WO2024129228A1

WO2024129228A1 - Compositions for selective removal of tin layer over tungsten

Info

Publication number: WO2024129228A1
Application number: PCT/US2023/074130
Authority: WO
Inventors: Laisheng SUN; Yuanmei Cao; Aaron Pejlovas; Aiping Wu
Original assignee: Versum Materials Us, Llc
Priority date: 2022-12-13
Filing date: 2023-09-14
Publication date: 2024-06-20

Abstract

The disclosed and claimed subject matter relates to formulations that selectively etch TiN layer over tungsten (W) as well as methods of manufacturing the same and/or employing the same for fabricating a semiconductor device.

Description

COMPOSITIONS FOR SELECTIVE REMOVAL OF TIN LAYER OVER TUNGSTEN

BACKGROUND

[0001] Field

[0002] The disclosed and claimed subject matter relates to formulations that selectively etch TiN layer over tungsten (W) as well as methods of manufacturing the same and/or employing the same for fabricating a semiconductor device.

[0003] Related Art

[0004] As scaling continues to ever smaller feature sizes, integrated circuit (IC) reliability is an increasing concern in IC fabrication technology. The impact of trace interconnect failure mechanisms on device performance and reliability demand much more from integration schemes, interconnect materials, and processes. Titanium nitride (TiN) has been used as hard mask layer that is deposited other material layers for different applications. For example, an optimal low-k dielectric material and its related deposition, pattern lithography, etching and cleaning are required to form dual-damascene interconnect patterns. The dual -damascene process involves forming a photoresist mask, typically a titanium, or titanium nitride (TiN) on a low-k dielectric layer overlying a metal conductor layer, such as a copper or a cobalt layer. The low-k dielectric layer is then etched in those regions not protected by the photoresist mask to form a via and/or trench that expose the metal conductor layer. The via and trench, commonly known as dual-damascene structure, are usually defined using two lithography steps. The photoresist mask is then removed from the low-k dielectric layer before a conductive material is deposited into the via and/or trench to form an interconnect. A hard-mask scheme approach of interconnects-patterning wafer fabrication allows the transfer of patterns into the under layers with tightest optimal dimension control.

[0005] In other applications, TiN layer may be directly deposited on layers of different metal materials without dielectric layers in between for dimension control. Those metal material may include aluminum, copper, cobalt, molybdenum, tungsten etc.

[0006] Compositions have been developed to “pull back” or remove these types of metal hardmasks from substrates without damaging the exposed materials. To protect those exposed metal layers, inhibitors are usually added into the compositions to prevent the metal layer loss to obtain better metal surface for later metal deposition. Different from the compositions for selectively removing TiN hard mask over exposed copper or cobalt, for which there are many good inhibitors available to protect their surface, there are few compositions that could selectively remove TiN layer over tungsten due to the limited inhibitors for protecting W. Therefore, there is a need to develop compositions that could etch significant amount titanium nitride mask layer while protect the exposed tungsten layer from etching.

SUMMARY

[0007] The disclosed and claimed subject matter relates to formulations that selectively etch TiN layer over tungsten (W) as well as methods of manufacturing the same and/or employing the same for fabricating a semiconductor device.

[0008] In one embodiment, the etching formulations include, consist essentially of or consist of:

(a) at least one quaternary ammonium hydroxide compound without alkanol chains;

(b) at least one oxidizing agent;

(c) at least one oxidizing stabilizer;

(d) at least one non-azole corrosion inhibitor; and

(e) at least one solvent.

DETAILED DESCRIPTION

[0009] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0010] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosed and claimed subject matter (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (z.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the disclosed and claimed subject matter and does not pose a limitation on the scope of the disclosed and claimed subject matter unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosed and claimed subject matter.

[0011] Preferred embodiments of this disclosed and claimed subject matter are described herein, including the best mode known to the inventors for carrying out the disclosed and claimed subject matter. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the disclosed and claimed subject matter to be practiced otherwise than as specifically described herein. Accordingly, this disclosed and claimed subject matter includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosed and claimed subject matter unless otherwise indicated herein or otherwise clearly contradicted by context. [0012] The disclosed and claimed subject matter relates generally to compositions useful for the selective removal of TiN over tungsten (W) from a microelectronic device having such material(s) thereon during its manufacture.

[0013] For ease of reference, “microelectronic device” or “semiconductor substrates” correspond to semiconductor wafers, flat panel displays, phase change memory devices, solar panels and other products including solar substrates, photovoltaics, and microelectromechanical systems (MEMS), manufactured for use in microelectronic, integrated circuit, or computer chip applications. Solar substrates include, but are not limited to, silicon, amorphous silicon, poly crystalline silicon, monocrystalline silicon, CdTe, copper indium selenide, copper indium sulfide, and gallium arsenide on gallium. The solar substrates may be doped or undoped. It is to be understood that the term “microelectronic device” is not meant to be limiting in any way and includes any substrate that will eventually become a microelectronic device or microelectronic assembly. The microelectronic device or semiconductor substrates may include low-k dielectric material, barrier materials, and metals, such as, AICu alloys, W, Ti, TiN, as well as other materials thereon.

[0014] As defined herein, “low-k dielectric material” corresponds to any material used as a dielectric material in a layered microelectronic device, wherein the material has a dielectric constant less than about 3.5. Preferably, the low-k dielectric materials include low-polarity materials such as silicon-containing organic polymers, silicon-containing hybrid organic/inorganic materials, organosilicate glass (OSG), TEOS, fluorinated silicate glass (FSG), silicon dioxide, and carbon-doped oxide (CDO) glass. It is to be appreciated that the low-k dielectric materials may have varying densities and varying porosities.

[0015] As defined herein, the term “barrier material” corresponds to any material used in the art to seal the metal lines, e.g., copper interconnects, to minimize the diffusion of said metal, e.g., copper, into the dielectric material. Preferred barrier layer materials include tantalum, titanium, ruthenium, hafnium, and other refractory metals and their nitrides and silicides.

[0016] “Substantially free” is defined herein as less than 2 wt. %, preferably less than 1 wt. %, more preferably less than 0.5 wt. %, and most preferably less than 0.1 wt. %. “Substantially free” also includes 0.0 wt. %. The term “free of’ means 0.0 wt. %.

[0017] As used herein, the terms "about" and “approximately” are each intended to correspond to ± 5% of the stated value.

[0018] As used herein, “neat” refers to the weight % amount of an undiluted acid or other material. For example, the inclusion 100 g of 85% phosphoric acid constitutes 85 g of the acid and 15 grams of diluent.

[0019] In all such compositions, wherein specific components of the composition are discussed in reference to weight percentage ranges including a zero lower limit, it will be understood that such components may be present or absent in various specific embodiments of the composition, and that in instances where such components are present, they may be present at concentrations as low as 0.001 weight percent, based on the total weight of the composition in which such components are employed. Note all defined weight percents of the components unless otherwise indicated are based on the total weight of the composition. Further, all weight percents unless otherwise indicated are “neat” meaning that they do not include the aqueous composition in which they are present when added to the composition. Any reference to “at least one” could be substituted with “one or more.” “At least one” and/or “one or more” includes “at least two” or “two or more” and “at least three” and “three or more” and so on.

[0020] In the broad practice the disclosed and claimed subject matter pertains to the above-described etching composition which includes, or consists essentially of, or consists of components (a), (b), (c), (d) and (e). In some aspect, the etching compositions can include other ingredients. In some embodiments, the etching compositions disclosed herein are formulated to be free or substantially free of at least one of the following chemical compounds: acids (inorganic and organic), ammonium ions, halide ions (e.g., fluoride ions, chloride ions), inorganic base, metal-containing chemicals, reducing agents, hydroxylamine, hydroxylamine derivatives, amidoxime compounds, organic solvents and abrasives.

[0021] In a further embodiment, the etching compositions consist essentially of (a), (b), (c), (d) and (e) in varying concentrations. In such an embodiment, the combined amounts of (a), (b), (c), (d) and (e) do not equal 100% by weight and can include other ingredients that do not materially change the effectiveness of the etching compositions.

[0022] In another embodiment, the etching compositions consist of( a), (b), (c), (d) and (e) in varying concentrations. In such an embodiment, the combined amounts of (a), (b), (c), (d) and (e) equal or equal approximately 100% by weight but may include other small and/or trace amounts of impurities that are present in such small quantities that they do not materially change the effectiveness of the composition. For example, in one such embodiment, the etching composition can contain 2% by weight or less of impurities. In another embodiment, the etching composition can contain 1% by weight or less than of impurities. In a further embodiment, the etching composition can contain 0.05% by weight or less than of impurities. [0023] When referring to compositions of the inventive composition described herein in terms of weight %, it is understood that in no event shall the weight % of all components, including non-essential components, such as impurities, add to more than 100 weight %. In compositions “consisting essentially of’ recited components, such components may add up to 100 weight % of the composition or may add up to less than 100 weight %. Where the components add up to less than 100 weight %, such composition may include some small amounts of a non-essential contaminants or impurities. For example, in one such embodiment, the etching composition can contain 2% by weight or less of impurities. In another embodiment, the etching composition can contain 1% by weight or less than of impurities. In a further embodiment, the etching composition can contain 0.05% by weight or less than of impurities. In other such embodiments, the ingredients can form at least 90 wt%, more preferably at least 95 wt%, more preferably at least 99 wt%, more preferably at least 99.5 wt%, most preferably at least 99.9 wt%, and can include other ingredients that do not material affect the performance of the etching compositions. Otherwise, if no significant non-essential impurity component is present, it is understood that the combination of all essential constituent components will essentially add up to 100 weight %.

