよいモノケトン化合物(好ましくは炭素数4~10)、アルキレンカーボネート、アルコキシ酢酸アルキル、ピルビン酸アルキル等の有機溶剤を挙げることができる。
これらの溶剤の具体例は、米国特許出願公開2008/0187860号明細書[0441]~[0455]に記載のものを挙げることができる。
水酸基を含有する溶剤、水酸基を含有しない溶剤としては前述の例示化合物が適宜選択可能であるが、水酸基を含有する溶剤としては、アルキレングリコールモノアルキルエーテル、乳酸アルキル等が好ましく、プロピレングリコールモノメチルエーテル(PGME、別名1-メトキシ-2-プロパノール)、乳酸エチル、2-ヒドロキシイソ酪酸メチルがより好ましい。また、水酸基を含有しない溶剤としては、アルキレングリコールモノアルキルエーテルアセテート、アルキルアルコキシプロピオネート、環を含有してもよいモノケトン化合物、環状ラクトン、酢酸アルキルなどが好ましく、これらの内でもプロピレングリコールモノメチルエーテルアセテート(PGMEA、別名1-メトキシ-2-アセトキシプロパン)、エチルエトキシプロピオネート、2-ヘプタノン、γ-ブチロラクトン、シクロヘキサノン、酢酸ブチルが特に好ましく、プロピレングリコールモノメチルエーテルアセテート、エチルエトキシプロピオネート、2-ヘプタノンが最も好ましい。
水酸基を含有する溶剤と水酸基を含有しない溶剤との混合比(質量)は、1/99~99/1、好ましくは10/90~90/10、更に好ましくは20/80~60/40である。水酸基を含有しない溶剤を50質量%以上含有する混合溶剤が塗布均一性の点で特に好ましい。
溶剤は、プロピレングリコールモノメチルエーテルアセテートを含むことが好ましく、プロピレングリコールモノメチルエーテルアセテート単独溶剤、又は、プロピレングリコールモノメチルエーテルアセテートを含有する2種類以上の混合溶剤であることが好ましい。
本発明の組成物は、更に界面活性剤を含有してもしなくてもよく、含有する場合、フッ素系及び/又はシリコン系界面活性剤(フッ素系界面活性剤、シリコン系界面活性剤、フッ素原子とケイ素原子との両方を有する界面活性剤)のいずれか、あるいは2種以上を含有することがより好ましい。
フッ素系及び/又はシリコン系界面活性剤として、米国特許出願公開第2008/0248425号明細書の段落[0276]に記載の界面活性剤が挙げることができる。
また、本発明では、米国特許出願公開第2008/0248425号明細書の段落[0280]に記載の、フッ素系及び/又はシリコン系界面活性剤以外の他の界面活性剤を使用することもできる。
本発明の組成物が界面活性剤を含有する場合、界面活性剤の使用量は、組成物の全固形分に対して、好ましくは0.0001~2質量%、より好ましくは0.0005~1質量%である。
一方、界面活性剤の添加量を、組成物の全量(溶剤を除く)に対して、10ppm以下とすることで、疎水性樹脂の表面偏在性があがり、それにより、レジスト膜表面をより疎水的にすることができ、液浸露光時の水追随性を向上させることができる。
本発明の組成物は、カルボン酸オニウム塩を含有してもしなくてもよい。このようなカルボン酸オニウム塩は、米国特許出願公開2008/0187860号明細書[0605]~[0606]に記載のものを挙げることができる。
これらのカルボン酸オニウム塩は、スルホニウムヒドロキシド、ヨードニウムヒドロキシド、アンモニウムヒドロキシドとカルボン酸を適当な溶剤中酸化銀と反応させることによって合成できる。
本発明の組成物には、必要に応じて更に、酸増殖剤、染料、可塑剤、光増感剤、光吸収剤、アルカリ可溶性樹脂、溶解阻止剤及び現像液に対する溶解性を促進させる化合物(例えば、分子量1000以下のフェノール化合物、カルボキシル基を有する脂環族、又は脂肪族化合物)等を含有させることができる。
カルボキシル基を有する脂環族、又は脂肪族化合物の具体例としてはコール酸、デオキシコール酸、リトコール酸などのステロイド構造を有するカルボン酸誘導体、アダマンタンカルボン酸誘導体、アダマンタンジカルボン酸、シクロヘキサンカルボン酸、シクロヘキサンジカルボン酸などが挙げられるがこれらに限定されるものではない。
固形分濃度とは、組成物の総重量に対する、溶剤を除く他のレジスト成分の重量の重量百分率である。
