WO2016021648A1 - シール組成物、及び半導体装置の製造方法 - Google Patents
シール組成物、及び半導体装置の製造方法 Download PDFInfo
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- WO2016021648A1 WO2016021648A1 PCT/JP2015/072250 JP2015072250W WO2016021648A1 WO 2016021648 A1 WO2016021648 A1 WO 2016021648A1 JP 2015072250 W JP2015072250 W JP 2015072250W WO 2016021648 A1 WO2016021648 A1 WO 2016021648A1
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- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K3/00—Materials not provided for elsewhere
- C09K3/10—Materials in mouldable or extrudable form for sealing or packing joints or covers
- C09K3/1006—Materials in mouldable or extrudable form for sealing or packing joints or covers characterised by the chemical nature of one of its constituents
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- H—ELECTRICITY
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- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02041—Cleaning
- H01L21/02082—Cleaning product to be cleaned
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L79/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen or carbon only, not provided for in groups C08L61/00 - C08L77/00
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- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D157/00—Coating compositions based on unspecified polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C09D157/06—Homopolymers or copolymers containing elements other than carbon and hydrogen
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- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
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- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3205—Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers
- H01L21/32051—Deposition of metallic or metal-silicide layers
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
- H01L21/76801—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
- H01L21/76829—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
- H01L21/76831—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers in via holes or trenches, e.g. non-conductive sidewall liners
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- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
- H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
- H01L21/76877—Filling of holes, grooves or trenches, e.g. vias, with conductive material
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- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/52—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames
- H01L23/522—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
- H01L23/532—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body characterised by the materials
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
- C09K2200/04—Non-macromolecular organic compounds
- C09K2200/0441—Carboxylic acids, salts, anhydrides or esters thereof
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
- C09K2200/04—Non-macromolecular organic compounds
- C09K2200/0458—Nitrogen-containing compounds
- C09K2200/0476—Heterocyclic nitrogen compounds, e.g. melamine
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
- H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
- H01L21/02118—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC
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- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
Definitions
- the present invention relates to a sealing composition and a method for manufacturing a semiconductor device.
- a composition containing a polymer is applied to a member.
- a technique is known in which a semiconductor composition containing a polymer having a weight average molecular weight of 2000 to 100,000 having two or more cationic functional groups is applied to an interlayer insulating layer of a semiconductor device (for example, Patent Document 1). reference).
- a semiconductor sealing layer is formed by applying a semiconductor sealing composition containing a resin having a cationic functional group and a weight average molecular weight of 2,000 to 600,000 to at least a part of the surface of the semiconductor substrate,
- a technique is known in which a surface of a semiconductor substrate on which a semiconductor sealing layer is formed is washed with a rinsing liquid having a pH of 6 or less at 25 ° C. (see, for example, Patent Document 2).
- a semiconductor sealing composition containing a polymer having a cationic functional group and a weight average molecular weight of 2,000 to 1,000,000 is applied to at least the bottom and side surfaces of the recess of the semiconductor substrate, and at least the bottom and side surfaces of the recess.
- a semiconductor sealing layer is formed on the exposed surface of the wiring by forming a semiconductor sealing layer on the semiconductor substrate and heat-treating the surface of the semiconductor substrate on which the semiconductor sealing layer is formed at a temperature of 200 ° C. to 425 ° C.
- a technique for removing at least part of the layer is described (for example, see Patent Document 3).
- Patent Literature 1 International Publication No. 2010/137711
- Patent Literature 2 International Publication No. 2012/033172
- Patent Literature 3 International Publication No. 2014/013956
- a semiconductor device having an interlayer insulating layer provided with a recess and a wiring on a semiconductor substrate has been further miniaturized.
- Any sealing composition can be used as long as it can seal the pores in the interlayer insulating layer and does not remain on the wiring such as copper, but the conventional sealing composition elutes the wiring material such as copper. This cannot be suppressed and the wiring material may be reduced. As a result, there is a risk that the electrical conductivity of the wiring cannot be maintained. Particularly, in a miniaturized semiconductor device, a reduction in wiring material becomes a serious problem.
- One aspect of the present invention has been made in view of the above problems, and the polymer (A) of the sealing composition on the bottom surface of the recess and the wiring while maintaining the sealing performance of the side surface of the recess of the interlayer insulating layer by the sealing composition.
- a semiconductor device capable of maintaining the electrical conductivity of the wiring material by suppressing a decrease in the wiring material such as copper, and a seal used in manufacturing such a semiconductor device
- An object is to provide a composition.
- the polymer (A) of the sealing composition does not easily remain on the wiring while maintaining the sealing performance of the surface of the interlayer insulating layer by the sealing composition, and the wiring material such as copper is reduced. It aims at providing the manufacturing method of the semiconductor device which can suppress and maintain the electrical conductivity of this wiring material, and the sealing composition used when manufacturing such a semiconductor device.
- the content of the benzotriazole compound in the seal composition is 3 mass ppm to 200 mass ppm, and the pH of the seal composition is 3 parts by mass.
- a sealing composition that is 0.0 to 6.5.
- ⁇ 5> An interlayer insulating layer provided with a recess, and a wiring containing copper at least a part of the surface of which is exposed on at least a part of the bottom of the recess, and at least the bottom of the recess
- a polyvalent carboxylic acid monomer is contained in an amount of 0.3 mmol / liter to 230 mmol / liter.
- a cleaning step of cleaning at least a side surface and a bottom surface of the recess with a rinsing liquid.
- ⁇ 7> The method for manufacturing a semiconductor device according to ⁇ 5> or ⁇ 6>, wherein the polyvalent carboxylic acid monomer satisfies at least one of having two aromatic rings and having a molecular weight of 342 or more.
- ⁇ 8> The method for manufacturing a semiconductor device according to any one of ⁇ 5> to ⁇ 7>, wherein the pH of the rinse liquid is 4.0 to 7.0.
- ⁇ 9> The method for manufacturing a semiconductor device according to any one of ⁇ 5> to ⁇ 8>, wherein the seal composition has a sodium and potassium content of 10 mass ppb or less on an element basis.
- ⁇ 10> The method according to any one of ⁇ 5> to ⁇ 9>, further including a heating step of heating the semiconductor substrate at a temperature of 70 ° C. to 125 ° C. after the sealing composition applying step and before the cleaning step.
- Semiconductor device manufacturing method
- ⁇ 11> The method for manufacturing a semiconductor device according to any one of ⁇ 5> to ⁇ 10>, further including a high-temperature heating step of heating the semiconductor substrate at a temperature of 200 ° C. to 425 ° C. after the cleaning step.
- ⁇ 12> The method for manufacturing a semiconductor device according to any one of ⁇ 5> to ⁇ 11>, wherein the sealing composition further contains a monocarboxylic acid.
- the polymer (A) of the sealing composition hardly remains on the bottom surface of the recess and the wiring while maintaining the sealing performance of the recess side surface of the interlayer insulating layer by the sealing composition, and copper or the like. It is possible to provide a method for manufacturing a semiconductor device capable of maintaining the electrical conductivity of the wiring material by suppressing a decrease in the wiring material, and a sealing composition used when manufacturing such a semiconductor device. According to another aspect of the present invention, the polymer (A) of the sealing composition hardly remains on the wiring while maintaining the sealing property of the surface of the interlayer insulating layer by the sealing composition, and the wiring material such as copper is not used. It is an object of the present invention to provide a method of manufacturing a semiconductor device capable of suppressing the decrease and maintaining the electrical conductivity of the wiring material, and a sealing composition used in manufacturing such a semiconductor device. it can.
- a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
- FIGS. 1 to 6 specific embodiments (first embodiment, second embodiment) of the present invention will be described in detail with reference to FIGS. 1 to 6, but the present invention is not limited to the following embodiments.
- the present invention can be implemented with appropriate modifications within the scope of the object of the present invention.
- FIGS. 1 to 6 illustrations of components that are not essential in the present invention (for example, an etching stopper layer) are omitted.
- symbol is attached
- the manufacturing method of the semiconductor device according to the first embodiment includes an interlayer insulating layer provided with a recess, and a wiring including copper at least a part of the surface of which is exposed on at least a part of the bottom surface of the recess.
- the content of the benzotriazole compound in the Lumpur composition is 3 mass ppm ⁇ 200 mass ppm
- pH of the sealing composition is 3.0 to 6.5.
- a sealing composition in which the polymer (A) and the benzotriazole compound described above are combined and each adjusted to a predetermined concentration is used at least on the bottom surface of the recess of the semiconductor substrate and Give to the side.
- the polymer (A) of the sealing composition hardly remains on the bottom surface of the concave portion and the wiring while maintaining the sealing performance of the side surface of the concave portion by the sealing composition.
- the elution of wiring materials such as copper is suppressed, and the decrease in wiring materials is suppressed, so that the electrical conductivity of the wiring is maintained without being impaired, particularly in the manufacture of miniaturized semiconductor devices. Useful.
- the polymer (A) of the sealing composition is more easily adsorbed to the interlayer insulating layer, thereby maintaining the sealing property of the side surface of the recess.
- the pH of the sealing composition is 6.5 or less, the polymer (A) is difficult to adhere to the wiring containing copper, and the polymer (A) hardly remains on the wiring.
- the content of the polymer (A) in the seal composition is 0.05 parts by mass or more, the sealing property of the seal composition can be suitably maintained, and the polymer (A) in the seal composition can be maintained.
- the content is 0.20 part by mass or less
- the amount of the sealing composition adhering to the bottom surface of the recess and the wiring surface can be reduced, and the sealing composition (seal layer) on the bottom surface of the recess and the wiring surface. Removability is improved.
- content of the benzotriazole compound in a sealing composition is 3 mass ppm or more, it can suppress that wiring materials, such as copper, elute, and when it is 200 mass ppm or less, A decrease in sealing performance can be suppressed.
- FIG. 1 is a schematic cross-sectional view schematically showing a cross section of a semiconductor substrate before a sealing composition application step.
- a first interlayer insulating layer 14 and a second interlayer insulating layer 12 disposed on a lower layer side (a side closer to the semiconductor substrate 10) than the first interlayer insulating layer 14 on the semiconductor substrate 10.
- the wiring 20 contains at least copper.
- the first interlayer insulating layer 14 is provided with a recess 16 in advance by etching such as dry etching, and the wiring 20 is exposed on at least a part of the bottom surface of the recess 16. That is, at least a part of the bottom surface of the recess 16 is constituted by the exposed surface 20 a of the wiring 20.
- the semiconductor substrate before the sealing composition application step is not limited to this example.
- a barrier layer or the like may be provided on at least a part of the side surface of the recess 16.
- another layer such as an etching stopper layer may exist between the first interlayer insulating layer 14 and the second interlayer insulating layer 12.
- the first interlayer insulating layer 14 and the second interlayer insulating layer 12 may be integrated to form one interlayer insulating layer.
- the cross-sectional shape of the recessed part in 1st invention is not limited to this example, A cross-sectional shape having only one depth (that is, a constant depth) may be used, or a cross-sectional shape having three or more depths may be used.
- the interlayer insulating layer may be provided with another recess having a deepest depth different from that of the recess 16.
- a semiconductor circuit such as a transistor may be provided between the semiconductor substrate 10 and the wiring 20 and the second interlayer insulating layer 12 as necessary.
- sealing composition application step In the sealing composition applying step, at least a part of the surface of the interlayer insulating layer (the first interlayer insulating layer 14 and the second interlayer insulating layer 12) provided with the recess 16 is exposed to at least a part of the bottom surface of the recess 16. In this step, the sealing composition is applied to at least the bottom and side surfaces of the recess 16 of the semiconductor substrate 10 having the copper-containing wiring 20.
- FIG. 2 is a schematic cross-sectional view schematically showing a cross section of the semiconductor substrate after the sealing composition application step.
- the sealing composition is applied to the side of the semiconductor substrate 10 shown in FIG.
- the sealing layer 30 is formed as a semiconductor sealing layer.
- the seal layer 30 is also formed on the exposed surface 20 a of the wiring 20.
- the semiconductor substrate 10 can be used without limitation as long as it is a commonly used semiconductor substrate. Specifically, a silicon wafer or a substrate in which a circuit such as a transistor is formed on the silicon wafer can be used. On the semiconductor substrate 10, at least an interlayer insulating layer provided with a recess 16 and a wiring 20 containing copper with at least a part of the surface exposed at least at a part of the bottom surface of the recess 16 are provided. It has been. On the semiconductor substrate 10, a recess that is not provided with a wiring containing copper may be formed on the bottom surface.
- interlayer insulation layer for example, an insulating layer containing silica can be used, but at least a part thereof is preferably a porous interlayer insulating layer.
- the pores of the porous interlayer insulating layer can be covered with the sealing composition, so that an increase in dielectric constant or leakage current, which may occur due to the penetration of a metal component (such as copper) or a plasma component into the pores. Generation can be further suppressed.
- the porous interlayer insulating layer contains porous silica, and has a silanol residue derived from the porous silica on a surface thereof (preferably, a surface to which a sealing composition is applied, such as a side surface of the recess 16). It is preferable. This silanol residue interacts with a cationic functional group contained in the polymer (A) described later, whereby the pore coverage by the polymer (A) is further improved.
- the pore radius (pore radius) in the porous interlayer insulating layer is not particularly limited, but from the viewpoint of more effectively achieving the sealing effect by the seal layer 30, the pore radius is 0.5 nm to 3 nm. 0.0 nm is preferable, and 1.0 nm to 2.5 nm is more preferable.
- the porous silica normally used for the interlayer insulation layer of a semiconductor device can be especially used without a restriction
- silica gel and a surfactant described in International Publication No. 91/11390 uniform using a self-organization of an organic compound and an inorganic compound that are hydrothermally synthesized in a sealed heat-resistant container Oxides having mesopores, and alkoxysilane condensates and surfactants described in Nature, 1996, 379 (page 703) or Supramolecular Science, 1998, 5 (page 247).
- porous silica porous silica described in International Publication Nos.
- porous interlayer insulating layer can be formed, for example, by applying the above-described composition for forming porous silica on a semiconductor substrate and then appropriately performing a heat treatment or the like.
- the recess 16 provided in the interlayer insulating layer is a recess (gap) formed in the interlayer insulating layer by etching or the like.
- the recess 16 is provided in a later process for embedding a wiring material, for example.
- Specific examples of the recess 16 include a trench and a via.
- the width of the recess 16 can be, for example, 10 nm to 32 nm.
- the bottom surface of the recess 16 is a surface located at the deepest portion of the recess 16 among the wall surfaces of the recess 16 (that is, a surface having the closest distance from the surface of the semiconductor substrate 10) and is substantially the same as the surface of the semiconductor substrate 10. Refers to parallel surfaces. Further, the side surface of the recess 16 refers to a surface other than the bottom surface of the wall surface of the recess 16.
- the step of forming the recess 16 in the interlayer insulating layer can be performed according to the manufacturing process conditions of a semiconductor device that is normally used.
- the hard mask and the photoresist are formed on the interlayer insulating layer, and the recess 16 having a desired pattern can be formed by etching according to the pattern of the photoresist.
- the porous interlayer insulating layer contains porous silica as described above, the surface of the porous silica is scraped with the formation of the recess 16, so that the density of silanol groups on the surface tends to increase.
- the semiconductor substrate 10 is provided with a wiring 20 containing copper, and at least a part of the surface of the wiring 20 is exposed to at least a part of the bottom surface of the recess 16. That is, at least a part of the bottom surface of the recess 16 is an exposed surface 20a of the wiring 20 containing copper.
- the exposed surface 20a electrically connects the wiring 20 having the exposed surface 20a and the wiring (first wiring 40) embedded in the recess 16 in a later step.
- the wiring containing copper (for example, first wiring 40 and second wiring 50 described later) preferably contains copper as a main component.
- the main component refers to a component having the highest content ratio (atomic%).
- the content ratio is preferably 50 atomic% or more, more preferably 80 atomic% or more, and further preferably 90 atomic% or more.
- other elements for example, metal elements such as Cu, Al, Ni, Fe, Sn, Cr, Pt, Zn, Mg, Ta, Ti, Mn, Co, W, and Ru, N, as necessary, may be used.
- Nonmetallic elements such as O).
- a wiring (for example, a second wiring 50 described later) including copper having at least a part of the surface exposed on at least a part of the bottom surface of the recess 16 is also a wiring (for example, described later) embedded in the recess 16 in a later step.
- the first wiring 40) can also be formed according to known process conditions. For example, copper wiring is formed directly on a silicon wafer or on an interlayer insulating layer having a recess 16 formed by metal CVD, sputtering, or electrolytic plating, and the film is smoothed by chemical mechanical polishing (CMP). Turn into. Further, if necessary, a multilayer can be formed by forming a cap film on the surface of the film, then forming a hard mask, and repeating the steps of forming an interlayer insulating layer and forming a wiring.
- CMP chemical mechanical polishing
- the configuration of the semiconductor substrate (semiconductor device) described above for example, the configuration of the semiconductor device described in International Publication No. 2009/153834 (particularly, paragraphs 0040 to 0041, FIG. 2E) can be referred to.
- the sealing composition used in the first embodiment is applied to at least the bottom and side surfaces of the recess 16 of the semiconductor substrate 10 to form the seal layer 30 as a semiconductor seal layer on at least the bottom and side surfaces of the recess 16.
- the sealing composition includes a polymer (A) having a cationic functional group and a weight average molecular weight of 2,000 to 1,000,000, and a benzotriazole compound, and the content of the polymer (A) is 100 masses of the sealing composition.
- the content of the benzotriazole compound in the seal composition is 3 mass ppm to 200 mass ppm, and the pH of the seal composition is 3.0. Is 6.5.
- the polymer (A) has a cationic functional group and has a weight average molecular weight of 2,000 to 1,000,000. Moreover, the polymer (A) should just have at least 1 sort (s) of a cationic functional group, and may further have an anionic functional group and a nonionic functional group as needed.
