JP2005274594A - Photosensitive resin composition and method for forming resist pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for dry development with which it is possible to form a high resolution pattern with low line edge roughness in a silylation process, and a method for forming the resist pattern. <P>SOLUTION: The photosensitive resin composition used for photolithography, which has high resolution and of which the aspect is heightened, is constructed by including a polymer satisfying a condition of having 1,000-50,000 weight average molecular weight (Mw) in terms of polystyrene and 1.0-1.5 molecular weight variance ((weight average molecular weight)/(number average molecular weight) (Mw/Mn)) in terms of polystyrene as a component (A), and a radiation sensitive acid generating agent as a component (B) and at least one functional group out of a hydroxyl group, a carboxyl group, an amino group, a thiol group and an amide group, protected with an acid dissociative group, as a component (C). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photosensitive resin composition (hereinafter referred to as a resist) used in photolithography, particularly for dry development, and a method for forming a resist pattern using the resist.

  In recent years, in the field of various electronic devices that require fine processing, such as semiconductor devices, there is an increasing demand for higher density and higher integration of devices. Has become essential. In the process of manufacturing such a semiconductor device, photolithography plays an important role in forming a fine pattern.

  Conventionally, a single layer resist has been used in the photolithography process. However, in such a single layer resist, the step difference and inclination of the substrate tend to increase with higher integration, and the depth of focus decreases with the shortening of the wavelength of the light source for high miniaturization and the increase of NA. Due to the tendency to become shallow, it has become difficult to form a thick and high aspect resist pattern with high accuracy.

For this reason, a surface imaging process has been proposed as a method for solving such a problem. In this surface imaging process, only the resist surface of a single layer or a multilayer structure is exposed, and wet development is performed as necessary, and a pattern having high resistance to oxygen dry etching is selectively formed on the resist surface. The part is dry-developed with oxygen plasma.
According to this, since it is only necessary to photoreact only on the resist surface, an exposure apparatus with a shallow depth of focus can be used, and it is difficult to be affected by light reflection from the substrate and steps. Further, since dry etching has high anisotropy, a high aspect resist pattern can be formed. In addition, there are advantages such as no pattern collapse during development and rinsing, and no influence of impurities or deterioration of the developer.

Several surface imaging processes such as silylation processes have been proposed.
For example, there exists a thing as shown to patent document 1 as said silylation process.
This silylation process is a hydroxyl group, a carboxyl group, an amino group, a thiol group, an amide group selectively in either the exposed or unexposed area by exposure and post-exposure heat treatment performed as necessary. The functional groups to be silylated are generated, and these functional groups are silyl etherified with a silylating agent, followed by dry development with oxygen plasma to form a pattern.
Japanese Patent Laid-Open No. 11-282165

The conventional silylation process as shown in Patent Document 1 has a problem in that the line edge roughness is large and the resolution is low.
In the present invention, the line edge roughness is defined as 3σ of the line pattern width. For the measurement, a scanning electron microscope, an atomic force microscope, or the like can be used. In general, it is said that the line edge roughness allowed in device fabrication with a design rule of 100 nm L / S or less is about 5 nm, but the line edge roughness of the pattern fabricated by the conventional resist process is about 10 nm. is there.

  In view of the above-described problems, the present invention provides a photosensitive resin composition for dry development and a method for forming a resist pattern capable of forming a high resolution pattern with low line edge roughness in a silylation process. The purpose is to do.

The present invention provides a photosensitive resin composition and a resist pattern forming method configured as follows.
That is, in the photosensitive resin composition of the present invention, as the component (A), the weight average molecular weight (Mw) is 1,000 to 50,000 in terms of polystyrene, and the molecular weight dispersion (weight average molecular weight / number average molecular weight (Mw / Mn)) a polymer that satisfies the conditions of 1.0 to 1.5 in terms of polystyrene,
(B) a radiation-sensitive acid generator as a component;
(C) at least one functional group of hydroxyl group, carboxyl group, amino group, thiol group, and amide group protected with an acid dissociable group as a component;
It is comprised so that it may contain.
Further, the resist pattern forming method of the present invention includes a laminating step of laminating the above-described photosensitive resin composition on a substrate, and forming an exposed portion by irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays. An exposure step, a step of heating the substrate, a step of silylating the exposed portion, and a dry developing step of removing portions other than the exposed portion of the photosensitive resin composition layer by oxygen plasma. It has the composition provided.