本発明は上記感活性光線性又は感放射線性樹脂組成物を用いたパターン形成方法にも関する。以下、本発明のパターン形成方法について説明する。また、パターン形成方法の説明と併せて、本発明の感活性光線性又は感放射線性膜(典型的には、レジスト膜)についても説明する。
(i)上述した感活性光線性又は感放射線性樹脂組成物によって感活性光線性又は感放射線性膜を形成する工程(膜形成工程)、
(ii)上記感活性光線性又は感放射線性膜に活性光線又は放射線を照射する工程(露光工程)、及び、
(iii)活性光線又は放射線が照射された感活性光線性又は感放射線性膜を、現像液を用いて現像する工程、を有する。
本発明のパターン形成方法は、(ii)露光工程における露光方法が、液浸露光であることが好ましい。
本発明のパターン形成方法は、(ii)露光工程の前に、(iv)前加熱工程を含むことが好ましい。
本発明のパターン形成方法は、(ii)露光工程の後に、(v)露光後加熱工程を含むことが好ましい。
本発明のパターン形成方法は、(ii)露光工程を、複数回含んでいてもよい。
本発明のパターン形成方法は、(iv)前加熱工程を、複数回含んでいてもよい。
本発明のパターン形成方法は、(v)露光後加熱工程を、複数回含んでいてもよい。
本発明のパターン形成方法において、上述した(i)感活性光線性又は感放射線性膜形成工程、(ii)露光工程、及び(iii)現像工程は、一般的に知られている方法により行うことができる。
また、必要に応じて、感活性光線性又は感放射線性膜と基板との間に反射防止膜を形成させてもよい。反射防止膜としては、公知の有機系又は無機系の反射防止膜を適宜用いることができる。
また、(ii)露光工程の後、且つ(iii)現像工程の前に、(v)露光後加熱工程(PEB;PostExposure Bake)を含むことも好ましい。
上記のようなベークにより露光部の反応が促進され、感度及び/又はパターンプロファイルが改善する。
加熱時間は、PB及びPEBのいずれにおいても、30~300秒が好ましく、30~180秒がより好ましく、30~90秒が更に好ましい。
加熱は、通常の露光機及び現像機に備わっている手段で行うことができ、ホットプレート等を用いて行ってもよい。
具体的には、アルカリ現像液としては、例えば、水酸化ナトリウム、水酸化カリウム、炭酸ナトリウム、ケイ酸ナトリウム、メタケイ酸ナトリウム、アンモニア水などの無機アルカリ類;エチルアミン、n-プロピルアミンなどの第一アミン類;ジエチルアミン、ジ-n-ブチルアミンなどの第二アミン類;トリエチルアミン、メチルジエチルアミンなどの第三アミン類;ジメチルエタノールアミン、トリエタノールアミンなどのアルコールアミン類;テトラメチルアンモニウムヒドロキシド、テトラエチルアンモニウムヒドロキシドなどの第四級アンモニウム塩;ピロール、ピペリジンなどの環状アミン類;等のアルカリ性水溶液を使用することができる。これらの中でもテトラエチルアンモニウムヒドロキシドの水溶液を用いることが好ましい。
さらに、上記アルカリ現像液にアルコール類、界面活性剤を適当量添加してもよい。アルカリ現像液のアルカリ濃度は、通常0.1~20質量%である。アルカリ現像液のpHは、通常10.0~15.0である。
アルカリ現像液を用いて現像を行う時間は、通常10~300秒である。
アルカリ現像液のアルカリ濃度(及びpH)及び現像時間は、形成するパターンに応じて、適宜調整することができる。
なお、炭化水素系溶剤である脂肪族炭化水素系溶剤においては、同じ炭素数で異なる構造の化合物の混合物であってもよい。例えば、脂肪族炭化水素系溶媒としてデカンを使用した場合、同じ炭素数で異なる構造の化合物である2-メチルノナン、2,2-ジメチルオクタン、4-エチルオクタン、イソオクタンなどが脂肪族炭化水素系溶媒に含まれていてもよい。
また、上記同じ炭素数で異なる構造の化合物は、1種のみが含まれていてもよいし、上記のように複数種含まれていてもよい。
すなわち、有機系現像液に対する有機溶剤の使用量は、現像液の全量に対して、90質量%以上100質量%以下であることが好ましく、95質量%以上100質量%以下であることがより好ましい。
