Lithography method using silicon photoresist

Abstract

A method of forming a pattern, the method comprising: providing a substrate in which a pattern is to be formed; forming a silicon photoresist (20) layer on the substrate; exposing a portion of the silicon photoresist to an activation radiation wavelength; curing the silicon photoresist (20); the cured silicon photoresist is developed to remove portions of the photoresist exposed to the activation radiation wavelength, and the substrate is etched to form the pattern.

Description

Technical Field

[0001] The present invention relates to photolithography for the manufacture of microelectronic products. Background Art

[0002] In photolithography, a photoresist is applied to a substrate including a layer in which a feature such as a line or a via is desired to be formed. The photoresist is exposed to an activating radiation wavelength, cured and developed to remove the uncured portion in an image-wise manner, leaving an image of the cured portion. Development can be performed by applying a developer solution to remove the uncured portion. Commonly used photoresists include hydrocarbon-based polymer materials. Hydrocarbon photoresists are usually applied (by spin coating) to a bare substrate, a thin organic bottom anti-reflective coating (BARC) or a thick organic BARC combined with a thin silicon BARC (sometimes referred to as a hard mask).

[0003] BARCs are desirable to reduce reflections of radiation from the substrate which can negatively impact the accuracy of the image formed.There remains a need for an improved method of forming patterns of lines or vias. Summary of the invention

[0004] Disclosed herein is a method for forming a pattern, the method comprising: providing a substrate in which a pattern is to be formed; forming a silicon photoresist layer on the substrate; exposing a portion of the silicon photoresist to an activating radiation wavelength; curing the silicon photoresist; developing the cured silicon photoresist to remove the portion of the photoresist exposed to the activating radiation wavelength, and etching the substrate to form the pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Reference is now made to the drawings, which are exemplary embodiments, and in which like elements are numbered like throughout.

[0006] 1(a) to 1(c) illustrate a prior art method of forming a pattern using a hydrocarbon photoresist and a hydrocarbon BARC.

[0007] 2(a) to 2(d) illustrate a prior art method of forming a pattern using a hydrocarbon photoresist and a combination of a silicon-containing BARC and a hydrocarbon-containing BARC.

[0008] Figures 3(a) to 3(c) An example of a method of forming a pattern using a hydrocarbon-containing BARC and a silicon photoresist is shown.

[0009] Figures 4(a) to 4(c) An example of a method of forming a pattern using a silicon BARC and a silicon photoresist is shown.

[0010] Figures 5(a) to 5(c) An example of a method of patterning using thick silicon BARC and silicon photoresist is shown.

[0011] Figures 6(a) to 6(c) An example of a method of forming a pattern in a silicon substrate using a silicon photoresist is shown.

[0012] Figures 7(a) to 7(c) An example of a method of forming a pattern in a silicon substrate using a photosensitive hydrocarbon BARC and a silicon photoresist is shown. DETAILED DESCRIPTION

[0013] In photolithography, a bottom anti-reflective coating (BARC) includes a chromophore that has strong absorption at the wavelength of activating radiation. BARC can reduce radiation reflection from the substrate that can negatively affect the accuracy of the image formed. In addition, BARC can adjust the adhesion of the photoresist to the substrate.

[0014] The BARC may be a hydrocarbon-based material (also referred to as a hydrocarbon-containing material or hydrocarbon BARC). Note that while "hydrocarbon" generally refers to a compound having only C and H atoms, as used herein, "hydrocarbon-based," "hydrocarbon-containing," or "hydrocarbon BARC" may include compounds having only C and H atoms, or compounds including C and H atoms and heteroatoms such as O, N, S, etc., or a combination thereof.

[0015] The hydrocarbon-containing BARC includes a hydrocarbon-containing polymer that can be cured to ensure that the hydrocarbon BARC is resistant to the developing solution of the photoresist. Such curing can occur, for example, at about 200° C. Due to the high curing temperature, the chromophore is preferably grafted onto the polymer chain to avoid migration (e.g., outgassing) during high temperature curing. For example, as shown in FIG. 1( a), a thin, cured hydrocarbon BARC 11 is formed on a substrate including a polysilicon layer 13 on silicon oxide 14. A hydrocarbon photoresist layer is applied to the hydrocarbon BARC 11, exposed to an activating radiation wavelength, and developed to form a patterned hydrocarbon photoresist 16.

[0016] After the photoresist is developed, the exposed BARC is at least partially removed by reactive ion etching (referred to herein as "RIE"), and the substrate may also be patterned by etching (e.g., RIE). As shown in FIG. 1(b), the hydrocarbon BARC 11 is etched using RIE to expose the polysilicon layer 13. Next, as shown in FIG. 1(c), the polysilicon layer 13 is etched using RIE to form a pattern protected by the hydrocarbon photoresist 16, and the remaining photoresist 16 and the hydrocarbon BARC 11 are removed. The residual photoresist may also be removed using a stripper solution.

[0017] The lack of etch selectivity between hydrocarbon photoresists and hydrocarbon BARCs limits the effective use of hydrocarbon photoresists with thick hydrocarbon BARC layers. Therefore, if a thick hydrocarbon BARC is used, an additional thin silicon BARC (also called a hard mask) is typically also used. For example, as shown in FIG2(a), a hydrocarbon photoresist is applied, exposed, and developed to form a pattern of hydrocarbon photoresist 16 on a stack that includes, from the bottom, metal 15, silicon oxide 14, thick hydrocarbon BARC 11, and thin silicon BARC 12. In FIG2(b), silicon BARC 12 is etched by RIE and the hydrocarbon photoresist is removed. In FIG2(c), hydrocarbon BARC 11 is etched using silicon BARC as a mask, and the silicon BARC is removed. In FIG2(d), a pattern is etched in silicon oxide 14 using hydrocarbon BARC 11 as a mask, and hydrocarbon BARC 11 is removed.

[0018] Hydrocarbon photoresists cannot be effectively used with silicon-containing BARCs alone due to insufficient etch resistance. Furthermore, although silicon-containing hardmasks have been disclosed, see, for example, US 8,911,932; US 8,728,710; CN102236253 and JP6144000, improved methods are needed to simplify and / or enhance the photolithography process.

[0019] To address these and other defects, the method disclosed herein includes providing a substrate including a portion on which a pattern is desired to be formed. A silicon photoresist is applied to the substrate, exposed to an activating radiation wavelength in an image-level manner, cured and developed to remove the exposed portion of the silicon photoresist. The activating radiation wavelength can be, for example, a wavelength in the range of 10 to 400 nanometers (nm), such as 13.5, 193, 248 or 365nm. The development step can directly expose a portion of the substrate. (See, for example, FIG. 6). Alternatively, a BARC can be formed on the substrate before applying the silicon photoresist, in which case the development of the photoresist exposes the BARC, which is then etched (e.g., using reactive ion etching, RIE) to expose a portion of the substrate. (See, for example, FIGS. 3-5 and 7). Once the substrate is exposed, the pattern can be etched (e.g., using RIE) into the substrate using the silicon photoresist and / or the inserted BARC as a mask.