- the cationic functional group is not particularly limited as long as it is a functional group that can be positively charged. Examples of the cationic functional group include an amino group and a quaternary ammonium group. Among these, from the viewpoint of suppressing diffusion of the metal component, at least one selected from a primary amino group and a secondary amino group is preferable.
- the nonionic functional group may be a hydrogen bond accepting group or a hydrogen bond donating group.
- nonionic functional groups include a hydroxy group, a carbonyl group, and an ether group.
- the anionic functional group is not particularly limited as long as it is a functional group that can be negatively charged. Examples of the anionic functional group include a carboxylic acid group, a sulfonic acid group, and a sulfuric acid group.
- the polymer (A) may have a repeating unit structure having a cationic functional group, and does not have a specific repeating unit structure, and is formed by branching polymerization of monomers constituting the polymer (A). It may have a random structure. From the viewpoint of suppressing the diffusion of the metal component, the polymer (A) does not have a specific repeating unit structure, and has a random structure formed by branching polymerization of monomers constituting the polymer (A). Is preferred.
- the polymer (A) can suppress diffusion of the metal component by having a cationic functional group in one molecule. Moreover, it is preferable that it is a polymer with a high cation density from a viewpoint of the spreading
- the cationic functional group equivalent is preferably 27 to 430, more preferably 43 to 430, and even more preferably 200 to 400.
- the surface of the porous interlayer insulating layer is hydrophobized by a known method, for example, the method described in International Publication No. 04/026765, International Publication No. 06/025501, or the like, the polar group on the surface It is also preferable that the density is 200 to 400, since the density of the resin decreases.
- the cationic functional group equivalent means the weight average molecular weight per cationic functional group
- the polymer (A) corresponding to one molecule contains the weight average molecular weight (Mw) of the polymer (A). It is a value (Mw / n) obtained by dividing by the number of functional groups (n). The larger the cationic functional group equivalent, the lower the density of the cationic functional group, while the smaller the cationic functional group equivalent, the higher the density of the cationic functional group.
- the cationic functional group is at least a part of the main chain in the specific unit structure. May be included as at least a part of the side chain, and may be further included as at least a part of the main chain and at least a part of the side chain. Furthermore, when the specific unit structure contains two or more cationic functional groups, the two or more cationic functional groups may be the same or different.
- the cationic functional group is a ratio of the main chain length of the specific unit structure to the average distance between the adsorption points (for example, silanol residues) of the cationic functional group present on the surface of the porous interlayer insulating layer (hereinafter,
- the relative distance between the cationic functional groups) is preferably 0.08 to 1.2, and preferably 0.08 to 0.6. Is more preferable. With such an embodiment, the polymer (A) can be more easily adsorbed on the surface of the porous interlayer insulating layer more efficiently.
- the specific unit structure preferably has a molecular weight of 30 to 500, more preferably 40 to 200, from the viewpoint of adsorptivity to the interlayer insulating layer.
- the molecular weight of a specific unit structure means the molecular weight of the monomer which comprises a specific unit structure.
- the specific unit structure preferably has a relative distance between the cationic functional groups of 0.08 to 1.2 and a molecular weight of 30 to 500 from the viewpoint of adsorptivity to the interlayer insulating layer. More preferably, the relative distance between the groups is 0.08 to 0.6 and the molecular weight is 40 to 200.
- Specific unit structures containing a cationic functional group are specifically unit structures derived from ethyleneimine, unit structures derived from allylamine, unit structures derived from diallyldimethylammonium salt, unit structures derived from vinylpyridine, and lysine. And the like, unit structures derived from methyl vinyl pyridine, unit structures derived from p-vinyl pyridine, and the like. Among these, from the viewpoint of adsorptivity to the interlayer insulating layer, at least one of a unit structure derived from ethyleneimine and a unit structure derived from allylamine is preferable.
- the polymer (A) may further include at least one of a unit structure containing a nonionic functional group and a unit structure containing an anionic functional group.
- a unit structure containing the nonionic functional group include a unit structure derived from vinyl alcohol, a unit structure derived from alkylene oxide, and a unit structure derived from vinyl pyrrolidone.
- a unit structure containing an anionic functional group specifically, a unit structure derived from styrene sulfonic acid, a unit structure derived from vinyl sulfate, a unit structure derived from acrylic acid, a unit structure derived from methacrylic acid, Examples include a unit structure derived from maleic acid and a unit structure derived from fumaric acid.
- each of the specific unit structures may be different in any of the kinds or number of polar groups contained, the molecular weight, and the like.
- the two or more specific unit structures may be included as a block copolymer or a random copolymer.
- the polymer (A) may further contain at least one repeating unit structure other than the specific unit structure (hereinafter also referred to as “second unit structure”).
- the specific unit structure and the second unit structure may be included as a block copolymer or a random copolymer.
- the second unit structure is not particularly limited as long as it is a unit structure derived from a monomer polymerizable with the monomer constituting the specific unit structure. Examples include unit structures derived from olefins.
- the cationic functional group May be included as at least part of the main chain, may be included as at least part of the side chain, and may be included as at least part of the main chain and at least part of the side chain.
- the monomer that can constitute such a polymer (A) include ethyleneimine and derivatives thereof.
- polymer (A) containing a cationic functional group examples include polyethyleneimine (PEI), polyallylamine (PAA), polydiallyldimethylammonium (PDDA), polyvinylpyridine (PVP), polylysine, and polymethylpyridylvinyl (PMPyV). ), Protonated poly (p-pyridylvinylene) (R-PHPyV), and derivatives thereof.
- PEI polyethyleneimine
- PAA polyallylamine
- PAA polydiallyldimethylammonium
- PVP polyvinylpyridine
- PMPyV polymethylpyridylvinyl
- R-PHPyV Protonated poly (p-pyridylvinylene)
- derivatives thereof examples include polyethyleneimine (PEI), polyallylamine (PAA), polydiallyldimethylammonium (PDDA), polyvinylpyridine (PVP), polylysine, and polymethylpyridylvinyl
- Polyethyleneimine can be generally produced by polymerizing ethyleneimine by a commonly used method.
- a polymerization catalyst, polymerization conditions, and the like can also be appropriately selected from those generally used for polymerization of ethyleneimine. Specifically, for example, the reaction can be carried out at 0 ° C. to 200 ° C. in the presence of an effective amount of an acid catalyst such as hydrochloric acid.
- ethyleneimine may be addition-polymerized based on polyethyleneimine.
- the polyethyleneimine may be a homopolymer of ethyleneimine or a compound copolymerizable with ethyleneimine, for example, a copolymer of amines and ethyleneimine.
- the polyethyleneimine may be obtained using crude ethyleneimine obtained from monoethanolamine.
- JP-A-2001-2213958 can be referred to.
- Polyethyleneimine produced as described above has not only a partial structure in which ethyleneimine is opened and bonded in a straight chain, but also a branched partial structure and a linear partial structure are linked together. It has a complicated skeleton having a partial structure.
- the polymer (A) having a cationic functional group having such a structure the polymer (A) is more efficiently adsorbed at multiple points. Furthermore, the seal layer is more effectively formed by the interaction between the polymers.
- polyethyleneimine derivative is not particularly limited as long as it is a compound that can be produced using the polyethyleneimine.
- Specific examples include a polyethyleneimine derivative in which an alkyl group (preferably having 1 to 10 carbon atoms) or an aryl group is introduced into polyethyleneimine, a polyethyleneimine derivative obtained by introducing a crosslinkable group such as a hydroxyl group into polyethyleneimine, and the like. be able to.
- These polyethyleneimine derivatives can be produced by a method usually performed using polyethyleneimine. Specifically, for example, it can be produced according to the method described in JP-A-6-016809.
- polyethyleneimine and its derivatives may be commercially available.
- it can be appropriately selected from polyethyleneimine and derivatives thereof commercially available from Nippon Shokubai Co., Ltd., BASF, etc.
- the weight average molecular weight of the polymer (A) is from 2,000 to 1,000,000, preferably from 2,000 to 600,000, more preferably from 2,000 to 300,000, still more preferably from 2,000 to 100,000, and from 10,000 to 80,000. More preferably, it is particularly preferably 20,000 to 60,000.
- an excellent covering property (sealing property) for the recess 16 of the interlayer insulating layer is obtained, and the dielectric constant when the polymer layer (sealing layer) is formed is obtained. Reduction is suppressed.
- the weight average molecular weight of the polymer (A) when the weight average molecular weight of the polymer (A) is larger than 1,000,000, the size of the polymer molecule is larger than that of the concave portion 16, the polymer (A) cannot enter the concave portion 16, and the coverage with respect to the concave portion 16 is lowered. There is a case.
- the weight average molecular weight of the polymer (A) is less than 2,000, the molecules of the polymer (A) may not be adsorbed on the interlayer insulating layer at multiple points.
- the size of the polymer molecules may be smaller than the pore diameter of the interlayer insulating layer, and the resin molecules may enter the pores of the interlayer insulating layer, increasing the dielectric constant of the interlayer insulating layer.
- a weight average molecular weight and molecular weight distribution point out the weight average molecular weight and molecular weight distribution of polyethylene glycol conversion measured by GPC (Gel Permeation Chromatography) method.
- GPC Gel Permeation Chromatography
- the weight average molecular weight and molecular weight distribution were determined by using an aqueous solution having an acetic acid concentration of 0.5 mol / L and a sodium nitrate concentration of 0.1 mol / L as a developing solvent, and using an analytical apparatus Shodex GPC-101 and column Asahipak GF-7M HQ.
- polyethylene glycol is calculated as a standard product.
- the polymer (A) is also preferably a polymer having a critical micelle concentration in an aqueous solvent of 1% by mass or more or substantially not forming a micelle structure.
- substantially not forming a micelle structure means that micelles are not formed under normal conditions such as in an aqueous solvent at room temperature, that is, the critical micelle concentration cannot be measured.
- the polymer (A) is preferably a polyethyleneimine having a weight average molecular weight of 2,000 to 600,000 and a cationic functional group equivalent of 43 to 430, and having a weight average molecular weight of 10,000 to 80,000, More preferred is polyethyleneimine having a functional group equivalent of 200 to 400. With this mode, the diffusion of the metal component into the interlayer insulating layer is more effectively suppressed, and the adhesion between the interlayer insulating layer and the wiring material is further improved.
- the content of the polymer (A) in the sealing composition is 0.05 to 0.20 parts by mass and 0.08 to 0.19 parts by mass with respect to 100 parts by mass of the sealing composition. It is preferably 0.11 to 0.18 parts by mass.
- the content of the polymer (A) in the seal composition can also be adjusted based on the area and pore density of the surface on which the polymer layer is formed using the seal composition.
- the sealing property of the sealing composition can be suitably maintained, and the content of the polymer (A) in the sealing composition is By being 0.20 mass part or less, the quantity of the sealing composition adhering to a recessed part bottom face and a wiring surface can be reduced, and the removability of the sealing composition on a recessed part bottom face and a wiring surface improves.
- the sealing composition contains a benzotriazole compound
- a hydrophobic group is formed on the surface of the sealing composition when it is applied to the surface of the wiring containing copper.
- the benzotriazole compound is a compound having a benzotriazole skeleton.
- benzotriazole compound examples include benzotriazole (BTA: 1,2,3-benzotriazole), 5,6-dimethylbenzotriazole (DBTA), and 1- (1,2-dicarboxyethyl) benzotriazole.
- DCEBTA 1- [N, N-bis (hydroxyethyl) aminomethyl] benzotriazole
- HEABTA 1- (hydroxymethyl) benzotriazole
- HMBTA 1- (hydroxymethyl) benzotriazole
- 5-methylbenzotriazole 1H-benzotriazole-5
- carboxylic acid carboxybenzotriazole, 4,5-dimethylbenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole, and derivatives thereof.
- 1 type of compound illustrated above may be sufficient and 2 or more types of compounds may be sufficient.
- the content of the benzotriazole compound in the seal composition is 3 ppm by mass to 200 ppm by mass, preferably 3 ppm by mass to 100 ppm by mass, and more preferably 3 ppm by mass to 30 ppm by mass. preferable.
- the content of the benzotriazole compound is 3 mass ppm or more, elution of wiring materials such as copper can be suppressed, and when the content is 200 mass ppm or less, deterioration of the sealing performance of the seal composition is suppressed. be able to.
- the seal composition of the first embodiment preferably contains at least one acid. This form is suitable when the pH of the seal composition of the first embodiment is adjusted to be acidic. A preferable range of the pH of the sealing composition is as described later. There is no restriction
- monocarboxylic acid compounds include aliphatic monocarboxylic acid compounds (for example, formic acid, acetic acid, propionic acid, butyric acid, methoxyacetic acid, ethoxyacetic acid, lactic acid, glycolic acid, glyceric acid, etc.), aromatic monocarboxylic acid compounds (for example, Benzoic acid, picolinic acid, salicylic acid, 3,4,5-trihydroxybenzoic acid, etc.).
- aliphatic monocarboxylic acid compounds for example, formic acid, acetic acid, propionic acid, butyric acid, methoxyacetic acid, ethoxyacetic acid, lactic acid, glycolic acid, glyceric acid, etc.
- aromatic monocarboxylic acid compounds for example, Benzoic acid, picolinic acid, salicylic acid, 3,4,5-trihydroxybenzoic acid, etc.
- a monocarboxylic acid compound is preferable, and aliphatic Monocarboxylic acid compounds are more preferred, and formic acid and acetic acid are particularly preferred.
- a monocarboxylic acid compound that does not have a hydroxyl group and an amino group and has a van der Waals volume of 40 cm 3 / mol or more (hereinafter also referred to as “specific monocarboxylic acid compound”) is preferable.
- the sealing composition application step in which the sealing composition contains the specific monocarboxylic acid compound to provide the sealing composition containing the polymer (A) on the surface of the wiring the polymer in the sealing composition on the surface of the wiring ( A) has an advantage that it is difficult to adhere. The reason for this is not clear, but is presumed as follows.
- the specific monocarboxylic acid compound having a van der Waals volume of 40 cm 3 / mol or more is composed of a bulky hydrophobic group and one carboxyl group.
- the sealing composition containing the specific monocarboxylic acid compound and the polymer (A) is applied to the surface of the wiring including copper, the carboxyl group of the specific monocarboxylic acid compound reacts with the copper on the wiring surface, and the wiring The surface of the wiring is covered with a bulky hydrophobic group, and as a result, the surface of the wiring is considered to be hydrophobized.
- the surface of the wiring is more strongly hydrophobized (that is, the surface energy is lower) due to the bulky hydrophobic groups covering the surface of the wiring.
- the surface of the wiring is kept more hydrophobic because the specific monocarboxylic acid does not have a hydroxyl group or an amino group. For these reasons, it is considered that the adhesion of the polymer (A) to the surface of the wiring is more effectively inhibited, and the polymer (A) in the sealing composition is difficult to adhere to the surface of the wiring.
- the case where the sealing composition contains a specific monocarboxylic acid compound will be described with reference to FIG. 1, for example.
- a polymer layer is formed on the exposed surface 20a. It has the advantage of becoming difficult to do. Therefore, for example, the removal process of the polymer layer on the exposed surface 20a can be omitted. For example, even when the polymer layer removal process is omitted, the polymer layer is formed on the exposed surface of each insulating layer, and the exposed surface 20a is not covered with the polymer layer.
- the value described in “CHEMICAL PROPERTIES handbook” (edited by YAWS, published by McGrawHill) is used as the numerical value of the van der Waals volume of the specific monocarboxylic acid compound.
- the van der Waals volume of the specific monocarboxylic acid compound is more preferably 40 cm 3 / mol or more and 85 cm 3 / mol or less.
- monocarboxylic acid compounds (monocarboxylic acid compounds having no hydroxyl group and amino group and having a van der Waals volume of 40 cm 3 / mol or more), specifically, propionic acid, picolinic acid, butyric acid, valeric acid Hexanoic acid, heptanoic acid, acrylic acid, picolinic acid and the like are preferable. In particular, propionic acid and picolinic acid are preferable.
- the sealing composition contains a benzotriazole compound, even when formic acid or acetic acid is used instead of the specific monocarboxylic acid compound, a polymer (A ) Can be made difficult to adhere.
- the sealing composition has a sodium and potassium content of 10 ppb or less on an element basis.
- 10 ppb or less means that sodium and potassium are not actively contained. Since the contents of sodium and potassium are each 10 ppb or less on an element basis, generation of leakage current can be suppressed.
- the seal composition may contain a solvent as required in addition to the polymer (A), and at least in the sealing composition application step, a solvent is contained.
- the solvent is not particularly limited as long as the polymer (A) is uniformly dissolved and does not easily form micelles.
- water preferably ultrapure water
- a water-soluble organic solvent for example, alcohol etc.
- the boiling point of the solvent is not particularly limited, but is preferably 210 ° C. or lower, and more preferably 160 ° C. or lower.
- the boiling point of the solvent is within the above range, for example, when a cleaning process or a drying process is provided after the sealing composition application process, the sealing composition is not intercalated without significantly impairing the insulating properties of the interlayer insulating layer.
- the solvent can be removed and a semiconductor sealing layer can be formed at a low temperature at which the insulating layer is not peeled off.
- the sealing composition may further contain a cation such as cesium ion, if necessary, as long as the effects of the invention are not impaired.
- a cation such as cesium
- the resin in the seal composition can more easily spread on the surface of the interlayer insulating layer.
- the sealing composition does not contain a compound (such as a fluorine compound) that corrodes or dissolves the interlayer insulating layer.
- a compound such as a fluorine compound
- the main material of the interlayer insulating layer is an inorganic compound such as silica
- the interlayer insulating layer dissolves and the insulating property is impaired.
- the dielectric constant may increase.