界面活性剤としては特に限定されないが、例えば、イオン性又は非イオン性のフッ素系及び/又はシリコン系界面活性剤等を用いることができる。これらのフッ素及び/又はシリコン系界面活性剤として、例えば特開昭62-36663号公報、特開昭61-226746号公報、特開昭61-226745号公報、特開昭62-170950号公報、特開昭63-34540号公報、特開平7-230165号公報、特開平8-62834号公報、特開平9-54432号公報、特開平9-5988号公報、米国特許第5405720号明細書、同5360692号明細書、同5529881号明細書、同5296330号明細書、同5436098号明細書、同5576143号明細書、同5294511号明細書、又は同5824451号明細書記載の界面活性剤を挙げることができ、好ましくは、非イオン性の界面活性剤である。非イオン性の界面活性剤としては特に限定されないが、フッ素系界面活性剤又はシリコン系界面活性剤を用いることが更に好ましい。
本発明において、有機溶剤現像工程によって露光強度の弱い部分が除去されるが、更にアルカリ現像工程を行うことによって露光強度の強い部分も除去される。このように現像を複数回行う多重現像プロセスにより、中間的な露光強度の領域のみを溶解させずにパターン形成が行えるので、通常より微細なパターンを形成できる(特開2008-292975号公報[0077]と同様のメカニズム)。
炭化水素系溶剤、ケトン系溶剤、エステル系溶剤、アルコール系溶剤、アミド系溶剤、及びエーテル系溶剤の具体例としては、有機溶剤を含む現像液において説明したものと同様のものが挙げられる。
リンス液としてエステル系溶剤を用いる場合には、エステル系溶剤(1種又は2種以上)に加えて、グリコールエーテル系溶剤を用いてもよい。この場合の具体例としては、エステル系溶剤(好ましくは、酢酸ブチル)を主成分として、グリコールエーテル系溶剤(好ましくはプロピレングリコールモノメチルエーテル(PGME))を副成分として用いることが挙げられる。これにより、残渣欠陥を抑制することができる。
リンス液中の含水率は、10質量%以下が好ましく、5質量%以下がより好ましく、3質量%以下が更に好ましくい。含水率を10質量%以下とすることで、良好な現像特性を得ることができる。
リンス工程においては、有機溶剤を含む現像液を用いる現像を行ったウエハを上記の有機溶剤を含むリンス液を用いて洗浄処理する。洗浄処理の方法は特に限定されないが、例えば、一定速度で回転している基板上にリンス液を吐出しつづける方法(回転塗布法)、リンス液が満たされた槽中に基板を一定時間浸漬する方法(ディップ法)、又は、基板表面にリンス液を噴霧する方法(スプレー法)等を適用することができる。なかでも、回転塗布方法で洗浄処理を行い、洗浄後に基板を2000rpm~4000rpmの回転数で回転させ、リンス液を基板上から除去することが好ましい。また、リンス工程の後に加熱工程(Post Bake)を含むことも好ましい。ベークによりパターン間及びパターン内部に残留した現像液及びリンス液が除去される。リンス工程の後の加熱工程は、通常40~160℃、好ましくは70~95℃で、通常10秒~3分、好ましくは30秒から90秒間行う。
上記各種材料から金属等の不純物を除去する方法としては、例えば、フィルターを用いた濾過を挙げることができる。フィルター孔径としては、ポアサイズ10nm以下が好ましく、5nm以下がより好ましく、3nm以下が更に好ましい。フィルターの材質としては、ポリテトラフロロエチレン製、ポリエチレン製、又はナイロン製のフィルターが好ましい。フィルターは、有機溶剤であらかじめ洗浄したものを用いてもよい。フィルター濾過工程では、複数種類のフィルターを直列又は並列に接続して用いてもよい。複数種類のフィルターを使用する場合は、孔径及び/又は材質が異なるフィルターを組み合わせて使用してもよい。また、各種材料を複数回濾過してもよく、複数回濾過する工程が循環濾過工程であってもよい。
また、上記各種材料に含まれる金属等の不純物を低減する方法としては、各種材料を構成する原料として金属含有量が少ない原料を選択する、各種材料を構成する原料に対してフィルター濾過を行う、又は、装置内をテフロン(登録商標)でライニングする等してコンタミネーションを可能な限り抑制した条件下で蒸留を行う等の方法が挙げられる。各種材料を構成する原料に対して行うフィルター濾過における好ましい条件は、上記した条件と同様である。