[0020] The substrate may include a metal, a semiconductor, a dielectric material, or a combination of two or more thereof. For example, the substrate may include a semiconductor material such as Si, SiGe, SiGeC, SiC, GaAs, InAs, InP, or other III / V or II / VI compound semiconductors. The substrate may include, for example, a silicon wafer or a process wafer, such as a wafer produced in various steps of a semiconductor manufacturing process, such as an integrated semiconductor wafer. The substrate may include multiple layers or may be a single layer. The substrate may include a layered substrate such as, for example, Si / SiGe, Si / SiC, silicon on insulator (SOI) or silicon germanium on insulator (SGOI). The substrate may include silicon, polycrystalline silicon, silicon dioxide or aluminum-aluminum oxide microelectronic wafers, gallium arsenide, silicon carbide, ceramics, quartz, metals, or a combination of two or more thereof. For example, the substrate may include a polycrystalline silicon layer on a silicon oxide layer. As another example, the substrate may include silicon oxide on a metal layer. As yet another example, the substrate may include, consist essentially of, or consist of a silicon substrate. When a substantially bare silicon substrate is used, the surface of the silicon substrate may be treated before applying the silicon photoresist. For example, a silicon substrate may be treated with an adhesion promoter such as, for example, a silanizing agent (eg, an alkylsilylamine such as bis(trimethylsilyl)amine, also known as hexamethyldisilazane or HMDS).

[0021] Silicon photoresist compositions can include a silicon-containing resin, a catalyst capable of catalyzing a condensation reaction of the silicon-containing resin, and a photoacid generator, wherein the catalyst can be deactivated by the presence of an acid so that it loses the ability to catalyze the condensation reaction. Such a catalyst can be referred to as a condensation catalyst or a curing catalyst. Therefore, when the coating area comprising the silicon photoresist composition is exposed to activating radiation, an acid is formed and the catalyst is deactivated. Subsequent curing occurs in unexposed areas. The exposed area is removed by development in a suitable developing solution. Therefore, the silicon photoresist can be a positive photoresist.

[0022] The silicon-containing polymer resin may be prepared from one or more monomers having the following molecular structures or a combination of two or more thereof:

[0023]

[0024]

[0025] Each R is independently hydrogen or an alkyl group of 1 to 4 carbon atoms, preferably 1 to 3 carbon atoms and more preferably 1 or 2 carbon atoms at each occurrence, and R is preferably an alkyl group of 1 or 2 carbon atoms. Each R1 is independently a monovalent organic group having 1 to 30 carbon atoms and optionally including 1 to 5 heteroatoms selected from N, O, P, S or a combination of two or more thereof at each occurrence. A combination including at least one of the foregoing can be used. For example, each R1 can be an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, an olefin group having 2 to 30 carbon atoms or an alicyclic group having 3 to 30 carbon atoms, each of which optionally includes -O-, -CO-, -OCO-, -COO- or -OCOO- as part of its structure. Each R1 can be further substituted independently by one or more epoxy groups. R1 is preferably an alkyl group of 1 or 2 carbon atoms, to provide a cured resin having a silicon content higher than 42 weight percent based on the gross weight of the cured resin.

[0026] Examples of preferred monomers include methyltrimethoxysilane, tetraethoxysilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, cyclohexyltrimethoxysilane, cyclohexenyltriethoxysilane, alkyl, cyclohexenyl triethoxysilane, phenyl trimethoxysilane, phenyl triethoxysilane, benzyl trimethoxysilane, benzyl triethoxysilane, phenethyl trimethoxysilane, phenethyl triethoxysilane, dimethyl dimethoxy silane, dimethyl diethoxy silane, diethyl dimethoxy silane, diethyl diethoxy silane, methyl ethyl dimethoxy silane, methyl ethyl diethoxy silane, dipropyl dimethoxy silane, dibutyl dimethoxy silane, methyl phenyl dimethoxy silane, methyl phenyl diethoxy silane, trimethyl methoxy silane, dimethyl ethyl methoxy silane, dimethyl phenyl methoxy silane, dimethyl benzyl methoxy silane, dimethyl phenethyl methoxy silane, etc., or a combination of two or more thereof. A combination comprising at least one of the foregoing can be used.

[0027] The polymerization of monomer can be carried out in an organic solvent. The exemplary organic solvent used for polymerization includes methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, acetone, acetonitrile, tetrahydrofuran, toluene, hexane, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl amyl ketone, butanediol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, butanediol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, 3-methoxy methyl propionate, 3-ethoxy ethyl propionate, tert-butyl acetate, tert-butyl propionate, propylene glycol monotert-butyl ether acetate, γ-butyrolactone (y-butyrolactone) etc., or two or more combinations thereof. A combination including at least one of the aforementioned can be used. The organic solvent may be propylene glycol methyl ether or propylene glycol methyl ether acetate.

[0028] The polymerization of the monomers can be carried out in the presence of one or more polymerization catalysts. The polymerization catalyst can be an acid catalyst. Exemplary acid catalysts include organic acids such as formic acid, acetic acid, oxalic acid, maleic acid, methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, etc., or a combination of two or more thereof; or inorganic acids such as hydrofluoric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, perchloric acid, phosphoric acid, etc., or a combination of two or more thereof. A combination including at least one of the foregoing can be used. The acid catalyst can be acetic acid. The acid catalyst can be used in any suitable amount, such as 1 to 10 weight percent (wt%), 2 to 8 wt% or 3 to 7 wt% based on the total charge weight in the reactor.

[0029] The polymerization may be carried out at a temperature of 0°C to 110°C, 20°C to 110°C, 50°C to 110°C, or 80°C to 110°C.

[0030] The volatile alkanol formed during the reaction can be removed by distillation as the reaction proceeds. The distillate may also include catalyst, water and / or solvent. A stream of nitrogen flushed through the reactor may assist the distillation. The removal of the volatile alkanol may be carried out during or after the polymerization reaction.

[0031] The silicon-containing polymer resin thus formed may include polysiloxane, polysilsesquioxane, or a combination thereof. For example, the silicon-containing polymer resin includes both polysiloxane and polysilsesquioxane. The silicon-containing polymer resin may include a crosslinked or network structure. The network may include a complex and diverse set of molecular structures of polysiloxane and polysilsesquioxane. For example, the network structure may include a variety of structures, including the following molecular structures:

[0032]

[0033] wherein each R and R1 are each independently as defined herein. However, the above structure is not an accurate and complete description of the silicon-containing polymer resin, such that the selected monomers and polymerization process may provide the most accurate description of the polymer.

[0034] The weight average molecular weight (M) of the silicone-containing polymer resin before curing w ) may be 1,000 to 50,000 grams per mole (g / mol), 1,500 to 30,000 g / mol, 2,000 to 20,000 g / mol, or 3,000 to 10,000 g / mol. w It can be determined using gel permeation chromatography (GPC) with polystyrene standards as described in Williams and Ward, J. Polymer. Sci., Polymer. Letters, 6, 621 (1968), the contents of which are incorporated herein by reference in their entirety.

[0035] Exemplary silicon-containing resins may include siloxanes, silsesquioxanes, polysiloxanes or polysilsesquioxanes, such as methylsiloxane, methylsilsesquioxane, phenylsiloxane, phenylsilsesquioxane, methylphenylsiloxane, methylphenylsilsesquioxane, dimethylsiloxane, diphenylsiloxane, methylphenylsiloxane, polyphenylsilsesquioxane, polyphenylsiloxane, polymethylphenylsiloxane, polymethylphenylsilsesquioxane, substituted polymethylsilsesquioxane, or a combination of two or more thereof. A combination comprising at least one of the foregoing may be used. These resins may be substituted or unsubstituted.

[0036] The amount of the silicon-containing resin that can be included in the photoresist precursor composition is 0.5 to 40 wt %, 1 to 30 wt % or 2 to 20 wt % based on the total weight of the dielectric precursor composition, corresponding to a film thickness of 10 nm to 2 μm at a normal spin coating speed (e.g., 500 to 2000 revolutions per minute (RPM)).