[0024] The ensuing detailed description provides preferred exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the disclosed and claimed subject matter. Rather, the ensuing detailed description of the preferred exemplary embodiments will provide those skilled in the art with an enabling description for implementing the preferred exemplary embodiments of the disclosed and claimed subject matter. Various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosed and claimed subject matter, as set forth in the appended claims.

[0025] Etching Formulations

[0026] Disclosed herein are etching formulations of chemical strippers for TiN hard mask removal or etching (“removal” and “etching” are used interchangeably herein) on integrated circuit bearing wafers. TiN hard mask is used to provide fine feature control during plasma etching. Suitable stripper/cleaning chemistries must be able to pull back or totally remove the TiN hard mask as well as any residues from the plasma etch process. However, it is also desirable for such chemistries to provide compatibility with tungsten within the device. [0027] In particular, the disclosed and claimed etching formulations include, consist essentially of or consist of:

(a) at least one quaternary ammonium hydroxide compound without alkanol chains;

(b) at least one oxidizing agent;

(c) at least one oxidizing stabilizer;

(d) at least one non-azole corrosion inhibitor; and

(e) at least one solvent.

[0028] In some aspects of this embodiment, the etching formulations can include other optional ingredients.

[0029] (a) Quaternary Ammonium Hydroxide Without Alkanol Chains

[0030] As noted above, the disclosed and claimed etching formulations include (a) at least one quaternary ammonium hydroxide compound. Such quaternary ammonium hydroxide compound is a quaternary ammonium hydroxide without alkanol chains of the following general structure:

where each of R¹, R², R³ and R⁴ is independently selected from an unsubstituted Ci-Ce alkyl group, a branched C3-C6 alkyl group, an unsubstituted benzyl group, a benzyl group substituted with one or more Ci-Ce alkyl groups, an unsubstituted phenyl group and a phenyl group substituted with one or more Ci-Ce alkyl groups. In one embodiment, one or more of R¹, R², R³ and R⁴ is a benzyl group. In one embodiment, one or more of R¹, R², R³ and R⁴ is a phenyl group. In one embodiment, three of R¹, R², R³ and R⁴ are a methyl group and the other of R¹, R², R³ and R⁴ is a phenyl group. Suitable quaternary ammonium hydroxides without alkanol chains include, but are not limited to, tetraethylammonium hydroxide (TEAH), trimethylphenylammonium hydroxide (IMP AH), tetramethylammonium hydroxide (TMAH), ethyltrimethylammonium hydroxide (ETMAH), diethyldimethylammonium hydroxide (DEDMAH), methyltriethylammonium hydroxide (MTEAH), tetrapropylammonium hydroxide (TPAH), tetrabutyl ammonium hydroxide (TBAH), benzyltriethylammonium hydroxide (BTEAH), dimethyldipropylammonium hydroxide (DMDPAH), benzyltrimethylammonium hydroxide (BTMAH) and combinations thereof.

[0031] The amount of quaternary ammonium hydroxide without alkanol chains in the formulations of the disclosed and claimed subject matter is in a percent weight, based on the total weight of the formulations, within any range having start and end points selected from the following: 0.1, 0.25, 0.4, 0.5, 0.6, 0.8, 0.9, 1, 1.5, 2, 3, 4, 5,6, 7, 8, 9, 10. for examples, from about 0.1 wt% to about 10 wt% of the solution, or from about 0.25 wt% to about 5 wt% or from about 0.25 wt% to about 3 wt%, or from about 0.25 wt% to about 2 wt%, or from about 0.4 wt% to about 5 wt% or from about 0.4 wt% to about 3 wt%, or from about 0.4 wt% to about 2 wt%, preferably from about 0.25 wt% to about 4 wt%, and more preferably from about 0.4 wt% to about 2.0 wt%. In one embodiment, that the amount of quaternary ammonium hydroxide without alkanol chains in the formulations is from about 0.4 wt% to about 1.5 wt%.

[0032] In one embodiment, the disclosed and claimed etching formulations further optionally include one or more long chain alkyammonium hydroxide such as, but not limited to, trimethylphenylammonium hydroxide (TMPAH), tetrabutylammonium hydroxide and/or a “mixed” tetraalkylammonium hydroxide, where the alkylammonium cation contains alkyl groups of at least two different chain lengths.

[0033] (b) Oxidizing Agent

[0034] As noted above, the disclosed and claimed etching formulations include (b) at least one oxidizing agent. The cleaning compositions employ a peroxide such as, for example, hydrogen peroxide, as an oxidizing agent for TiN hard mask removal. The peroxide to be used in the composition may include but is not limited to hydrogen peroxide, ammonium persulfate, peracetic acid, peroxybenzoic acid, oxone (2KHSO5.KHSO4.K2SO4), n-methylmorpholine oxide(NMMO or NMO), benzoyl peroxide, tetrabutyl ammonium peroxymonosulfate, ferric chloride, permanganate peroxoborate, periodic acid, iodic acid, vanadium (V) oxide, vanadium(IV, V) oxide, ammonium vanadate, perchlorate, persulfate, ammonium peroxydisulfate, per acetic acid, urea hydroperoxide, nitric acid (HNO3), ammonium hypochlorite (NH4CIO), ammonium tungstate ((NH4)IOH2(W20?)), ammonium chlorite (NH4CIO2), ammonium chlorate (NH4CIO3), ammonium iodate (NH4IO3), ammonium perborate (NH4BO3), ammonium perchlorate (NH4CIO4), ammonium periodate (NH4IO3), ammonium persulfate ((NH4)2S20s), tetramethylammonium chlorite ((N(CH₃)₄)CIO₂), tetramethylammionium chlorate ((N(CH3)4)CIO3), tetramethylammonium iodate ((N(CH3)4)IO3), tetramethylammonium perborate ((N(CH3)4)BO3), tetramethylammonium perchlorate ((N(CH3)4)CIO4), tetramethylammonium periodate ((N(CH3)₄)IO₄), tetramethylammonium persulfate ((N(CH3)4)S20s), ((CO(NH2)2)H2O2), peracetic acid (CH(CO)OOH), and combinations thereof.

[0035] The amount of oxidizer in the formulations of the disclosed and claimed subject matter is in a percent weight, based on the total weight of the formulations, within any range having start and end points selected from the following: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 26, 28. For example, from about 3 wt% to about 24 wt% of the formulations, or from about 3 wt% to about 18 wt% or from about 6 wt% to about 18 wt%, or from about 9 wt% to about 18 wt%, or from about 9 wt% to about 15 wt% or from about 6 wt% to about 15 wt%, or from about 12 wt% to about 15 wt%, preferably from about 6 wt% to about 15 wt%, and more preferably from about 9 wt% to about 15 wt%. In one embodiment, that the amount of hydrogen peroxide in the solution is from about 9 wt% to about 15 wt%.

[0036] (c) Oxidizing Stabilizer

[0037] As noted above, the disclosed and claimed etching formulations include (c) at least one oxidizing stabilizer, such as a metal chelating agent. The metal chelating agent stabilizes the formulations by complexing with trace metals that may accumulate in the composition during use of the formulations, thereby preventing the trace metals from decomposing the oxidizer of the composition. Free trace metal cations, such as copper ions, catalyze the decomposition of hydrogen peroxide into and water, which will accelerate the reduction of etching and cleaning performance of the formulations over time. Examples of suitable chelating agents include, but are not limited to nitrilotriacetic acid, ethylenediaminetetraacetic acid (EDTA), (l,2-cyclohexylenedinitrilo)tetraacetic acid (CDTA), uric acid, tetraglyme, diethylenetriamine pentaacetic acid, propylenediamine tetraacetic acid, ethylenediamine disuccinic acid, sulfanilamide, 1,4,7,10- tetraazacyclododecane- 1,4, 7, 10 tetraacetic acid; ethylene glycol tetraacetic acid (EGTA); 1.2-bis(o-aminophenoxy)ethane-N,N,N',N' -tetraacetic acid; N-2- bis(carboxymethyl)aminoethyl-N-(2-hydroxy ethyl)glycine (HEDTA); and ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid) (EDDHA), 1,3-diaminopropane-

N,N,N’,N’ -tetraacetic acid, N,N,N',N'-ethylenediaminetetrakis(methylenephosphonic acid), nitrilotris(methylene)triphosphonic acid, 3,4-dihydroxybenzoic acid, 8-HQ, N-(2- hydroxyethyl)ethylenediamine-N,N',N' -triacetic acid, 1 ,3 -propanediamine-N,N,N',N'- tetraacetic acid, and combinations thereof.