  According to the present invention, in a silylation process, a photosensitive resin composition for dry development capable of forming a high-resolution pattern with low line edge roughness, and formation of a resist pattern using the photosensitive resin composition A method can be realized.

Hereinafter, embodiments of the present invention will be described in detail.
In the present embodiment, first, the photosensitive resin composition containing the components (A), (B) and (C) described above is applied, and the novel is capable of high resolution and high aspect ratio. The photosensitive resin composition will be described. By using this photosensitive resin composition (hereinafter referred to as a resist), a low line edge can be obtained by surface imaging by an arbitrary exposure method and a subsequent selective silylation process. With roughness (hereinafter referred to as LER), a high aspect resist pattern can be formed.

  In the present embodiment, the weight average molecular weight (Mw) of the polymer (A) is preferably 1,000 to 50,000, more preferably 1,000 to 30,000, It is particularly preferably 000 to 20,000. If the weight average molecular weight is less than 1,000, there are problems such as low film-forming properties and low dry etch resistance during the base processing. When the weight average molecular weight exceeds 50,000, the LER increases. However, the weight average molecular weight and number average molecular weight in the present embodiment are values measured by gel permeation chromatography and converted to standard polystyrene.

  The molecular weight dispersion (Mw / Mn) of the polymer in the component (A) is preferably 1.0 to 1.5, more preferably 1.0 to 1.2, and 1.0 to 1.1. It is particularly preferred that When the degree of dispersion is greater than 1.5, the LER is large. When the weight average molecular weight and molecular weight dispersion of the component (A) are small, the component (B) that is a silylating agent is uniformly and densely dispersed. Further, since the permeation rate and the silylation reaction rate of the silylating agent depend on the average molecular weight of the system, if the dispersion of the molecular weight of the component (A) is small, the silylation rate of the component (B) and thus the oxygen dry etch resistance space Distribution is small. For the above reasons, a resist pattern having a small LER is formed according to the present invention.

Examples of the polymer in the component (A) include acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, phenol resins, and the like. Those containing no group, amino group, thiol group or amide group are preferred, those containing an aromatic ring are more preferred, and polystyrene is particularly preferred. When a functional group capable of being silylated such as a hydroxyl group, a carboxyl group, an amino group, a thiol group or an amide group is contained, the silylated contrast is low and the resolution is poor. A polymer containing an aromatic ring has high dry etching resistance when processing the base substrate and has an excellent processing margin.
Polystyrene having a molecular weight dispersion of 1.0 to 1.5 is synthesized by known living anionic polymerization. In living anionic polymerization, the weight average molecular weight is easily controlled by adjusting the weight of monomer and the number of moles of initiator.
In addition, the radiation sensitive acid generator (hereinafter referred to as photoacid generator) in the component (B) is a chemical substance by irradiation with radiation such as charged particles such as infrared rays, visible rays, ultraviolet rays, far ultraviolet rays, X-rays, and electron beams. It is a compound that generates a reaction and generates an acid. Examples of such a photoacid generator include onium salt compounds, sulfone compounds, sulfonic acid ester compounds, sulfonimide compounds, diazomethane compounds, and the like. In the present invention, it is preferable to use an onium salt compound.