[0037] The catalyst (curing catalyst or condensation catalyst) in the silicon photoresist composition may include quaternary ammonium and / or amines, such as, for example, methylamine, ethylamine, propylamine, butylamine, ethylenediamine, hexamethylenediamine, dimethylamine, diethylamine, ethylmethylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, cyclohexylamine, dicyclohexylamine, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, hexamethylenetetramine, aniline, N,N-dimethylaniline, N,N-dimethylaminopyridine, pyrrole, piperazine, pyrrolidine, piperidine, benzyltriethylammonium chloride (BTEAC), tetramethylammonium chloride (TMAC), guanidine carbonate, tetramethylammonium hydroxide (TMAH), tetramethylammonium acetate (TMAA), tetrabutylammonium hydroxide (TBAH), tetrabutylammonium acetate (TBAA), cetyltrimethylammonium acetate (CTAA), tetramethylammonium nitrate (TMAN), or a combination of two or more thereof. A combination comprising at least one of the foregoing may be used.

[0038] The amount of the curing catalyst may be 0.0005 to 0.2 wt %, or 0.001 to 0.05 wt %, based on the total weight of the dielectric precursor composition. The amount of the catalyst may be 0.045 to 4 wt %, or 0.01 to 0.5 wt %, based on the total weight of the silicon-containing polymer resin.

[0039] The photoacid generator is preferably a compound that generates an organic acid by irradiation with actinic rays or radiation. The sensitive wavelength of the photoacid generator is preferably, for example, a wavelength of 10 to 450 nanometers (nm) or 300 to 450 nm. In other words, the photoacid generator is preferably a compound that generates an acid in response to actinic radiation within the above wavelength range. In addition, the pKa of the acid generated by the photoacid generator is preferably 4.0 or less and more preferably 3.0 or less.

[0040] The photoacid generator may include an onium salt, a triazine compound (preferably a halomethylated triazine compound, or more preferably a trichloromethyl-s-triazine compound), an oxime sulfonate compound, a bissulfonyldiazomethane compound, an imide sulfonate compound, a diazodisulfone compound, a disulfone compound, or a nitrobenzylsulfonate compound (preferably an o-nitrobenzylsulfonate compound). Preferably, the photoacid generator includes a sulfonium or iodonium salt, more preferably a compound having a sulfonium cation or a sulfonate or a methide or an iodonium cation or a sulfonate. Exemplary sulfonium cations include triphenylsulfonium and tris(4-tert-butyloxyphenyl)sulfonium. Exemplary sulfonates include trifluoromethanesulfonate and perfluoro-1-butanesulfonate. Exemplary methyl anions include tris(trifluoromethyl)methyl anions. Exemplary iodonium cations include aryl iodonium cations, including diphenyl iodonium and bis(4-tert-butylphenyl)iodonium. Exemplary sulfonates include trifluoromethanesulfonate and perfluoro-1-butanesulfonate.Combinations comprising at least one of the foregoing can be used.

[0041] Exemplary photoacid generators include onium salts such as triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoroacetate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyldiphenylsulfonium trifluoroacetate, 4-phenylphenylthiodiphenylsulfonium trifluoromethanesulfonate, 4-phenylphenylthiodiphenylsulfonium trifluoromethanesulfonate, diphenyliodonium trifluoromethanesulfonate, (p-tert-butoxyphenyl)phenyliodonium trifluoromethanesulfonate, diphenyliodonium p-toluenesulfonate, (p-tert-butoxyphenyl)phenyliodonium p-toluenesulfonate, triphenylsulfonium trifluoromethanesulfonate , (p-tert-butoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, bis(p-tert-butoxyphenyl)phenylsulfonium trifluoromethanesulfonate, tris(p-tert-butoxyphenyl)sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, (p-tert-butoxyphenyl)diphenylsulfonium p-toluenesulfonate, bis(p-tert-butoxyphenyl)phenylsulfonium p-toluenesulfonate, tris(p-tert-butoxyphenyl)sulfonium p-toluenesulfonate, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium butanesulfonate, trimethylsulfonium trifluoromethanesulfonate, trimethylsulfonium p-toluenesulfonate, cyclohexylmethyl (2 1-(2-oxyylidenecyclohexyl)sulfonium trifluoromethanesulfonate, cyclohexylmethyl (2-oxyylidenecyclohexyl)sulfonium p-toluenesulfonate, dimethylphenylsulfonium trifluoromethanesulfonate, dimethylphenylsulfonium p-toluenesulfonate, dicyclohexylphenylsulfonium trifluoromethanesulfonate, dicyclohexylphenylsulfonium p-toluenesulfonate, trinaphthylsulfonium trifluoromethanesulfonate, cyclohexylmethyl (2-oxyylidenecyclohexyl)sulfonium trifluoromethanesulfonate, (2-norbornyl)methyl (2-oxyylidenecyclohexyl)sulfonium trifluoromethanesulfonate, ethylenebis[methyl (2-oxyylidenecyclopentyl)sulfonium trifluoromethanesulfonate Salt], 1,2'-naphthylcarbonylmethyltetrahydrothiophenium trifluoromethanesulfonate, diphenyliodonium trifluoroacetate, diphenyliodonium trifluoromethanesulfonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, 4-methoxyphenylphenyliodonium trifluoroacetate, phenyl-4-(2'-hydroxy-1'-tetradecyloxy)phenyliodonium trifluoromethanesulfonate, 4-(2'-hydroxy-1'-tetradecyloxy)phenyliodonium hexafluoroantimonate, phenyl-4-(2'-hydroxy-1'-tetradecyloxy)phenyliodonium p-toluenesulfonate, or a combination of two or more thereof. A combination comprising at least one of the foregoing may be used.

[0042] Exemplary diazomethane compounds include bis(benzenesulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(xylenesulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(cyclopentylsulfonyl)diazomethane, bis(n-butylsulfonyl)diazomethane, bis(isobutylsulfonyl)diazomethane, bis(isopentylsulfonyl)diazomethane, 1-tert-amylsulfonyl-1-(tert-butylsulfonyl)diazomethane, etc., or a combination of two or more thereof. A combination comprising at least one of the foregoing may be used.

[0043] Exemplary triazine compounds include 2-(3-chlorophenyl)-bis(4,6-trichloromethyl)-s-triazine, 2-(4-methoxyphenyl)-bis(4,6-trichloromethyl)-s-triazine, 2-(4-methylthiophenyl)-bis(4,6-trichloromethyl)-s-triazine, 2-(4-methoxy-β-phenylphenyl)-bis(4,6-trichloromethyl)-s-triazine, 2-piperonyl-bis(4,6-trichloromethyl)-s-triazine, 2-[2 -(furan-2-yl)vinyl]-bis(4,6-trichloromethyl)-s-triazine, 2-[2-(5-methyl)furan-2-yl)vinyl]-bis(4,6-trichloromethyl)-s-triazine, 2-[2-(4-diethylamino-2-methylphenyl)vinyl]-bis(4,6-trichloromethyl)-s-triazine, 2-(4-methoxynaphthyl)-bis(4,6-trichloromethyl)-s-triazine, or a combination of two or more thereof. A combination comprising at least one of the foregoing may be used.

[0044] Exemplary imide sulfonate compounds include trifluoromethylsulfonyloxybicyclo[2.2.1]-hept-5-ene-dicarboxylic imide, succinimide trifluoromethylsulfonate, phthalimide trifluoromethylsulfonate, N-hydroxynaphthalimide methanesulfonate, N-hydroxy-5-norbornene-2,3-dicarboxylic imide propanesulfonate, and the like, or a combination of two or more thereof. A combination comprising at least one of the foregoing may be used.