[0038] The amount of oxidizing stabilizer in the formulations of the disclosed and claimed subject matter is in a percent weight, based on the total weight of the formulations, within any range having start and end points selected from the following: 0.001, 0.002,

O.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.010, 0.012, 0.014, 0.015, 0.016, 0.018, 0.020, 0.040, 0.050, 0.060, 0.080. 0.10, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0. For example, from about 0.001 wt% to about 5 wt% of the solution, or from about 0.001 wt% to about 2.5 wt% or from about 0.001 wt% to about 1 wt%, or from about 0.001 wt% to about 0.5 wt%, or from about 0.001 wt% to about 0.1 wt% or from about 0.001 wt% to about 0.05 wt%, or from about 0.001 wt% to about 0.01 wt%, preferably from 0.001 wt% to 0.05 wt%, and more preferably from 0.001 wt% to 0.015 wt%.

[0039] (d) Non-Azole Corrosion Inhibitor

[0040] As noted above, the disclosed and claimed etching formulations include (d) at least one non-azole corrosion inhibitor to minimize loss of metal substrates such as tungsten. The corrosion inhibitors to be used in the formulations include, but are not limited to polyethylene glycol MW 400 (PEG400), polypropylene glycol), surfynol-485, diallyldimethylammonium chloride, hexadecyltrimethylammonium bromide, polyethyleneimines, L-histidine, 2-aminopyrimidine, tryptophan, phosphoric acid, octyl phosphonic acid, gluconic acid, triammonium citrate (TAC), citric acid, glycine, picolinic acid, etidronic acid, sebacic acid, salicylic acid, benzenesulfonic acid, benzoic acid, lactic acid, oxalic acid, methionine, [nitrilotris(methylene)] triphosphonic acid, malonic acid, adipic acid, acetic acid, iminodiacetic acid and combinations thereof.

[0041] The preferred weight percentage of corrosion inhibitor will depend on the specific non-azole corrosion inhibitor being used. For example, if the non-azole corrosion inhibitor is histidine, it preferably is present in an amount of about 0.001 wt% to about 5 wt%, more preferably about 0.01 wt% to about 5 wt%, and most preferably about 0.01 to about 3 wt%. The amount of non-azole corrosion inhibitor in the formulations of the disclosed and claimed subject matter is in a percent weight, based on the total weight of the formulations, within any range having start and end points selected from the following: 0.001, 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, 3.5, 4, 4.5, 5.0. For example, from about 0.001 wt% to about 5.0 wt% of the solution, or from about 0.01 wt% to about 2.0 wt% or from about 0.01 wt% to about 1.5 wt%, or from about 0.01 wt% to about 1 wt%, or from about 0.1 wt% to about 2 wt% or from about 0.5 wt% to about 2 wt%, or from about 0.01 wt% to about lwt%, preferably from 0.01 wt% to 1 wt%, and more preferably from 0.05 wt% to 1.0 wt%.

[0042] (e) Solvent

[0043] As noted above, the disclosed and claimed etching formulations include (e) at least one solvent.

[0044] In one embodiment, the (e) at least one solvent includes, consists essentially of or consists of water. The water may be deionized water (“DI water”), purified water and/or distilled water.

[0045] In another embodiment, the (e) at least one solvent includes water and one or more non-aqueous solvent. Examples of non-aqueous solvents that may be used in the formulations include, but are not limited to, dimethyl sufoxide (DMSO), dimethyl sulfone (DMSO2), sulfolane ((CEb^SC ), n-methylpyrrolidone, dipropyleneglycolmethylether, tripropyleneglycolmethyl ether, propylene glycol and combinations thereof.

[0046] In another embodiment, the (e) at least one solvent does not include water and is instead non-aqueous.

[0047] The at least one solvent preferably constitutes about 5 wt% to about 99 wt%, more preferably about 30 wt% to about 95 wt%, and most preferably about 50 wt% to about 95 wt%. In all instances, the amount of solvent (ie., the wt% thereof) makes up the balance of the disclosed and claimed formulations. The amount of solvent in the formulations of the disclosed and claimed subject matter is in a percent weight, based on the total weight of the formulations, within any range having start and end points selected from the following: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99. For example, from about 5 wt% to about 99 wt% of the solution, or from about 10 wt% to about 95 wt% or from about 20 wt% to about 95 wt%, or from about 30 wt% to about 95 wt%, or from about 40 wt% to about 95 wt% or from about 50 wt% to about 95 wt%, or from about 60 wt% to about 95 wt%, or from about 70 wt% to about 95 wt%, or from about 80 wt% to about 95 wt%, or from about 85 wt% to about 95 wt%, preferably from 75 wt% to 95 wt%, and more preferably from 80 wt% to 90 wt%. [0048] Other Optionally Included Ingredients

[0049] The etching composition, including those exemplified above, can include other optional components as described below.

[0050] In a further aspect, the solutions further optionally include, consist essentially of or consist of (f) one or more azole corrosion inhibitor. Suitable azole corrosion inhibitors include, but are not limited to, aromatic triazoles such as benzotriazole (BZT); alkylbenzotriazoles and methylbenzotriazole, aminobenzotriazoles, such as, 1- aminobenzotriazole; benzotriazole-5-carboxylic acid; triazoles such as 1,2,4-triazole and 1,2, 3 -triazole; pyrazole, imidazole, thiazoles, such as, 2-aminobenzothiazole (ABT).

[0051] In one embodiment, the (f) one or more one or more optional azole corrosion inhibitor is present in the formulations at levels ranging from about 0.001 wt% to about 5 wt%. In one embodiment, the formulation may contain about 0.001 wt% to about 2 wt% or about 0.01 wt% to about 2 wt% or about 0.001 wt% to about 1 wt% or about 0.01 wt% to about 1 wt% or 0.05 weight percent to about 2 wt% or about 0.05 wt% to about 1 wt% or about 0.001 wt% to about 0.05 wt% or about 0.01 wt% to about 0.05 wt% or about 0.01 wt% to about 0.1 wt% or about 0.1 wt% to about 0.5 wt% or about 0.01 wt% to about 0.5 wt%. The one or more azole corrosion inhibitors may be present in any amount defined by the endpoints selected from the following weight percents: 0.001, 0.005, 0.01, 0.015, 0.02, 0.025, 0.050, 0.10, 0.15, 0.20, 0.25, 0.3, 0.4, 0.5, 0.75, 0.9, 1.0, 2.0, 3.0, 4.0, 5.0.

[0052] Excluded Ingredients

[0053] In some embodiments, the disclosed and claimed etching formulations are substantially free of or free of one or more of the following: metal hydroxides (e.g., KOH, Li OH, NaOH), alkanolamine, inhibitors (e.g., nitrogen or sulfur containing heterocyclic molecules such as thiazoles), abrasives.

[0054] In some embodiments, the solution may be substantially free of or free of a halide-containing compound other than one or more fluorine-containing compounds, for example it may be substantially free or free of one or more of the following: bromine-, chlorine- or iodine-containing compounds. In other embodiments, the solution may be substantially free or free of sulfates and/or nitrates and/or sulfites and/or nitrites.

[0055] In some embodiments, the disclosed and claimed etching formulations are substantially free of or free of: ammonium hydroxide and/or ethyl diamine. In other embodiments, the solution may be substantially free or free of: sodium-containing compounds and/or calcium-containing compounds and/or manganese-containing compounds or magnesium-containing compounds and/or chromium-containing compounds and/or sulfur-containing compounds. In other embodiments, the solution may be substantially free or free of amidoxime compounds and/or abrasives.

[0056] In some embodiments, the disclosed and claimed etching formulations are substantially free of or free of other ammonium salts and/or quaternary ammonium hydroxide with alkanol chains and metal ions.

[0057] In some embodiments, the disclosed and claimed etching formulations are substantially free of or free of alkanolamine.

[0058] pH

[0059] The disclosed and claimed etching formulations preferably have a pH of greater than about 5. In one embodiment, the disclosed and claimed etching formulations have a pH of between about 5 and about 14. In another embodiment, the disclosed and claimed etching formulations have a pH of between about 6 and about 12. In another embodiment, the disclosed and claimed etching formulations have a pH of between about 6 and about 10. Preferably, the pH is between about 6 and about 10.

[0060] In one embodiment, the disclosed and claimed etching formulations have a pH of about 5. In one embodiment, the disclosed and claimed etching formulations have a pH of about 6. In one embodiment, the disclosed and claimed etching formulations have a pH of about 7. In one embodiment, the disclosed and claimed etching formulations have a pH of about 8. In one embodiment, the disclosed and claimed etching formulations have a pH of about 9. In one embodiment, the disclosed and claimed etching formulations have a pH of about 10. In one embodiment, the disclosed and claimed etching formulations have a pH of about 11. In one embodiment, the disclosed and claimed etching formulations have a pH of about 12. In one embodiment, the disclosed and claimed etching formulations have a pH of about 13. In one embodiment, the disclosed and claimed etching formulations have a pH of about 14.

[0061] Exemplary Embodiments of Formulations

[0062] The following are exemplary embodiments of formulations that selectively etch TiN layer over tungsten (W), which include:

(a) at least one quaternary ammonium hydroxide compound without alkanol chains;

(b) at least one oxidizing agent;

(c) at least one oxidizing stabilizer;

(d) at least one non-azole corrosion inhibitor; and

(e) at least one solvent. It is to be understood that the disclosed and claimed subject matter is not limited to these exemplary embodiments of the formulations.

[0063] In one aspect of the above embodiment, the composition includes, consists essentially of or consists of one quaternary ammonium hydroxide compound without alkanol chains, one oxidizing agent, one stabilizer and one non-azole corrosion inhibitor and water.

