WO1998037458A1

WO1998037458A1 - Resist composition

Info

Publication number: WO1998037458A1
Application number: PCT/JP1998/000705
Authority: WO
Inventors: Atsushi Sone; Kimiaki Tanaka
Original assignee: Nippon Zeon Co., Ltd.
Priority date: 1997-02-20
Filing date: 1998-02-20
Publication date: 1998-08-27

Abstract

A resist composition comprising (A) a high-molecular compound having at least one functional group which is decomposed by an acid to impart alkali solubility and containing no aromatic rings, (B) a compound which generates an acid upon irradiation with an actinic radiation, and (C) an amine having a molecular weight of 100 to 240 and a boiling point at 760 mmHg of 200 to 350 °C.

Description

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1

Description Register composition Technical field

The present invention relates to a resist composition useful for manufacturing an integrated circuit (IC), a large-scale integrated circuit (LSI), or the like using a lithography technique. The present invention relates to a resist composition useful for manufacturing semiconductor devices by ultra-fine processing using activating radiation such as far-ultraviolet rays such as ArF excimer lasers, charged particles such as electron beams, and X-rays. Background art

When manufacturing semiconductor devices such as ICs and LSIs, liquid crystal display substrates (LCDs), and print substrates (PWBs), a fine pattern is formed on the substrate using lithography technology. I have. Specifically, in the lithography technology, (1) a photosensitive polymer material called a resist is dissolved in an organic solvent on a substrate such as a silicon wafer on which a layer to be processed (for example, an oxide film) is formed. The resist solution is applied, and the excess organic solvent is evaporated by a pre-bake to form a resist film. (2) The resist film is partially exposed to light (ultraviolet rays, (Ultraviolet rays, electron beams, X-rays, etc.) to form a latent image. (3) Use a developer to remove unnecessary portions of the resist film to form a negative or positive resist pattern. ④ Dry etching of the exposed surface of the substrate etc. using this resist pattern as an etching resistant mask. ⑤ Finally, removing unnecessary resist. I have.

By the way, in recent years, ICs and LSIs, and very large scale integrated circuits (VLSI) As the integration, density, size, and speed of semiconductor devices increase, the demand for fine processing of semiconductor devices increases.

A technology capable of forming a fine pattern of 0.5 / m or less is required. However, it is extremely difficult to form such a fine pattern by the conventional lithography technology using visible light or near-ultraviolet light having a wavelength of 350 to 450 nm as an exposure source. And the yield has been significantly reduced. For this reason, instead of visible light and near-ultraviolet light, in order to increase the exposure resolution, far-ultraviolet light (short-wave ultraviolet light) with a short wavelength, a KrF excimer laser with a wavelength of 248 nm, and a wavelength of 193 A lithographic technique using a nm ArF excimer laser is being studied.

Conventionally, in one lithographic technique utilizing near-ultraviolet light, a novolak resin is used as a base polymer for a resist. However, although nopolak resin has good transparency to ultraviolet light with a wavelength of 350 to 450 nm, it has a shorter wavelength of far ultraviolet light and a KrF or ArF excimer laser. For light having a very short wavelength, such as that described above, the transmittance is extremely deteriorated. Therefore, if a resist using a novolak resin as a base polymer was used, there was a problem that sufficient sensitivity could not be obtained and the pattern shape was poor.

In recent years, as a method of increasing the sensitivity of a resist, research and development of a chemically amplified resist using a photoacid generator as a photosensitive agent have been advanced. Representative examples of chemically amplified resists include, for example, (1) a base polymer, (2) a photoacid generator (a compound that generates an acid by light irradiation), and (3) an acid sensitive substance (light A three-component resist composition is known, which reacts with an acid generated from an acid generator by irradiation as a catalyst to change the solubility of a base polymer. In addition, as a chemically amplified resist: (1) Protect the functional group that controls the solubility of the base polymer with an acid-labile group A two-component resist composition comprising a (blocked) polymer compound and a photoacid generator is known. In the chemically amplified resist composition, the acid (protonic acid) generated by the photoacid generator upon irradiation with light is transferred to the resist solid phase by heat treatment after exposure to light. Acids are used to catalytically amplify chemical changes in the base polymer and other components. For example, in the above-mentioned two-component chemically amplified resist composition, the protecting group is removed by a chain reaction using an acid generated by light irradiation as a catalyst, so that the base polymer can be used in a developer. Restores solubility.

Conventionally, various proposals have been made on chemically amplified resist compositions that can be exposed using activating radiation having a short wavelength such as a KrF excimer laser. Japanese Patent Application Laid-Open No. 5-249673 discloses a photosensitive composition comprising a resin binder and a photoacid generator, wherein the resin binder comprises a phenolic unit and a non-aromatic cyclic compound. A photosensitive composition comprising a polymer having an alcohol unit, wherein at least a part of the hydroxyl group of the polymer is protected by an acid labile (1 abi 1 e) group. Proposed. In this photosensitive composition, as a base polymer, a polymer formed by partial hydrogenation of a novolak resin or a poly (vinyl alcohol) is used. By using a partially hydrogenated polymer as the base polymer, the transmittance for short-wavelength activating radiation can be increased. However, such as ArF excimer laser exposure In lithography using light having a shorter wavelength, it is not preferable that an aromatic ring absorbing the shorter wavelength be present in the base polymer.