[0045] A specific example of a photoacid generator is 2-(4-methoxyphenyl)([((4-methylphenyl)sulfonyl)oxy]imino)acetonitrile.

[0046] The content of the photoacid generator is preferably 0.01 to 3 wt %, 0.05 to 2 wt %, 0.1 to 1 wt % or 0.2 wt % based on the total solid content of the composition.

[0047] The molar ratio of photoacid generator to catalyst can be, for example, 0.5:1 to 10:1, or 0.5:1 to 5:1, or 0.5:1 to 1.5:1.

[0048] The silicon photoresist can have a high silicon atomic content, for example, greater than 35, greater than 38, greater than 39, greater than 40, greater than 41, or at least 42 wt%, and up to 46 or up to 45 wt% atomic silicon based on the total weight of the photoresist composition.

[0049] Silicon photoresists can provide better protection from ion bombardment than hydrocarbon photoresists. This feature is particularly beneficial in applications where the photoresist is applied to a bare (treated or untreated) silicon substrate.

[0050] Forming a silicon photoresist layer on a substrate may include applying a coating composition including a silicon-containing resin, a catalyst, a photoacid generator, optionally additives, and a coating solvent to the substrate.

[0051] Exemplary coating solvents also include solvents that are not part of the hydrocarbon solvent compound family, such as ketones, including acetone, diethyl ketone, methyl ethyl ketone, etc., alcohols, esters, ethers or amines. Examples of solvents include propylene glycol methyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), propylene glycol propyl ether (PGPE) and ethyl lactate (EL).

[0052] The coating solvent may be included in the composition in an amount of 50 to 99 wt %, 55 to 95 wt %, 60 to 90 wt %, or 65 to 85 wt %, based on the total weight of the dielectric precursor composition.

[0053] Suitable application methods may include spin coating, spray coating, etc. The solvent is removed to form a solid layer of the photo-patternable dielectric precursor composition.

[0054] Optional additional components of the coating composition may include film modifiers for controlling the diffusion of ingredients in the film, or the like, or a combination of two or more thereof.

[0055] The membrane modifier can be a polymer, an oligomer or a non-polymer compound. The weight average molecular weight (M) of the polymer or oligomer used as the membrane modifier is w) is preferably less than 5,000 g / mol and more preferably less than 2,000 g / mol, as determined by GPC. The molecules of the membrane modifier must be small enough to fill the membrane pores. The membrane modifier can be a compound containing only C and H, a hydrocarbon compound, and is preferably a silicon-containing compound. At least one hydroxyl group is connected to each molecule of the membrane modifier. The hydroxyl group can participate in the condensation reaction of the membrane resin. Exemplary hydrocarbon membrane modifiers include polyols, such as polyether glycols, glycerol, 2-(hydroxymethyl)-1,3-propanediol, dihydrogen phosphate 1,3-dihydroxypropane-2-yl ester, ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, etc., or a combination of two or more thereof. Examples of the branched alkylene glycol may include neopentyl glycol, 2,4-diethyl-1,5-pentanediol, 2,4-dibutyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1-methylethylene glycol, 1-ethylethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,1,1-tri(hydroxymethyl)ethane, 2-hydroxymethyl-1,3-propanediol, 2-ethyl-2-(hydroxymethyl)-1,3-propanediol, 2-hydroxymethyl-2-propyl-1,3-propanediol, 2-hydroxymethyl-1,4-butanediol, 2-hydroxyethyl-2-methyl-1,4-butanediol, 2-hydroxymethyl-2-propyl-1,4-butanediol, 2-ethyl-2-hydroxyethyl-1,4-butanediol, 1,2,3-butanetriol, 1,2,4-butanetriol, and 1,2,3-butanetriol. triol, 3-(hydroxymethyl)-3-methyl-1,4-pentanediol, 1,2,5-pentanetriol, 1,3,5-pentanetriol, 1,2,3-trihydroxyhexane, 1,2,6-trihydroxyhexane, 2,5-dimethyl-1,2,6-hexanetriol, tris(hydroxymethyl)nitromethane, 2-methyl-2-nitro-1,3-propanediol, 2-bromo-2-nitro-1,3-propanediol, 1,2,4-cyclopentanetriol, 1,2,3-cyclopentanetriol, 1,3,5-cyclohexanetriol, 1,3,5-cyclohexanetrimethanol, butane-1,2,3,4-tetrol, 2,2-bis(hydroxymethyl)-1,3-propanediol, pentane-1,2,4,5-tetrol, and the like, or a combination of two or more thereof. The film modifier can be 1,1,1-tris(hydroxymethyl)ethane, pentaerythritol or a combination thereof. Exemplary silicon-containing film modifiers include silanols such as diphenylsilanediol, diisobutylsilanediol, 1,4-bis(hydroxydimethylsilyl)benzene, 4-vinylphenylsilanediol, etc., or a combination of two or more thereof. The content of the film modifier should not exceed 30wt% of the total weight of the resin, and more preferably not exceed 10wt%, and can be 0.01 to 15wt%, or 0.1 to 10wt% of the total weight of the resin.The concentration of the membrane modifier in the composition is used to control the diffusion lengths of the catalyst, photoacid generator, and quencher.A variety of membrane modifiers can be used.

[0056] Removal of the solvent may include baking (e.g., on a hot plate surface) at 40 to 120° C., 50 to less than 100° C., or 60 to less than 80° C. for 15 to 120 seconds or 30 to 60 seconds. The baking step must not be long enough or hot enough to cause curing of the silicone-containing resin so that the dried film remains soluble in the developer solution.

[0057] Exposure may include exposure to an activating radiation wavelength. To generate a pattern in the silicon photoresist, exposure is performed in an image-level manner. This may be performed through a mask or by direct addressing with a laser. The wavelength may be, for example, in the range of 10 to 400 nm, or a specific wavelength such as 365 nm, 248 nm, 193 nm or 13.5 nm.

[0058] Exposure deactivates the catalyst. Thus, during subsequent heating to induce curing, the silicon-containing resin precursor cures (eg, crosslinks) only in areas not exposed to radiation. Curing may be performed at a temperature of 60 to 120° C. or 80 to 111° C. for 30 to 120 seconds.

[0059] Silicon photoresists can be developed with solutions, such as organic solvents, particularly polar organic solvents, or alkaline aqueous solutions. Examples of organic solvents include, but are not limited to, cyclohexanone, propylene glycol methyl ether, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethoxyethyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, ethyl 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, carbonyl acetate The developer may be ethyl ester, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, or a combination of two or more thereof. A combination comprising at least one of the foregoing may be used. The organic solvent may be propylene glycol methyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), ethyl lactate (EL) or cyclohexanone. Examples of alkaline (basic) developers may be aqueous solutions of organic or inorganic bases, including, for example, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, ethanolamine, propylamine, ethylenediamine, choline, potassium hydroxide, sodium hydroxide or a combination thereof. A specific example of the developer is an aqueous solution of tetramethylammonium hydroxide at a concentration of 2.5 to 25 g / L. Development is performed under appropriately determined conditions; namely, at a temperature of 5 to 50° C. and for a time of 10 to 600 seconds.