[0064] In one aspect of the above embodiment, the composition includes, consists essentially of or consists of one quaternary ammonium hydroxide compound without alkanol chains, one oxidizing agent, one stabilizer and more than one non-azole corrosion inhibitor and water.

[0065] In one aspect of the above embodiment, the composition includes, consists essentially of or consists of one quaternary ammonium hydroxide compound without alkanol chains, one oxidizing agent, one stabilizer, more than one non-azole corrosion inhibitor and water and is free of ammonium salts.

[0066] In one aspect of the above embodiment, the composition includes, consists essentially of or consists of one quaternary ammonium hydroxide compound without alkanol chains, one oxidizing agent, one stabilizer, more than one non-azole corrosion inhibitor and water and is free of alkanolamine.

[0067] In one aspect of the above embodiment, the composition includes, consists essentially of or consists of:

(a) at least one quaternary ammonium hydroxide compound without alkanol chains that includes, consists essentially of or consists of at least one of neat TEAH and neat DMDPAH;

(b) at least one oxidizing agent that includes, consists essentially of or consists of neat hydrogen peroxide;

(c) at least one oxidizing stabilizer that includes, consists essentially of or consists of neat EDTA;

(d) at least one non-azole corrosion inhibitor that includes, consists essentially of or consists of at least one of neat phosphoric acid, neat oxalic acid, neat citric acid, neat diallyldimethylammonium chloride, neat histidine, neat etidronic acid and neat polyethyleneimine; and

(e) at least one solvent that includes, consists essentially of or consists of water.

[0068] In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of neat TEAH.

[0069] In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes neat DMDPAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of neat DMDPAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of neat DMDPAH.

[0070] In one aspect of the above embodiment, the (b) at least one oxidizing agent includes neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists essentially of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists of neat hydrogen peroxide. [0071] In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer includes neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists essentially of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists of neat EDTA.

[0072] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of neat phosphoric acid.

[0073] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of neat oxalic acid.

[0074] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes neat citric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of neat citric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of neat citric acid.

[0075] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of neat diallyldimethylammonium chloride.

[0076] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of neat histidine.

[0077] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes neat etidronic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of neat etidronic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of neat etidronic acid.

[0078] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of neat polyethyleneimine.

[0079] In one aspect of the above embodiment, the (e) at least one solvent includes water. In one aspect of the above embodiment, the (e) at least one solvent consists essentially of water. In one aspect of the above embodiment, the (e) at least one solvent consists of water. [0080] In another aspect of the above embodiment, the composition includes, consists essentially of or consists of:

(a) about 0.25 wt% to about 2.0 wt% of at least one quaternary ammonium hydroxide compound without alkanol chains that includes, consists essentially of or consists of at least one of neat TEAH and neat DMDPAH;

(b) about 7.5 wt% to about 15 wt% of at least one oxidizing agent that includes, consists essentially of or consists of neat hydrogen peroxide;

(c) about 0.001 wt % to about 0.2 wt % of at least one oxidizing stabilizer that includes, consists essentially of or consists of neat EDTA;

(d) about 0.05 wt% to about 5.0 wt% of at least one non-azole corrosion inhibitor that includes, consists essentially of or consists of at least one of neat phosphoric acid, neat oxalic acid, neat citric acid, neat diallyldimethylammonium chloride, neat histidine, neat etidronic acid and neat polyethyleneimine; and

(e) a balance of at least one solvent that includes, consists essentially of or consists of water. [0081] In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 0.25 wt% to about 1.75 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of about 0.25 wt% to about 1.75 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of about 0.25 wt% to about 1.75 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 0.35 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of about 0.35 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of about 0.35 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 0.55 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of about 0.55 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of about 0.55 wt% neat TEAH.

[0082] In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 1.15 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of about 1.15 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of about 1.15 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 1.28 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of about 1.28 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of about 1.28 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 1.35 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of about 1.35 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of about 1.35 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 1.55 wt% of neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of about 1.55 wt% neat TEAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of about 1.55 wt% neat TEAH.

[0083] In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 1.0 wt% to about 1.50 wt% of neat DMDPAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of 1.0 wt% to about 1.50 wt% of neat DMDPAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of 1.0 wt% to about 1.50 wt% of neat DMDPAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains includes about 1.25 wt% of neat DMDPAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists essentially of about 1.25 wt% of neat DMDPAH. In one aspect of the above embodiment, the (a) at least one quaternary ammonium hydroxide compound without alkanol chains consists of about 1.25 wt% of neat DMDPAH.

[0084] In one aspect of the above embodiment, the (b) at least one oxidizing agent includes about 7.5 wt% to about 15 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists essentially of about 7.5 wt% to about 15 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists of about 7.5 wt% to about 15 wt% neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent includes about 9.0 wt% to about 13.5 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists essentially of about 9.0 wt% to about 13.5 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists of about 9.0 wt% to about 13.5 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent includes about 9.0 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists essentially of about 9.0 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists of about 9.0 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent includes about 13.5 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists essentially of about 13.5 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists of about 13.5 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent includes about 15 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists essentially of about 15 wt% of neat hydrogen peroxide. In one aspect of the above embodiment, the (b) at least one oxidizing agent consists of about 15 wt% of neat hydrogen peroxide.

[0085] In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer includes about 0.001 wt% to about 0.1 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists essentially of about 0.001 wt% to about 0.1 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists of about 0.001 wt% to about 0.1 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer includes about 0.001 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists essentially of about 0.001 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists of about 0.001 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer includes about 0.01 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists essentially of about 0.01 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists of about 0.01 of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer includes about 0.02 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists essentially of about 0.02 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists of about 0.02 of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer includes about 0.1 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists essentially of about 0.1 wt% of neat EDTA. In one aspect of the above embodiment, the (c) at least one oxidizing stabilizer consists of about 0.1 wt% of neat EDTA. [0086] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.025 wt% to about 0.25 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.025 wt% to about 0.25 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.025 wt% to about 0.25 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.04 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.04 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.04 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.11 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.11 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.11 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.21 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.21 wt% of neat phosphoric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.21 wt% of neat phosphoric acid.

[0087] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.08 wt% to about 0.25 wt% of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.08 wt% to about 0.25 wt% of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.08 wt% to about 0.25 wt% of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.08 wt% of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.08 wt% of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.08 wt% of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.25 wt% of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.25 wt% of neat oxalic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.25 wt% of neat oxalic acid.

[0088] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.5 wt% of neat citric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.5 wt% of neat citric acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.5 wt% of neat citric acid.

[0089] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.015 wt% to about 0.4 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.015 wt% to about 0.4 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.015 wt% to about 0.4 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.0175 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.0175 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.0175 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.0525 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.0525 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.0525 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.175 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.175 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.175 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.35 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.35 wt% of neat diallyldimethylammonium chloride. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.35 wt% of neat diallyldimethylammonium chloride.

[0090] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.25 wt% to about 1.0 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.25 wt% to about 1.0 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.25 wt% to about 1.0 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.25 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.25 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.25 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.5 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.5 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.5 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.75 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.75 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.75 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 1.0 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 1.0 wt% of neat histidine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 1.0 wt% of neat histidine.

[0091] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.15 wt% of neat etidronic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.15 wt% of neat etidronic acid. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.15 wt% of neat etidronic acid.

[0092] In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.005 wt% to about 0.06 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists essentially of about 0.005 wt% to about 0.06 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.005 wt% to about 0.06 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.005 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non- azole corrosion inhibitor consists essentially of about 0.005 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.005 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.02 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non- azole corrosion inhibitor consists essentially of about 0.02 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.02 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor includes about 0.06 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non- azole corrosion inhibitor consists essentially of about 0.06 wt% of neat polyethyleneimine. In one aspect of the above embodiment, the (d) at least one non-azole corrosion inhibitor consists of about 0.06 wt% of neat polyethyleneimine.

[0093] In one aspect of the above embodiment, the (e) at least one solvent includes water. In one aspect of the above embodiment, the (e) at least one solvent consists essentially of water. In one aspect of the above embodiment, the (e) at least one solvent consists of water. [0094] In another embodiment, the etching composition includes, consists essentially of or consists of:

(a) TEAH;

(b) H2O2;

(c) EDTA;

(d) etidronic acid and polyethyleneimine; and

(e) H₂O.

In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 1.15 wt% of neat TEAH; (b) about 13.5 wt% of neat H2O2; (c) about 0.1 wt% of neat EDTA; (d) about 0.15 wt% of neat etidronic acid and about 0.06 wt% of neat polyethyleneimine; and (e) a balance of H2O. [0095] In one embodiment, the etching composition includes, consists essentially of or consists of:

(a) TEAH;

(b) H2O2;

(c) EDTA;

(d) citric acid and diallyldimethylammonium chloride; and

(e) H₂O.

In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 1.28 wt% of neat TEAH; (b) about 13.5 wt% of neat H2O2; (c) about 0.02 wt% of neat EDTA; (d) about 0.05 wt% of neat citric acid and about 0.0175 wt% of neat diallyldimethylammonium chloride; and (e) a balance of H2O. In another aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 1.28 wt% of neat TEAH; (b) about 13.5 wt% of neat H2O2; (c) about 0.02 wt% of neat EDTA; (d) about 0.05 wt% of neat citric acid and about 0.0525 wt% of neat diallyldimethylammonium chloride; and (e) a balance of H2O.