For this reason, Japanese Patent Application Laid-Open Publication No. Hei 7-199467 describes a polymer having no aromatic ring as a “polymer compound containing a group that converts polarity by reacting with an acid”. Lulic acid ester copolymers [for example, tricyclodecanoinolemethacrylate, tetrahydrobiranylmethacrylate / It is proposed to use methacrylic acid copolymer]. In addition, many proposals have been made for chemically amplified resist compositions using a (meth) acrylic acid ester copolymer as a base polymer. Among them, there are many proposals. (Meth) acrylic acid ester with an adamantan skeleton or a norbornane skeleton in the ester part to improve the transmittance to short-wavelength activating radiation such as far ultraviolet light Attention has been drawn to resist compositions using (co) polymers as the base polymer (Japanese Patent Application Laid-Open Nos. 4-36965 and 5-257284). Gazette, JP-A-5-265215, JP-A-7-234511).

However, research on lithography using short-wavelength activating radiation such as an ArF excimer laser has not yet reached a practical level, and resolution, sensitivity, pattern shape, At present, the emergence of a new registry is desired in order to obtain a highly excellent balance of various registry characteristics such as mask linearity.

Since the amount of acid generated by exposure to light is very small, the chemically amplified resist composition may cause an abnormality in the cross-sectional shape of the pattern due to the influence of the surroundings. For example, under the influence of the substrate material, a footing may occur at the interface between the pattern and the substrate. When the acid is neutralized by a trace amount of a basic substance present in the atmosphere and loses its catalytic activity, a poorly soluble layer is formed on the resist pattern film surface, and this poorly soluble layer is formed. It is known that it remains like an eave (T-Topping).

In order to solve the above problems, JP-A-6-26611 discloses that (a) an alkali-soluble polymer of an alkali-soluble polymer is modified by an acid-labile group. A chemically amplified resist composition comprising a protected polymer and (b) a compound capable of generating an acid upon exposure to light, It has been proposed to add an amine compound selected from the group consisting of an imidazole compound, an alanine compound, an adenine compound, and an adenosine compound. However, since these amine compounds are strongly basic or sublimable compounds having no boiling point, there was a problem in the storage stability of the resist composition. Further, in the chemically amplified resist composition, as the polymer of the component (a), an alcohol-soluble polymer having a phenol skeleton is regarded as a polymer. However, since the phenolic hydroxyl group is etherified or esterified by treating it with an etherified ester IJ or an esterifying agent, the transmittance of short-wavelength activating radiation is reduced. Not enough.

Further, Japanese Patent Application Laid-Open No. 7-129929 proposes to add a basic compound having a pKa of 6 or less to a chemically amplified resist composition. However, the basic compound used in the examples is a low-boiling amide compound such as pyridine or N-methylaniline, and in a semiconductor manufacturing process including a step of baking at a high temperature, It does not always provide sufficient performance. In the chemically amplified resist composition, the base polymer is an aromatic ring-containing polymer such as polyvinyl phenol or partially hydrogenated polyvinyl phenol. , The transmittance of short-wavelength activating radiation is not sufficient. Disclosure of the invention

An object of the present invention is to form a pattern having a high sensitivity and a high resolution with respect to short-wavelength activating radiation, a good cross-sectional shape, a good mask linearity, and a light exposure. An object of the present invention is to provide a chemically amplified resist composition having excellent post-baking resistance and excellent storage stability. The present inventors have conducted intensive studies to overcome the above-mentioned problems of the prior art. (1) Protecting the functional group that controls the solubility of the base polymer with an acid-labile group The chemically amplified resist composition containing the polymer compound obtained above and (2) a photoacid generator has, as the polymer compound, a functional group which is decomposed by an acid to impart solubility to the acid. By using a polymer compound having no aromatic ring and selecting and adding specific amines, a chemically amplified resist in which the above-mentioned various properties are highly balanced is obtained. It has been found that a composition can be obtained. The present invention has been completed based on these findings.

Thus, according to the present invention, a polymer compound (A) having a functional group which is decomposed by an acid to impart solubility, and has no aromatic ring, is obtained by irradiation with activating radiation. A compound (B) which generates an acid and an amine (C) having a molecular weight of 100 to 240 and a boiling point of 200 to 350 ° C at 760 mmHg. ) Is provided. BEST MODE FOR CARRYING OUT THE INVENTION

(A) Polymer compound

The polymer compound (A) used in the present invention is a polymer compound having a functional group that is decomposed by an acid to impart alkali solubility and does not have an aromatic ring such as a benzene nucleus. . Here, the high molecular compound having a functional group that is decomposed by an acid to impart alkali solubility generally refers to an alkali-soluble group of an alkali-soluble polymer that is not stable to an acid. It is a polymer protected by a group.