- the sealing composition preferably contains only a compound having a boiling point of 210 ° C. or lower, preferably 160 ° C. or lower, or a compound that does not have decomposability even when heat-treated up to 250 ° C.
- the “compound that is not decomposable even when heat-treated up to 250 ° C.” means that the change in mass after holding at 250 ° C. under nitrogen for 1 hour with respect to the mass measured at 25 ° C. is less than 50%. Refers to a compound.
- the sealing composition has a pH of 3.0 to 6.5, preferably 3.5 to 6.0.
- the polymer (A) has a cationic functional group as a polar group, and the pH of the sealing composition is in a pH range where the cationic functional group is in a cationic state. Therefore, the polymer (A) is more efficiently adsorbed on the surface of the interlayer insulating layer by electrostatic interaction between the interlayer insulating layer and the polymer (A). Moreover, when the pH of the sealing composition is in the above range, the polymer (A) is less likely to adhere to the wiring containing copper and the like, and the polymer (A) is less likely to remain on the surface of the wiring.
- the pH range where the cationic functional group is in a cationic state means that the pH of the sealing composition is not more than the pKa of the resin containing the cationic functional group.
- the pKa is 8 to 9
- the pKa is 7 to 11.
- the pH (25 ° C.) is measured using a commonly used pH measuring device.
- a surface to which at least the seal composition is applied among the surfaces of the wiring including copper may be provided with a pretreatment process for performing a pretreatment before the seal composition application process.
- the pretreatment includes a chelating agent that forms a hydrophobic group on the surface of the wiring, such as a benzotriazole compound, phenanthroline, bipyridine, tripyridine, acetylacetone, triaminopropane, 8-quinololol, or a saturated aliphatic monocarboxylic acid (propionic acid, Butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, etc.), unsaturated aliphatic monocarboxylic acid (Acry), uns
- the pretreatment is preferably performed using a benzotriazole compound.
- the pretreatment may be performed by either a liquid phase method or a gas phase method, and a commonly performed method is used.
- a liquid phase method or a gas phase method
- a commonly performed method is used.
- the pretreatment described above only the surface of the wiring can be made hydrophobic, thereby further reducing the interaction between the surface of the wiring and the sealing composition, and consequently the adhesion of the composition to the surface of the wiring. Is more suppressed.
- the selectivity when the polymer (A) remains in the interlayer insulating layer can be further improved.
- a rinsing liquid containing 0.3 to 230 mmol / l of a polyvalent carboxylic acid monomer is used.
- the rinse liquid is a liquid containing 0.3 mmol / liter to 230 mmol / liter of polyvalent carboxylic acid monomer.
- the rinse liquid contains a polyvalent carboxylic acid monomer of 230 mmol / liter or less, dissolution of copper and the interlayer insulating layer contained in the wiring can be further reduced.
- the rinse liquid contains a polyvalent carboxylic acid monomer of 0.3 mmol / liter or more, the plasma resistance of the seal layer described later can be improved.
- the content of the polyvalent carboxylic acid monomer in the rinse liquid is preferably 0.5 mmol / liter to 200 mmol / liter, and more preferably 0.6 mmol / liter to 100 mmol / liter.
- the rinsing liquid is not particularly limited as long as it contains a predetermined amount of a polyvalent carboxylic acid monomer, but preferably contains a highly polar solvent from the viewpoint of improving cleaning efficiency. Since the sealing composition contains the polymer (A) having a cationic functional group and has a high polarity, it is easily dissolved in a highly polar solvent. For this reason, the removability of the seal layer on the exposed surface of the wiring is further improved by using a rinse liquid containing a solvent having a high polarity. Specifically, the rinsing liquid preferably contains a polar solvent such as water, methanol, ethanol, propanol, butanol, and propylene glycol monomethyl ether acetate.
- a polar solvent such as water, methanol, ethanol, propanol, butanol, and propylene glycol monomethyl ether acetate.
- the rinse liquid may contain only one type of polar solvent or two or more types of polar solvents.
- the temperature of the rinsing liquid in this step is preferably 15 ° C. to 100 ° C., more preferably 30 ° C. to 100 ° C., further preferably 40 ° C. to 100 ° C., and particularly preferably 50 ° C. to 100 ° C.
- the temperature of the rinse liquid is 15 ° C. or higher (more preferably 30 ° C. or higher)
- the removability of the seal layer on the exposed surface of the wiring is further improved.
- the temperature of the rinse liquid is 100 ° C. or less, evaporation of the rinse liquid can be further suppressed.
- the cleaning in this step may be performed while applying ultrasonic waves to the rinsing liquid.
- the rinse liquid contains a reducing agent or a compound having a reducing action from the viewpoint of suppressing oxidation of the wiring material containing copper.
- a reducing agent or a compound having a reducing action from the viewpoint of suppressing oxidation of the wiring material containing copper.
- the reducing agent and the compound having a reducing action include formalin.
- the rinsing liquid prevents the carbon bonds and the like in the polymer (A) of the sealing composition from being broken and peels off the sealing layer (the sealing layer that functions effectively) provided on the surface of the interlayer insulating layer.
- an oxidizing compound for example, hydrogen peroxide or nitric acid
- the content of an oxidizing compound is preferably 10% by mass or less, and more preferably no oxidizing compound is contained.
- the rinsing liquid preferably has an ionic strength of 0.003 or more, and preferably 0.01 or more.
- the ionic strength is 0.003 or more, it is preferable in that the seal layer (the polymer layer) is more easily dissolved, but the interaction between the interlayer insulating layer and the seal layer is not greatly impaired.
- the upper limit of ionic strength What is necessary is just the ionic strength of the density
- an ionic compound such as an acid or an organic base (ammonia, pyridine, ethylamine, etc.) described later can be added as necessary.
- the rinse liquid is preferably a rinse liquid having a pH at 25 ° C. of 7.0 or less (preferably 6.0 or less).
- a rinse liquid having a pH at 25 ° C. of 7.0 or less (preferably 6.0 or less).
- the removability of the seal layer on the exposed surface of the wiring is further improved.
- the copper oxide formed on the exposed surface of the wiring can be dissolved and removed.
- the lower limit of the pH of the rinsing liquid in this case is not particularly limited, but the pH is preferably 4.0 or more, and more preferably 5.0 or more.
- the pH is 4.0 or more, it is easy to maintain the sealing layer on the side surface of the concave portion of the interlayer insulating layer, and as a result, it is possible to maintain the sealing property that prevents the entry of wiring material (such as copper) into the interlayer insulating layer. it can. Furthermore, if pH is 5.0 or more, melt
- the pH of the rinse liquid is 4.0 to 7 from the viewpoint of more effectively achieving both the removability of the seal layer on the exposed surface of the wiring and the maintenance of the seal layer provided on the surface of the interlayer insulating layer. 0.0 is preferable, and 5.0 to 6.0 is more preferable.
- the semiconductor device may be cleaned by plasma with the seal layer exposed, or a layer may be formed on the seal layer by a plasma CVD method or the like. For this reason, plasma resistance may be required for the seal layer.
- the rinsing liquid contains at least one kind of polyvalent carboxylic acid monomer.
- the polyvalent carboxylic acid monomer is not particularly limited as long as it has a plurality of carboxylic acid groups in the monomer. Is preferred.
- the polyvalent carboxylic acid monomer includes a carboxyl group
- the seal layer includes a polymer (for example, polyethyleneimine) including at least one of a primary amino group and a secondary amino group (imino group).
- the carboxyl group reacts with at least one of a primary amino group and a secondary amino group (imino group) in the polymer to form an amide bond or an imide bond. This further improves the plasma resistance of the seal layer.
- the number of carboxyl groups in one molecule is preferably 2 or more, more preferably 3 or more, and particularly preferably 4 or more. The upper limit of this number is not particularly limited, but this number can be, for example, 6 or less.
- polyvalent carboxylic acid monomer examples include dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, and phthalic acid; And tricarboxylic acids such as carbaryl acid; oxydicarboxylic acids such as malic acid and tartaric acid; oxytricarboxylic acids such as citric acid; and aminocarboxylic acids such as aspartic acid and glutamic acid.
- dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, and phthalic acid
- tricarboxylic acids such as carbaryl acid
- oxydicarboxylic acids such as malic acid and tartaric acid
- oxytricarboxylic acids such as citric acid
- aminocarboxylic acids such as aspartic acid and glut
- naphthalenetetracarboxylic acid for example, naphthalene-2,3,6,7-tetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid
- biphenyltetracarboxylic acid is more preferable.
- Carboxylic acid for example, 3,3 ′, 4,4′-biphenyltetracarboxylic acid
- benzophenone tetracarboxylic acid for example, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid
- benzenehexacarboxylic acid pyro Merit acid, trimellitic acid (ie, 1,2,4-benzenetricarboxylic acid), diphenyl ether tetracarboxylic acid (3,3 ′, 4,4′-diphenyl ether tetracarboxylic acid), phenylenediacetic acid (eg, metaphenylene diacetate) Acetic acid, orthophenylenediacetic acid), bicyclo [2.2.2] oct-7-ene-2,3 5,6-tetracarboxylic acid, ethylenediaminetetraacetic acid, citric acid, meso-butane-1,2,3,4-tetracarboxy
- the weight average molecular weight of the polyacrylic acid is preferably from 1,000 to 800,000, more preferably from 1,000 to 600,000, further preferably from 1,000 to 200,000, still more preferably from 5,000 to 80,000, still more preferably from 10,000 to 50,000, and from 20,000 to 30,000. Is particularly preferred.
- the weight average molecular weight of polyacrylic acid is measured in the same manner as the weight average molecular weight of the polymer contained in the seal layer.
- the polyvalent carboxylic acid monomer has a structure in which two or more carboxyl groups are contained in one molecule and a carboxyl group is bonded to each of two adjacent carbon atoms, or three aligned carbon atoms.
- a compound having a structure in which a carboxyl group is bonded to each of carbon atoms at both ends is also preferable.
- the seal layer contains a polymer (for example, polyethyleneimine) containing at least one of a primary amino group and a secondary amino group (imino group), the carboxyl group in the polyvalent carboxylic acid monomer and the above polymer By the reaction with at least one of the primary amino group and secondary amino group (imino group), an imide bond is more effectively formed.
- examples of the structure in which a carboxyl group is bonded to each of two adjacent carbon atoms include, for example, a citric acid structure, a structure in which a carboxyl group is bonded to the ortho position of a benzene ring, and the second and third positions of a naphthalene ring.
- examples include a structure in which a carboxyl group is bonded to the position (or 6-position and 7-position).
- a carboxyl group is bonded to each of carbon atoms at both ends of the three aligned carbon atoms.
- a carboxyl group is bonded to the 1st and 8th positions (or 4th and 5th positions) of the naphthalene ring.
- Examples of the polyvalent carboxylic acid monomer in this case include 3,3 ′, 4,4′-diphenyl ether tetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 3,3 ′ , 4,4'-benzophenonetetracarboxylic acid, naphthalene-2,3,6,7-tetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid, benzenehexacarboxylic acid, pyromellitic acid, trimellit Acid, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid, meso-butane-1,2,3,4-tetracarboxylic acid, citric acid Acid is particularly preferred.
- the polyvalent carboxylic acid monomer is preferably an aromatic ring polyvalent carboxylic acid monomer, and examples of the aromatic ring polyvalent carboxylic acid monomer include naphthalenetetracarboxylic acid, biphenyltetracarboxylic acid, benzophenonetetracarboxylic acid, and benzenehexahexane.
- Carboxylic acid, pyromellitic acid, trimellitic acid, diphenyl ether tetracarboxylic acid, and phenylenediacetic acid are particularly preferable.
- one molecule contains at least one of a benzene ring and naphthalene, three or more carboxyl groups, and two adjacent carbon atoms.
- a compound having a structure in which a carboxyl group is bonded to each is more preferable.
- the polyvalent carboxylic acid monomer is particularly preferably a compound satisfying at least one of having two aromatic rings and having a molecular weight of 342 or more.
- Particularly preferred polyvalent carboxylic acid monomers include naphthalenetetracarboxylic acid (eg, naphthalene-2,3,6,7-tetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid), biphenyltetracarboxylic acid (For example, 3,3 ′, 4,4′-biphenyltetracarboxylic acid), benzophenone tetracarboxylic acid (for example, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid), benzenehexacarboxylic acid, diphenyl ether tetracarboxylic acid And acids (for example, 3,3 ′, 4,4′-diphenyl ether tetracarboxylic acid).
- naphthalenetetracarboxylic acid eg, naphthalene-2,3,6,7-tetracarboxylic acid, naphthalen
- the rinsing liquid described above is applied to the sealing layer provided in a portion other than the recess and the sealing layer provided on the semiconductor substrate where the wiring containing copper is not exposed. It can also be used.
- generated from hydrogen gas, helium gas, argon gas, nitrogen gas, ammonia gas etc. is mentioned, for example.
- the conditions for generating the plasma are not particularly limited, but conditions that do not excessively remove the polymer layer (seal layer) deposited on at least the side surface of the recess and greatly contributing to the sealing function are preferable. Examples of such conditions include, for example, conditions of a total pressure of 20 mTorr to 200 mTorr, a gas flow rate of 20 sccm to 100 sccm, a cathode electrode diameter of 5 cm to 15 cm, a discharge power of 20 W to 200 W, and a processing time (discharge time) of 10 seconds to 60 seconds. It can be illustrated.
- the amount of the above-mentioned solvent, polyvalent carboxylic acid, reducing agent, ionic compound, etc. that may be contained in the rinse liquid is not particularly limited, and for example, the pH and ionic strength of the rinse liquid are within the above-mentioned preferred ranges. You may adjust suitably so that it may become.
- the rinse liquid can be prepared, for example, by mixing the above-mentioned solvent, polyvalent carboxylic acid, reducing agent, ionic compound, etc., but in order to prevent contamination of the semiconductor circuit, clean room such as a clean room is used. It is preferable to remove the contaminating components to the semiconductor circuit by purification or filtration after the production under the environment or the rinse solution.
- the excess sealing layer formed on the wiring is sealed with the rinse liquid to the interlayer insulating layer. It is possible to quickly remove and clean (rinse) while maintaining an effective seal layer. Furthermore, as described above, the oxide of the wiring material can also be removed, which can suppress the separation between the wiring material, the low dielectric constant material, and the wiring material.
- a non-oxidizing atmosphere By performing cleaning in a non-oxidizing atmosphere, the copper oxide on the wiring surface that existed before rinsing is removed with the rinsing liquid, and then the copper on the wiring surface is further oxidized to become copper oxide. It is possible to prevent the copper wiring from being excessively removed by repeating the dissolution (removal).
- a non-oxidizing atmosphere for example, a reducing atmosphere gas may be used.
- the washing in this step can be performed by a commonly used method, and the method is not particularly limited.
- the washing time is not particularly limited, but can be, for example, 0.1 to 60 minutes, and more preferably 0.1 to 10 minutes.
- the semiconductor device manufacturing method of the first embodiment preferably includes a heating process (soft baking process) in which heating is performed at a temperature of 70 ° C. to 125 ° C. after the sealing composition application process and before the cleaning process.
- the temperature is the temperature of the surface of the semiconductor substrate on which the seal layer is formed.
- the polymer (A) can be more difficult to remain in the wiring.
- the temperature is more preferably 80 ° C. to 120 ° C., more preferably 85 ° C. to 120 ° C., further preferably 90 ° C. to 115 ° C., and particularly preferably 90 ° C. to 110 ° C.
- Heating in this step can be performed by a normal method, but can be performed using, for example, a hot plate.
- atmosphere atmosphere There is no restriction
- a minimum can be 10 seconds (preferably 20 seconds, More preferably, 30 seconds).
- the semiconductor device manufacturing method of the first embodiment preferably includes a high-temperature heating step of heating at a temperature of 200 ° C. to 425 ° C. after the cleaning step.
- the seal layer formed on the exposed surface of the wiring containing copper is preferentially (preferably the exposed) over the seal layer formed on a portion other than the exposed surface (for example, the side surface of the recess).
- the temperature is the temperature of the surface of the semiconductor substrate on which the seal layer is formed.
- the temperature is 200 ° C. or higher, the seal layer on the exposed surface of the wiring can be suitably removed. Further, when the temperature is 425 ° C. or lower, migration of copper contained in the wiring can be suppressed.
- the temperature is preferably 250 ° C. to 400 ° C., more preferably 300 ° C. to 400 ° C.
- the pressure at which heating is performed in the high-temperature heating step is not particularly limited, but is preferably an absolute pressure of 17 Pa or more and atmospheric pressure or less.
- the absolute pressure exceeds 17 Pa, the removal speed when removing the seal layer on the exposed surface of the wiring is further improved.
- the absolute pressure is equal to or lower than atmospheric pressure, it is easier to adjust the removal speed when removing the seal layer on the exposed surface of the wiring.
- the absolute pressure is more preferably 1000 Pa to atmospheric pressure, further preferably 5000 Pa to atmospheric pressure, and particularly preferably 10,000 Pa to atmospheric pressure.
- Heating in this step can be performed by a normal method using a furnace or a hot plate.
- a furnace for example, SPX-1120 manufactured by Apex Co., Ltd. or VF-1000LP manufactured by Koyo Thermo System Co., Ltd. can be used.
- the heating in this step may be performed in an air atmosphere, but from the viewpoint of suppressing the oxidation of copper, which is a wiring material, in an inert gas (nitrogen gas, argon gas, helium gas, etc.) atmosphere. It is more preferable to carry out, and it is particularly preferable to carry out in a nitrogen gas atmosphere.
- the time of a heating in a high temperature heating process For example, it is 1 hour or less, 30 minutes or less are preferable, 10 minutes or less are more preferable, and 5 minutes or less are especially preferable.