[0096] In one embodiment, the etching composition includes, consists essentially of or consists of:

(a) DMDPAH;

(b) H2O2;

(c) EDTA;

(d) citric acid, histidine and diallyldimethylammonium chloride; and

(e) H₂O.

In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 1.25 wt% of neat DMDPAH; (b) about 13.5 wt% of neat H2O2; (c) about 0.02 wt% of neat EDTA; (d) about 0.5 wt% of neat citric acid, about 0.5 wt% of neat histidine and about 0.35 wt% of neat diallyldimethylammonium chloride; and (e) a balance of H2O. [0097] In one embodiment, the etching composition includes, consists essentially of or consists of:

(a) TEAH;

(b) H2O2;

(c) EDTA;

(d) histidine; and

(e) H₂O. In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 1.55 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.25 wt% of neat histidine; and (e) a balance of H2O. In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 1.55 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine; and (e) a balance of H2O. In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 1.55 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.75 wt% of neat histidine; and (e) a balance of H2O. In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 1.55 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 1.0 wt% of neat histidine; and (e) a balance of H2O. [0098] In one embodiment, the etching composition includes, consists essentially of or consists of:

(a) TEAH;

(b) H2O2;

(c) EDTA;

(d) histidine and H3PO4; and

(e) H₂O.

In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 0.54 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine and about 0.21 wt% of neat H3PO4; and (e) a balance of H2O.

[0099] In one embodiment, the etching composition includes, consists essentially of or consists of:

(a) TEAH;

(b) H2O2;

(c) EDTA;

(d) histidine and oxalic acid; and

(e) H₂O.

In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 0.54 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine and about 0.08 wt% of neat oxalic acid; and (e) a balance of H2O. [0100] In one embodiment, the etching composition includes, consists essentially of or consists of:

(a) TEAH;

(b) H2O2;

(c) EDTA;

(d) histidine; and

(e) H₂O.

In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 0.35 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.01 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine; and (e) a balance of H2O. In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 0.54 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine; and (e) a balance of H2O. In one aspect of this embodiment, the etching composition includes, consists essentially of or consists of: (a) about 0.71 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.01 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine; and (e) a balance of H2O.

[0101] Methods of Manufacture

[0102] The disclosed and claimed subject matter further includes method of manufacturing the disclosed and claimed etching formulations.

[0103] In one embodiment, the method for forming the etching composition includes combining:

(a) at least one quaternary ammonium hydroxide compound without alkanol chains;

(b) at least one oxidizing agent;

(c) at least one oxidizing stabilizer;

(d) at least one non-azole corrosion inhibitor; and

(e) at least one solvent.

[0104] In another embodiment, the etching formulations are prepared by combining the elements identified above except the oxidizing agent to form a “pre-diluted composition” wherein only a portion of a desired amount of the at least one solvent is used. The pre-diluted composition is then diluted with the remaining portion of the desired amount of the at least one solvent de-ionized (e.g., water) to form a “diluted composition.” Thereafter, prior to use, the diluted composition is mixed with the oxidizing agent. In one embodiment, the pre-diluted composition is diluted with the at least one solvent de-ionized (e.g., water) at a weight ratio of about 100: 1 to about 1 : 100 to form the diluted composition. In one embodiment, the pre-diluted composition is diluted with the at least one solvent deionized (e.g., water) at a weight ratio of about 20: 1 to about 1 :20 to form the diluted composition. In one embodiment, the pre-diluted composition is diluted with the at least one solvent de-ionized (e.g., water) at a weight ratio of about 1 : 1 to about 1 : 10 to form the diluted composition. In one embodiment, the diluted composition is mixed with the oxidizing agent at a weight ratio of diluted composition to oxidizing agent of about 99: 1 to about 10:90. In one embodiment, the diluted composition is mixed with the oxidizing agent at a weight ratio of diluted composition to oxidizing agent of about 99: 1. In one embodiment, the diluted composition is mixed with the oxidizing agent at a weight ratio of diluted composition to oxidizing agent of about 10:90. In one embodiment, the diluted composition is mixed with the oxidizing agent at a weight ratio of diluted composition to oxidizing agent of about 80:20 to about 20:80. In one embodiment, the diluted composition is mixed with the oxidizing agent at a weight ratio of diluted composition to oxidizing agent of about 80:20. In one embodiment, the diluted composition is mixed with the oxidizing agent at a weight ratio of diluted composition to oxidizing agent of about 20:80.

[0105] In another embodiment, the method for forming the etching composition includes the steps of:

(ia) forming a diluted composition by combining (a) at least one quaternary ammonium hydroxide without alkanol chains, (c) at least one oxidizing stabilizer; (d) at least one non-azole corrosion inhibitor and (e) at least one solvent;

(ib) combining the diluted composition with (b) at least one oxidizing agent. In one aspect of this embodiment, the (e) at least one solvent includes water. In one aspect of this embodiment, the (e) at least one solvent consists essentially of water. In one aspect of this embodiment, the (e) at least one solvent consists of water.

[0106] Thus, in one embodiment, the method for forming the etching composition includes the steps of:

(i) forming a pre-diluted composition by combining (a) at least one quaternary ammonium hydroxide without alkanol chains, (c) at least one oxidizing stabilizer and (d) at least one non-azole corrosion inhibitor;

(ii) forming a diluted composition by combining the prediluted composition with (e) at least one solvent; and

(iii) combining the diluted composition with (b) at least one oxidizing agent. In one aspect of this embodiment, the (e) at least one solvent includes water. In one aspect of this embodiment, the (e) at least one solvent consists essentially of water. In one aspect of this embodiment, the (e) at least one solvent consists of water.

[0107] Methods of Use

[0108] The disclosed and claimed subject matter further includes a method of using the disclosed and claimed etching compositions to selectively remove a TiN layer while minimizing the etch rate of W layer and to a method for fabricating a semiconductor, which includes an etching process employing the disclosed and claimed etching compositions. The wafer device may then be exposed to the diluted composition and oxidizing agent mixture for a desired amount of time, at a desired temperature. Subsequently, the wafer device is removed from the mixture, rinsed in de-ionized water, and dried by exposure to nitrogen gas. [0109] In one embodiment, the method includes the steps of: a. contacting the composite semiconductor device including TiN layer and W layer film with one or more of the etching compositions disclosed and claimed herein; and b. rinsing the composite semiconductor device after the TiN layer is at least partially removed.

In as further aspect of this embodiment, the contacting step is performed at a temperature of about 25 °C to about 90 °C.

[0110] In a further embodiment, the method can include c. a drying step.

[oni] In the described methods, “at least partially removed” means removal of at least 90% of the material, preferably at least 95% removal. Most preferably, at least 99% removal using the compositions of the present development.

[0112] In some embodiments, the contacting step can be carried out by any suitable means such as, for example, immersion, spray, or via a single wafer process.

[0113] In some embodiments, the temperature of the composition during the contacting step is preferably from about 25 °C to about 90 °C. In a further aspect, the temperature is about 30 °C to about 60 °C. In a further aspect, the temperature is about 40 °C to about 60 °C In a further aspect, the temperature of the composition during the contacting step is about 50 °C.

[0114] In some embodiments, the etch selectivity of TiN over W of the disclosed and claimed subject etch compositions is above about 1. In some embodiments, the etch selectivity of TiN over We of the disclosed and claimed subject etch compositions is above about 5. In some embodiments, the etch selectivity of TiN over W of the disclosed and claimed subject etch compositions is above about 10. In some embodiments, the etch selectivity of TiN over W of the disclosed and claimed subject etch compositions is above about 20. In some embodiments, the etch selectivity of TiN over W of the disclosed and claimed subject etch compositions is above about 50. In some embodiments, the etch selectivity of TiN over W of the disclosed and claimed subject etch compositions is above about 100.

[0115] In some embodiments, the W etch is less than about 5 A/min. In a further aspect the W etch is less than about 3 A/min. In a further aspect, the W etch is less than about 1 A/min.

[0116] In some embodiments, the rinsing step c. is carried out by any suitable means, for example, rinsing the substrate with de-ionized water by immersion or spray techniques. In another aspect, the rinsing step is carried out employing a mixture of deionized water and a water-miscible organic solvent such as, for example, isopropyl alcohol. [0117] In some embodiments, the drying step is carried out by any suitable means, for example, isopropyl alcohol (IP A) vapor drying, heat, or by centripetal force.

[0118] It is contemplated that the disclosed and claimed formulations are used in a “drain mode” process, in which the cleaning composition is used once, then is removed from the system by being directed to waste. Optionally, the cleaning compositions described herein may be utilized in a circulation mode system, where after use on a wafer or device, the composition is recycled for treatment of additional wafers or devices. In a circulation mode system, the components of the cleaning composition other than the solvent and oxidant are preferably provided in higher concentrations than is needed in a drain mode system.

EXAMPLES

[0119] Reference will now be made to more specific embodiments of the present disclosure and experimental results that provide support for such embodiments. The examples are given below to more fully illustrate the disclosed subject matter and should not be construed as limiting the disclosed subject matter in any way.