フィルター濾過のほか、吸着材による不純物の除去を行ってもよく、フィルター濾過と吸着材を組み合わせて使用してもよい。吸着材としては、公知の吸着材を用いることができ、例えば、シリカゲル若しくはゼオライト等の無機系吸着材、又は活性炭等の有機系吸着材を使用することができる。
本発明のパターン形成方法は、DSA(Directed Self-Assembly)におけるガイドパターン形成(例えば、ACS Nano Vol.4 No.8 Page4815-4823参照)にも用いることができる。
また、上記の方法によって形成されたレジストパターンは、例えば特開平3-270227号公報及び特開2013-164509号公報に開示されたスペーサープロセスの芯材(コア)として使用できる。
また、本発明は、上記した本発明のパターン形成方法を含む、電子デバイスの製造方法にも関する。本発明の電子デバイスの製造方法により製造された電子デバイスは、電気電子機器(例えば、家電、OA(Office Automation)関連機器、メディア関連機器、光学用機器、及び、通信機器等)に、好適に搭載されるものである。
下記合成スキームの通り、ブロモフルオロ酢酸エチル 50g、亜硫酸ナトリウム(Na2SO3) 34.1gにアセトニトリル(MeCN)200mL、水 100mLを加え、85℃で6時間攪拌した。反応液を濾過し、アセトニトリルを減圧下で留去した後、反応液を分液ロートに移し、水層をヘキサン100mLで洗浄した。水層に塩化ナトリウム 36gを加えた後、水層をアセトニトリル 100 mLで3回抽出した。アセトニトリルを減圧下で留去し、化合物1を白色固体で得た。(28g、収率50%)1H-NMR、400MHz、δ((d-DMSO)ppm:1.34(3H、d)、4.32(2H、q)、5.50(1H、d)。
下記合成スキームに基づき、化合物(PAG-5)を合成した。
アダマンタンエタノール52.7gに塩化メチレン450gを加え溶解させた液を-20℃に冷却し、トリフルオロメタンスルホン酸無水物(Tf2O)90.0gを滴下した。滴下後、ジイソプロピルエチルアミン(iPr2EtN)43.4gを滴下した。滴下終了後-10℃から0℃の間で2時間撹拌した。反応液を冷却した塩化アンモニウム水溶液500mL、ヘキサン1Lに注ぎ、有機層を抽出後、塩化アンモニウム水溶液、水、飽和塩化ナトリウム水溶液で洗浄した。硫酸ナトリウムで乾燥後に溶媒を留去して化合物(A-1)を89.4g得た。(収率98%)1H-NMR、400MHz、δ((CDCl3)ppm:1.52-1.56(6H、m)、1.59-1.76(8H、m)、1.94-2.02(3H、m)、4.61(2H、t)。
イソブタノール 120g、塩化メチレン(CH2Cl2)600gの溶液を0℃に冷却し、メシル酸クロリド(MsCl)204gを滴下した。その後、ジイソプロピルエチルアミン(iPr2EtN)251gを滴下し、滴下後0℃で1時間撹拌した。その後、反応液に水を添加し、有機層を飽和重曹水、続いて飽和食塩水で洗浄した。硫酸ナトリウムで乾燥後溶媒を留去することで、粗生成物を得た。粗生成物を減圧蒸留することで、化合物(A-2)を199.6g得た。(収率81%)1H-NMR、400MHz、δ((CDCl3)ppm:0.99(6H、d)、2.04(1H、m)、3.00(3H、s)、4.00(2H、d)。
化合物(A-2) 36.5g、テトラヒドロフラン(THF)460mL、ジメチルイミダゾリジノン(DMI)40mLの混合液を-60℃に冷却し、そこへn-ブチルリチウム(nBuLi)(2.67M ヘキサン溶液)90mLを滴下した。滴下後-60℃で1時間撹拌した後、化合物(A-1) 50.0gとテトラヒドロフラン90mLの溶液を滴下し、滴下後に-20℃~0℃で4時間撹拌した。その後、反応液に飽和塩化アンモニウム水溶液を添加し、テトラヒドロフランを減圧留去した。そこへ酢酸エチルを添加し、飽和食塩水で洗浄し、有機層を硫酸ナトリウムで乾燥後、溶媒を留去した。粗生成物をシリカゲルカラムで精製することで、化合物(A-3)を32.2g得た。(収率64%)1H-NMR、400MHz、δ((CDCl3)ppm:0.99(6H、d)、1.16(2H、m)、1.45-1.50(6H、m)、1.58-1.75(6H、m)、1.76-1.88(2H、m)、1.91-2.10(4H、m)、3.00-3.07(2H、m)、3.98(2H、d)。