- the minimum of heating time For example, it can be 0.1 minute. When the heating time is 1 hour or less, the sealing performance of the sealing layer with respect to the interlayer insulating layer is maintained higher.
- the manufacturing method of the semiconductor device of the first embodiment includes the above-described heating process (soft baking process) and the high temperature heating process (hard baking process), the sealing composition applying process, heating process ( A soft baking step), a cleaning step, and a high temperature heating step (hard baking step) are preferred.
- FIG. 3 is a schematic cross-sectional view schematically showing a cross section of the semiconductor substrate when the semiconductor sealing layer formed on the exposed surface of the wiring is removed.
- the removability is improved, and the seal layer 30 can be removed by high-temperature heat treatment.
- the semiconductor sealing layer on the exposed surface 20a does not need to be completely removed, and wiring (for example, a first wiring 40 in FIG. 4 described later) embedded in the recess 16 in a later process, and wiring 20 to the extent that it does not increase the connection resistance.
- wiring for example, a first wiring 40 in FIG. 4 described later
- wiring 20 to the extent that it does not increase the connection resistance.
- at least a part of the seal layer on the wiring 20 can be removed while leaving the seal layer 30 on the side surface of the recess 16.
- the semiconductor device 100 in which the seal layer 30 is provided on at least the side surface of the recess 16 and the formation of the seal layer on the wiring 20 is suppressed is manufactured.
- the manufacturing method of the semiconductor device according to the first embodiment includes, as other steps, an electronic device (for example, a semiconductor device) such as a plasma processing step for performing the plasma processing, a wiring formation step, and a barrier layer formation step as necessary. It may further include a process performed in manufacturing.
- an electronic device for example, a semiconductor device
- a plasma processing step for performing the plasma processing a wiring formation step, and a barrier layer formation step as necessary. It may further include a process performed in manufacturing.
- the wiring formation step can be performed by a known process such as a metal CVD method, a sputtering method, or an electrolytic plating method.
- a barrier layer (copper barrier layer) formation step can be further provided before the wiring formation step.
- the barrier layer forming step can be performed in accordance with commonly used process conditions.
- a titanium compound titanium nitride, etc.
- a tantalum compound tantalum nitride, etc.
- a ruthenium compound a manganese compound
- a barrier layer made of a cobalt compound (CoW or the like), a tungsten compound, or the like can be formed.
- a post-rinsing step of further cleaning the rinse liquid remaining on the semiconductor device may be included.
- the description in paragraph 0093 of International Publication No. 2012/033172 can be appropriately referred to.
- FIG. 4 is a schematic cross-sectional view schematically showing a cross section of the semiconductor device 200 manufactured by the semiconductor device manufacturing method according to the first embodiment.
- the semiconductor device 200 includes a first interlayer insulating layer 14 provided with a recess and a second interlayer insulating layer 12 disposed on the lower layer side of the first interlayer insulating layer 14 on the semiconductor substrate 10. And an interlayer insulating layer made up of.
- the semiconductor device 200 further includes a second wiring 50 including copper embedded in the second interlayer insulating layer 12 and a first wiring 40 including copper embedded in the recess.
- the semiconductor device 200 further includes a seal layer 30 provided at least between the side surface of the recess of the first interlayer insulating layer 14 and the first wiring 40. The first wiring 40 and the second wiring 50 are electrically connected, and the seal layer 30 does not exist at this connection portion.
- the semiconductor device 200 is a semiconductor device having a configuration in which the first wiring 40 is embedded in the concave portion 16 of the semiconductor device 100 (FIG. 3).
- the configuration of the semiconductor substrate 10, the first interlayer insulating layer 14, the second interlayer insulating layer 12, the second wiring 50, and the seal layer 30 in the semiconductor device 200 is respectively the semiconductor substrate 10 and the first interlayer insulating in the semiconductor device 100.
- the configuration of the layer 14, the second interlayer insulating layer 12, the wiring 20, and the seal layer 30 is the same.
- the modification of the semiconductor device 200 is the same as the modification of the semiconductor device 100.
- the seal layer 30 is also present in a portion other than between the side surface of the recess of the first interlayer insulating layer 14 and the first wiring 40 (that is, on the first interlayer insulating layer 14).
- the sealing layer 30 on the first interlayer insulating layer 14 may not exist.
- the seal layer 30 on the first interlayer insulating layer 14 may be removed by a planarization process (for example, CMP) when forming the first wiring 40.
- Second Embodiment >> Hereinafter, the manufacturing method and sealing composition of the semiconductor device according to the second embodiment will be described. Note that description of matters common to the first embodiment is omitted.
- a manufacturing method of a semiconductor device includes a sealing composition that applies a sealing composition to at least the interlayer insulating layer and the surface of the wiring of a semiconductor substrate having an interlayer insulating layer and wiring containing copper. After the applying step and the sealing composition applying step, cleaning is performed to wash at least the surface of the interlayer insulating layer and the wiring with a rinse solution containing 0.3 mmol / liter to 230 mmol / liter of polyvalent carboxylic acid monomer.
- the sealing composition in which the polymer (A) and the benzotriazole compound described above are combined and adjusted to a predetermined concentration is applied to the surface of the interlayer insulating layer and the wiring.
- the effect that the polymer (A) of the sealing composition hardly remains on the wiring while maintaining the sealing performance of the surface by the sealing composition is obtained.
- the elution of wiring materials such as copper is suppressed, and the decrease in wiring materials is suppressed, so that the electrical conductivity of the wiring is maintained without being impaired, particularly in the manufacture of miniaturized semiconductor devices. Useful.
- the content of the polymer (A) in the seal composition used in the method for manufacturing a semiconductor device according to the second embodiment is 0.05 to 0.20 mass. It is not limited to the department.
- the content of the polymer (A) in the seal composition used in this embodiment is preferably 0.05 parts by mass to 0.70 parts by mass with respect to 100 parts by mass of the seal composition. More preferred is from 0.5 to 0.50 parts by mass.
- the content of the polymer (A) in the seal composition can also be adjusted based on the area and pore density of the surface on which the polymer layer is formed using the seal composition.
- the sealing property of the sealing composition can be suitably maintained, and the content of the polymer (A) in the sealing composition is By being 0.70 mass part or less, the quantity of the sealing composition adhering on the wiring surface can be reduced, and the removability of the sealing composition on the wiring surface is improved.
- the second embodiment unlike the first embodiment, there is no problem of polymer accumulation in which the polymer (A) in the sealing composition adheres to the bottom surface of the recess, so the inclusion of the polymer (A) in the sealing composition It is possible to make the amount larger than 0.20 part by mass which is the content of the sealing composition used in the first embodiment.
- the sealing composition can be used even when the pore radius of the interlayer insulating layer is larger (eg, 0.5 nm to 3.0 nm). It is possible to more suitably maintain the sealing performance.
- FIG. 5 is a schematic cross-sectional view schematically showing the manufacturing method of the semiconductor device according to the second embodiment.
- the interlayer insulating layer 22 formed on the substrate 10 trenches, vias, and the like for providing wirings are formed by etching such as dry etching, and a wiring material containing copper is embedded in the trenches, vias, and the like.
- etching such as dry etching
- a wiring material containing copper is embedded in the trenches, vias, and the like.
- the sealing composition application step is a step of applying the sealing composition to at least the surface of the interlayer insulating layer 22 and the surface of the wiring 60 of the semiconductor substrate 10.
- the sealing composition is applied to the side of the semiconductor substrate 10 on which the interlayer insulating layer 22 and the like are provided, and the surface of the interlayer insulating layer 22 and the surface of the wiring 60
- a sealing layer 31 is formed as a semiconductor sealing layer.
- the manufacturing method of the semiconductor device of the second embodiment may include steps other than the above-described sealing composition applying step and the cleaning step.
- the above-described pretreatment step, heating step, high-temperature heating step, Each process such as other processes may be included.
- 5C and 6 are schematic cross-sectional views schematically showing the semiconductor substrate when the semiconductor seal layer formed on the surface on the wiring is removed, and the semiconductor device according to the second embodiment. It is a schematic sectional drawing which shows typically the cross section of the semiconductor device manufactured by this manufacturing method.
- the surface on the surface of the wiring 60 is cleaned by cleaning the surface of the semiconductor substrate on which the sealing layer 31 is formed after the sealing composition applying step shown in FIG.
- the sealing layer 31 can be removed by high heat treatment, and the semiconductor device 300 is obtained.
- a seal layer 31 is formed on the surface of the interlayer insulating layer 22, and the pores of the interlayer insulating layer 22 are sealed. Therefore, when an insulating layer, a cap film or the like is laminated on the surface of the interlayer insulating layer 22, or when the surfaces of the interlayer insulating layer 22 and the wiring 60 are cleaned with plasma, the surface of the interlayer insulating layer 22 is sealed by the seal layer 31. Is in a protected state.
- a multilayer may be formed by forming a cap film on the surface of the interlayer insulating layer 22, then forming a hard mask, and repeating the steps of forming the insulating layer and forming the wiring.
- a trench for providing wiring by etching such as dry etching.
- Vias or the like may be formed in the insulating layer on the interlayer insulating layer 22 and the wiring 60, and a wiring material containing copper may be embedded in the trenches and vias.
- FIG. 5F the semiconductor in which the interlayer insulating layer 22 and the wiring 60 are provided on the semiconductor substrate 10, and the interlayer insulating layer 24 and the wiring 70 are further stacked thereon.
- Device 400 is obtained.
- Example 1 Polyethyleneimine 1 was synthesized as follows, and then a seal composition containing the obtained polyethyleneimine 1 was prepared. Details will be described below.
- reaction scheme 1 The detailed operation of the above reaction scheme 1 is as follows. 61.06 g of polyethyleneimine (50% aqueous solution) manufactured by MP-Biomedicals was dissolved in 319 mL of isopropanol, and Nt-butoxycarbonyl (in this example, the t-butoxycarbonyl group is also referred to as “Boc”) 102 g of aziridine ( 710 mmol) was added and heated under reflux for 3 hours to obtain a modified polyethyleneimine 1 having a structure in which a Bocated aminoethyl group was introduced into polyethyleneimine.
- Boc Nt-butoxycarbonyl
- polyethyleneimine 1 (Synthesis of polyethyleneimine 1) Using the modified polyethyleneimine 1 as a starting material, polyethyleneimine 1 was synthesized according to the following reaction scheme 2.
- the detailed operation of the above reaction scheme 2 is as follows. 124 mL of 12N hydrochloric acid was slowly added to the isopropanol solution of the modified polyethyleneimine 1 described above. The resulting solution was heated and stirred at 50 ° C. for 4 hours while paying attention to gas generation. With the generation of gas, a gum-like reaction product was generated in the reaction system. After the completion of gas generation, the mixture was cooled, and after cooling, the solvent separated from the gum-like reaction product was removed, and the mixture was washed with 184 mL of methanol three times. The washed reaction product was dissolved in water, chlorine ions were removed with an anion exchange polymer, and an aqueous solution containing 58 g of polyethyleneimine 1 was obtained.
- a weight average molecular weight, molecular weight distribution, a cationic functional group (a primary nitrogen atom, a secondary nitrogen atom, a tertiary nitrogen atom, and a quaternary nitrogen atom) equivalent, the quantity of a primary nitrogen atom (mol%) )
- the amount of secondary nitrogen atoms (mol%), the amount of tertiary nitrogen atoms (mol%), the amount of quaternary nitrogen atoms (mol%), and the degree of branching (%) were measured.
- the weight average molecular weight was 40575
- the molecular weight distribution was 17.47
- the cationic functional group equivalent was 43
- the amount of primary nitrogen atoms was 46 mol%
- the amount of secondary nitrogen atoms was 11 mol%
- the amount of tertiary nitrogen atoms was 43 mol%
- the amount of quaternary nitrogen atoms was 0 mol%
- the degree of branching was 80%.
- the cationic functional group equivalent is a molecular weight value for one cationic functional group, and can be calculated from the polymer structure.
- the amount of primary nitrogen atoms (mol%), the amount of secondary nitrogen atoms (mol%), the amount of tertiary nitrogen atoms (mol%), the amount of quaternary nitrogen atoms (mol%), and the degree of branching ( %), the polymer sample (polyethyleneimine 1) was dissolved in heavy water, the obtained solution, by decoupling method with a single pulse reverse gate with Bruker AVANCE500-type nuclear magnetic resonance apparatus, the 13 C-NMR at 80 ° C. Based on the measurement results, it was analyzed what level of amine (nitrogen atom) each carbon atom was bonded to and was calculated based on the integral value. The attribution is described in European Polymer Journal, 1973, Vol. 9, pp. 559.
- the weight average molecular weight and molecular weight distribution were measured using a column Asahipak GF-7M HQ using an analyzer Shodex GPC-101, and were calculated using polyethylene glycol as a standard product.
- As the developing solvent an aqueous solution having an acetic acid concentration of 0.5 mol / L and a sodium nitrate concentration of 0.1 mol / L was used.
- the GPC calibration curve changes as the degree of branching increases, so the obtained weight average molecular weight and molecular weight distribution are numerical values in terms of polyethylene glycol.
- the amount of primary nitrogen atoms (mol%), the amount of secondary nitrogen atoms (mol%), the amount of tertiary nitrogen atoms (mol%), and the amount of quaternary nitrogen atoms (mol%) are respectively ,
- the degree of branching was determined by the following formula E.
- Amount of primary nitrogen atom (mol%) (mol number of primary nitrogen atom / (mol number of primary nitrogen atom + mol number of secondary nitrogen atom + mol number of tertiary nitrogen atom + mol number of quaternary nitrogen atom)) ) ⁇ 100
- a Amount of secondary nitrogen atom (mol%) (mol number of secondary nitrogen atom / (mol number of primary nitrogen atom + mol number of secondary nitrogen atom + mol number of tertiary nitrogen atom + mol number of quaternary nitrogen atom)) ) ⁇ 100
- ⁇ Preparation of sealing composition> Water, acetic acid and benzotriazole (1,2,3-benzotriazole) are added to and mixed with the aqueous solution of polyethyleneimine 1 (weight average molecular weight 40575, cationic functional group equivalent 43) obtained above, and a sealing composition 1A was obtained.
- the amount of water, acetic acid and benzotriazole added is such that the concentration of polyethyleneimine 1 in the sealing composition is 0.18% by mass and the pH of the sealing composition is 4.3.
- the amount of benzotriazole was 10 mass ppm.
- the pH here is a value measured for a sealing composition at 25 ° C. (hereinafter the same).
- the pH of the seal composition was adjusted to a pH meter (KR5E) manufactured by AS ONE with a pH standard solution, and the pH value was read when the value was automatically stabilized by immersing the pH meter in the measurement solution. .
- Example 2 to 10 Seal compositions 2A to 10A (respectively referred to as Examples 2 to 10) were obtained in the same manner as the seal composition 1A, except that the contents and pH described in Table 1 were changed.
- seal compositions 4B to 18B were obtained in the same manner as the seal composition 1A except that the content and pH described in Table 1 were changed.
- Seal compositions 4B and 5B are examples that do not contain benzotriazole.
- Seal compositions 7B to 16B are examples containing no benzotriazole, but containing oxalic acid, 8-quinolinol, propargylamine, 2,2′-bipyridine, and phenanthroline, which are generally used as rust inhibitors.
- Seal composition 17B is an example containing more than 200 mass ppm of benzotriazole.
- Seal composition 6B is an example containing less than 10 ppm by mass of benzotriazole
- seal composition 18B is an example of containing less than 10 ppm by mass of benzotriazole
- the pH of the seal composition is more than 6.5. is there.
- the sodium content and the potassium content were measured with a dielectric coupled plasma mass spectrometer (ICP-MS), and both were below the detection limit ( ⁇ 1 mass ppb). .
- ICP-MS dielectric coupled plasma mass spectrometer
- the elution amount of copper into the seal composition was measured by applying the seal composition to the copper film.
- the copper film surface of the substrate on which a copper film was formed to 100 nm by plating on a silicon substrate was cleaned by helium plasma treatment and then washed with pure water. This was taken out after being immersed in 20 cc of the sealing composition 1A for 3 minutes.
- the copper ion content in the seal composition 1A after immersion was measured with a dielectric coupled plasma mass spectrometer (ICP-MS), and the value was defined as the elution amount of copper ions.
- ICP-MS dielectric coupled plasma mass spectrometer
- the elution amount of copper ions was measured for the sealing compositions 2A to 10A and 4B to 18B.
- Table 1 shows the composition of each seal composition and the results of copper elution amount.
- a sealing composition 19B was obtained in the same manner as the sealing composition 2A, except that the content and pH described in Table 2 were changed (an example not containing benzotriazole).
- a seal layer (polymer layer) was formed on the silicon wafer, and a laminate having a structure in which the silicon wafer and the polymer layer were laminated (hereinafter also referred to as “sample (Si / PEI)”) was obtained.
- the sample Si / PEI
- the soft bake temperature here is the temperature of the silicon wafer surface (the temperature of the surface on which the silicon wafer before film formation is formed).
- the thickness (nm) of the polymer layer on the silicon wafer having silica on the surface was measured by an ordinary method using an ellipsometer of an optical porosimeter (PS-1200) manufactured by SEMILAB. The results are shown in Table 2.
- ⁇ Evaluation of thickness of polymer layer on copper exposed on via bottom of pattern wafer> (Preparation of thickness measurement sample) A silicon wafer in which a 100 nm copper film is formed on a silicon wafer by a plating method and a 100 nm SiO 2 film is formed on the copper film by a CVD method is prepared until the copper film is exposed on the SiO 2 film. A 110 nm wide via through hole was processed to obtain a patterned wafer. The pattern wafer is placed on a spin coater, and 1.0 mL of the sealing composition shown in Table 2 is dropped on the pattern forming surface at a constant speed for 10 seconds and held for 13 seconds.