[0120] It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed subject matter and specific examples provided herein without departing from the spirit or scope of the disclosed subject matter. Thus, it is intended that the disclosed subject matter, including the descriptions provided by the following examples, covers the modifications and variations of the disclosed subject matter that come within the scope of any claims and their equivalents.

[0121] Materials and Methods:

[0122] All ingredients used herein are commercially available.

[0123] All compositions which are the subject of the present examples were prepared by mixing the components in a 100 mL beaker with a 1” Teflon-coated stir bar. Typically, the first material added to the beaker was deionized (DI) water (only in a portion of a desired amount). Other components were then added to dissolve in water to make the compositions.

[0124] The etch solutions were prepared from the compositions by diluting the composition with the remaining amount of the desired amount of water and then mixing with 30% hydrogen peroxide solution. The dilution ratio between the compositions and water could be range from 1 : 1 to 1 : 100. If no specific described, the dilution was made by mixing 10 parts of pre-diluted solutions with 90 parts of water. The hydrogen peroxide concentration could be between 1.5% to 27% neat.

[0125] Etching tests were run using 100 g of the etching compositions in a 150 mL beaker with a 1” round Teflon stir bar set at 400 rpm. The etching compositions were heated to a temperature of 30-60 °C on a hot plate and then 2 cm x 2 cm wafer coupons were immersed in the solutions for processing time between 0.5 minutes to 10 minutes. The wafer coupons were then rinsed for 3 minutes in a DI water bath and subsequently dried using nitrogen gas. The TiN rates were estimated from changes in the thickness before and after etching and was measured by spectroscopic ellipsometry (SCI Filmtek 2000 PAR-SE). The W rates were estimated from changes in the thickness before and after etching and was measured by CDE 4-probe Resmap. Typical starting layer thickness was 1000 A for W and 300 A for TiN.

[0126] The following series of tables show the evaluation of several aspects of the compositions evaluated.

[0127] Table 1 shows the effect of different inhibitors on W etch rates. The initial compositions were first prepared with 10% neat tetraethyl ammonium hydroxide (TEAH) and 0.01% ethylenediaminetetraacetic acid (EDTA) with different inhibitors. Then 10 parts of the initial pre-diluted compositions were then diluted with 60 parts of water and mixed with 30 parts of 30% of hydrogen peroxide solution. The neat component concentration in final compositions contained 3% TEAH, 0.01% EDTA and 9% H2O2 with less than 0.5% of different inhibitors. W etch rates were measured at 40 °C with processing time 5 minutes.

Table 1 Effect of Different Inhibitors on W Etch Rates

[0128] From Table 1, among those inhibitors, histidine, etidronic acid, nitrilotris(methylene)) triphosphonic acid, 2-aminopyrimidine, polyethyleneimines, octyl phosphonic acid, pyrazole, and 3-amino-l,2,4-triazole showed obvious W etch inhibition, with histidine and polyethyleneimine exhibiting the greatest W etch inhibition.

[0129] Table 2 shows the effect of the inhibitor polyethyleneimine concentration on W etch rates at 40 °C. The concentrations shown in Table 2 are neat component concentrations in the composition made from 55 parts of the pre-diluted compositions mixed with 45 parts of 30% H2O2. Table 2 shows that increasing the polyethyleneimine concentration correlates with a significant decrease in W etch rates.

Table 2 Polyethyleneimine Concentration Effect on W Etch Rate

[0130] Table 3 shows the effect of the inhibitor diallyl dimethylammonium chloride concentration on W etch rates at 40 °C. The concentrations shown in Table 3 are neat component concentrations in the composition made from 55 parts of the pre-diluted compositions mixed with 45 parts of 30% H2O2. Table 3 shows that increasing the diallyldimethylammonium chloride concentration correlates with a significant decrease in W etch rates.

Table 3 Diallyldimethylammonium Chloride Concentration Effect on W Etch Rate

[0131] Table 4 shows the effect of different quaternary ammonium hydroxide compounds without alkanol chains on W and TiN etch rates at 40 °C. The concentrations shown in Table 4 are already the neat component concentrations in the composition made from 55 parts of the pre-diluted compositions mixed with 45 parts of 30% H2O2. From the results, TEAH and DMDPAH as etchants showed similar inhibition effect on W etching while BTMAH showed slightly higher W etch rates. Choline hydroxide clearly showed much higher W etch rate among all the etchant agents used. However, there was no obvious change in TiN etch rates. The TiN etch selectivity was significantly related to W etch rates.

Table 4 Effect of Different Quaternary Ammonium Hydroxide Compounds Without Alkanol Chains on W and TiN Etch Rates at 40 °C

[0132] Table 5 shows the effect of the inhibitor histidine concentration on W etch rates at 40 °C. The concentrations shown in Table 5 are already the neat component concentrations in the composition made from 70 parts of the pre-diluted compositions mixed with 30 parts of 30% H2O2. Table 5 showed with increase in histidine concentration, W etch rates decreased significantly while TiN etch rates did not.

Table 5 Histidine Concentration Effect on W and TiN etch rates

[0133] Table 6 shows the effect of different acids on the etch rates of W and TiN at

40 °C. The concentrations shown in Table 6 are already the neat component concentrations in the composition made from 70 parts of the pre-diluted compositions mixed with 30 parts of 30% H2O2. Table 6 shows that compared to histidine alone, the addition of phosphoric acid could decrease W etch rates and the selectivity of TiN/W was also increased while use of oxalic acid and gluconic acid could further decrease W etch rates. The addition of gluconic acid further decreased W etch rates. For oxalic acid, lower oxalic acid concentration decreased both W and TiN etch rates. At higher oxalic acid concentration, W etch rate slightly increased while TiN etch rate increased more obviously and there for TiN/W selectivity was increased.

Table 6 Effect of Different Acids on W and TiN Etch Rates

[0134] Table 7 shows the effect of alkanolamine and ammonium salt on TiN and W etch rates at 40 °C. The concentrations shown in Table 7 are already the neat component concentrations in the composition made from 70 parts of the pre-diluted compositions mixed with 30 parts of 30% H2O2. Table 7 also shows addition of triammonium citrate and alkanolamine could significantly increase W etch rates and therefore lower TiN/W selectivity.

Table 7 Effect of Alkanolamine and Ammonium Salt on TiN and W Etch Rates

[0135] Table 8 shows the effect of TEAH concentration on TiN and W etch rates at 40 °C. The concentrations shown in Table 8 are already the neat component concentrations in the composition made from 70 parts of the pre-diluted compositions mixed with 30 parts of 30% H2O2. Table 8 also shows higher TEAH concentration increased W and TiN etch rates but lower TiN/W selectivity.

Table 8 Effect of TEAH Concentration on W and TiN Etch Rate

[0136] Table 9 shows the component concentrations in the pre-diluted composition 19. Table 10 shows the TiN and W etch rates in solutions containing 9% H2O2 and the different concentration of the pre-diluted composition 19 diluted with water. W etch rates were gradually decreased with increase in composition concentration at above 50 °C while no obvious change in TiN etch rates. At the same composition concentration, TiN and W etch rates were increased obviously and W etch rates were increased more significantly than TiN.

Table 9 Component Concentrations in the Pre-Diluted Composition

Table 10 Effect of Composition Concentrations on TiN and W Etch Rates

[0137] Table 11 shows the TiN and W etch rates in solutions made from mixing with different hydrogen peroxide concentration and 5% of the pre-diluted composition 19 in water. With increase in H2O2 concentration, both TiN and W etch rates were increased obviously. Higher processing temperatures resulted in much higher W etch rates than TiN etch rates, and therefore lower TiN/W etch selectivity.

Table 11 Hydrogen Peroxide Concentration Effect on TiN and W Etch Rates

[0138] The foregoing examples and description of the preferred embodiments should be taken as illustrating, rather than as limiting the disclosed and claimed subject matter as defined by the claims. As will be readily appreciated, numerous variations and combinations of the features set forth above can be utilized without departing from the disclosed and claimed subject matter as set forth in the claims. Such variations are not regarded as a departure from the spirit and scope of the disclosed and claimed subject matter, and all such variations are intended to be included within the scope of the following claims.

Claims

CLAIMS What is claimed is:

1. An etching formulation comprising:

(a) at least one quaternary ammonium hydroxide compound without alkanol chains;

(b) at least one oxidizing agent;

(c) at least one oxidizing stabilizer;

(d) at least one non-azole corrosion inhibitor; and

(e) at least one solvent.

2. The etching formulation of claim 1, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains has the structure:

wherein each of R¹, R², R³ and R⁴ is independently selected from an unsubstituted Ci-Ce alkyl group, a branched C3-C6 alkyl group, an unsubstituted benzyl group, a benzyl group substituted with one or more Ci-Ce alkyl groups, an unsubstituted phenyl group and a phenyl group substituted with one or more Ci-Ce alkyl groups.

3. The etching formulation of claim 2, wherein one or more of R¹, R², R³ and R⁴ is a benzyl group.

4. The etching formulation of claim 2, wherein one or more of R¹, R², R³ and R⁴ is a phenyl group.

5. The etching formulation of claim 2, wherein three of R¹, R², R³ and R⁴ are a methyl group and the other of R¹, R², R³ and R⁴ is a phenyl group.