Examples of the functional group that is decomposed by an acid to impart alkanol solubility include t-butyl ester group and t-butyl carbonate described in Japanese Patent Publication No. 2-27660; Japanese Patent Publication No. 5 — 6 9 4 2 0 Tertiary alkyloxy group, t-aminoloxy group, t-aminoloxycarbonyl group, tertiary alkyloxy group, tertiary alkyloxycarbonyl group, tertiary alkyloxycarbonyloxy group; -Acetal structure described in Japanese Patent Application Laid-Open No. 4-3451; Ketal structure described in Japanese Unexamined Patent Application Publication No. 2-161634; A quinoleoxy cycloanolequinoleoxy group, a 1-alkylcycloanolequinoxycarbonyl group; a substituted aryloxy group or a substituted aryl group having two or more functional groups described in JP-A-8-21613; Roxycarbonyl group, substituted aryloxycarbonyloxy group; 1-viranyl group, 3-methyl- 1-viranyl group, etc. Substitutable 1-viranyl group; 3-oxocyclohexyl group Or 5—Me 3 Substitutable such as oxocyclohexyl group, etc. Substitutable such as 3-oxocyclohexyl group; 3- (5-pentanoid) group, 3-methyl-5- (5-pentanoide) group 3 — (5 — pentanoide) group; 2 — methyl-1 2 — adamantyl group etc. Substitutable 2 — adamantyl group; cyclic ester-containing groups such as mevalonic crackon group Is exemplified. These groups may be directly bonded to the base polymer, or may be bonded via a divalent or higher valent organic group.

Specific examples of such a polymer compound (A) include 2-substituted 2-norbornane-2-substituted methacrylate esters described in JP-A-5-80515. A copolymer of an acrylate ester compound having a norpolnanone skeleton in the ester moiety and an adamantan skeleton in the ester moiety described in JP-A-5-257284 (Co) polymers of acrylate esters based on acrylates and acrylates having an adamantanone skeleton in the ester moiety described in JP-A-5-265212 Copolymers of lylic acids with tetrahydroviranyl ester, (meta) acrylic acid 3 —isolated as described in JP-A-5-346666 Copolymers having repeating units derived from hexyl hexyl, (1) a (meth) acrylate having a functional group decomposed by an acid, and (2) an alicyclic alkyl (meta) acrylate. Copolymers with relays and the like can be mentioned.

Among these polymer compounds (A), a copolymer containing a structural unit derived from an alicyclic alkyl (meth) acrylate is preferable because it has excellent register properties. In addition, the polymer compound (A) has a (meth) acrylate (a ^) having a functional group decomposed by an acid and an alicyclic alkyl (meth) acrylate (a _The copolymer (A) with ₂ ) is more preferable in order to achieve a high balance of resist properties. The polymer (A) is a functional group that is decomposed by an acid. In many cases, it is more preferable that the copolymer is a copolymer of methacrylate having a methacrylate and an alicyclic alkyl methacrylate. A copolymer of a (meth) acrylate compound having a cyclic ester such as an amino acid structure and a (meta) acrylate compound having an adamantane skeleton in an ester portion is exemplified.

More specifically, a (meth) acrylate having a functional group that can be decomposed by an acid (where a ^ is (soil) is a nickel lactone (Meta) acrylates are preferred, (c) nick lactones are preferred, and alicyclic alkyl (meta) acrylates are preferred. As the create (a ₂ ), 2-methinolate 2-adamantyl (meta) acrylate is preferable, and 2-methylone 2-adamantyl methacrylate Is more preferred.

More specifically, the polymer compound (A) is formed by co-polymerization of (Sat) -mevalonic crack methacrylate and 2—methyl-1-2—adamantyl methacrylate. Most preferably, they are united. Such a copolymer is represented by the formula (1)

[Wherein, R ¹ and R ² each independently represent an alkyl group having 1 to 3 carbon atoms, m and n each represent a ratio of each repeating unit, and m: n is a molar ratio, usually 30: 70 to 70: 30; preferably 40: 60 to 60: 40, more preferably 45: 55 to 55: 45. ]

Can be represented by In this copolymer, if the structural unit derived from the compound having an adamantan skeleton in the ester portion is too small, sufficient dry etching resistance cannot be obtained, and if it is too large, adhesion to the substrate will be poor. Neither is preferred.

In the formula (1), examples of the alkyl group having 1 to 3 carbon atoms include a linear or branched alkyl group such as a methyl group, an ethyl group, a propyl group, and an isopropyl group. Particularly preferred examples of the copolymer represented by the formula (1) include 2-methyl-2 -adamantyl methacrylate in which R ¹ is a methyl group, and R ^{2 in a} methyl group. Certain (Sat) is a copolymer with nickel lactone methacrylate. Such a copolymer is prepared, for example, by dissolving a monomer component in an organic solvent, adding a polymerization initiator such as azosobutyronitrile, and reacting at a reaction temperature of 40 to 150 ° C. It can be obtained by reacting for 1 to 24 hours. After the polymerization reaction, it can be optionally purified by a conventional method.