- a seal layer (polymer layer) was formed on the pattern wafer, and a laminate having a structure in which the pattern wafer and the polymer layer were laminated (hereinafter also referred to as “sample (VIA / PEI)”) was obtained.
- the sample (VIA / PEI) was placed on a hot plate so that the silicon wafer surface and the hot plate were in contact with each other and soft-baked (heat-treated) for 60 seconds at a soft baking temperature of 100 ° C. in an air atmosphere.
- the thickness of the polymer layer on copper exposed on the via bottom of the pattern wafer was measured as follows. Pt (platinum) sputtering is performed on the surface on which the polymer layer after soft baking is formed, and then carbon is deposited to form a protective layer, and then FIB processing apparatus SMI-2050 (manufactured by Seiko Instruments) And thinned (thinned in the direction in which the cross section of the copper wiring appears) to obtain an observation specimen. This specimen is observed with a field emission transmission electron microscope (FE-TEM) (JEM-2200FS, manufactured by JEOL Ltd.), and the thickness of the polymer layer on the copper wiring exposed at the bottom of the via is measured. did. The measured value indicates a value obtained by measuring the thickness (also referred to as paddle amount) of the polymer layer at the center of the via. The results are shown in Table 2.
- Example 2 the paddle amount was 5 nm, and the thickness of the polymer layer on copper was sufficiently reduced. In Comparative Examples 1 and 16, a large amount of paddle was observed. Here, it was determined that the paddle amount was small when the paddle amount was 35 nm or less.
- a seal layer (polymer layer) was formed on the silicon wafer, and a laminate having a structure in which the silicon wafer and the polymer layer were laminated (hereinafter also referred to as “sample (Si / PEI)”) was obtained.
- the sample Si / PEI
- the soft bake temperature here is the temperature of the silicon wafer surface (the temperature of the surface on which the silicon wafer before film formation is formed).
- Liquid temperature 22 ° C. was dropped at a drop rate of 0.1 mL / second for 30 seconds to wash the polymer layer, and then the sample was rotated at 2000 rpm for 60 seconds to dry, and then ultrapure water (liquid temperature 22 ° C.) ) was dropped at a drop rate of 0.1 mL / sec for 30 seconds, and then the sample was dried by rotating at 2000 rpm for 60 seconds.
- ⁇ Evaluation of thickness of polymer layer on copper (Cu)> (Preparation of thickness measurement sample) In order to form a seal layer (polymer layer) on the copper film surface after the plasma treatment using a substrate obtained by plating a copper film on a silicon substrate to a thickness of 100 nm and cleaning the copper film surface by a helium plasma treatment. The same treatment as in ⁇ Evaluation of thickness of polymer layer on silicon (Si)> was performed. As described above, a polymer layer was formed on copper, and a laminate having a structure in which copper and a polymer layer were laminated (hereinafter also referred to as “sample (Cu / PEI)”) was obtained.
- Liquid temperature 22 ° C. was dropped at a drop rate of 0.1 mL / second for 30 seconds to wash the polymer layer, and then the sample was rotated at 2000 rpm for 60 seconds to dry, and then ultrapure water (liquid temperature 22 ° C.) ) was dropped at a drop rate of 0.1 mL / sec for 30 seconds, and then the sample was dried by rotating at 2000 rpm for 60 seconds.
- the thickness of the polymer layer (PEI) of the washed sample obtained as described above was measured.
- the thickness (nm) of the polymer layer on copper (Cu) was measured by the following method using an ellipsometer of an optical porosimeter (PS-1200) manufactured by SEMILAB. That is, the thickness of the polymer layer on the optically flat copper substrate is calculated using the polarization parameter measured by ellipsometry as a multilayer optical model using WinElli II; (air) / (polymer layer) / (copper substrate) Calculated by regression with The range of light energy used is 2.2 to 5.0 eV.
- the refractive index of the polymer layer always used the same value as silica (SiO 2 ).
- the refractive index and extinction coefficient of the copper substrate used the value calculated
- the thickness of the polymer layer on copper was 1.5 nm or less, and the thickness of the polymer layer on copper was sufficiently reduced.
- the thickness of the polymer layer on copper was slightly larger than in each example, and the polymer layer was mottled when the polymer layer was formed on a silicon wafer, and the film thickness on the wafer was measured. I could't.
- Comparative Examples 4 and 15 particularly Comparative Example 15, it was observed that the thickness of the polymer layer on copper was larger than in each Example.
- composition for forming porous silica (Preparation of composition for forming porous silica) To 472 g of the precursor solution, 3.4 g of dimethyldiethoxysilane and 1.8 g of hexamethyldisiloxane were added and stirred at 25 ° C. for 1 hour to obtain a composition for forming porous silica. At this time, the addition amounts of dimethyldiethoxysilane and hexamethyldisiloxane were 10 mol% and 5 mol% with respect to bistriethoxysilylethane, respectively.
- the pore radius of the obtained interlayer insulating layer was 1.6 nm. Further, the relative dielectric constant k of the obtained interlayer insulating layer was 2.5. Moreover, the elasticity modulus of the obtained interlayer insulation layer was 8.8 GPa.
- the pore radius was calculated from the desorption isotherm of toluene.
- the toluene desorption isotherm was measured using an optical porosimeter (PS-1200) manufactured by SEMILAB in the same manner as the sealability evaluation described later.
- the pore radius was calculated according to the method described in M. R. Baklanov, K. P. Mogilnikov, V. G. Polovinkin, and F. N. Dultsey, Journal of Vacuum Science and Technology B (2000) 18, 1385-1391.
- the relative dielectric constant was measured by a conventional method at a frequency of 1 MHz in an atmosphere of 25 ° C. and a relative humidity of 30% using a mercury probe apparatus (SSM5130).
- the elastic modulus was measured by a conventional method using a nanoindenter (Hysitron, Triboscope) at an indentation depth of 1/10 or less of the film thickness.
- a seal composition 20B was obtained in the same manner as the seal composition 1A except that the content and pH described in Table 4 were changed (an example not containing benzotriazole).
- sample for measuring thickness of polymer layer on low-k film A polymer layer is formed on the low-k film surface of the silicon wafer with the low-k film obtained above using the sealing composition described in Table 4, and the silicon wafer with the low-k film and the polymer layer are separated from each other.
- a laminated body having a laminated structure hereinafter also referred to as “sample (Si / low-k / PEI)”.
- the polymer layer was formed by the following method.
- the silicon wafer with the low-k film obtained above is placed on a spin coater, and the seal composition (seal composition 1A or seal composition 20B) shown in Table 4 is fixed on the low-k film surface for 10 seconds. After dropping 1.0 mL at a speed and holding for 13 seconds, the silicon wafer was rotated at 2000 rpm for 1 second, further rotated at 600 rpm for 30 seconds, and then rotated at 2000 rpm for 10 seconds and dried.
- the sample Si / low-k / PEI
- the soft bake here is the temperature of the silicon wafer surface.
- the sample (Si / low-k / PEI) was placed in a furnace (SPX-1120 manufactured by Apex), and a nitrogen gas (N 2 ) atmosphere was applied to the side of the sample where the seal layer (PEI) was formed.
- a heat treatment at 350 ° C. was performed for 2 minutes under the condition of a pressure of 10,000 Pa.
- the above temperature is the surface temperature of the sample (Si / low-k / PEI) on the side where the seal layer (PEI) is formed.
- a sample for evaluating sealing properties before plasma treatment was obtained.
- sealing property evaluation was performed as follows.
- the seal property was evaluated by measuring toluene adsorption on the surface of the seal layer (PEI) of the sample (Si / low-k / PEI). This toluene adsorption measurement indicates that the smaller the toluene adsorption amount, the higher the sealing performance for preventing the entry of the wiring material (such as copper) into the low-k film.
- the toluene adsorption measurement was performed using an optical porosimeter (PS-1200) manufactured by SEMILAB.
- the measuring method was performed according to the method described in M. R. Baklanov, K. P. Mogilnikov, V. G. Polovinkin, and F. N. Dultsey, Journal of Vacuum Science and Technology B (2000) 18, 1385-1391. Specifically, in a temperature range of 23 to 26 ° C., the sample chamber containing the sample (Si / low-k / PEI) was evacuated to 5 mTorr, and then toluene gas was introduced sufficiently slowly into the sample chamber. At each pressure, the refractive index of the low-k film was measured in situ with an ellipsometer.