6. The etching formulation of claim 1, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises one or more of tetraethylammonium hydroxide (TEAH), trimethylphenylammonium hydroxide (TMPAH), tetramethylammonium hydroxide (TMAH), ethyltrimethylammonium hydroxide (ETMAH), diethyldimethylammonium hydroxide (DEDMAH), methyltriethylammonium hydroxide (MTEAH), tetrapropylammonium hydroxide (TP AH), tetrabutylammonium hydroxide (TBAH), benzyltri ethyl ammonium hydroxide (BTEAH), dimethyldipropylammonium hydroxide (DMDPAH), and benzyltrimethylammonium hydroxide (BTMAH).

7. The etching formulation of claim 1, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises tetraethylammonium hydroxide (TEAH).

8. The etching formulation of claim 1, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises dimethyldipropylammonium hydroxide (DMDPAH).

9. The etching formulation of claim 1, wherein the (b) at least one oxidizing agent comprises one or more of hydrogen peroxide, ammonium persulfate, peracetic acid, peroxybenzoic acid, oxone (2KHSO5.KHSO4.K2SO4), n-methylmorpholine oxide(NMMO or NMO), benzoyl peroxide, tetrabutylammonium peroxymonosulfate, ferric chloride, permanganate peroxoborate, periodic acid, iodic acid, vanadium (V) oxide, vanadium(IV, V) oxide, ammonium vanadate, perchlorate, persulfate, ammonium peroxy di sulfate, per acetic acid, urea hydroperoxide, nitric acid (HNO3), ammonium hypochlorite (NEUCIO), ammonium tungstate ((NH4)IOH2(W20?)), ammonium chlorite (NH4CIO2), ammonium chlorate (NH4CIO3), ammonium iodate (NH4IO3), ammonium perborate (NH4BO3), ammonium perchlorate (NH4CIO4), ammonium periodate (NH4IO3), ammonium persulfate ((NH4)2S20S), tetramethylammonium chlorite ((N(CH3)4)CIO2), tetramethylammionium chlorate ((N(CH3)4)CIO3), tetramethylammonium iodate ((N(CH3)4)IO3), tetramethylammonium perborate ((N(CH3)4)BO3), tetramethylammonium perchlorate ((N(CH₃)4)CIO₄), tetramethylammonium periodate ((N(CH3)4)IO4), tetramethylammonium persulfate ((N(CH3)4)S20s), ((COlNEb^EbC ), and peracetic acid (CH(CO)OOH).

10. The etching formulation of claim 1, wherein the (b) at least one oxidizing agent comprises hydrogen peroxide.

11. The etching formulation of claim 1, wherein the (c) at least one oxidizing stabilizer comprises a metal chelating agent.

12. The etching formulation of claim 1, wherein the (c) at least one oxidizing stabilizer comprises one or more of nitrilotriacetic acid, ethylenediaminetetraacetic acid (EDTA), (l,2-cyclohexylenedinitrilo)tetraacetic acid (CDTA), uric acid, tetraglyme, diethylenetriamine pentaacetic acid, propylenediamine tetraacetic acid, ethylendiamine disuccinic acid, sulfanilamide, l,4,7,10-tetraazacyclododecane-l,4,7,10 tetraacetic acid; ethylene glycol tetraacetic acid (EGTA), 1.2-bis(o-aminophenoxy)ethane-N,N,N',N'- tetraacetic acid, N-2-bis(carboxymethyl)aminoethyl-N-(2-hydroxy ethyl)glycine (HEDTA), and ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid) (EDDHA), 1,3- diaminopropane-N,N,N’,N’ -tetraacetic acid, N,N,N',N'- ethylenediaminetetrakis(methylenephosphonic acid), nitrilotris(methylene)triphosphonic acid, 3,4-dihydroxybenzoic acid, 8-HQ, N-(2-hydroxyethyl)ethylenediamine-N,N',N'- triacetic acid, l,3-propanediamine-N,N,N',N' -tetraacetic acid, and cystine.

13. The etching formulation of claim 1, wherein the (c) at least one oxidizing stabilizer comprises ethylenedi aminetetraacetic acid (EDTA).

14. The etching formulation of claim 1, wherein the (d) at least one non-azole corrosion inhibitor one or more of polyethylene glycol MW 400 (PEG400), poly(propylene glycol), surfynol-485, diallyldimethylammonium chloride, hexadecyltrimethylammonium bromide, polyethyleneimines L-histidine, 2-aminopyrimidine, tryptophan, phosphoric acid, octyl phosphonic acid, gluconic acid, triammonium citrate (TAC), citric acid, glycine, picolinic acid, etidronic acid, sebacic acid, salicylic acid, benzenesulfonic acid, benzoic acid, lactic acid, oxalic acid, methionine, nitrilotris(methylene)) triphosphonic acid, malonic acid, adipic acid, acetic acid, iminodiacetic acid and combinations thereof.

15. The etching formulation of claim 1, wherein the (e) at least one solvent comprises one or more of water, dimethyl sufoxide (DMSO), dimethyl sulfone (DMSO2), sulfolane ((CEE^SCh), n-methylpyrrolidone, dipropyleneglycolmethylether, tripropyleneglycolmethyl ether and propylene glycol.

16. The etching formulation of claim 1, wherein the (e) at least one solvent comprises water.

17. The etching formulation of claim 1, wherein the (e) at least one solvent comprises a non-aqueous solvent.

18. The etching formulation of claim 1, wherein the (e) at least one solvent comprises water and at least one non-aqueous solvent.

19. The etching formulation of claim 1, further comprising (f) one or more azole corrosion inhibitor.

20. The etching formulation of claim 1, wherein the formulation has a pH of between about 5 and about 14.

21. The etching formulation of claim 1, wherein the formulation has a pH of between about 6 and about 10.

22. The etching formulation of claim 1, wherein the formulation comprises:

(a) the at least one quaternary ammonium hydroxide compound without alkanol chains comprising at least one of neat TEAH and neat DMDPAH;

(b) the at least one oxidizing agent comprises neat hydrogen peroxide;

(c) the at least one oxidizing stabilizer comprises neat EDTA; (d) the at least one non-azole corrosion inhibitor comprises at least one of neat phosphoric acid, neat oxalic acid, neat citric acid, neat diallyldimethylammonium chloride, neat histidine, neat etidronic acid and neat polyethyleneimine; and

(e) the at least one solvent comprises water.

23. The etching formulation of claim 22, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises neat TEAH.

24. The etching formulation of claim 22, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises neat DMDPAH.

25. The etching formulation of claim 22, wherein the (b) at least one oxidizing agent consists of neat hydrogen peroxide.

26. The etching formulation of claim 22, wherein the (c) at least one oxidizing stabilizer consists of neat EDTA.

27. The etching formulation of claim 22, wherein the (d) at least one non-azole corrosion inhibitor comprises neat phosphoric acid.

28. The etching formulation of claim 22, wherein the (d) at least one non-azole corrosion inhibitor comprises neat oxalic acid.

29. The etching formulation of claim 22, wherein the (d) at least one non-azole corrosion inhibitor comprises neat citric acid.

30. The etching formulation of claim 22, wherein the (d) at least one non-azole corrosion inhibitor comprises neat diallyldimethylammonium chloride.

31. The etching formulation of claim 22, wherein the (d) at least one non-azole corrosion inhibitor comprises neat histidine.

32. The etching formulation of claim 22, wherein the (d) at least one non-azole corrosion inhibitor comprises neat etidronic acid.

33. The etching formulation of claim 22, wherein the (d) at least one non-azole corrosion inhibitor comprises neat polyethyleneimine.

34. The etching formulation of claim 22, wherein the (e) at least one solvent consists of water.

35. The etching formulation of claim 1, wherein the formulation comprises:

(a) about 0.25 wt% to about 2.0 wt% of the at least one quaternary ammonium hydroxide compound without alkanol chains comprises at least one of neat TEAH and neat DMDPAH;

(b) about 7.5 wt% to about 15 wt% of the at least one oxidizing agent comprises neat hydrogen peroxide; (c) about 0.001 wt % to about 0.2 wt % of the at least one oxidizing stabilizer comprises neat EDTA;

(d) about 0.05 wt% to about 5.0 wt% of the at least one non-azole corrosion inhibitor comprises at least one of neat phosphoric acid, neat oxalic acid, neat citric acid, neat diallyldimethylammonium chloride, neat histidine, neat etidronic acid and neat polyethyleneimine; and

(e) a balance of the at least one solvent that comprises water.

36. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 0.25 wt% to about 1.75 wt% of neat TEAH.

37. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 0.35 wt% of neat TEAH.

38. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 0.55 wt% of neat TEAH.

39. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 1.15 wt% of neat TEAH.

40. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 1.28 wt% of neat TEAH.

41. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 1.35 wt% of neat TEAH.

42. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 1.55 wt% of neat TEAH.

43. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 1.0 wt% to about 1.50 wt% of neat DMDPAH.

44. The etching formulation of claim 35, wherein the (a) at least one quaternary ammonium hydroxide compound without alkanol chains comprises about 1.25 wt% of neat DMDPAH.

45. The etching formulation of claim 35, wherein the (b) at least one oxidizing agent consists of about 7.5 wt% to about 15 wt% of neat hydrogen peroxide.