[0060] Due to high etch resistance, silicon photoresist can be thinner than the typical thickness of hydrocarbon photoresist. This is beneficial because thinner photoresists can provide more precise patterns. When used with thin BARC, the thickness of the photoresist should be thick enough to protect the substrate. The thickness of the photoresist can be from 2, 5 or 10 to 1000nm, to 900, to 800, to 700, to 600, to 500, to 400, to 300, to 200 or to 100nm. When used with a thin BARC layer (e.g., a thickness of about 2 to 200nm), the thickness of the silicon BARC can be from 5nm or 10nm to 1000nm, to 900, to 800, to 700, to 600, to 500, to 400, to 300 or to 200nm. Any suitable combination of the aforementioned thicknesses can be used. When silicon photoresist is used with a thick hydrocarbon BARC (eg, having a thickness of 10 to 2000 nm), the silicon photoresist can be thinner, ranging from 2 nm, 5 nm, or 10 nm to 200, to 100, to 90, to 80, to 70, or to 60 nm.

[0061] The hydrocarbon BARC, if used, may include a polymer and include a light absorbing group, such as a chromophore. The chromophore may be bonded to the polymer backbone. The polymer may be, for example, an epoxy cresol novolac, a phenol novolac, an acrylic polymer, a polyester, a polysaccharide, a polyether, a polyacetate, a styrenic polymer (e.g., polystyrene or a copolymer of styrene and another monomer such as acrylonitrile), or a polyimide. The composition used to form the hydrocarbon BARC layer may include a crosslinking agent, such as, for example, an aminoplast (e.g., 1174, Products), epoxy resins, polyols, anhydrides, glycidyl ethers, vinyl ethers or combinations thereof. The polymer may include an epoxide ring in the repeating unit. For example, the epoxide group accounts for about 20 to 80 wt % and preferably about 20 to 40 wt % of the total weight of the polymer. The chromophore includes an aromatic or heterocyclic light absorbing moiety. The chromophore may be covalently bonded to the polymer.

[0062] For example, a chromophore may have the formula

[0063]

[0064] wherein R is selected from the group consisting of -H and substituted and unsubstituted alkyl groups (preferably C1-C8, and more preferably C1-C4), and X 1 is an aromatic or heterocyclic light absorbing moiety. This includes chromophores having phenolic -OH, -COOH and -NH2 functional groups. The chromophore may include, for example, phenyl, thiophene, naphthoic acid, anthracene, naphthalene, benzene, chalcone, phthalimide, pamoic acid, acridine, azo compounds, dibenzofuran or derivatives thereof.

[0065] The hydrocarbon BARC may be uncrosslinked.

[0066] The hydrocarbon BARC can be coated, for example, by spin coating, from a composition comprising a hydrocarbon BARC in a solvent. The solvent can be removed by baking (eg, at a temperature of 30 to 150° C. or 50 to less than 100° C. for from 10 or 30 seconds to 120 seconds or to 90 seconds).

[0067] The hydrocarbon BARC may be thin (eg, having a thickness of 2 to 200 nm, preferably 5 to 60 nm), as shown, for example, in FIG. 3 , or may be thick (eg, having a thickness of 10 to 2000 nm, preferably 20 to 1000 nm), as shown, for example, in FIG. 5 .

[0068] The silicon BARC, if used, may include a silicon polymer and may include a light absorbing functional group (e.g., a chromophore). For example, the silicon BARC may include an oligomer or polymer alkyl siloxane, an oligomer or polymer alkyl silsesquioxane, an oligomer or polymer aryl siloxane, an oligomer or polymer aryl silsesquioxane, an oligomer or polymer alkenyl siloxane, an oligomer or polymer alkenyl silsesquioxane, or a combination thereof. In the above, the alkyl group may include, for example, 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms. In the above, the aryl group may include, for example, 6 to 16 carbon atoms. The chromophore may include, for example, phenyl, thiophene, naphthoic acid, anthracene, naphthalene, benzene, chalcone, phthalimide, pamoic acid, acridine, an azo compound, or dibenzofuran or a derivative thereof.

[0069] The silicon BARC may be coated, for example, by spin coating, from a composition comprising the silicon BARC in a solvent. The solvent may be removed by baking (eg, at a temperature of 30 to 150° C. or 50 to less than 100° C. for from 10 or 30 seconds to 120 seconds or to 90 seconds).

[0070] The silicon BARC may have a thickness in the range of 2 to 200 nm, preferably 5 to 60 nm.

[0071] refer to Figures 3(a) to 3(c), one example of a method as described herein includes forming a thin (e.g., 2 to 200 nm) hydrocarbon BARC 11 on a substrate including a polysilicon layer 13 on a silicon oxide 14. In FIG3(a), a silicon photoresist composition is applied, image-wise exposed to an activating radiation wavelength, cured, and developed to remove the photoresist composition in the exposed areas, leaving a silicon photoresist 20 patterned on the hydrocarbon BARC 11. In FIG3(b), the hydrocarbon BARC 11 is etched using the silicon photoresist 20 as a mask, exposing the polysilicon layer 13. In FIG3(c), the polysilicon layer 13 has been etched using the remaining silicon photoresist 20 and the underlying hydrocarbon BARC 11 as a mask.

[0072] refer to Figures 4(a) to 4(c) , another example of a method as described herein includes forming a thin (e.g., 2 to 200 nm) silicon BARC 12 on a substrate including a polysilicon layer 13 on a silicon oxide 14. In FIG4(a), a silicon photoresist composition is applied, image-wise exposed to an activating radiation wavelength, cured and developed to remove the photoresist composition in the exposed areas, leaving a silicon photoresist 20 patterned on the silicon BARC 12. In FIG4(b), the silicon BARC 12 is etched using the silicon photoresist 20 as a mask, exposing the polysilicon layer 13. In FIG4(c), the polysilicon layer 13 has been etched using the remaining silicon photoresist 20 and the underlying silicon BARC 12 as a mask.

[0073] refer to Figures 5(a) to 5(c) , another example of a method as described herein includes forming a thick (e.g., 10 to 2000 nm) hydrocarbon BARC 11 on a substrate including silicon oxide 14 on a metal 15. In FIG5(a), a silicon photoresist composition is applied, image-wise exposed to an activating radiation wavelength, cured and developed to remove the photoresist composition in the exposed areas, leaving a silicon photoresist 20 patterned on the hydrocarbon BARC 11. In FIG5(b), the hydrocarbon BARC 11 is etched using the silicon photoresist 20 as a mask, exposing the silicon oxide 14. In FIG5(c), the silicon oxide 14 has been etched using the remaining silicon photoresist 20 and the underlying hydrocarbon BARC 11 as a mask.

[0074] refer to Figures 6(a) to 6(c), another example of the method described herein includes applying a silicon photoresist layer 20 to a silicon substrate 21. After image-level exposure, curing and development, the pattern of the silicon photoresist 20 remains on the silicon substrate 21 as a mask, as shown in Figure 6(b). The silicon substrate (21) is then etched using the silicon photoresist 20 as a mask. Residues of the silicon photoresist 20 may remain, as shown in Figure 6(c), or may be completely removed during etching (not shown). Any remaining silicon photoresist may act as a mask during subsequent ion implantation of exposed portions of the silicon substrate.

[0075] refer to Figures 7(a) to 7(c) Another example of a method as described herein includes forming a thin (e.g., 2 to 200 nm) photosensitive hydrocarbon BARC 10 on a substrate including a polysilicon layer 13 on a silicon oxide 14. The photosensitive BARC is positive tone because the dissolution rate of the photosensitive BARC in a developer increases when the photosensitive BARC is exposed to activating radiation.