  Examples of onium salts include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, ammonium salts, pyridinium salts, and the like. Specific examples of the onium salt compound include bis (4-t-butylphenyl) iodonium perfluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, and bis (4-t-butylphenyl). Iodonium 2-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium pyrenesulfonate, bis (4-t-butylphenyl) iodonium n-dodecylbenzenesulfonate, bis (4-t-butylphenyl) iodonium p- Toluene sulfonate, bis (4-tert-butylphenyl) iodonium benzene sulfonate, bis (4-tert-butylphenyl) iodonium 10-camphor sulfonate, bis (4-tert-butylphenyl) iodonium n-oct Sulfonate, diphenyliodonium perfluoro-n-butanesulfonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium 2-trifluoromethylbenzenesulfonate, diphenyliodonium pyrenesulfonate, diphenyliodonium n-dodecylbenzenesulfonate, diphenyliodonium p-toluenesulfonate, diphenyl Iodonium benzenesulfonate, diphenyliodonium 10-camphorsulfonate, diphenyliodonium n-octanesulfonate, triphenylsulfonium perfluoro-n-butanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium 2-trifluoromethylbenzenesulfone , Triphenylsulfonium pyrenesulfonate, triphenylsulfonium n-dodecylbenzenesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfoniumbenzenesulfonate, triphenylsulfonium 10-camphorsulfonate, triphenylsulfonium n-octanesulfonate, diphenyl ( 4-t-butylphenyl) sulfonium perfluoro-n-butanesulfonate, diphenyl (4-t-butylphenyl) sulfonium trifluoromethanesulfonate, diphenyl (4-t-butylphenyl) sulfonium 2-trifluoromethylbenzenesulfonate, diphenyl ( 4-t-butylphenyl) sulfonium pyrenesulfonate, diphenyl (4-t-butylphenyl) L) sulfonium n-dodecylbenzenesulfonate, diphenyl (4-t-butylphenyl) sulfonium p-toluenesulfonate, diphenyl (4-t-butylphenyl) sulfoniumbenzenesulfonate, diphenyl (4-t-butylphenyl) sulfonium 10-camphor Sulfonate, diphenyl (4-t-butylphenyl) sulfonium n-octanesulfonate, tris (4-methoxyphenyl) sulfonium perfluoro-n-butanesulfonate, tris (4-methoxyphenyl) sulfonium trifluoromethanesulfonate, tris (4-methoxy Phenyl) sulfonium 2-trifluoromethylbenzenesulfonate, tris (4-methoxyphenyl) sulfonium pyrenesulfonate, tris (4-methoxy) Phenyl) sulfonium n-dodecylbenzenesulfonate, tris (4-methoxyphenyl) sulfonium p-toluenesulfonate, tris (4-methoxyphenyl) sulfoniumbenzenesulfonate, tris (4-methoxyphenyl) sulfonium 10-camphorsulfonate, tris (4- And methoxyphenyl) sulfonium n-octanesulfonate.

Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds thereof. Specific examples of the sulfone compound include phenacylphenylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, 4-trisphenacylsulfone, and the like.
Examples of the sulfonic acid ester compounds include alkyl sulfonic acid esters, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates. Specific examples of the sulfonate compound include α-methylol benzoin perfluoro-n-butane sulfonate, α-methylol benzoin trifluoromethane sulfonate, α-methylol benzoin 2-trifluoromethylbenzene sulfonate and the like.

  Specific examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyl). Oxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene -2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) ) Naphthylimide, N- (10-camphorsulfonyloxy) s Synimide, N- (10-camphorsulfonyloxy) phthalimide, N- (10-camphorsulfonyloxy) diphenylmaleimide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2, 3-dicarboximide, N- (10-camphorsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) Bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (10-camphorsulfonyloxy) naphthylimide, N- (4-methylphenylsulfonyloxy) succinimide, N- (4-Methylphenylsulfonyloxy) phthalimide, N- (4-methylpheny Sulfonyloxy) diphenylmaleimide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) -7 -Oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy- 2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) naphthylimide, N- (2-trifluoromethylphenylsulfonyloxy) succinimide, N- (2-trifluoromethylphenylsulfonyloxy) phthalimide, N -(2-trifluoromethylphenylsulfonyloxy) diphenylmaleimide, N- (2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) -7-oxabicyclo [ 2.2.1] Hept-5-ene-2,3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2, 3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) naphthylimide, N- (4-fluorophenylsulfonyloxy) succinimide, N- (4-fluorophenyl) phthalimide, N- (4-fluorophenyl) Sulfonyloxy) diphenylmaleimide, N- (4-fluorophenylsulfonyloxy) bi Chlo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene- 2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (4-fluorophenylsulfonyl) And oxy) naphthylimide.

Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, methylsulfonyl p-toluenesulfonyldiazomethane, (cyclohexyl) And sulfonyl) (1,1-dimethylethylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, and the like.
Of these acid generators, onium salt compounds are preferred. In this invention, an acid generator can be used individually or in mixture of 2 or more types.

Compounds containing at least one functional group of at least one of hydroxyl group, carboxyl group, amino group, thiol group, and amide group protected with an acid dissociable group in the component (C) are low in the molecule. It may be a molecular compound or a polymer compound.
Examples of the acid dissociable group in the component (C) include a substituted methyl group, a 1-substituted ethyl group, a 1-branched alkyl group, an alkoxycarbonyl group, an acyl group, and a cyclic acid dissociable group. . Examples of the substituted methyl group include methoxymethyl group, methylthiomethyl group, ethoxymethyl group, ethylthiomethyl group, methoxyethoxymethyl group, benzyloxymethyl group, benzylthiomethyl group, phenacyl group, p-bromophenacyl group, p -Methoxyphenacyl group, p-methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, p-bromobenzyl group, p-nitrobenzyl group, p -Methoxybenzyl group, p-methylthiobenzyl group, p-ethoxybenzyl group, p-ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, i-propoxycarbonylmethyl group , N-but Aryloxycarbonyl methyl group, and a t- butoxycarbonyl methyl group.