The weight average molecular weight (Mw) of the polymer compound (A) used in the present invention is not particularly limited, but is usually from 1,000 to 100,000, preferably More preferably, it is 2, 000 to 50,000, 0000, more preferably, 3, 000 to 20, 0, 000. If the weight average molecular weight of the high molecular compound (A) is too low, the resist film tends to be brittle and the heat resistance of the resist film tends to decrease. Conversely, if the weight average molecular weight is too high, There is a problem that the resist film becomes cloudy during coating.

The weight-average molecular weight / number-average molecular weight (MwZMn) of the polymer compound (A) used in the present invention is usually from 1.0 to 3.0, preferably from 1.0 to 2.5. Preferably it is between 1.0 and 2.0. Here, both the weight average molecular weight (M w) and the number average molecular weight (M n) were measured using a refractive index meter (RI) in gel solvent in tetrahydrofuran solvent. It is measured as a polystyrene equivalent value measured by chromatography.

(B) Photoacid generator

The resist composition of the present invention contains the polymer compound (A) and a compound (B) that generates an acid upon irradiation with activating radiation (that is, a photoacid generator; PAG). It is a chemically amplified resist. An acid is generated from the photoacid generator by the irradiation of the activating radiation, and the acid is used as a catalyst to remove the protecting group of the polymer compound (A) in a chain reaction, thereby improving the alkali solubility. I do.

The photoacid generator (B) used in the present invention is not particularly limited as long as it is a substance that generates brenstead acid or Louis acid when exposed to activating radiation. , A halogenated organic compound, a quinone diazide compound, a, a'-bis (sulfonyl) diazomethane compound, α-force olevoninole α'-sulfoninoresizometanide compound, a sulfone compound, Known compounds such as organic acid ester compounds, organic acid amide compounds, and organic acid imide compounds can be used. Examples of sodium salts include sodium salts such as diazonium salts, ammonium salts, diphenyl-donium triflate; sulfonates such as triphenylsulfonium triflate; Dimethyl salt; examples include phosphonium salt, arsonium salt, and oxonium salt.

Examples of halogenated organic compounds include halogen-containing oxazine-based compounds, halogen-containing triazine-based compounds, halogen-containing acetate-non-compounds, and halogen-containing benzophenone-containing compounds. Compounds, halogen-containing sulfoxide compounds, halogen-containing sulfon compounds, halogen-containing thiazole compounds, halogen-containing oxazole compounds, and halogen-containing triazoles Compounds, halogen-containing 2-pyrone compounds, other halogen-containing heterocyclic compounds, halogen-containing aliphatic hydrocarbon compounds, halogen-containing aromatic hydrocarbon compounds, sulfenylhalai Compounds. More specifically, examples of the halogenated organic compound include tris (2,3—dibromopropinole) phosphate and tris (2,3—jib-mouth). (B) Propinolate) Phosphate, Tetrabromochlorobutane, Hexaclo benzene, Hexabromobenzene, Hexabuta Cyclododecane, Heki Micrododesen for sub mouth, Mobifenil for hex sub mouth, bisect phenyl alcohol, Tetraclo bis bisphenol A, Tetrablo bisphenol Bis (chloroethyl) ether of bisphenol A, bis (chloroethyl) ether of tetrachloro, bis (bromoethyl) ether of tetrabromobisphenol A, bisphenol -Nore A's screw (2,3 Pill) Ether, bisphenol A bis (2,3—dipropyl propyl) Ether, tetrachloride bisphenol A bis (2,3—dichloropropyl) Ether, Tetrabromobisphenol A bis (2,3—dibromopropyl) Ether, Tetraclo mouth bis Phenolone S, Tetrabromobisphenol 3, Tetraclos-opened bisphenol S bis (chloroethyl) ether, Tetrabromobisphenol Bis (bromoethyl) ether of enol S, bis (2,3—dichloropropyl) ether of bisphenol S, bis (23—dibro) of bisphenol S Mopropyr) Ether, Tris (2,3—dibromopropyl) Isonurate, 22—Bis (4hydroxy-3-5—dibromophenyl) Halogen flame retardants such as bis, bis (bis- (2-hydroxyloxy) 1-3, 5-dibromophenyl) Eniltrichloroethane, Pentachlorophenyl, 2, 4, 6 Cloth mouth 4-Nitrophenyl ether, 2,4-dichlorobenzene 3 '-Methoxy 1 4' Trophenylene ether, 2, 4-Dichlorophenoxyacetic acid, 4, 5, 6, 7—Tetrachlorophthalide, 1, 1—Bis (4—Chlorophenyl) ethanol , 1, 1 — Screws (41 cross mouths) 12, 2, 2 — Tricro mouths Ethanol holes, 2, 4, 4 ', 5 — Tetrakuro mouths Examples thereof include divinyl sulfide, 2, 4, 4 ', and 5—organic macro-pesticides such as tetrachloro diphenyl sulfone; and the like. Examples of quinone diazide compounds include 1,2—benzoquinone diazide 4—snolefonic acid ester and 1,2—naphthoquinone diazide. 4-Sulfonate ester, 1, 2-Naphthoquinone diazide 1-5-Sulfonate ester, 2, 1-Naphthoquinone diazide 4-Sulfonate Acid ester, 2,1—benzoquinonediazide-15-sulfonate of quinonediazide derivative such as sulfonate ester; 1,2-benzoquinodia 1-2-diazido 4-snorrephonic acid chloride, 1, 2-naphthoquinone 1-2-diazide 1-4-sulphonic acid chloride, 1, 2-naph Tokinon-1 2 — Diazide 5 — Sulfonic acid chloride, 1, 2 —Naphthoquinone 1 —Diazido 6 —Sulfonyl chloride, 1,2 —Benzoquinone-1-diazide-1 5 —Quinondiazide derivative such as sulfonyl chloride Sulfonyl chloride; and the like.