化合物(A-3) 11.9g、テトラヒドロフラン160mLの溶液を-60℃に冷却し、n-ブチルリチウム(2.67M ヘキサン溶液)16mL滴下した。滴下後0℃まで昇温して1時間撹拌し、その後-40℃に冷却した。反応液にN-フルオロベンゼンスルホンイミド13.2g添加した後に、0℃に昇温し、2時間撹拌した。その後、飽和塩化アンモニウム水溶液を添加し、テトラヒドロフランを減圧留去した。酢酸エチルを添加し、飽和食塩水で洗浄後、硫酸ナトリウムで乾燥し、溶媒を減圧留去することで粗生成物を得た。この粗生成物をシリカゲルカラムで精製することで、化合物(A-4)を5.3g得た。(収率42%)1H-NMR、400MHz、δ((CDCl3)ppm:0.99(6H、d)、1.12-1.44(2H、m)、1.45-1.50(6H、m)、1.58-1.76(6H、m)、1.90-2.10(6H、m)、4.14(2H、d)、5.17(1H、dddd)。
化合物(A-4) 5.3g、ヨウ化ナトリウム(NaI)2.4g、アセトニトリル(MeCN)56gを60℃に加熱し、4時間撹拌した。その後溶媒を減圧留去することで化合物(A-5)を4.7g得た。(収率99%)
化合物(A-5) 4.7g、トリフェニルスルホニウムブロミド5.4g、ジクロロメタン65g、イオン交換水65gを室温で撹拌する。その後有機層を抽出し、イオン交換水で洗浄後溶媒を留去する。得られたオイル状の粗生成物をジイソプロピルエーテルに加え晶析することで、目的物である化合物(PAG-5)を6.2g得た。(収率73%)
1H-NMR、400MHz、δ((CDCl3)ppm:1.11-1.24(1H、m)、1.34-1.53(7H、m)、1.54-1.72(6H、m)、1.84-2.14(5H、m)、4.83-5.04(1H、m)、7.64-7.87(15H、m)。
<レジスト組成物の調製>
下表2に記載の各成分を溶剤に溶解させ、固形分濃度3.8質量%の溶液を調製した。次いで、得られた溶液を0.1μmのポアサイズを有するポリエチレンフィルターで濾過することで、感活性光線性又は感放射線性樹脂組成物(レジスト組成物)を調製した。
(A)EL/NILSにおけるELの測定
上記のようにして調製した感活性光線性又は感放射線性樹脂組成物の各々に対して、上記(1)~(6)の手順に従い、EL/NILSにおけるELを測定し、上述の手順に従い、EL/NILSにおけるNILSを測定し、EL/NILSを算出した。EL/NILSの値を表2に示す。
シリコンウエハ上に有機反射防止膜形成用組成物ARC29SR(日産化学社製)を塗布し、205℃で60秒間ベークを行い、膜厚95nmの反射防止膜を形成した。得られた反射防止膜上にレジスト組成物を塗布し、100℃で60秒間に亘ってベーク(PB:Prebake)を行い、膜厚85nmのレジスト膜を形成した。
得られたウエハをArFエキシマレーザー液浸スキャナー(ASML社製;XT1700i、NA1.20、C-Quad、アウターシグマ0.900、インナーシグマ0.812、XY偏向)を用い、線幅44nmの1:1ラインアンドスペースパターンの6%ハーフトーンマスクを通して露光した。液浸液としては超純水を用いた。その後、105℃で60秒間加熱(PEB:Post Exposure Bake)した。次いで、有機系現像液(酢酸ブチル)で30秒間パドルして現像し、リンス液〔メチルイソブチルカルビノール(MIBC)〕で30秒間パドルしてリンスした。続いて、4000rpmの回転数で30秒間ウエハを回転させることにより、線幅44nmの1:1ラインアンドスペースのパターンを形成した。
得られたレジストパターンを、下記の評価方法に基づき、ラインウィズスラフネス、露光ラチチュード、及び、フォーカス余裕度について評価した。結果を下表2に示す。
得られた線幅44nmの1:1ラインアンドスペースパターンについて、測長走査型電子顕微鏡(SEM((株)日立製作所S-8840))にてパターン上部から観察し、ラインパターンの長手方向のエッジ2μmの範囲について、線幅を50ポイント測定し、その測定ばらつきについて標準偏差を求め、3σを算出した。値が小さいほど良好な性能であることを示す。