[0076] Such a photosensitive hydrocarbon BARC composition may include an aromatic polymer resin and a photosensitizer. For example, the aromatic polymer resin may include a novolac resin (polymer derived from phenol and formaldehyde), a polyamic acid or polyamic acid ester resin or a combination thereof. For example, the hydrocarbon BARC composition may include a novolac resin and a diazonaphthoquinone (DNQ). DNQ inhibits the dissolution of the novolac resin, and the dissolution rate increases when exposed to light, potentially increasing the dissolution rate higher than the base novolac resin. The hydrocarbon BARC composition may include a novolac resin, DNQ and a polyamic acid or polyamic acid ester. Based on the gross weight of the hydrocarbon BARC composition, the polyamic acid or polyamic acid ester may be present in an amount of 2 to 20 wt%, or 5 to 10 wt%. The photosensitive hydrocarbon BARC including novolac resin and DNQ may be developed in an alkali or alkaline developer. Examples of alkaline (basic) developers can be aqueous solutions of organic or inorganic bases, including, for example, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, ethanolamine, propylamine, ethylenediamine, choline, potassium hydroxide, sodium hydroxide, or a combination thereof. Specific examples of developing solutions can include 0.1 to 0.4 standard (N) tetraalkylammonium hydroxide (e.g., C1 to C4 tetraalkylammonium hydroxide, such as tetramethylammonium hydroxide).

[0077] The polyamic acid or polyamic acid ester can protect the hydrocarbon BARC from the mixed solvent used for silicon photoresist.The polyamic acid or polyamic acid ester can be the reaction product of a dianhydride, especially an aromatic dianhydride, and a diamine, especially an aromatic diamine.

[0078] Examples of aromatic dianhydrides include pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, diphenyl ethertetracarboxylic dianhydride; hydroquinone diphthalic anhydride; isopropylidene diphenyloxy)bis-(phthalic anhydride); (hexafluoroisopropylidene) diphthalic anhydride, or a combination of two or more thereof. In one aspect, a combination comprising at least one of the foregoing may be used. Examples of diamines include phenylenediamine, oxydiphenylamine, or a combination thereof.

[0079] FIG7(a) shows a film stack including a silicon photoresist 20 on a photosensitive hydrocarbon BARC 10 on a polysilicon layer 13 on a silicon dioxide layer 14. In FIG7(b), the silicon photoresist composition and the photosensitive hydrocarbon BARC are image-wise exposed to an activating radiation wavelength, cured, and developed to remove the photoresist composition and the photosensitive hydrocarbon BARC in the exposed areas, leaving the silicon photoresist 20 patterned on the photosensitive hydrocarbon BARC 10. Note that the exposure may include exposing areas of the silicon photoresist 20 to radiation, which simultaneously exposes the underlying photosensitive hydrocarbon BARC 10 to radiation. The development may be performed sequentially, first developing the silicon photoresist, and then developing the underlying photosensitive BARC. Alternatively, the development of both layers may be performed simultaneously using a mixed solution of an alkaline developer as described herein. In FIG7(c), the polysilicon layer 13 has been etched using the silicon photoresist 20 and the underlying photosensitive hydrocarbon BARC 10 as a mask.

[0080] Also disclosed herein are articles made by the methods described herein. For example, the article can be an electronic device, such as a chip or integrated circuit or a display device, or a system including such a device. Examples of such systems include computers, cellular phones, transportation vehicles, appliances, manufacturing systems, robotic devices, etc.

[0081] Example

[0082] Example 1: Synthesis of Silicon-Containing Polymer Resins for Silicon Photoresists

[0083] In a 500-mL round-bottom flask, 65 grams of methyltrimethoxysilane, 30 grams of tetraethoxysilane, 10 grams of phenyltrimethoxysilane, 250 grams of 1-methoxy-2-propanol acetate, 48 grams of water, and 10 grams of acetic acid were combined, mixed thoroughly, and distilled for five hours. The flask was removed from the distillation heater and transferred to a rotary evaporator to remove all solvents at a temperature of 80° C. under a vacuum of 20 Torr for 40 minutes. The silicon-containing resin was recovered from the flask.

[0084] Example 2: Formulating a thin silicon photoresist coating composition.

[0085] Five grams of the silicon-containing polymer resin obtained as shown in Example 1 were combined with 90 grams of n-butanol, 10 grams of propylene carbonate, 0.004 grams of benzyltrimethylammonium chloride and 0.12 grams of mixed triarylsulfonium hexafluoroantimonate (TR-PAG-201, Tronly New Electrionic Materials Co., Ltd, Changzhou, China) in a container and mixed until all ingredients were dissolved. The solution was a thin silicon photoresist in liquid form.

[0086] Example 3: Preparation of Thick Silicon Photoresist Coating Composition

[0087] Twenty grams of the silicon-containing polymer resin obtained as discussed in Example 1 was combined with 30 grams of n-butanol, 10 grams of propylene carbonate, 0.008 grams of benzyltrimethylammonium chloride, and 0.24 grams of mixed triarylsulfonium hexafluoroantimonate (TR-PAG-201, Changzhou Qiangli Electronic New Materials Co., Ltd., China) in a container and mixed until all ingredients were dissolved. The solution was a thick silicon photoresist in liquid form.

[0088] Example 4: Formulation of Thin Hydrocarbon BARC Compositions

[0089] Two grams of polystyrene resin having a weight average molecular weight of 50,000 Daltons was dissolved in 200 grams of 1-methoxy-2-propanol acetate. The solution was a thin hydrocarbon BARC in liquid form.

[0090] Example 5: Preparation of Thick Hydrocarbon BARC Compositions

[0091] One hundred and eighty grams of acrylonitrile-styrene copolymer resin having a weight average molecular weight of 50,000 Daltons was dissolved in 720 grams of 1-methoxy-2-propanol acetate. This solution is acrylonitrile-styrene thick hydrocarbon BARC in liquid form.

[0092] Example 6: Formulation of another thick hydrocarbon BARC composition

[0093] Forty grams of a 9,000 dalton weight average molecular weight novolac, 4 grams of hexamethoxymethylmelamine and 0.4 grams of p-toluenesulfonic acid were dissolved in 92 grams of 1-methoxy-2-propanol acetate and 40 grams of 1-methoxy-2-propanol. This solution was a liquid form of novolac BARC.

[0094] Example 7: Formulation of Thin Silicon BARC Compositions

[0095] In a 500-mL round-bottom flask, 52 grams of methyltrimethoxysilane, 8 grams of phenyltrimethoxysilane and 24 grams of β-(3,4-epoxycyclohexane)ethyltrimethoxysilane, 240 grams of 1-methoxy-2-propanol acetate, 40 grams of water and 8 grams of acetic acid were combined, mixed thoroughly, and distilled for five hours. A silicon-containing polymer resin was formed in the flask. Ten grams of this silicon-containing polymer resin, 0.08 grams of p-toluenesulfonic acid and 590 grams of n-butanol were combined and mixed until all ingredients were dissolved. The solution was a thin silicon BARC in liquid form.

[0096] Example 8: Processing of Thick Silicon Photoresist and Thin Hydrocarbon BARC

[0097] A thin hydrocarbon BARC composition as in Example 4 was spin coated on a silicon wafer at a rotation speed of 2000 revolutions per minute, and then baked at 120°C for 60 seconds to obtain a 17 nanometer film. The thick silicon photoresist composition from Example 3 was then spin coated on the thin hydrocarbon BARC film at a rotation speed of 1000 revolutions per minute to form a film of about 800 nanometers. The wafers with these coatings were image-wise exposed to radiation having a wavelength of 365nm to produce acid in the exposed areas. The wafer was then baked on a hot surface at a temperature of 120°C for 60 seconds. After this baking, the wafer was immersed in a 2.38wt% tetramethylammonium hydroxide aqueous solution for 20 seconds to form a desired pattern form on the silicon photoresist film.