a, a'—Examples of bis (sulfonyl) diazomethane compounds include unsubstituted, symmetrically or asymmetrically substituted alkyl, alkenyl, aralkyl, aromatic, and the like. And a, a'-bis (sulfonyl) diazomethane having a heterocyclic group. Examples of a-carbonyl-unsulfonyldiazomethane compounds include unsubstituted, symmetrically or asymmetrically substituted alkyl, alkenyl, aralkyl, aromatic, And carbonyl-α-sulfoninoresizomethane having a heterocyclic group. Examples of the sulfone compound include a sulfone compound having an unsubstituted, symmetrically or asymmetrically substituted alkyl group, alkenyl group, aralkyl group, aromatic group, or heterocyclic group. And disulfone compounds.

Examples of the organic acid ester include a carboxylic acid ester, a sulfonate, a phosphate and the like. Examples of the organic acid amide include carboxylic acid amide, sulfonate amide, and phosphoric acid amide. Examples of the organic acid imide include a carboxylic acid imide, a sulfonate imide, and a phosphoric acid imide.

The above-mentioned photoacid generator is also used for a KrF excimer laser resist, and among these, the wavelength near the ArF excimer laser (18) (5.5 to 220 nm), for example, the formula (2) disclosed in Japanese Patent Application Laid-Open No. R,

(2)

R ₂ -S ⁺ -R ₃

Y—

[Wherein, and R. Is a linear, branched or cyclic alkyl, R ₃ is a linear, branched or cyclic alkyl group, a 2-oxo cyclic alkyl group, or a 2-oxo linear chain Joma other branched alkyl group, Y one is, BF, A s -, S b F 6 -, PF 6 -, CF 3 C 0 0 one, C 1 0 ₄ - or the CF ₃ S 0 ₃ — And so on. ]

And formula (3)

[Wherein, and R ₂ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group; Is a hydrogen atom, a straight-chain, branched or cyclic alkyl group, or a haloalkyl group represented by a benzoalkyl group such as trifluorophenol. ]

The compound represented by is preferred. Specific examples of these compounds include, for example, cyclohexylmethyl (2-year-old cyclohexyl) sulfonium trifluorene snorrehonate, dicytamine Chromohexyl (2-oxocyclohexyl) sulfonium trifluorene snorehonate, 2-oxocyclohexyl (2-nonorebornyl) ) Sulfonium trifluorene methanol snorehonate, 2-cyclohexenoresinolenorhinolene cyclohexanone, dimethyl (2-year old ciscyclohexyl) Tri-Fol-Lo-Norme, Tri-Fenol Sulfonium, Tri-Fr-No-Sl Tri-no-re-no-me, sn-re-ho-na-to, N-Hydroxy-succinimide-tri-fluoro-no-me-no-s-ho-re-ho-nat, fenirno ,. Rat norenen sulfonate and the like. Further, compounds represented by the following formulas (4) to (13) are preferable as the photoacid generator.

These photoacid generators (B) can be used alone or in combination of two or more. The mixing ratio of the photoacid generator (B) is usually from 0.01 to 50 parts by weight, preferably from 0.2 to 30 parts by weight, per 100 parts by weight of the polymer compound (A). Parts by weight. If the proportion of the photoacid generator is too small, it is difficult to form a resist pattern. On the other hand, if the proportion is too large, development residue tends to be generated during development, and Problems such as the deterioration of the cross-sectional shape of the car.

(C) Amines

In the present invention, as a modifying agent for improving the pattern shape, etc., the molecular weight is 100 to 240, preferably 120 to 220, more preferably 1 to 220. 40-200, boiling point at 720 mm Hg is 200-350. C, preferably using amines at 210-330 ° C.

If the molecular weight of the amines is too large, the melting point generally tends to be high, so that when the resist composition (especially a solution of the resist composition) is stored, or when the resist film is developed with an alkaline developer. However, amines tend to precipitate, and conversely, if they are too small, the boiling point will be low. If the boiling point of amines is too high, the molecular weight usually increases and the molecular structure becomes a bulky compound, so that diffusion in the resist film becomes insufficient and the surface becomes a hardly soluble layer. Pattern shape is reduced due to the influence of If the boiling point of the amines is too low, they will volatilize at the baking temperature at the time of pattern formation, and there is a tendency that a sufficient reforming effect cannot be obtained by the addition.