線幅44nmの1:1ラインアンドスペースパターンを再現する露光量を求め、これを最適露光量Eoptとした。次いでラインの線幅が目的の値である44nmの±10%(即ち、39.6nm及び48.4nm)となるときの露光量を求めた。そして、次式で定義される露光ラチチュード(EL)を算出した。なお、評価基準(A~D)については下記のとおりである。ELの値が大きいほど、露光量変化による線幅の変化が小さく、良好であることを示す。
EL(%)=[〔(ラインの線幅が48.4nmとなる露光量)-(ラインの線幅が39.6nmとなる露光量)〕/Eopt]×100
線幅44nmのラインパターンを形成する上記最適露光量Eoptにおいて、フォーカス方向に10nm刻みで、露光フォーカスの条件を変更して露光及び現像を行い、得られる各パターンのスペース線幅(CD)を線幅測長走査型電子顕微鏡SEM((株)日立製作所S-9380)を使用して測定し、上記の各CDをプロットして得られる曲線の極小値又は極大値に対応するフォーカスをベストフォーカスとした。このベストフォーカスを中心にフォーカスを変化させた際に、ライン幅が44nm±10%を許容するフォーカスの変動幅、すなわち、フォーカス余裕度(nm)を算出した。フォーカス余裕度の値は大きいほど好ましい。
以下、各樹脂における繰り返し単位の構造の他、繰り返し単位のモル比率、重量平均分子量(Mw)、及び、分散度(Mw/Mn)についても示す。
以下、各樹脂における繰り返し単位の構造の他、繰り返し単位のモル比率、重量平均分子量(Mw)、及び、分散度(Mw/Mn)についても示す。
W-1:PolyFox PF-6320(OMNOVA Solutions Inc.製;フッ素系)
SL-1: プロピレングリコールモノメチルエーテルアセテート(PGMEA:1-メトキシ-2-アセトキシプロパン)
SL-2: プロピレングリコールモノメチルエーテル(PGME:1-メトキシ-2-プロパノール)
SL-3: シクロヘキサノン
SL-4: γ-ブチロラクトン
本出願は、2016年12月22日出願の日本特許出願(特願2016-250127)に基づくものであり、その内容はここに参照として取り込まれる。
Claims (10)
- 露光ラチチュードをELとし、空中像強度対数勾配をNILSとした場合に、下記式(1)で表わされる関係を満たす感活性光線性又は感放射線性樹脂組成物。
EL/NILS>12.0 ・・・(1)
上記式(1)において、ELは下記式により算出される。
EL(%)={[(ラインパターンの線幅が75nmの+10%となる露光量)-(ラインパターンの線幅が75nmの-10%となる露光量)]/(ラインパターンの線幅が75nmとなる露光量)}×100
NILSは、線幅75nmの光学像における空中像強度対数勾配である。 - 前記感活性光線性又は感放射線性樹脂組成物が、(A)活性光線又は放射線の照射によりpKaが-1.40以上の酸を発生する光酸発生剤、及び、(B)酸分解性基を有する繰り返し単位を有する樹脂を含有し、前記酸分解性基を有する繰り返し単位のEth感度が5.64以下である、請求項1に記載の感活性光線性又は感放射線性樹脂組成物。
- 前記pKaが-1.40以上の酸がスルホン酸である、請求項2に記載の感活性光線性又は感放射線性樹脂組成物。
- 前記スルホン酸が、スルホン酸基のα位の炭素原子に1つのフッ素原子が結合するアルキルスルホン酸である、請求項3に記載の感活性光線性又は感放射線性樹脂組成物。
- 活性光線又は放射線の照射により前記光酸発生剤(A)が発生する酸が、下記一般式(a)、(b)及び(I)~(V)のいずれかで表されるスルホン酸である、請求項3に記載の感活性光線性又は感放射線性樹脂組成物。
上記一般式(a)中、Rf1は、フッ素原子、又は、フッ素原子を含むアルキル基を表す。R1は、1価の有機基を表す。
上記一般式(b)中、Rf2及びRf3は、各々独立して、フッ素原子、又は、フッ素原子を含むアルキル基を表す。R2は、1価の有機基を表す。
上記一般式(I)中、R11及びR12は、各々独立して、1価の有機基を表す。R13は、水素原子又は1価の有機基を表す。L1は、-CO-O-、-CO-、-O-、-S-、-O-CO-、-S-CO-又は-CO-S-で表される基を表す。R11、R12及びR13の2つは互いに結合して環を形成しても良い。
上記一般式(II)中、R21及びR22は、各々独立して、1価の有機基を表す。R23は、水素原子又は1価の有機基を表す。L2は、-CO-、-O-、-S-、-O-CO-、-S-CO-又は-CO-S-で表される基を表す。R21、R22及びR23の2つは互いに結合して環を形成しても良い。