- the toluene gas adsorption / desorption isotherm is the relative pressure of toluene (P / P 0 ; where P represents the partial pressure of toluene at room temperature, and P 0 represents the saturated vapor pressure of toluene at room temperature).
- 2 is an isotherm showing the relationship between the volume fraction of toluene adsorption (the ratio of the adsorption volume of toluene at room temperature to the volume of the entire low-k film; the unit is “%”).
- the volume fraction of toluene adsorption was determined based on the refractive index of the low-k film using the Lorentz-Lorentz equation.
- the volume fraction (%) of the toluene adsorption amount when the toluene relative pressure (P / P 0 ) is 1.0 is determined, and the sealing property is determined based on the obtained value. Evaluated. In this evaluation, the smaller the volume fraction of toluene adsorption (%), the higher the sealing performance. The evaluation results are shown in Table 4.
- Example 1 using the sealing composition 1A and using 4,4′-oxydiphthalic acid (0.62 mmol / liter) / ethylamine aqueous solution (pH 5.2, liquid temperature 22 ° C.) as the rinse liquid, plasma treatment was performed. It was found that the volume fraction of the subsequent toluene adsorption amount was sufficiently low and the sealing performance was high. On the other hand, in Comparative Example 17 using the sealing composition 20B and the pyromellitic acid (pH 3.4) as the rinsing liquid even at the same polyethyleneimine concentration, the volume fraction of toluene adsorption after plasma treatment is high, and the sealing property It was found that was not secured.
Abstract
Description
例えば、半導体装置の層間絶縁層に、2以上のカチオン性官能基を有する重量平均分子量が2000~100000のポリマーを含有する半導体用組成物を付与する技術が知られている(例えば、特許文献1参照)。
また、例えば、半導体基板の表面の少なくとも一部に、カチオン性官能基を有する重量平均分子量が2000~600000の樹脂を含有する半導体用シール組成物を付与することで半導体用シール層を形成し、半導体基板の半導体用シール層が形成された面を、25℃におけるpHが6以下のリンス液で洗浄する技術が知られている(例えば、特許文献2参照)
さらに、例えば、半導体基板の少なくとも凹部の底面及び側面に、カチオン性官能基を有し重量平均分子量が2000~1000000であるポリマーを含有する半導体用シール組成物を付与し、少なくとも凹部の底面及び側面に半導体用シール層を形成し、半導体基板の半導体用シール層が形成された側の面を、温度200℃以上425℃以下の条件で熱処理し、配線の露出面上に形成された半導体用シール層の少なくとも一部を除去する技術が記載されている(例えば、特許文献3参照)。
特許文献2:国際公開第2012/033172号
特許文献3:国際公開第2014/013956号
本発明の他の形態は、シール組成物による層間絶縁層の表面のシール性を維持しつつ、配線上にシール組成物のポリマー(A)が残存し難く、かつ銅などの配線材料の減少を抑制してこの配線材料の電気伝導性を維持することが可能な半導体装置の製造方法及びそのような半導体装置を製造する際に用いられるシール組成物を提供することを目的とする。
<1> カチオン性官能基を有し、重量平均分子量が2000~1000000であるポリマー(A)と、ベンゾトリアゾール化合物と、を含み、前記ポリマー(A)の含有量が、シール組成物100質量部に対して0.05質量部~0.20質量部であり、前記シール組成物中における前記ベンゾトリアゾール化合物の含有量が、3質量ppm~200質量ppmであり、前記シール組成物のpHが3.0~6.5である、シール組成物。
本発明の他の形態によれば、シール組成物による層間絶縁層の表面のシール性を維持しつつ、配線上にシール組成物のポリマー(A)が残存し難く、かつ銅などの配線材料の減少を抑制してこの配線材料の電気伝導性を維持することが可能な半導体装置の製造方法及びそのような半導体装置を製造する際に用いられるシール組成物を提供することを目的とすることができる。
<半導体装置の製造方法>
第1実施形態に係る半導体装置の製造方法は、凹部が設けられた層間絶縁層と、凹部の底面の少なくとも一部にその表面の少なくとも一部が露出している銅を含む配線と、を有する半導体基板の少なくとも凹部の底面及び側面に、シール組成物を付与するシール組成物付与工程と、シール組成物付与工程の後、多価カルボン酸モノマーを0.3ミリモル/リットル~230ミリモル/リットル含有するリンス液で、少なくとも凹部の側面及び底面を洗浄する洗浄工程と、を有し、シール組成物が、カチオン性官能基を有し、重量平均分子量が2000~1000000であるポリマー(A)と、ベンゾトリアゾール化合物と、を含み、ポリマー(A)の含有量が、シール組成物100質量部に対して0.05質量部~0.20質量部であり、シール組成物中におけるベンゾトリアゾール化合物の含有量が、3質量ppm~200質量ppmであり、シール組成物のpHが3.0~6.5である。
上記の半導体装置の製造方法によれば、銅などの配線材料の減少を抑制して電気伝導性を維持することが可能な半導体装置を製造することができる。
より詳細には、シール組成物のpHが3.0以上であることにより、シール組成物のポリマー(A)がより層間絶縁層と吸着しやすくなることで、凹部の側面のシール性を維持することができ、シール組成物のpHが6.5以下であることにより、銅を含む配線にポリマー(A)が付着し難く、配線上にポリマー(A)が残存し難くなる。さらに、シール組成物におけるポリマー(A)の含有量は、0.05質量部以上であることにより、シール組成物のシール性を好適に維持することができ、シール組成物におけるポリマー(A)の含有量が0.20質量部以下であることにより、凹部の底面及び配線表面上に付着するシール組成物の量を低減することができ、凹部の底面及び配線表面のシール組成物(シール層)の除去性が向上する。
また、シール組成物中におけるベンゾトリアゾール化合物の含有量が、3質量ppm以上であることにより、銅などの配線材料が溶出することを抑制でき、200質量ppm以下であることにより、シール組成物のシール性の低下を抑制することができる。
第1層間絶縁層14には、ドライエッチング等のエッチングにより予め凹部16が設けられており、凹部16の底面の少なくとも一部には、配線20が露出している。即ち、凹部16の底面の少なくとも一部は、配線20の露出面20aによって構成されている。
例えば、凹部16の側面の少なくとも一部には、バリア層等が設けられていてもよい。
また、第1層間絶縁層14と第2層間絶縁層12との間には、エッチングストッパー層等の他の層が存在していてもよい。また、第1層間絶縁層14と第2層間絶縁層12とが一体となって一つの層間絶縁層を構成していてもよい。
また、図1に示す凹部16の断面形状は、2種の深さを持つ(階段状の)断面形状となっているが、第一の発明における凹部の断面形状はこの一例に限定されず、1種のみの深さを持つ(即ち、深さが一定の)断面形状であってもよいし、3種以上の深さを持つ断面形状であってもよい。また、層間絶縁層には、前記凹部16に加え、前記凹部16とは最深部の深さが異なる別の凹部が設けられていてもよい。
また、半導体基板10と配線20及び第2層間絶縁層12との間には、必要に応じ、トランジスタ等の半導体回路等が設けられていてもよい。
シール組成物付与工程は、凹部16が設けられた層間絶縁層(第1層間絶縁層14、第2層間絶縁層12)と、凹部16の底面の少なくとも一部にその表面の少なくとも一部が露出している銅を含む配線20と、を有する半導体基板10の少なくとも凹部16の底面及び側面に、シール組成物を付与する工程である。
以下、半導体基板、層間絶縁層、配線などの構成について説明する。
半導体基板10としては、通常用いられる半導体基板であれば制限なく用いることができるが、具体的にはシリコンウエハや、シリコンウエハ上にトランジスタなどの回路を形成されたものを用いることができる。
この半導体基板10上には、少なくとも、凹部16が設けられた層間絶縁層と、凹部16の底面の少なくとも一部にその表面の少なくとも一部が露出している銅を含む配線20と、が設けられている。半導体基板10上には、底面に銅を含む配線が設けられていない凹部が形成されていてもよい。
層間絶縁層としては、例えば、シリカを含む絶縁層を用いることができるが、その少なくとも一部は、多孔質層間絶縁層であることが好ましい。
かかる形態では、多孔質層間絶縁層の細孔をシール組成物によって被覆できるので、細孔への金属成分(銅等)やプラズマ成分の侵入により生じることがある、誘電率の上昇やリーク電流の発生をより抑制できる。
前記多孔質層間絶縁層における細孔半径(ポア半径)には特に限定はないが、シール層30によるシール性の効果をより効果的に奏する観点から、前記細孔半径は、0.5nm~3.0nmが好ましく、1.0nm~2.5nmがより好ましい。
前記多孔質シリカとしては、国際公開第2009/123104号や国際公開第2010/137711号に記載された多孔質シリカ(例えば、特定のシロキサン化合物を含む組成物を用いて形成された多孔質シリカ)を用いることも好ましい。
多孔質層間絶縁層は、例えば、上記の多孔質シリカの形成用組成物を半導体基板上に塗布した後、適宜、加熱処理等を行うことにより形成することができる。
凹部16の幅は、例えば、10nm~32nmとすることができる。
銅を含む配線(例えば、後述の第1配線40、第2配線50)は、銅を主成分として含むことが好ましい。
ここで、主成分とは、含有比率(原子%)が最も高い成分を指す。
前記含有比率は50原子%以上が好ましく、80原子%以上がより好ましく、90原子%以上がさらに好ましい。
前記配線には、必要に応じ、その他の元素(例えば、Cu、Al、Ni、Fe、Sn、Cr、Pt、Zn、Mg、Ta、Ti、Mn、Co、W、Ruなどの金属元素、N、Oなどの非金属元素)が含まれていてもよい。
次に、第1実施形態に係る半導体装置の製造方法にて用いるシール組成物について説明する。
第1実施形態にて用いられるシール組成物は、半導体基板10の少なくとも凹部16の底面及び側面に付与することで、少なくとも凹部16の底面及び側面に、半導体用シール層としてシール層30を形成するためのものである。
シール組成物は、カチオン性官能基を有し、重量平均分子量が2000~1000000であるポリマー(A)と、ベンゾトリアゾール化合物と、を含み、ポリマー(A)の含有量は、シール組成物100質量部に対して0.05質量部~0.20質量部であり、シール組成物中におけるベンゾトリアゾール化合物の含有量は、3質量ppm~200質量ppmであり、シール組成物のpHが3.0~6.5である。
ポリマー(A)は、カチオン性官能基を有し、重量平均分子量が2000~1000000である。また、ポリマー(A)は、カチオン性官能基を少なくとも1種有していればよく、必要に応じて、アニオン性官能基やノニオン性官能基をさらに有していてもよい。
カチオン性官能基は、正電荷を帯びることができる官能基であれば特に限定されない。カチオン性官能基としては、例えば、アミノ基、4級アンモニウム基等を挙げられる。中でも金属成分の拡散抑制の観点から、1級アミノ基及び2級アミノ基から選択された少なくとも1種であることが好ましい。
アニオン性官能基は、負電荷を帯びることができる官能基であれば特に限定されない。アニオン性官能基としては、例えば、カルボン酸基、スルホン酸基、硫酸基等が挙げられる。
さらに、多孔質の層間絶縁層の表面を公知の方法、例えば、国際公開第04/026765号、国際公開第06/025501号などに記載の方法で疎水化処理した場合は、前記表面の極性基の密度が減少するので、200~400であることもまた好ましい。
ここで、カチオン性官能基当量とは、カチオン性官能基当たりの重量平均分子量を意味し、ポリマー(A)の重量平均分子量(Mw)を、1分子に相当するポリマー(A)が含むカチオン性官能基数(n)で除して得られる値(Mw/n)である。このカチオン性官能基当量が大きいほどカチオン性官能基の密度が低く、一方、カチオン性官能基当量が小さいほどカチオン性官能基の密度が高い。
さらに、前記特定単位構造がカチオン性官能基を2以上含む場合、2以上のカチオン性官能基は同一であっても異なっていてもよい。
また前記カチオン性官能基は、多孔質層間絶縁層の表面に存在するカチオン性官能基の吸着点(例えば、シラノール残基)間の平均距離に対する、特定単位構造の主鎖長の比(以下、「カチオン性官能基間の相対距離」ともいう)が、0.08~1.2となるように含まれていることが好ましく、0.08~0.6となるように含まれていることがより好ましい。かかる態様であることでポリマー(A)が多孔質層間絶縁層の表面に、より効率的に多点吸着しやすくなる。
特定単位構造は、層間絶縁層への吸着性の観点から、カチオン性官能基間の相対距離が0.08~1.2であって、分子量が30~500であることが好ましく、カチオン性官能基間の相対距離が0.08~0.6であって、分子量が40~200であることがより好ましい。
前記ノニオン性官能基を含む単位構造として、具体的には、ビニルアルコールに由来する単位構造、アルキレンオキシドに由来する単位構造、ビニルピロリドンに由来する単位構造等を挙げることができる。
前記第2単位構造としては、前記特定単位構造を構成するモノマーと重合可能なモノマーに由来する単位構造であれば特に制限はない。例えば、オレフィンに由来する単位構造等を挙げることができる。
かかるポリマー(A)を構成し得るモノマーとしては、例えば、エチレンイミン及びその誘導体を挙げることができる。
またポリエチレンイミンは、モノエタノールアミンから得られる粗エチレンイミンを用いて得られたものであってもよい。具体的には例えば特開2001-2123958号公報等を参照することができる。
これらのポリエチレンイミン誘導体は、ポリエチレンイミンを用いて通常行われる方法により製造することができる。具体的には例えば、特開平6―016809号公報等に記載の方法に準拠して製造することができる。
例えば、ポリマー(A)の重量平均分子量が1000000よりも大きいと、ポリマー分子の大きさが凹部16よりも大きくなり、ポリマー(A)が凹部16に入り込めず、凹部16に対する被覆性が低下する場合がある。
ポリマー(A)の重量平均分子量が2000未満であると、ポリマー(A)の分子が層間絶縁層に多点で吸着しない場合がある。また、層間絶縁層の細孔直径よりもポリマー分子の大きさが小さくなり、樹脂分子が層間絶縁層の細孔に入り込んで層間絶縁層の誘電率が上昇する場合がある。
なお、重量平均分子量及び分子量分布は、GPC(Gel Permeation Chromatography)法によって測定された、ポリエチレングリコール換算の重量平均分子量及び分子量分布を指す。
具体的には、重量平均分子量及び分子量分布は、展開溶媒として酢酸濃度0.5mol/L、硝酸ナトリウム濃度0.1mol/Lの水溶液を用い、分析装置Shodex GPC-101及びカラムAsahipak GF-7M HQを用いて測定し、ポリエチレングリコールを標準品として算出される。
シール組成物は、ベンゾトリアゾール化合物を含むことにより、銅などを含む配線の表面に付与された際に、その表面に疎水基が形成される。疎水基が形成されることにより、配線表面へのポリマー(A)の付着がより効果的に阻害され、配線表面にシール組成物中のポリマー(A)が付着し難くなると考えられる。
ここで、ベンゾトリアゾール化合物は、ベンゾトリアゾール骨格を有する化合物である。ベンゾトリアゾール化合物としては、具体的には、ベンゾトリアゾール(BTA:1,2,3-ベンゾトリアゾール)、5,6-ジメチルベンゾトリアゾール(DBTA)、1-(1,2-ジカルボキシエチル)ベンゾトリアゾール(DCEBTA)、1-[N,N-ビス(ヒドロキシエチル)アミノメチル]ベンゾトリアゾール(HEABTA)、1-(ヒドロキシメチル)ベンゾトリアゾール(HMBTA)、5-メチルベンゾトリアゾール、1H-ベンゾトリアゾール-5-カルボン酸、カルボキシベンゾトリアゾール、4,5-ジメチルベンゾトリアゾール、2-(3,5-ジ-t-ブチル-2-ヒドロキシフェニル)ベンゾトリアゾール又はこれらの誘導体などが挙げられる。なお、シール組成物に含まれるベンゾトリアゾール化合物としては、上に例示された1種の化合物であってもよく、2種以上の化合物であってもよい。
第1実施形態のシール組成物は、酸を少なくとも1種を含有することが好ましい。
この形態は、第1実施形態のシール組成物のpHを酸性よりに調整する場合に好適である。シール組成物のpHの好ましい範囲については後述のとおりである。
酸としては特に制限はなく、例えば、モノカルボン酸化合物、ジカルボン酸化合物、オキシジカルボン酸化合物が挙げられる。
モノカルボン酸化合物としては、脂肪族モノカルボン酸化合物(例えば、ギ酸、酢酸、プロピオン酸、酪酸、メトキシ酢酸、エトキシ酢酸、乳酸、グリコール酸、グリセリン酸等)、芳香族モノカルボン酸化合物(例えば、安息香酸、ピコリン酸、サルチル酸、3,4,5-トリヒドロキシ安息香酸等)が挙げられる。
上記のうち、配線表面へのポリマー(A)の残存し難さと層間絶縁層へのポリマー(A)の残存し易さとをより効果的に両立させる観点から、モノカルボン酸化合物が好ましく、脂肪族モノカルボン酸化合物がより好ましく、ギ酸、酢酸が特に好ましい。
シール組成物が特定モノカルボン酸化合物を含有することにより、配線の表面にポリマー(A)を含有するシール組成物を付与するシール組成物付与工程において、配線の表面にシール組成物中のポリマー(A)が付着し難くなるという利点を有する。この理由は明らかではないが、以下のように推測される。ファンデルワールス体積が40cm3/mol以上である特定モノカルボン酸化合物は、嵩高い疎水基と一個のカルボキシル基とから構成されている。この特定モノカルボン酸化合物及びポリマー(A)を含有するシール組成物が銅などを含む配線の表面に付与されると、特定モノカルボン酸化合物のカルボキシル基と配線表面の銅とが反応し、配線の表面が嵩高い疎水基で被覆され、その結果、配線の表面が疎水化されると考えられる。ここで、配線の表面を被覆する疎水基が嵩高いことにより、配線の表面がより強く疎水化される(即ち、表面エネルギーがより低くなる)と考えられる。更に、特定モノカルボン酸が水酸基及びアミノ基を有しないことにより、配線の表面がより疎水的に保たれると考えられる。これらの理由により、配線の表面へのポリマー(A)の付着がより効果的に阻害され、配線の表面にシール組成物中のポリマー(A)が付着し難くなると考えられる。
シール組成物が特定モノカルボン酸化合物を含有する場合について、例えば、図1を用いて説明すると、この場合、シール組成物が露出面20aに付与される工程において、露出面20aにポリマー層が形成され難くなるという利点を有する。