Specific examples of the amines (C) include, for example, fats such as nonylamine, desilamine, tridecinoleamine, tetradecylamine, pentadecylamine, etc. Aliphatic N-amimins such as Jamilamin; Aliphatic N-amimins such as Triptylamin and Triamilamin; 4-Aminobenzene Benzomin) Aromatic amines such as amin, diphenylamine, tribenzylamine, and cycloaliphatic amines such as hexamethylentramine And the like. Among them, aromatic amines such as diphenylamine and cycloaliphatic amines such as hexamethylenetetramine are preferred.

The mixing ratio of A Mi emissions such (C) is Soo Doo composition (A + B) with respect to 2 0 g, typically, 0. 0 0 IX 1 0 one ⁴ ~ 1 0 0 x 1 0 one ⁴ mol , Preferred Ku is ^{0. 0 1 x 1 0- 4} ~ 1 0 X 1 0 _ 4 mol. When the compounding ratio of the amines is within the above range, various resist properties such as resolution, pattern shape, and maskability are improved.

(D) Solvent

Each component constituting the resist composition of the present invention is usually used by dissolving it in an organic solvent to form a resist film. The proportion of the organic solvent used is such that the components constituting the resist composition are dissolved in a uniform amount. The organic solvent is not particularly limited, and any of those generally used as a solvent for a resist composition can be used.

Is a specific example of the organic solvents, e.g., acetone tons, main Chiruechiruke tons, which keto emissions such as shea click Ropen evening Bruno emissions, Kisano down to shea click b; n - flop ⁰ Bruno Lumpur, i -loop ⁰ Bruno Lumpur, n - butanoate Lumpur, i - butanoate Lumpur, t - butanoate one Honoré, shea click b to hexa Roh one Norre of any Anoreko one Honoré acids; E Ji les ring Li Koruji main Ethers such as ethyl alcohol, ethylene glycol, and dioxane; ethyl alcohol, methyl alcohol, ethylene glycol, ethyl alcohol, etc. Alcohol ethers such as propylene monomethyl ether and propylene glycol monoether; propyl formate, butyrate, propyl acetate, butyl acetate, propionic acid Esters such as methyl, ethyl propionate, methyl butyrate, ethyl butyrate; methyl 2-oxypropionate, methyl 2-oxypropionate, methyl 2-methoxypropionate, 2 — Oxycarbonates such as methyl ethoxypropionate; cello sonolecetate, methyl cellosol acetate, solvent ethyl acetate, solvent sorbate acetate, solvent sorbase acetate, butyl cellulose, etc. Cerro Solves Ternes: propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monobutyl ether Propylene glycols; ethylene glycol, methyl ether, diethyl alcohol methyl ether, diethyl alcohol methyl ether, diethyl glycol 1-Diethylenic alcohols such as rutile ether; Halogenated hydrocarbons such as trichloroethylene; aromatic hydrocarbons such as toluene and xylene N, N-dimethylformamide, N, N-dimethylinolacetamide, N-methylacetamide, N-methylpyro Polar solvents such as redox; and the like. These organic solvents can be used alone or in combination of two or more.

(E) Other additives

Various additives generally added to the resist composition can be added to the resist composition of the present invention, if necessary. Such additives include, for example, silicone-based or fluorine-based surfactants, storage stabilizers, sensitizers, and striation inhibitor. Compatible additives can be mentioned.

(F) Developer

In the resist composition of the present invention, an acid generated from the photoacid generator (B) by the irradiation of the activating radiation acts on the developer of the high molecular compound (A) in the irradiated portion. The solubility changes. That is, the protecting group in the functional group of the polymer compound (A) is removed by the catalytic action of the acid, and the polymer compound is converted into an alkali-soluble group. Therefore, the resist composition of the present invention acts as a post-type resist by using an alkaline developer. The resolution can be improved by adding amines (C). Improves register characteristics such as properties, pattern shape, and maskability.

In the resist composition of the present invention, an alkali developer is usually used as a developer. Specific examples of the alkali developer include, for example, aqueous solutions of inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium gayate, and ammonia; Aqueous solutions of primary amines such as pyramin; Aqueous solutions of secondary amines such as getylamine and dipropylamine; Tertiary amines such as trimethylammine and triethylamine Aqueous solutions of alcohols; aqueous solutions of alcohol amines such as getyl ethanolamine, triethanolamine, etc .; Labylammonium Hydroxide, Trimethyl Hydroxymethylide Ammonium Hydroxide, Triethyl Hydroxymethide A Nmoniu shuttleless Dorokishi de, such as an aqueous solution of Application Benefits main Chinorehi Doroki Shechirua Nmoniu shuttleless Doroki shea de of any quaternary A Nmoniu arm hydroxycarboxylic de is like et be. If necessary, add methanol, ethanol, prono, etc. to the above aqueous solution. A water-soluble organic solvent such as isopropanol, a surfactant, a resin dissolution inhibitor or the like can be preferably added, such as ethanol or ethylene glycol.