[0098] Example 9: Process of Thick Silicon Photoresist and Thin Silicon BARC

[0099] The thin silicon BARC composition as in Example 7 was spin coated on a silicon wafer at a rotation speed of 2000 revolutions per minute, and then baked at 150°C for 60 seconds to obtain a film of about 20 nanometers. Then the thick silicon photoresist composition as in Example 3 was spin coated on the thin hydrocarbon BARC film at a rotation speed of 1000 revolutions per minute to form a film with a thickness of 800 nanometers. The wafers with these coatings were image-wise exposed to radiation with a wavelength of 365nm to produce acid in the exposed area. The wafer was then baked on a hot surface at a temperature of 120°C for 60 seconds. After this baking, the wafer was immersed in a 2.38wt% tetramethylammonium hydroxide aqueous solution for 20 seconds to form a desired pattern form on the silicon photoresist film.

[0100] Example 10: Processing of Thin Silicon Photoresist and Thick Hydrocarbon BARC

[0101] A thick hydrocarbon BARC composition as in Example 5 was spin coated on a silicon wafer at a rotation speed of 3000 revolutions per minute and baked at 150°C for 60 seconds to obtain a film of about 2000 nanometers. Then a thin silicon photoresist as in Example 2 was spin coated on the thick hydrocarbon BARC film at a rotation speed of 2000 revolutions per minute to form a film of about 100 nanometers. The wafers with these coatings were image-wise exposed to radiation having a wavelength of 365nm to produce acid in the exposed areas. The wafers were then baked on a hot surface at a temperature of 120°C for 60 seconds. After this baking, the wafers were immersed in a 2.38wt% tetramethylammonium hydroxide aqueous solution for 20 seconds to form the desired pattern form on the silicon photoresist film.

[0102] Example 11: Processing of Thin Silicon Photoresist and Another Thick Hydrocarbon BARC

[0103] A thick hydrocarbon BARC as in Example 6 was spin coated on a silicon wafer at a rotation speed of 3000 revolutions per minute and baked at 150°C for 60 seconds to obtain a film of about 2000 nanometers. The thin silicon photoresist of Example 2 was spin coated on the thick hydrocarbon BARC film at a rotation speed of 2000 revolutions per minute to form a film of about 100 nanometers. The wafers with these coatings were image-wise exposed to radiation having a wavelength of 365nm to produce acid in the exposed areas. The wafers were then baked on a hot surface at a temperature of 120°C for 60 seconds. After this baking, the wafers were immersed in a 2.38 weight percent tetramethylammonium hydroxide aqueous solution for 20 seconds to form the desired pattern form on the silicon photoresist film.

[0104] Example 12: Processing of Thick Silicon Photoresist on HMDS Treated Silicon Surface

[0105] On the surface of the HMDS pretreated silicon wafer, a thick silicon photoresist as in Example 3 was spin-coated at a rotation speed of 1000 revolutions per minute to form a film of about 800 nanometers. The wafers with these coatings were image-wise exposed to radiation having a wavelength of 365 nm to generate acid in the exposed areas. The wafers were then baked on a hot surface at a temperature of 120° C. for 60 seconds. After this baking, the wafers were immersed in a 2.38 weight percent tetramethylammonium hydroxide aqueous solution for 20 seconds to form the desired pattern form on the silicon photoresist film.

[0106] Example 13: Process for Thick Silicon Photoresist on Bare Silicon Surface

[0107] On the surface of the pre-cleaned and pre-dried silicon wafer, a thick silicon photoresist as in Example 3 was spin-coated at a rotation speed of 1000 revolutions per minute to form a film of about 800 nanometers. The wafers with these coatings were image-wise exposed to radiation having a wavelength of 365 nm to generate acid in the exposed areas. The wafers were then baked on a hot surface at a temperature of 120° C. for 60 seconds. After this baking, the wafers were immersed in a 2.38 weight percent tetramethylammonium hydroxide aqueous solution for 20 seconds to form the desired pattern form on the silicon photoresist film.

[0108] The present disclosure further encompasses the following aspects.

[0109] Aspect 1: A method for forming a pattern, the method comprising: providing a substrate in which a pattern is to be formed; forming a silicon photoresist layer on the substrate; exposing a portion of the silicon photoresist to an activating radiation wavelength; curing the silicon photoresist; developing the cured silicon photoresist to remove the portion of the photoresist exposed to the activating radiation wavelength, and etching the substrate to form the pattern.

[0110] Aspect 2: The method according to Aspect 1, wherein the silicon photoresist before curing comprises a silicon-containing resin, a catalyst capable of catalyzing a condensation reaction of the silicon-containing resin, and a photoacid generator, wherein the catalyst is characterized in that it is deactivated by the presence of an acid so that it loses the ability to catalyze the condensation reaction.

[0111] Aspect 3: The method according to aspect 1 or 2, wherein the silicon photoresist comprises at least 35%, preferably at least 40%, and more preferably greater than 41% by weight of atomic silicon based on the total weight of the silicon photoresist.

[0112] Aspect 4: A method according to any one of the preceding aspects, wherein the substrate comprises silicon, polysilicon, silicon dioxide or aluminum-aluminum oxide microelectronic wafers, gallium arsenide, silicon carbide, ceramics, quartz, metal or a combination of two or more thereof.

[0113] Aspect 5: The method according to any one of the preceding aspects, further comprising forming a bottom anti-reflective coating comprising a polymer on the substrate, and wherein the silicon photoresist layer is formed on the bottom anti-reflective coating, wherein the cured silicon photoresist is developed to expose a portion of the bottom anti-reflective coating, and further comprising etching the exposed portion of the bottom anti-reflective coating before etching the substrate to expose a portion of the substrate.

[0114] Aspect 6: The method according to aspect 5, wherein the bottom anti-reflective coating is characterized by one or both of the following: the polymer is not cross-linked; the bottom anti-reflective coating includes a chromophore that is not grafted to the polymer.

[0115] Aspect 7: The method of aspect 5 or 6, wherein the bottom anti-reflective coating comprises a hydrocarbon-containing polymer.

[0116] Aspect 8: The method of aspect 5 or 6, wherein the bottom anti-reflective coating comprises a silicon-containing polymer.

[0117] Aspect 9: The method of aspect 8, wherein the bottom anti-reflective coating is derived from an alkyl siloxane, an alkyl silsesquioxane, an aryl siloxane, an aryl silsesquioxane, an alkenyl siloxane, an alkenyl silsesquioxane, or a combination of two or more thereof.

[0118] Aspect 10: The method of aspect 5, 6 or 7, wherein the bottom anti-reflective coating is not cross-linked.

[0119] Aspect 11: The method of aspect 5, 8 or 9, wherein the bottom anti-reflective coating is cross-linked.

[0120] Aspect 12: The method according to any one of the preceding aspects, wherein the silicon photoresist layer has a thickness of 2 to 1000 nm.

[0121] Aspect 13: The method according to any one of aspects 5-11, wherein the silicon photoresist layer has a thickness of 2 to 1000 nm, and the bottom anti-reflective coating has a thickness of 2 to 200 nm.

[0122] Aspect 14: A method according to any one of Aspects 5-11, wherein the silicon photoresist layer has a thickness of 2 to 200 nm, preferably 3 to 90 nm, more preferably 5 to 60 nm, and the bottom anti-reflective coating has a thickness of 10 to 2000 nm, preferably 85 to 1000 nm.