46. The etching formulation of claim 35, wherein the (b) at least one oxidizing agent comprises about 9.0 wt% to about 13.5 wt% of neat hydrogen peroxide.

47. The etching formulation of claim 35, wherein the (b) at least one oxidizing agent comprises about 9.0 wt% of neat hydrogen peroxide.

48. The etching formulation of claim 35, wherein the (b) at least one oxidizing agent comprises about 13.5 wt% of neat hydrogen peroxide.

49. The etching formulation of claim 35, wherein the (c) at least one oxidizing stabilizer comprises about 0.001 wt% to about 0.1 wt% of neat EDTA.

50. The etching formulation of claim 35, wherein the (c) at least one oxidizing stabilizer comprises about 0.001 wt% of neat EDTA.

51. The etching formulation of claim 35, wherein the (c) at least one oxidizing stabilizer comprises about 0.01 wt% of neat EDTA.

52. The etching formulation of claim 35, wherein the (c) at least one oxidizing stabilizer comprises about 0.02 wt% of neat EDTA.

53. The etching formulation of claim 35, wherein the (c) at least one oxidizing stabilizer comprises about 0.1 wt% of neat EDTA.

54. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.025 wt% to about 0.25 wt% of neat phosphoric acid.

55. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.04 wt% of neat phosphoric acid.

56. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.11 wt% of neat phosphoric acid.

57. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.21 wt% of neat phosphoric acid.

58. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.08 wt% to about 0.25 wt% of neat oxalic acid.

59. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.08 wt% of neat oxalic acid.

60. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.25 wt% of neat oxalic acid.

61. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.5 wt% of neat citric acid.

62. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.015 wt% to about 0.4 wt% of neat diallyldimethylammonium chloride.

63. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.0175 wt% of neat diallyldimethylammonium chloride.

64. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.0525 wt% of neat diallyldimethylammonium chloride.

65. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.175 wt% of neat diallyldimethylammonium chloride.

66. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.35 wt% of neat diallyldimethylammonium chloride.

67. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.25 wt% to about 1.0 wt% of neat histidine.

68. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.25 wt% of neat histidine.

69. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.5 wt% of neat histidine.

70. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.75 wt% of neat histidine.

71. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 1.0 wt% of neat histidine.

72. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.15 wt% of neat etidronic acid.

73. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.005 wt% to about 0.06 wt% of neat polyethyleneimine.

74. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.005 wt% of neat polyethyleneimine.

75. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.02 wt% of neat polyethyleneimine.

76. The etching formulation of claim 35, wherein the (d) at least one non-azole corrosion inhibitor comprises about 0.06 wt% of neat polyethyleneimine.

77. The etching formulation of claim 35, wherein the (e) at least one solvent consists of water.

78. The etching formulation of claim 1, wherein the formulation comprises: (a) TEAH; (b) H2O2; (c) EDTA; (d) etidronic acid and polyethyleneimine; and (e) H2O.

79. The etching formulation of claim 1, wherein the formulation comprises: (a) about 1.15 wt% of neat TEAH; (b) about 13.5 wt% of neatEbC ; (c) about 0.1 wt% of neatEDTA;

(d) about 0.15 wt% of neat etidronic acid and about 0.06 wt% of neat polyethyleneimine; and

(e) a balance of H2O.

80. The etching formulation of claim 1, wherein the formulation comprises: (a) TEAH; (b) H2O2; (c) EDTA; (d) citric acid and diallyldimethylammonium chloride; and (e) H2O.

81. The etching formulation of claim 1, wherein the formulation comprises: (a) about 1.28 wt% of neat TEAH; (b) about 13.5 wt% of neat H2O2; (c) about 0.02 wt% of neat EDTA; (d) about 0.05 wt% of neat citric acid and about 0.0175 wt% of neat diallyldimethylammonium chloride; and (e) a balance of H2O.

82. The etching formulation of claim 1, wherein the formulation comprises: (a) about 1.28 wt% of neat TEAH; (b) about 13.5 wt% of neat H2O2; (c) about 0.02 wt% of neat EDTA; (d) about 0.05 wt% of neat citric acid and about 0.0525 wt% of neat diallyldimethylammonium chloride; and (e) a balance of H2O.

83. The etching formulation of claim 1, wherein the formulation comprises: (a) DMDPAH; (b) H2O2; (c) EDTA; (d) citric acid, histidine and diallyldimethylammonium chloride; and (e) H2O.

84. The etching formulation of claim 1, wherein the formulation comprises: (a) about 1.25 wt% of neat DMDPAH; (b) about 13.5 wt% of neat H2O2; (c) about 0.02 wt% of neat EDTA; (d) about 0.5 wt% of neat citric acid, about 0.5 wt% of neat histidine and about 0.35 wt% of neat diallyldimethylammonium chloride; and (e) a balance of H2O.

85. The etching formulation of claim 1, wherein the formulation comprises: (a) TEAH; (b) H2O2; (c) EDTA; (d) histidine; and (e) H2O.

86. The etching formulation of claim 1, wherein the formulation comprises: (a) about

1.55 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.25 wt% of neat histidine; and (e) a balance of H2O.

87. The etching formulation of claim 1, wherein the formulation comprises: (a) about

1.55 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine; and (e) a balance of H2O.

88. The etching formulation of claim 1, wherein the formulation comprises: (a) about

1.55 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.75 wt% of neat histidine; and (e) a balance of H2O.

89. The etching formulation of claim 1, wherein the formulation comprises: (a) about 1.55 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 1.0 wt% of neat histidine; and (e) a balance of H2O.

90. The etching formulation of claim 1, wherein the formulation comprises: (a) TEAH; (b) H2O2; (c) EDTA; (d) histidine and H3PO4; and (e) H2O.

91. The etching formulation of claim 1, wherein the formulation comprises: (a) about 0.54 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine and about 0.21 wt% of neat H3PO4; and (e) a balance of H2O.

92. The etching formulation of claim 1, wherein the formulation comprises: (a) TEAH; (b) H2O2; (c) EDTA; (d) histidine and oxalic acid; and (e) H2O.

93. The etching formulation of claim 1, wherein the formulation comprises: (a) about 0.54 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine and about 0.08 wt% of neat oxalic acid; and (e) a balance of H2O.

94. The etching formulation of claim 1, wherein the formulation consists essentially of: (a) TEAH; (b) H₂O₂; (c) EDTA; (d) histidine; and (e) H₂O.

95. The etching formulation of claim 1, wherein the formulation comprises: (a) about 0.35 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.01 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine; and (e) a balance of H2O.

96. The etching formulation of claim 1, wherein the formulation comprises: (a) about 0.54 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.001 wt% of neat EDTA; (d) about 0.5 wt% of neat histidine; and (e) a balance of H2O.

97. The etching formulation of claim 1, wherein the formulation comprises: (a) about 0.71 wt% of neat TEAH; (b) about 9.0 wt% of neat H2O2; (c) about 0.01 wt% of neat EDTA;

(d) about 0.5 wt% of neat histidine; and (e) a balance of H2O.

98. A method of forming the etching composition of any of claims 1-97 comprising combining: the (a) at least one quaternary ammonium hydroxide compound without alkanol chains; the (b) at least one oxidizing agent; the (c) at least one oxidizing stabilizer; the (d) at least one non-azole corrosion inhibitor; and the (e) at least one solvent.

99. A method of forming the etching composition of any of claims 1-97 comprising the steps of: (ia) forming a diluted composition by combining the (a) at least one quaternary ammonium hydroxide without alkanol chains, the (c) at least one oxidizing stabilizer; the (d) at least one non-azole corrosion inhibitor and the (e) at least one solvent; and

(ib) combining the diluted composition with the (b) at least one oxidizing agent.

100. A method of forming the etching composition of any of claims 1-97 comprising the steps of:

(i) forming a pre-diluted composition by combining the (a) at least one quaternary ammonium hydroxide without alkanol chains, the (c) at least one oxidizing stabilizer and the (d) at least one non-azole corrosion inhibitor;

(ii) forming a diluted composition by combining the prediluted composition with the (e) at least one solvent; and

(iii) combining the diluted composition with the (b) at least one oxidizing agent.

101. A method of selectively enhancing the etch rate of titanium nitride (TiN) relative to tungsten (W) on a semiconductor substrate comprising titanium nitride (TiN) relative to tungsten (W), the method comprising the steps of: a. contacting the semiconductor substrate including TiN layer and W layer film with one or more of the etching formulations of any of claims 1-97; and b. rinsing the semiconductor substrate after the TiN layer is at least partially removed.

102. The method of claim 101, further comprising the step of drying the semiconductor substrate.

103. The method of claim 101, wherein the selectivity of the etch for titanium nitride (TiN) relative to tungsten (W) is over about 10.

104. The method of claim 101, wherein the selectivity of the etch for titanium nitride (TiN) relative to tungsten (W) is over about 50.

105. The method of claim 101, wherein the selectivity of the etch for titanium nitride (TiN) relative to tungsten (W) is over about 100.

106. The method of claim 101, wherein the tungsten (W) etch is about 5 A/min.

107. The method of claim 101, wherein the tungsten (W) etch is about 3 A/min.

108. The method of claim 101, wherein the tungsten (W) etch is about 1 A/min.