(G) Pattern formation method

In order to form a pattern using the resist composition of the present invention, a resist composition solution is applied to a substrate by a method such as spin coating and dried, and dried to a desired film thickness (dry film thickness). Usually, a resist film of about 0.01 / m to 2 ^ m) is formed. This resist film is subjected to butter exposure using activating radiation. As the activating radiation, a short wavelength of 190 to 250 nm, such as a deep ultraviolet ray, a KrF excimer laser, an ArF excimer laser, etc. Light sources can be used. After forming the resist film and before exposure, a temperature within a range where the resist film is not deteriorated by heat, usually 80 to 190 ° C, preferably 100 to 170 ° C Prebaking at ° C is preferred. If the pre-bake temperature is lower than this range, a hardly soluble layer is likely to be generated on the surface, and if the pre-bake temperature is higher, thermosetting or thermal decomposition may occur. I don't like it. When an ArF excimer laser beam that can be exposed through a mask is used as an exposure light source, the effect of the present invention is particularly exerted. After exposure, a post-exposure bake is usually performed. The post-exposure bake temperature is usually 70 to 18 ° C. In order to develop the resist film after the exposure, the above-described developer may be used. Example

Hereinafter, the present invention will be described more specifically with reference to examples. Parts and percentages in each case are by weight unless otherwise specified.

The methods for evaluating the physical properties and register characteristics of the polymer compound are as follows.

(1) Weight average molecular weight (Mw) and number average molecular weight (Mn)

Weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) in tetrahydrofuran solvent using a refractometer (RI). ) Is the Polystyrene conversion value measured by). The measurement conditions are as follows.

Column temperature: 40 ° C

RI temperature: 40 ° C

Column: Two Tosoh columns G500HXL were connected in series. Flow rate of tetrahydrofuran: 1. O ml Z min (2) Composition ratio of copolymer

The composition ratio of the copolymer is a value measured by an ifi-NMR spectrum.

(3) Resolution

The minimum line size (unit: 〃m) where the line width of the line and space (hereinafter abbreviated as L & S) and the space width pass equally And

(4) Sensitivity

The exposure amount (unit: mJ / cm ² ) when the above-mentioned resolution was obtained was defined as the sensitivity.

(5) Hemming

Observe the cross-sectional shape of the pattern, and if the bottom dimension at the interface with the substrate is 10% or more thicker than the pattern size at a height of 0.25 m from the substrate, there is tailing (Table The score was evaluated as “Yes” in the middle, and if less than 10%, there was no tailing (No in the table). (6) Eaves (T—Top)

Observe the cross-sectional shape of the pattern with an SEM (scanning electron microscope). If there is an eaves at the top of the pattern, it is evaluated as T-top ("Ari" in the table). When there was no, it was evaluated as T-no top ("None" in the table).

(7) PED (Post Exposure Delay) resistance

After exposing the resist film at an exposure amount of 0.20 m L & S, the film was left in a room with an ammonia concentration of 0. S ^ g Z cm * ³ for 24 hours, and then 1 3 A BOSS 'exposure' bake (PEB) after 60 seconds at 0 ° C was performed, and after further development, the cross-sectional shape of the obtained pattern was observed by SEM. On the other hand, the same exposure Immediately after exposure without exposure to an ammonia atmosphere, a bake was performed at 130 ° C for 60 seconds, and after further development, the cross-sectional shape of the obtained pattern was observed by SEM. . Those with no change in the pattern shape were evaluated as “good”, and those with change were evaluated as “bad”.

(8) Mask cleanliness

The resist film is exposed at an exposure amount such that the L & S line width and space width of 0.2 μm pass through at the same length, and then the exposure starts from the 0.1 m L & S. The actual dimensions of the 25 μm L & S were measured with a length-measuring SEM, and how much the dimensions differed from the mask dimensions was measured. If the difference is less than 10% of the mask dimension, it is judged that there is mask linearity ("Yes" in the table), and if it is more than 10%, there is no mask linearity. ("None" in the table).

(9) Storage stability

The resist composition solution is stored at room temperature for 6 months from the date of manufacture, and after 6 months, the resist composition solution is applied on a silicon wafer substrate, and a dust inspection device (silicon wafer surface) is applied. (Manufactured by Topcon Corporation). Those with less than 50 particles were evaluated as having good storage stability ("good" in the table), and those with 50 or more particles were evaluated as having poor storage stability ("bad" in the table). .

[Examples 1 and 2, and Comparative Examples 1 to 5]

The polymer compound (A) is mevalonic lactone methacrylate (MLMA) / 2-methyl-12-adamantyl methacrylate (2MAdMA) copolymer [composition ratio (MLMA: 2MA d MA) = 50: 50, M w = 9,65 8. Mw / M n = 2.17) 100 parts by weight and triphenylsulfonate as photoacid generator (B) Muturi Fluoro Meter 2 parts by weight of sodium hydroxide were dissolved in ethyl lactate, and then the compounds listed in Table 1 were added as amines at the blending ratio shown in Table 1 (ratio to 20 g of the resist composition). Was dissolved. The resulting solution was filtered using a 0.1 l / im filter made of Polytetrafluoroethylene (manufactured by Millipore) to prepare a solution of the resist composition.