従って、例えば、露出面20a上のポリマー層の除去処理を省略することもできる。例えば、ポリマー層の除去処理を省略した場合でも、各絶縁層の露出面にポリマー層が形成され、かつ、露出面20aはポリマー層で被覆されていない状態とすることができる。
上記特定モノカルボン酸化合物のファンデルワールス体積は、40cm3/mol以上85cm3/mol以下であることがより好ましい。
なお、前記「250℃まで熱処理しても分解性を有さない化合物」とは、25℃で測定した質量に対する、250℃、窒素下で1時間保持した後の質量の変化が50%未満の化合物のことをいう。
なお、前記カチオン性官能基がカチオンの状態であるpHの範囲とは、シール組成物のpHが、カチオン性官能基を含む樹脂のpKa以下であることをいう。例えば、カチオン性官能基を含む樹脂がポリアリルアミンである場合、pKaは8~9であり、ポリエチレンイミンである場合、pKaは7~11である。
pH(25℃)は通常用いられるpH測定装置を用いて測定される。
銅などを含む配線の表面のうち少なくともシール組成物が付与される面には、シール組成物付与工程の前に、前処理を施す前処理工程を設けてもよい。
上記前処理は、ベンゾトリアゾール化合物、フェナントロリン、ビピリジン、トリピリジン、アセチルアセトン、トリアミノプロパン、8-キノリロール等の配線の表面に疎水基を形成するキレート剤、又は、飽和脂肪族モノカルボン酸(プロピオン酸、酪酸、吉草酸、ヘキサン酸、ヘプタン酸、オクタン酸、ノナン酸、デカン酸、ラウリン酸、トリデカン酸、ミリスチン酸、ペンタデカン酸、パルミチン酸、ヘプタデカン酸、ステアリン酸等)、不飽和脂肪族モノカルボン酸(アクリル酸、α-リノレン酸、リノール酸、オレイン酸等)、芳香族モノカルボン酸(安息香酸、サリチル酸等)、フタル酸、ピコリン酸等の配線の表面に疎水基を形成する酸を用いて行うことが好ましい。特に、上記前処理は、ベンゾトリアゾール化合物を用いて行うことが好ましい。
上記前処理は、液相法、気相法のいずれの方法で行ってもよく、通常行われる方法が用いられる。
上記前処理によれば、配線の表面のみを疎水性にすることができ、これにより、配線の表面とシール組成物との相互作用がより低減され、ひいては、配線の表面への組成物の付着がより抑制される。その結果、層間絶縁層にポリマー(A)を残存させる際の選択性をより向上させることができる。
第1実施形態の半導体装置の製造方法は、前記シール組成物付与工程の後、多価カルボン酸モノマーを0.3ミリモル/リットル~230ミリモル/リットル含有するリンス液で、少なくとも前記凹部の側面及び底面を洗浄する洗浄工程を有する。
この洗浄工程を有することにより、配線の露出面上のシール層の除去性が更に向上する。
リンス液における多価カルボン酸モノマーの含有量としては、0.5ミリモル/リットル~200ミリモル/リットルであることが好ましく、0.6ミリモル/リットル~100ミリモル/リットルであることがより好ましい。
前記シール組成物は、カチオン性官能基を有するポリマー(A)を含んでおり極性が高いため、極性の高い溶媒に溶けやすい。このため、極性が高い溶媒を含むリンス液を用いることで、配線の露出面上のシール層の除去性が更に向上する。
具体的には、前記リンス液は、水、メタノール、エタノール、プロパノール、ブタノール、プロピレングリコールモノメチルエーテルアセテートなどの極性溶媒を含むことが好ましい。
また、このような極性溶媒は、層間絶縁層とシール組成物との相互作用を大きく損ねることはない。このため、かかる極性溶媒を含むリンス液によって洗浄を行なっても、層間絶縁層上のシール層(有効に機能しているシール層)は除去されにくい点で好ましい。
前記リンス液は、極性溶媒を1種のみ含んでいてもよいし、2種以上含んでいてもよい。
前記リンス液の温度が15℃以上(より好ましくは30℃以上)であると、配線の露出面上のシール層の除去性が更に向上する。
前記リンス液の温度が100℃以下であると、リンス液の蒸発をより抑制できる。
イオン強度が0.003以上であると、前記シール層(前記ポリマー層)をより溶解させ易い一方、層間絶縁層とシール層との相互作用を大きく損ねることがない点で好ましい。
また、イオン強度の上限については特に限定はなく、イオン性化合物が溶解できる濃度のイオン強度であればよい。
なお上記イオン強度は、下記式で表されるものである。
イオン強度=1/2×Σ(c×Z2)
(cはリンス液に含まれるイオン性化合物のモル濃度、Zはリンス液に含まれるイオン性化合物のイオン原子価を表す)
また、この場合のリンス液のpHの下限には特に限定はないが、pHは4.0以上が好ましく、5.0以上がより好ましい。pHが4.0以上であれば、層間絶縁層の凹部側面のシール層を維持しやすく、その結果、層間絶縁層中への配線材料(銅など)の進入を防ぐシール性を維持することができる。さらにpHが5.0以上であれば、配線に含まれる銅の溶解をより低減できる。
前記リンス液のpHは、配線の露出面上のシール層の除去性と、層間絶縁層の表面に設けられたシール層の維持と、をより効果的に両立させる観点より、4.0~7.0が好ましく、5.0~6.0がより好ましい。
このため、シール層にはプラズマ耐性が要求される場合がある。
シール層のプラズマ耐性を向上させるという観点から、前記リンス液は、少なくとも1種類の多価カルボン酸モノマーを含んでいる。前記多価カルボン酸モノマーとしては、モノマー中にカルボン酸基を複数有するものであれば特に限定はないが、層間絶縁層を汚染又は破壊しにくいもので、かつ、半導体基板上に残留しにくいものが好ましい。
これにより、シール層のプラズマ耐性がより向上する。
多価カルボン酸モノマーにおいて、カルボキシル基の1分子内における数は、2つ以上がより好ましく、3つ以上が更に好ましく、4つ以上が特に好ましい。
この数の上限には特に制限はないが、この数は、例えば、6つ以下とすることができる。
多価カルボン酸モノマーとしては、更に好ましくは、ナフタレンテトラカルボン酸(例えば、ナフタレン-2,3,6,7-テトラカルボン酸、ナフタレン-1,4,5,8-テトラカルボン酸)、ビフェニルテトラカルボン酸(例えば、3,3’,4,4’-ビフェニルテトラカルボン酸)、ベンゾフェノンテトラカルボン酸(例えば、3,3’,4,4’-ベンゾフェノンテトラカルボン酸)、ベンゼンヘキサカルボン酸、ピロメリット酸、トリメリット酸(即ち、1,2,4-ベンゼントリカルボン酸)、ジフェニルエーテルテトラカルボン酸(3,3’,4,4’-ジフェニルエーテルテトラカルボン酸)、フェニレン二酢酸(例えば、メタフェニレン二酢酸、オルトフェニレン二酢酸)、ビシクロ[2.2.2]オクト-7-エン-2,3,5,6-テトラカルボン酸、エチレンジアミン四酢酸、クエン酸、meso-ブタン-1,2,3,4-テトラカルボン酸、ポリアクリル酸、4,4-オキシジフタル酸、1,3,5-ベンゼントリカルボン酸などの多価カルボン酸モノマーである。
ポリアクリル酸の重量平均分子量としては、1000~800000が好ましく、1000~600000がより好ましく、1000~200000が更に好ましく、5000~80000が更に好ましく、10000~50000が更に好ましく、20000~30000であることが特に好ましい。ポリアクリル酸の重量平均分子量は、シール層に含まれるポリマーの重量平均分子量と同様にして測定される。
これにより、特に、シール層が1級アミノ基及び2級アミノ基(イミノ基)の少なくとも一方を含むポリマー(例えばポリエチレンイミン)を含む場合において、多価カルボン酸モノマー中のカルボキシル基と上記ポリマー中の1級アミノ基及び2級アミノ基(イミノ基)の少なくとも一方との反応により、イミド結合がより効果的に形成される。その結果、シール層のプラズマ耐性がより向上する。
ここで、隣り合う2個の炭素原子のそれぞれにカルボキシル基が結合した構造としては、例えば、クエン酸の構造や、ベンゼン環のオルト位にカルボキシル基が結合した構造、ナフタレン環の2位及び3位(又は6位及び7位)にカルボキシル基が結合した構造などが挙げられる。
また、3個並ぶ炭素原子のうちの両端の炭素原子のそれぞれにカルボキシル基が結合した構造としては、例えば、ナフタレン環の1位及び8位(又は4位及び5位)にカルボキシル基が結合した構造などが挙げられる
この場合の多価カルボン酸モノマーとしては、3,3’,4,4’-ジフェニルエーテルテトラカルボン酸、3,3’,4,4’-ビフェニルテトラカルボン酸、3,3’,4,4’-ベンゾフェノンテトラカルボン酸、ナフタレン-2,3,6,7-テトラカルボン酸、ナフタレン-1,4,5,8-テトラカルボン酸、ベンゼンヘキサカルボン酸、ピロメリット酸、トリメリット酸、ビシクロ[2.2.2]オクト-7-エン-2,3,5,6-テトラカルボン酸、meso-ブタン-1,2,3,4-テトラカルボン酸、クエン酸、が特に好ましい。
特に好ましい多価カルボン酸モノマーとしては、ナフタレンテトラカルボン酸(例えば、ナフタレン-2,3,6,7-テトラカルボン酸、ナフタレン-1,4,5,8-テトラカルボン酸)、ビフェニルテトラカルボン酸(例えば、3,3’,4,4’-ビフェニルテトラカルボン酸)、ベンゾフェノンテトラカルボン酸(例えば、3,3’,4,4’-ベンゾフェノンテトラカルボン酸)、ベンゼンヘキサカルボン酸、ジフェニルエーテルテトラカルボン酸(例えば、3,3’,4,4’-ジフェニルエーテルテトラカルボン酸)などが挙げられる。
洗浄時間は特に限定はないが、例えば0.1分~60分とすることができ、0.1分~10分がさらに好ましい。
第1実施形態の半導体装置の製造方法は、シール組成物付与工程後、前記洗浄工程の前に温度70℃~125℃で加熱する加熱工程(ソフトベーク工程)を有することが好ましい。また、前記温度は、半導体基板のシール層が形成された側の面の温度である。
加熱工程を有することにより、配線へのポリマー(A)の残存し難さと、層間絶縁層へのポリマー(A)の残存し易さと、をより効果的に両立させることができる。
具体的には、温度が70℃以上であることにより、層間絶縁層に付与されたポリマー(A)の残存性が好適に維持される。また、温度が125℃以下であることにより、配線にポリマー(A)がより残存し難くすることができる。
上記温度は、80℃~120℃がより好ましく、85℃~120℃がより好ましく、90℃~115℃がさらに好ましく、90℃~110℃が特に好ましい。
本工程における加熱を行う雰囲気には特に制限はなく、例えば、大気雰囲気下で行ってもよいし、不活性ガス(窒素ガス、アルゴンガス、ヘリウムガス等)雰囲気下で行なってもよい。
加熱の時間の下限には特に制限はないが、下限は、例えば10秒(好ましくは20秒、より好ましくは30秒)とすることができる。
第1実施形態の半導体装置の製造方法は、洗浄工程後に温度200℃~425℃で加熱する高温加熱工程を有することが好ましい。
本工程により、銅を含む配線の露出面上に形成されたシール層が、前記露出面以外の部分(例えば、前記凹部の側面)に形成されたシール層よりも優先的に(好ましくは前記露出面以外の部分に形成されたシール層に対して選択的に)除去される。
ここで、温度は、半導体基板のシール層が形成された側の面の温度である。
また、前記温度が425℃以下であると、配線に含まれる銅のマイグレーションを抑制できる。
前記温度は、250℃~400℃が好ましく、300℃~400℃がより好ましい。
前記絶対圧が17Paを超えると、配線の露出面上のシール層を除去する際の除去速度がより向上する。
前記絶対圧が大気圧以下であると、配線の露出面上のシール層を除去する際の除去速度をより調整し易い。
前記絶対圧は、1000Pa以上大気圧以下がより好ましく、5000Pa以上大気圧以下が更に好ましく、10000Pa以上大気圧以下が特に好ましい。
また、本工程における加熱は、大気雰囲気下で行なってもよいが、配線材料である銅の酸化を抑制する観点等からは、不活性ガス(窒素ガス、アルゴンガス、ヘリウムガス等)雰囲気下で行なうことがより好ましく、窒素ガス雰囲気下で行なうことが特に好ましい。
加熱時間が1時間以下であると、シール層による層間絶縁層に対するシール性がより高く維持される。
図2に示したシール組成物付与工程後の半導体基板のシール層30が形成された側の面を、洗浄工程にてリンス液により洗浄することにより、配線20の露出面上のシール層30の除去性が向上し、さらに、高温加熱処理によってシール層30を除去することができる。
以上のように、凹部16の側面のシール層30を残しながら、配線20上のシール層の少なくとも一部を除去することができる。
これにより、凹部16の側面の少なくとも側面にシール層30を備えるとともに、配線20上へのシール層の形成が抑制された半導体装置100が製造される。
第1実施形態の半導体装置の製造方法は、その他の工程として、必要に応じて、前述したプラズマ処理を行うプラズマ処理工程、配線形成工程、バリア層形成工程など、電子デバイス(例えば半導体装置)の製造において行われる工程をさらに含んでいてもよい。
半導体装置の製造方法が配線形成工程を有する場合、配線形成工程前にバリア層(銅バリア層)形成工程をさらに設けることができる。バリア層を形成することで層間絶縁層への金属成分やプラズマ成分の拡散をより効果的に抑制することができる。
前記バリア層形成工程は、通常用いられるプロセス条件に従って行うことができ、例えば気相成長法(CVD)により、チタン化合物(窒化チタン等)、タンタル化合物(窒化タンタル等)、ルテニウム化合物、マンガン化合物、コバルト化合物(CoW等)、タングステン化合物等からなるバリア層を形成することができる。
次に、第1実施形態の製造方法によって製造される半導体装置の一例について、図4を参照しながら説明する。図4は、第1実施形態にかかる半導体装置の製造方法によって製造される、半導体装置200の断面を模式的に示す概略断面図である。
図4に示すように、半導体装置200は、半導体基板10上に、凹部が設けられた第1層間絶縁層14と、第1層間絶縁層14の下層側に配された第2層間絶縁層12と、からなる層間絶縁層を備えている。半導体装置200は、更に、第2層間絶縁層12に埋め込まれた銅を含む第2配線50と、前記凹部に埋め込まれた、銅を含む第1配線40と、を備えている。半導体装置200は、更に、少なくとも第1層間絶縁層14の凹部の側面と第1配線40との間に設けられたシール層30を備えている。
第1配線40と第2配線50とは電気的に接続されており、この接続部にはシール層30が存在していない。
半導体装置200における、半導体基板10、第1層間絶縁層14、第2層間絶縁層12、第2配線50、シール層30の構成は、それぞれ、半導体装置100における、半導体基板10、第1層間絶縁層14、第2層間絶縁層12、配線20、シール層30の構成と同一である。半導体装置200の変形例も、半導体装置100の変形例と同様である。
また、半導体装置200では、第1層間絶縁層14の凹部の側面と第1配線40との間以外の部分(即ち、第1層間絶縁層14上)にもシール層30が存在しているが、この第1層間絶縁層14上のシール層30は、存在していなくてもよい。例えば、この第1層間絶縁層14上のシール層30は、第1配線40を形成する際の平坦化処理(例えばCMP)により除去されていてもよい。
以下、第2実施形態に係る半導体装置の製造方法及びシール組成物について説明する。なお、前述の第1実施形態と共通する事項については、その説明を省略する。
第2実施形態に係る半導体装置の製造方法は、層間絶縁層と、銅を含む配線と、を有する半導体基板の少なくとも前記層間絶縁層及び前記配線の表面に、シール組成物を付与するシール組成物付与工程と、前記シール組成物付与工程の後、多価カルボン酸モノマーを0.3ミリモル/リットル~230ミリモル/リットル含有するリンス液で、少なくとも前記層間絶縁層及び前記配線の表面を洗浄する洗浄工程と、を有し、重量平均分子量が2000~1000000であるポリマー(A)と、ベンゾトリアゾール化合物と、を含み、シール組成物中におけるベンゾトリアゾール化合物の含有量が、3質量ppm~200質量ppmであり、シール組成物のpHが3.0~6.5である。
上記の半導体装置の製造方法によれば、銅などの配線材料の減少を抑制して電気伝導性を維持することが可能な半導体装置を製造することができる。
第2実施形態に係る半導体装置の製造方法にて用いるシール組成物におけるポリマー(A)の含有量は、第1実施形態にて用いるシール組成物と異なり、0.05質量部~0.20質量部に限定されない。例えば、この実施形態で用いるシール組成物におけるポリマー(A)の含有量は、シール組成物100質量部に対して、0.05質量部~0.70質量部であることが好ましく、0.11質量部~0.50質量部であることがより好ましい。また前記シール組成物を用いてポリマー層を形成する面の面積及び細孔密度に基づいて、前記シール組成物におけるポリマー(A)の含有量を調整することもできる。シール組成物におけるポリマー(A)の含有量が0.05質量部以上であることにより、シール組成物のシール性を好適に維持することができ、シール組成物におけるポリマー(A)の含有量が0.70質量部以下であることにより、配線表面上に付着するシール組成物の量を低減することができ、配線表面上のシール組成物の除去性が向上する。また、第2実施形態では、第1実施形態と異なり、凹部の底面にシール組成物中のポリマー(A)が付着するポリマー溜りの問題が生じないため、シール組成物におけるポリマー(A)の含有量を、第1実施形態にて用いるシール組成物の含有量である0.20質量部よりも多くすることが可能である。シール組成物におけるポリマー(A)の含有量を0.20質量部超とすることにより、層間絶縁層の細孔半径がより大きい場合(例えば、0.5nm~3.0nm)にもシール組成物のシール性をより好適に維持することができる。
シール組成物付与工程は、半導体基板10の少なくとも層間絶縁層22の表面及び配線60の表面に、シール組成物を付与する工程である。
第2実施形態の半導体装置の製造方法は、前記シール組成物付与工程の後、多価カルボン酸モノマーを0.3ミリモル/リットル~230ミリモル/リットル含有するリンス液で、少なくとも層間絶縁層の表面及び配線の表面を洗浄する洗浄工程を有する。
この洗浄工程を有することにより、配線の表面上のシール層の除去性がさらに向上する。
図5(b)に示したシール組成物付与工程後の半導体基板のシール層31が形成された側の面を、洗浄工程にてリンス液により洗浄することにより、配線60の表面上のシール層の除去性が向上し、さらに、高熱加熱処理によってシール層31を除去することができ、半導体装置300が得られる。
以下において、「水」としては、超純水(Millipore社製Milli-Q水、抵抗18MΩ・cm(25℃)以下)を使用した。
以下のようにしてポリエチレンイミン1を合成し、次いで、得られたポリエチレンイミン1を含むシール組成物を調製した。詳細を以下に説明する。
(変性ポリエチレンイミン1の合成)
下記反応スキーム1に従い、ポリエチレンイミンを出発物質とし、変性ポリエチレンイミン1を合成した。なお、下記反応スキーム1及び反応スキーム2におけるポリマー構造は模式的に表した構造であり、3級窒素原子及び2級窒素原子の配置や、後述するBoc化アミノエチル基により置換される2級窒素原子の割合については、合成条件により種々変化するものである。
MP-Biomedicals社製ポリエチレンイミン(50%水溶液)61.06gをイソプロパノール319mL中に溶解し、N-t-ブトキシカルボニル(本実施例において、t-ブトキシカルボニル基を「Boc」ともいう)アジリジン102g(710mmol)を加え、3時間加熱還流を行い、ポリエチレンイミンにBoc化アミノエチル基が導入された構造の変性ポリエチレンイミン1を得た。薄層クロマトグラフィー(TLC)で原料のN-Bocアジリジンがなくなったことを確認し、少量サンプリングして1H-NMRで構造を確認した。1H-NMRより、ポリエチレンイミンに対するBoc化アミノエチル基の導入率は95%と算出された。
~変性ポリエチレンイミン1のNMR測定結果~
1H-NMR(CD3OD);δ3.3-3.0(br.s,2),2.8-2.5(
Br.s,6.2),1.45(s,9)
上記変性ポリエチレンイミン1を出発物質とし、下記反応スキーム2に従ってポリエチレンイミン1を合成した。
上記変性ポリエチレンイミン1のイソプロパノール溶液に12N塩酸124mLをゆっくり加えた。得られた溶液を、ガスの発生に注意しながら50℃で4時間加熱撹拌した。ガスの発生と共に、反応系内にガム状の反応物が生成した。ガスの発生が終了した後に冷却し、冷却後、このガム状の反応物から分離した溶媒を除き、メタノール184mLで3回洗浄した。洗浄後の反応物を水に溶解し、陰イオン交換高分子で塩素イオンを取り除き、ポリエチレンイミン1を58g含有する水溶液を得た。
~ポリエチレンイミン1のNMR測定結果~
1H-NMR(D2O);δ2.8-2.4(br.m)
13C-NMR(D2O);δ(積分比) 57.2(1.0),54.1(0.38
),52.2(2.26),51.6(0.27),48.5(0.07),46.7(
0.37),40.8(0.19),38.8(1.06).