上記一般式(III)中、R31及びR33は、各々独立して、水素原子又は1価の有機基を表す。R31とR33とは互いに結合して環を形成しても良い。
上記一般式(IV)中、R41及びR43は、各々独立して、水素原子又は1価の有機基を表す。R41とR43とは互いに結合して環を形成しても良い。
上記一般式(V)中、R51、R52及びR53は、各々独立して、水素原子又は1価の有機基を表す。R51、R52及びR53の2つは互いに結合して環を形成しても良い。 - 前記樹脂(B)が、前記酸分解性基を有する繰り返し単位として、下記一般式(A)又は(B)で表される繰り返し単位を有する樹脂である、請求項2~5のいずれか1項に記載の感活性光線性又は感放射線性樹脂組成物。
上記一般式(A)中、R4A、R5A及びR6Aは、それぞれ独立して、1価の有機基を表す。WAは、-CO-又は二価の芳香環基を表す。R7Aは、水素原子、メチル基又はトリフルオロメチル基を表す。R5A及びR6Aは、互いに結合して環を形成しても良い。
上記一般式(B)中、R4B、R5B及びR6Bは、それぞれ独立して、水素原子、又は、1価の有機基を表す。R5B及びR6Bは、互いに結合して環を形成しても良い。WBは、-CO-又は二価の芳香環基を表す。R7Bは、水素原子、メチル基又はトリフルオロメチル基を表す。 - 活性光線又は放射線の照射によりpKa-1.40未満の酸を発生する光酸発生剤を含まない、請求項2~6のいずれか1項に記載の感活性光線性又は感放射線性樹脂組成物。
- 請求項1~7のいずれか1項に記載の感活性光線性又は感放射線性樹脂組成物により形成された感活性光線性又は感放射線性膜。
- 請求項1~7のいずれか1項に記載の感活性光線性又は感放射線性樹脂組成物によって感活性光線性又は感放射線性膜を形成する工程と、
前記感活性光線性又は感放射線性膜に活性光線又は放射線を照射する工程と、
活性光線又は放射線が照射された感活性光線性又は感放射線性膜を、現像する工程と、を備えるパターン形成方法。 - 請求項9に記載のパターン形成方法を含む、電子デバイスの製造方法。
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JPWO2018168252A1 (ja) * | 2017-03-13 | 2019-12-19 | 富士フイルム株式会社 | 感活性光線性又は感放射線性樹脂組成物、レジスト膜、パターン形成方法、及び電子デバイスの製造方法 |
JP2021021773A (ja) * | 2019-07-25 | 2021-02-18 | 東京応化工業株式会社 | レジスト組成物及びレジストパターン形成方法 |
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WO2018116916A1 (ja) * | 2016-12-22 | 2018-06-28 | 富士フイルム株式会社 | 感活性光線性又は感放射線性樹脂組成物、感活性光線性又は感放射線性膜、パターン形成方法、電子デバイスの製造方法、及び、光酸発生剤 |
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JP7015295B2 (ja) | 2017-03-13 | 2022-02-02 | 富士フイルム株式会社 | 感活性光線性又は感放射線性樹脂組成物、レジスト膜、パターン形成方法、及び電子デバイスの製造方法 |
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US20190294042A1 (en) | 2019-09-26 |
TWI742217B (zh) | 2021-10-11 |
KR20190085069A (ko) | 2019-07-17 |
JP6911053B2 (ja) | 2021-07-28 |
JPWO2018116915A1 (ja) | 2019-11-21 |
TW201835190A (zh) | 2018-10-01 |
KR102327880B1 (ko) | 2021-11-17 |
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