This resist composition solution was spin-coated on a silicon wafer to a film thickness of 0.5 μm, and then pre-baked at 130 ° C for 60 seconds. Was. In the earthenware pots good this to shea Re co down Les Soo preparative film formed on the wafer, A r F excimer laser beam stearyl horns, ⁰ exposure using the (NA = 0. 5 5) was carried out. After the exposure, a post-exposure bake is performed at 130 ° C for 60 seconds, and then an immersion development is performed for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution. Rinse with pure water to obtain a positive pattern. Table 1 shows the results.

From the results in Table 1, it can be seen that the chemically amplified resist composition to which the amine having a molecular weight of 100 to 240 and a boiling point of 200 to 350 ° C is added is an ArF ferrite. Exposure with a single laser beam (193 nm wavelength) provides excellent resolution and It showed a pattern shape and maskability, and was found to be excellent in sensitivity, PED resistance, storage stability, etc. Industrial applicability

According to the present invention, a mask having high sensitivity, high resolution, and a good cross-sectional shape can be formed with respect to short-wavelength activating radiation such as an ArF excimer laser beam, and a mask can be formed. A chemically amplified resist composition having good linearity, excellent PED resistance, and excellent storage stability is provided. The resist composition of the present invention is useful when manufacturing semiconductor elements such as ICs and LSIs, liquid crystal display substrates, print substrates, and the like by lithography technology, It is suitable for a semiconductor element manufacturing process that requires pattern formation.

Claims

The scope of the claims

1. High molecular compound (A) that has a functional group that is decomposed by an acid to impart solubility, and has no aromatic ring (A), and a compound that generates an acid upon irradiation with activating radiation (B) , And a resist composition containing an amine (C) having a molecular weight of 100 to 240 and a boiling point of 76 to 350 ° C at 76 OmmHg. .

2. The polymer compound (A) has a functional group that can be decomposed by an acid (meth) acrylate (a ^ and alicyclic alkyl (meta) acrylate ( _2. The resist composition according to claim 1, which is a copolymer with a ₂ ) (A ^).

3. The registry composition according to claim 2, wherein the (meta) acrylate (a ^ is (soil) one-neck lactone (meta) acrylate. object.

4. alicyclic alkyl (meth) § click Li rate (a ₀₎ is 2 - main Chi Lu 2 - Adama pentyl (meth) § click Li rate der Ru according to claim 2, wherein Re Soo DOO Composition.

5. The copolymer (A is represented by the formula (1)

(1)

[Wherein, R ¹ and R ² are each independently an alkyl group having 1 to 3 carbon atoms, m and n each represent a ratio of each repeating unit, and m: n is a molar ratio of 30: 7. 0 to 70: 30. ]

Where the weight-average molecular weight (Mw) is 1.0000 to 100,000 and the ratio of weight-average molecular weight Z number-average molecular weight (Mw / Mn) is 1.0 to 3.0 3. The resist composition according to claim 2, which is a copolymer falling within the range.

6. Copolymer (A ^ is a mixture of (Sat) one-necked nickel methacrylate and 2—methyl-2—adamantyl methacrylate 6. The resist composition according to claim 5, which is a copolymer.

7. Amines (C) are aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines, aromatic amines, or cycloaliphatic amines. 2. The resist composition according to claim 1, which is a mineral.

8. Aliphatic primary amines are nonylamine, desilamine, tridecinoleamine, tetradecinoleamine, or pen desinoleamine, and aliphatic unsubstituted. Amines are diamylamines, aliphatic tertiary amines, triptylamins, or triamylamines, and aromatic The family amides are di (41-methylbenzyl) amine, diphenylamine, or tribenzilamine, and the cycloaliphatic amines are hexamethylene tentates. 8. The resist composition according to claim 7, which is a lamin.

9. With respect to 100 parts by weight of polymer compound (A), compound (B) that generates acid by irradiation with activating radiation (B) 0.01 to 50 parts by weight, and amines ( C) the registry compositions 2 0 g relative to 0. 0 0 lxl 0 one ^{4 ~ 1 0 0 X 1 0_} 4 mol les Soo DOO composition according to claim 1, further comprising.

10. The resist composition according to claim 1, further comprising an organic solvent in an amount sufficient to uniformly dissolve each of the components (A) to (C).

1 1. On the substrate, a polymer compound (A) that has a functional group that is decomposed by an acid to impart alkali solubility and does not have an aromatic ring. The acid is irradiated by irradiation with activating radiation. Contains the generated compound (B) and the amides (C) having a molecular weight of 100 to 240 and a boiling point of 76 to 350 ° C at 76 OmmHg. A step of forming a resist film made of a resist composition, a step of pattern-exposing the resist film, a step of boosting the resist film after the exposure, And a pattern forming method including a step of developing using an alkaline developer as a developer.