その結果、重量平均分子量は40575、分子量分布は17.47、カチオン性官能基当量は43、1級窒素原子の量は46mol%、2級窒素原子の量は11mol%、3級窒素原子の量は43mol%、4級窒素原子の量は0mol%、分岐度は80%であった。
また、1級窒素原子の量(mol%)、2級窒素原子の量(mol%)、3級窒素原子の量(mol%)、4級窒素原子の量(mol%)、及び分岐度(%)は、ポリマーサンプル(ポリエチレンイミン1)を重水に溶解し、得られた溶液について、ブルカー製AVANCE500型核磁気共鳴装置でシングルパルス逆ゲート付デカップリング法により、80℃で13C-NMRを測定した結果より、それぞれの炭素原子が何級のアミン(窒素原子)に結合しているかを解析し、その積分値を元に算出した。帰属については、European Polymer Journal, 1973, Vol. 9, pp. 559などに記載がある。
1級窒素原子の量(mol%) = (1級窒素原子のmol数/(1級窒素原子のmol数+2級窒素原子のmol数+3級窒素原子のmol数+4級窒素原子のmol数))×100 ・・・ 式A
2級窒素原子の量(mol%) = (2級窒素原子のmol数/(1級窒素原子のmol数+2級窒素原子のmol数+3級窒素原子のmol数+4級窒素原子のmol数))×100 ・・・ 式B
3級窒素原子の量(mol%) = (3級窒素原子のmol数/(1級窒素原子のmol数+2級窒素原子のmol数+3級窒素原子のmol数+4級窒素原子のmol数))×100 ・・・ 式C
4級窒素原子の量(mol%) = (4級窒素原子のmol数/(1級窒素原子のmol数+2級窒素原子のmol数+3級窒素原子のmol数+4級窒素原子のmol数))×100 ・・・ 式D
分岐度(%) = ((3級窒素原子の量(mol%)+4級窒素原子の量(mol%))/(2級窒素原子の量(mol%)+3級窒素原子の量(mol%)+4級窒素原子の量(mol%))×100 ・・・ 式E
〔実施例1〕
上記で得られたポリエチレンイミン1(重量平均分子量40575、カチオン性官能基当量43)の水溶液に、水、酢酸及びベンゾトリアゾール(1,2,3-ベンゾトリアゾール)を加えて混合し、シール組成物1Aを得た。
シール組成物1Aでは、水、酢酸及びベンゾトリアゾールの添加量は、シール組成物中のポリエチレンイミン1の濃度が0.18質量%となり、かつ、シール組成物のpHが4.3となる量となり、かつ、ベンゾトリアゾールの濃度が10質量ppmとなる量とした。ここでいうpHは、25℃のシール組成物について測定された値である(以下、同様である)。ここで、シール組成物のpHはアズワン社製pHメーター(KR5E)をpH標準液で校正後、測定液にpHメーターを浸漬して値が自動的に安定したところでpH値を読み取った値とした。
表1に記載の含有量及びpHに変更した以外は、シール組成物1Aと同様にしてシール組成物2A~10A(それぞれ実施例2~10とする)を得た。
また、比較として、表1に記載の含有量及びpHに変更した以外は、シール組成物1Aと同様にしてシール組成物4B~18B(それぞれ比較例1~15とする)を得た。シール組成物4B、5Bは、ベンゾトリアゾールを含まない例である。シール組成物7B~16Bは、ベンゾトリアゾールを含まないが、一般に防錆剤として用いられているシュウ酸、8-キノリノール、プロパルギルアミン、2,2’-ビピリジン、フェナントロリンを含む例である。シール組成物17Bは、ベンゾトリアゾールを200質量ppm超含む例である。また、シール組成物6Bは、ベンゾトリアゾールを10質量ppm未満含む例であり、シール組成物18Bは、ベンゾトリアゾールを10質量ppm未満含み、かつシール組成物のpHが6.5超となる例である。
次に、銅膜にシール組成物を付与することにより、シール組成物への銅の溶出量を測定した。
まず、シリコン基板上にめっきにて銅膜を100nm成膜した基板の銅膜面をヘリウムプラズマ処理でクリーニング後、純水で洗浄した。これを、上記シール組成物1A 20ccに3分間浸漬したのち取り出した。浸漬後のシール組成物1A中の銅イオン含有量を誘電結合プラズマ質量分析装置(ICP-MS)で測定し、その値を銅イオンの溶出量とした。
シール組成物2A~10A、4B~18Bについても同様に、銅イオンの溶出量測定を行った。
また、ベンゾトリアゾールを含まない場合、又はベンゾトリアゾールをわずかに含む場合、銅溶出量が多いことがわかった。
この結果から、シール組成物中のベンゾトリアゾール濃度が3ppm以上の場合、銅溶出量が低減可能であることがわかった。ここで、銅溶出量が150ppb以下であれば、銅溶出量が低くなり、好ましい。
比較として、表2に記載の含有量及びpHに変更した以外は、シール組成物2Aと同様にしてシール組成物19Bを得た(ベンゾトリアゾールを含まない例である)。
(厚さ測定用試料の作製)
表面にシリカが存在しているシリコンウエハを準備し、このシリコンウエハを、スピンコーターの上にのせ、表2に示すシール組成物(実施例1、比較例1、4)を10秒間一定速度で1.0mL滴下し、13秒間保持した後、このシリコンウエハを2000rpmで1秒間回転させ、さらに600rpmで30秒間回転させた後、2000rpmで10秒間回転させて乾燥させた。
以上により、シリコンウエハ上に、シール層(ポリマー層)を形成し、シリコンウエハとポリマー層とが積層された構造の積層体(以下、「試料(Si/PEI)」ともいう)を得た。
ここでいうソフトベーク温度は、シリコンウエハ表面の温度(成膜前シリコンウエハの成膜される面の温度)である。
表面にシリカが存在するシリコンウエハ上のポリマー層の厚さ(nm)は、SEMILAB社製光学式ポロシメータ(PS-1200)のエリプソメーターを使用して常法により測定した。
結果を表2に示す。
(厚さ測定用試料の作製)
シリコンウエハ上に100nmの銅膜がめっき法にて形成され、さらに銅膜上に100nmのSiO2膜がCVD法にて形成されたシリコンウエハを準備し、SiO2膜に銅膜が露出するまで110nm幅のビア貫通孔を加工し、パターンウエハを得た。
上記パターンウエハを、スピンコーターの上にのせ、パターン形成面上に、表2に示すシール組成物を10秒間一定速度で1.0mL滴下し、13秒間保持した後、このパターンウエハを2000rpmで1秒間回転させ、さらに600rpmで30秒間回転させた後、2000rpmで10秒間回転させて乾燥させた。
以上により、パターンウエハ上に、シール層(ポリマー層)を形成し、パターンウエハとポリマー層とが積層された構造の積層体(以下、「試料(VIA/PEI)」ともいう)を得た。
また、パターンウエハのビア底面に露出している銅上のポリマー層の厚さは、次のように測定した。
ソフトベーク後のポリマー層が形成された側の表面にPt(白金)スパッタを施し、その後炭素をデポジションして保護層とし、その後、FIB加工装置SMI-2050(セイコーインスツルメント製)を用いて薄片化(銅配線の断面が現れる方向に薄片化)し、観察検体とした。
この観察検体を電界放出型透過電子顕微鏡(FE-TEM)(JEM-2200FS、日本電子(株)製)によって観察し、ビアの底面に露出している銅配線上のポリマー層の厚さを測定した。測定値はビア中央部のポリマー層の厚み(パドル量ともいう)を測定した値を示す。
結果を表2に示す。
(厚さ測定用試料の作製)
表面にシリカが存在しているシリコンウエハを準備し、このシリコンウエハを、スピンコーターの上にのせ、表3に示すシール組成物を10秒間一定速度で1.0mL滴下し、23秒間保持した後、このシリコンウエハを2000rpmで1秒間回転させ、さらに600rpmで30秒間回転させた後、2000rpmで10秒間回転させて乾燥させた。
以上により、シリコンウエハ上に、シール層(ポリマー層)を形成し、シリコンウエハとポリマー層とが積層された構造の積層体(以下、「試料(Si/PEI)」ともいう)を得た。
ここでいうソフトベーク温度は、シリコンウエハ表面の温度(成膜前シリコンウエハの成膜される面の温度)である。
上記試料(Si/PEI)を、スピンコーターを用いて600rpmで回転させながら、ポリマー層上に、リンス液として4,4’-オキシジフタル酸(0.62ミリモル/リットル)/エチルアミン水溶液(pH5.2、液温22℃)を0.1mL/秒の滴下速度で30秒間滴下してポリマー層を洗浄し、次いで、試料を2000rpmで60秒間回転させ乾燥させ、次いで、超純水(液温22℃)を0.1mL/秒の滴下速度で30秒間滴下し、次いで、試料を2000rpmで60秒間回転させ乾燥させた。
次に、上記のようにして得られた洗浄処理後試料のポリマー層(PEI)の厚さを測定した。ポリマー層の厚さ(nm)は、SEMILAB社製光学式ポロシメータ(PS-1200)のエリプソメーターを使用して常法により測定した。
結果を表3に示す。
(厚さ測定用試料の作製)
シリコン基板上にめっきにて銅膜を100nm成膜し、この銅膜面をヘリウムプラズマ処理でクリーニングした基板を用い、プラズマ処理後の銅膜面上に、シール層(ポリマー層)を形成するため、<シリコン(Si)上のポリマー層の厚さ評価>と同様の処理を行なった。
以上により、銅上に、ポリマー層を形成し、銅とポリマー層とが積層された構造の積層体(以下、「試料(Cu/PEI)」ともいう)を得た。
上記試料(Cu/PEI)を、スピンコーターを用いて600rpmで回転させながら、ポリマー層上に、リンス液として4,4’-オキシジフタル酸(0.62ミリモル/リットル)/エチルアミン水溶液(pH5.2、液温22℃)を0.1mL/秒の滴下速度で30秒間滴下してポリマー層を洗浄し、次いで、試料を2000rpmで60秒間回転させ乾燥させ、次いで、超純水(液温22℃)を0.1mL/秒の滴下速度で30秒間滴下し、次いで、試料を2000rpmで60秒間回転させ乾燥させた。
次に、上記のようにして得られた洗浄処理後試料のポリマー層(PEI)の厚さを測定した。銅(Cu)上のポリマー層の厚さ(nm)は、SEMILAB社製光学式ポロシメータ(PS-1200)のエリプソメーターを使用して以下の手法により測定した。
即ち、光学的に平坦な銅基板上のポリマー層の厚さは、エリプソメトリーにより測定された偏光パラメーターを、WinElli IIを用いて多層光学モデル;(空気)/(ポリマー層)/(銅基板)で回帰することにより計算した。用いた光エネルギーの範囲は、2.2~5.0eVである。ここで、ポリマー層の屈折率には常にシリカ(SiO2)と同じ値を用いた。また、銅基板の屈折率及び消衰係数は、ポリマー層を有しない銅基板の偏光パラメーターを測定後、解析ソフトのWinElli IIを用いて求められた値を用いた。
結果を表3に示す。
(前駆体溶液の調製)
77.4gのビストリエトキシシリルエタンと70.9gのエタノールとを室温下で混合攪拌した後、1mol/Lの硝酸80mLを添加し、50℃で1時間撹拌した。次に、20.9gのポリオキシエチレン(20)ステアリルエーテルを280gのエタノールで溶解した溶液を滴下混合した。混合後、30℃で4時間撹拌した。得られた溶液を25℃、30hPaの減圧下、105gになるまで濃縮した。濃縮後、1-プロピルアルコールと2-ブチルアルコールを体積で2:1に混合した溶液を添加し、前駆体溶液1800gを得た。
前駆体溶液472gに、ジメチルジエトキシシラン3.4g及びヘキサメチルジシロキサン1.8gを添加し、25℃で1時間撹拌し、多孔質シリカ形成用組成物を得た。この時のジメチルジエトキシシラン、ヘキサメチルジシロキサンの添加量は、ビストリエトキシシリルエタンに対してそれぞれ10モル%、5モル%であった。
上記多孔質シリカ形成用組成物1.0mLをシリコンウエハ表面上に滴下し、2000rpmで60秒間回転させて、シリコンウエハ表面に塗布した後、窒素雰囲気下、150℃で1分間、次いで、350℃で10分間加熱処理した。その後、172nmエキシマランプを装備したチャンバー内で350℃まで熱処理し、圧力1Paで出力14mW/cm2により、紫外線を10分間照射することにより、層間絶縁層(多孔質シリカ膜)を得た。
以上により、上記層間絶縁層(以下、「low-k膜」又は「low-k」ともいう)付きシリコンウエハを得た。
また、得られた層間絶縁層の比誘電率kは、2.5であった。
また、得られた層間絶縁層の弾性率は、8.8GPaであった。
また、比誘電率は、水銀プローブ装置(SSM5130)を用い、25℃、相対湿度30%の雰囲気下、周波数1MHzにて常法により測定した。
また、弾性率は、ナノインデンテーター(Hysitron社、Triboscope)により、膜厚の1/10以下の押し込み深さで常法により測定した。
比較として、表4に記載の含有量及びpHに変更した以外は、シール組成物1Aと同様にしてシール組成物20Bを得た(ベンゾトリアゾールを含まない例である)。
上記で得られたlow-k膜付きシリコンウエハのlow-k膜面に、表4に記載のシール組成物を用いて、ポリマー層を形成し、low-k膜付きシリコンウエハとポリマー層とが積層された構造の積層体(以下、「試料(Si/low-k/PEI)」ともいう)を得た。
ポリマー層の形成は次の方法で行った。上記で得られたlow-k膜付きシリコンウエハを、スピンコーターの上にのせ、low-k膜面に、表4に示すシール組成物(シール組成物1Aまたはシール組成物20B)を10秒間一定速度で1.0mL滴下し、13秒間保持した後、このシリコンウエハを2000rpmで1秒間回転させ、さらに600rpmで30秒間回転させた後、2000rpmで10秒間回転させて乾燥させた。
ここでいうソフトベーク温度は、シリコンウエハ表面の温度である。
上記シール組成物1Aを用いた積層体のソフトベーク後の試料(Si/low-k/PEI)を、スピンコーターを用いて600rpmで回転させながら、ポリマー層上に、リンス液として4,4’-オキシジフタル酸(0.62ミリモル/リットル)/エチルアミン水溶液(pH5.2、液温22℃)を0.1mL/秒の滴下速度で30秒間滴下してポリマー層を洗浄し、次いで、試料を2000rpmで60秒間回転させ乾燥させ、次いで、超純水(液温22℃)を0.1mL/秒の滴下速度で30秒間滴下し、次いで、試料を2000rpmで60秒間回転させ乾燥させた。
上記シール組成物20Bを用いた積層体のソフトベーク後の試料(Si/low-k/PEI)を、スピンコーターを用いて600rpmで回転させながら、ポリマー層上に、リンス液としてピロメリット酸(pH3.4)を0.1mL/秒の滴下速度で30秒間滴下してポリマー層を洗浄し、次いで、試料を2000rpmで60秒間回転させ乾燥させ、次いで、超純水(液温22℃)を0.1mL/秒の滴下速度で30秒間滴下し、次いで、試料を2000rpmで60秒間回転させ乾燥させた。
次に、洗浄処理1、2を行なった後のそれぞれの試料(実施例1、比較例5)について、以下の条件で熱処理(ハードベーク処理)を行なった。まず、上記試料(Si/low-k/PEI)を炉(アペックス社製のSPX-1120)に入れ、この試料のシール層(PEI)が形成された側に対し、窒素ガス(N2)雰囲気中、圧力10,000Paの条件下で、350℃の熱処理を2分間施した。上記温度は、試料(Si/low-k/PEI)のシール層(PEI)が形成された側の表面温度である。
以上により、プラズマ処理前のシール性評価用試料を得た。
次に、上記のようにして得られた熱処理後のシール性評価用試料(プラズマ処理前のシール性評価用試料)のシール層(PEI)の厚さを測定した。シール層の厚さ(nm)は、SEMILAB社製光学式ポロシメータ(PS-1200)のエリプソメーターを使用して常法により測定した。
結果を表4に示す。
上記熱処理後のシール性評価用試料のシール層(PEI)側に、さらに下記条件のプラズマ処理を施し、プラズマ処理後のシール性評価用試料を作製した。
・使用ガス … 水素ガス
・使用電極 … 平行平板型電極(φ10cm)
・到達真空度 … 2×10-5Torr未満
・水素ガス流し … 5分
・放電電力 … 100W
・放電周波数 … 13.56MHz
・放電時の圧力 … 150mTorr
・電極の温度 … 室温
・試料表面の温度 … 室温
・水素ガス流量 … 50sccm
・サンプル設置側 … グラウンド電位(0V)が印加されたアノード電極上
・処理時間(放電時間) … 20秒
上記プラズマ処理後のシール性評価用試料について、以下のようにしてシール性評価を行なった。
シール性評価は、試料(Si/low-k/PEI)のシール層(PEI)表面におけるトルエン吸着測定により行った。このトルエン吸着測定では、トルエン吸着量が少ないほど、low-k膜中への配線材料(銅など)の侵入を防ぐシール性が高いことを表す。
測定方法は、M. R. Baklanov, K. P. Mogilnikov, V. G. Polovinkin, and F. N. Dultsey, Journal of Vacuum Science and Technology B (2000) 18, 1385-1391に記載の手法に従って行った。
具体的には、温度範囲23~26℃において、試料(Si/low-k/PEI)の入ったサンプル室を5mTorrまで排気した後、トルエンガスをサンプル室に十分にゆっくり導入した。各圧力において、low-k膜の屈折率をエリプソメータ装置によりその場測定した。この操作を、サンプル室内圧力がトルエンの飽和蒸気圧に達するまで繰り返した。同様に、サンプル室内雰囲気を徐々に排気しつつ、各圧力にて屈折率の測定を行った。以上の操作により、low-k膜へのトルエンの吸着及び脱離による屈折率変化を求めた。更に、ローレンツ-ローレンツ式を用いて、屈折率の相対圧力特性からトルエンガス吸着脱離等温線を求めた。
上記トルエンガス吸着脱離等温線は、トルエン相対圧(P/P0;ここで、Pはトルエンの室温での分圧を表し、P0はトルエンの室温での飽和蒸気圧を表す。)と、トルエン吸着量の体積分率(low-k膜全体の体積に対するトルエンの室温での吸着体積の比率;単位は「%」)と、の関係を示す等温線である。トルエン吸着量の体積分率は、ローレンツ・ローレンツ式を用いてlow-k膜の屈折率に基づいて求めた。
評価結果を表4に示す。
次に、上記のようにして得られたプラズマ処理後のシール性評価用試料のシール層(PEI)の厚さを測定した。シール層の厚さ(nm)は、SEMILAB社製光学式ポロシメータ(PS-1200)のエリプソメーターを使用して常法により測定した。
結果を表4に示す。
本明細書に記載された全ての文献、特許出願、及び技術規格は、個々の文献、特許出願、及び技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。
12 第2層間絶縁層
14 第1層間絶縁層
16 凹部
20 配線
20a 露出面
22 層間絶縁層
24 層間絶縁層
30、31 シール層
40 第1配線
50 第2配線
60、70 配線
100、200、300、400 半導体装置
Claims (12)
- カチオン性官能基を有し、重量平均分子量が2000~1000000であるポリマー(A)と、
ベンゾトリアゾール化合物と、
を含み、
前記ポリマー(A)の含有量が、シール組成物100質量部に対して0.05質量部~0.20質量部であり、
前記シール組成物中における前記ベンゾトリアゾール化合物の含有量が、3質量ppm~200質量ppmであり、
前記シール組成物のpHが3.0~6.5である、シール組成物。 - カチオン性官能基を有し、重量平均分子量が2000~1000000であるポリマー(A)と、
ベンゾトリアゾール化合物と、
を含み、
シール組成物中における前記ベンゾトリアゾール化合物の含有量が、3質量ppm~200質量ppmであり、
前記シール組成物のpHが3.0~6.5である、シール組成物。 - さらにモノカルボン酸化合物を含有する、請求項1又は請求項2に記載のシール組成物。
- ナトリウム及びカリウムの含有量がそれぞれ元素基準で10質量ppb以下である、請求項1~請求項3のいずれか1項に記載のシール組成物。
- 凹部が設けられた層間絶縁層と、前記凹部の底面の少なくとも一部にその表面の少なくとも一部が露出している銅を含む配線と、を有する半導体基板の少なくとも前記凹部の底面及び側面に、請求項1に記載のシール組成物を付与するシール組成物付与工程と、
前記シール組成物付与工程の後、多価カルボン酸モノマーを0.3ミリモル/リットル~230ミリモル/リットル含有するリンス液で、少なくとも前記凹部の側面及び底面を洗浄する洗浄工程と、
を有する、半導体装置の製造方法。 - 層間絶縁層と、銅を含む配線と、を有する半導体基板の少なくとも前記層間絶縁層及び前記配線の表面に、請求項2に記載のシール組成物を付与するシール組成物付与工程と、
前記シール組成物付与工程の後、多価カルボン酸モノマーを0.3ミリモル/リットル~230ミリモル/リットル含有するリンス液で、少なくとも前記層間絶縁層及び前記配線の表面を洗浄する洗浄工程と、
を有する、半導体装置の製造方法。 - 前記多価カルボン酸モノマーは、芳香環を二つ有すること、及び分子量が342以上であることの少なくとも一方を満たす、請求項5又は請求項6に記載の半導体装置の製造方法。
- 前記リンス液のpHが4.0~7.0である、請求項5~請求項7のいずれか1項に記載の半導体装置の製造方法。
- 前記シール組成物は、ナトリウム及びカリウムの含有量がそれぞれ元素基準で10質量ppb以下である、請求項5~請求項8のいずれか1項に記載の半導体装置の製造方法。
- 前記シール組成物付与工程後、前記洗浄工程の前に、前記半導体基板を温度70℃~125℃で加熱する加熱工程を有する、請求項5~請求項9のいずれか1項に記載の半導体装置の製造方法。
- 前記洗浄工程後に、前記半導体基板を温度200℃~425℃で加熱する高温加熱工程を有する、請求項5~請求項10のいずれか1項に記載の半導体装置の製造方法。
- 前記シール組成物は、さらにモノカルボン酸を含有する、請求項5~請求項11のいずれか1項に記載の半導体装置の製造方法。
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US20170162382A1 (en) | 2017-06-08 |
EP3159917B1 (en) | 2021-08-04 |
TWI660427B (zh) | 2019-05-21 |
TW201618188A (zh) | 2016-05-16 |
CN106537564A (zh) | 2017-03-22 |
IL250257B (en) | 2022-04-01 |
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EP3159917A1 (en) | 2017-04-26 |
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