[0123] Aspect 15: The method according to any one of the preceding aspects, wherein the substrate comprises a layer in which a pattern is to be formed, the layer comprising polysilicon or silicon oxide.

[0124] Aspect 16: The method of aspect 1, wherein the layer in the substrate consists essentially of silicon or silicon treated with an adhesion promoter.

[0125] Aspect 17: The method according to aspect 16, wherein the adhesion promoter is a silanizing agent.

[0126] Aspect 18: The method according to any one of Aspects 1-4, further comprising forming a bottom anti-reflective coating on the substrate, wherein the silicon photoresist layer is formed on the bottom anti-reflective coating, and wherein the bottom anti-reflective coating comprises a positive photosensitive hydrocarbon-containing composition, wherein the silicon photoresist is exposed to an activating radiation wavelength while a portion of the bottom anti-reflective coating is exposed to the activating radiation wavelength, and further comprising developing the exposed bottom anti-reflective coating to remove the exposed portion of the photosensitive bottom anti-reflective coating and expose a portion of the substrate.

[0127] Aspect 19: The method according to aspect 18, wherein the photosensitive hydrocarbon-containing composition comprises a novolac resin and a diazonaphthoquinone.

[0128] Aspect 20: The method according to aspect 18 or 19, wherein the developing of the bottom anti-reflective coating and the developing of the silicon photoresist are simultaneously performed using an alkaline solution.

[0129] Aspect 21: An article made by the method of any one of aspects 1-20.

[0130] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., the range of "up to 25 wt %, or more specifically, 5 wt % to 20 wt %" includes the endpoints of the range of "5 wt % to 25 wt %" and all intermediate values, etc.). In addition, the upper and lower limits can be combined to form ranges (e.g., "at least 1 or at least 2 weight percent" and "up to 10 or 5 weight percent" can be combined into the ranges "1 to 10 weight percent" or "1 to 5 weight percent" or "2 to 10 weight percent" or "2 to 5 weight percent").

[0131] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to be limited. As used herein, "a kind of (a)", "an", "the" and "at least one (at least one)" do not represent quantitative limitations, and are intended to include both the singular and the plural, unless the context clearly states otherwise. For example, "element" has the same meaning as "at least one (a)", unless the context clearly states otherwise. "At least one (a)" should not be interpreted as limiting "a kind of (a)" or "a kind of (an)". "Or" means "and / or". As used herein, the term "and / or" includes any and all combinations of one or more related listed items. It will be further understood that the term "comprises" and / or "comprising" or "includes" and / or "including (including)" when used in this specification specifies the presence of stated features, regions, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and / or their groups.

[0132] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless explicitly so defined herein.

[0133] The present disclosure may alternatively include, consist of, or consist essentially of any suitable component disclosed herein. Additionally or alternatively, the present disclosure may be formulated to lack or be substantially free of any component, material, ingredient, adjuvant, or substance used in prior art compositions or otherwise not necessary for achieving the functions and / or purposes of the present disclosure.

[0134] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term in the present application takes precedence over the conflicting term in the incorporated reference.

[0135] Unless specified to the contrary herein, all test standards are the most current standards in effect as of the filing date of this application or, if priority is claimed, the filing date of the earliest priority application in which such test standard appears.

Claims

1. A method for forming a pattern, the method comprising: providing a substrate in which a pattern is to be formed; forming a silicon photoresist layer on the substrate; exposing a portion of the silicon photoresist to an activating radiation wavelength; curing the silicon photoresist; developing the cured silicon photoresist to remove the portions of the photoresist exposed to the activating radiation wavelength, and The substrate is etched to form the pattern.

2. The method according to claim 1, wherein: The silicon photoresist comprises a silicon-containing resin, a catalyst capable of catalyzing a condensation reaction of the silicon-containing resin, and a photoacid generator before curing, wherein the catalyst is characterized in that it is deactivated by the presence of an acid so that it loses the ability to catalyze the condensation reaction.

3. The method according to claim 1 or 2, wherein: The silicon photoresist includes at least 35 wt %, preferably at least 40 wt %, or more preferably greater than 41 wt % atomic silicon based on the total weight of the silicon photoresist.

4. A method according to any one of the preceding claims, wherein: The substrate includes silicon, polysilicon, silicon dioxide or aluminum-aluminum oxide microelectronic wafers, gallium arsenide, silicon carbide, ceramic, quartz, metal, or a combination of two or more thereof.

5. The method of any one of the preceding claims, further comprising forming a bottom anti-reflective coating comprising a polymer on the substrate, and wherein the silicon photoresist layer is formed on the bottom anti-reflective coating layer, wherein the cured silicon photoresist is developed to expose a portion of the bottom anti-reflective coating layer, and Further comprising etching the exposed portion of the bottom anti-reflective coating before etching the substrate to expose a portion of the substrate.

6. The method according to claim 5, wherein: The bottom anti-reflective coating is characterized by one or both of the following: The polymer is not cross-linked; The bottom anti-reflective coating includes a chromophore that is not grafted to the polymer.

7. The method according to claim 5 or 6, wherein: The bottom anti-reflective coating includes a hydrocarbon-containing polymer.

8. The method according to claim 5 or 6, wherein: The bottom anti-reflective coating includes a silicon-containing polymer.

9. The method according to claim 8, wherein: The bottom anti-reflective coating is derived from an alkyl siloxane, an alkyl silsesquioxane, an aryl siloxane, an aryl silsesquioxane, an alkenyl siloxane, an alkenyl silsesquioxane, or a combination of two or more thereof.

10. The method according to any one of claims 5, 6 or 7, wherein: The bottom anti-reflective coating is not cross-linked.

11. The method according to any one of claims 5, 8 or 9, wherein: The bottom anti-reflective coating is cross-linked.

12. A method according to any one of the preceding claims, wherein: The silicon photoresist layer has a thickness of 2 to 1000 nm.

13. The method according to any one of claims 5 to 11, wherein: The silicon photoresist layer has a thickness of 2 to 1000 nm, and the bottom anti-reflective coating layer has a thickness of 2 to 200 nm.

14. The method according to any one of claims 5 to 11, wherein: The silicon photoresist layer has a thickness of 2 to 200 nm, preferably 3 to 90 nm, more preferably 5 to 60 nm, and the bottom anti-reflective coating has a thickness of 10 to 2000 nm, preferably 85 to 1000 nm.

15. A method according to any one of the preceding claims, wherein: The substrate includes a layer in which a pattern is to be formed, the layer including polysilicon or silicon oxide.

16. The method according to claim 1, wherein: The layer in the substrate consists essentially of silicon or silicon treated with an adhesion promoter.

17. The method according to claim 16, wherein: The adhesion promoter is a silanizing agent.

18. The method according to any one of claims 1 to 4, further comprising forming a bottom anti-reflective coating on the substrate, wherein the silicon photoresist layer is formed on the bottom anti-reflective coating, and wherein the bottom anti-reflective coating comprises a positive photosensitive hydrocarbon-containing composition, wherein the silicon photoresist is exposed to the activating radiation wavelength while a portion of the bottom anti-reflective coating is exposed to the activating radiation wavelength, Further comprising developing the exposed bottom anti-reflective coating to remove the exposed portion of the bottom anti-reflective coating and expose a portion of the substrate.

19. The method according to claim 18, wherein: The photosensitive hydrocarbon-containing composition includes a novolac resin and a diazonaphthoquinone.

20. The method according to claim 18 or 19, wherein: The development of the bottom anti-reflective coating and the development of the silicon photoresist are performed simultaneously using an alkaline solution.

21. An article made by the method of any one of claims 1-20.

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