  Examples of the 1-substituted ethyl group include 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1- Diethoxyethyl group, 1-phenoxyethyl group, 1-phenylthioethyl group, 1,1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzylthioethyl group, 1-cyclopropylethyl group, 1- Phenylethyl group, 1,1-diphenylethyl group, 1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group, 1-i-propoxycarbonylethyl group, 1-n-butoxycarbonyl Examples thereof include an ethyl group and a 1-t-butoxycarbonylethyl group.

  Examples of the 1-branched alkyl group include i-propyl group, sec-butyl group, t-butyl group, 1,1-dimethylpropyl group, 1-methylbutyl group, 1,1-dimethylbutyl group and the like. Can be mentioned. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an i-propoxycarbonyl group, and a t-butoxycarbonyl group.

  Examples of the acyl group include acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, laurylyl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group, malonyl group, Succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioloyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, canphoroyl group, benzoyl Group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, iso Kochinoiru group, p- toluenesulfonyl group, and mesyl group.

  Furthermore, examples of the cyclic acid dissociable group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a 4-methoxycyclohexyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, and a tetrahydro group. A thiofuranyl group, 3-bromotetrahydropyranyl group, 4-methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, 3-tetrahydrothiophene-1,1-dioxide group and the like can be mentioned. Among these acid dissociable groups, benzyl group, t-butoxycarbonylmethyl group, 1-methoxyethyl group, 1-ethoxyethyl group, t-butyl group, trimethylsilyl group, t-butoxycarbonyl group, tetrahydropyranyl group, A tetrahydrofuranyl group, a tetrahydrothiopyranyl group, a tetrahydrofuranyl group, and the like are preferable. In addition, although a silyl group and a germyl group are acid dissociable groups, they cannot be used in the present invention.

  As said (C) component, the compound containing the phenolic hydroxyl group protected by the acid dissociable group is preferable, and the compound etc. which are represented by following formula (1)-(4) are mentioned as a specific example.

  (In Formula (1), R1 represents the acid dissociable group, and a plurality of R1 may be the same or different from each other, and R2 represents an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a 1-naphthyl group. And a plurality of R2 may be the same or different from each other, p is an integer of 1 or more, q is an integer of 0 or more, and p + q ≦ 6.)

(In the formula (2), R1 and R2 have the same meanings as in the formula (1), X is a single bond, -S-, -O-, -CO-, -COO-, -SO-, -SO2-,- C (R3) 2- (wherein R11 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acyl group having 2 to 11 carbon atoms, a phenyl group or a naphthyl group, and a plurality of R11 are the same or different from each other) Or)

(Wherein R2 is the same as described above, and t is an integer of 0 to 4), and p, q, r and s are each an integer of 0 or more, and p + q ≦ 5, r + s ≦ 5, p + r ≧ 1. )

(In the formula (4), R1 and R2 have the same meanings as in the formula (1), R4 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a phenyl group, and p, q, r, s, u and v Are integers of 0 or more, and p + q ≦ 5, r + s ≦ 5, u + v ≦ 5, and p + r + u ≧ 1.)

(In Formula (5), R1 and R2 are synonymous with Formula (1), X is synonymous with Formula (2), R4 is synonymous with Formula (4), and a plurality of R4s are mutually identical. However, p, q, r, s, u, v, w, and x are integers of 0 or more, and p + q ≦ 5, r + s ≦ 5, u + v ≦ 5, w + x ≦ 5, p + r + u + w ≧ 1 .)

(In Formula (6), R1 and R2 are synonymous with Formula (1), R4 is synonymous with Formula (4), and multiple R4s may be the same or different from each other, and p, q, r , S, u, v, w, and x are integers of 0 or more, and p + q ≦ 5, r + s ≦ 5, u + v ≦ 5, x + w ≦ 4, and p + r + u + w ≧ 1.
As the component (C), a compound represented by the following formula (7), formula (8) or formula (9) is particularly preferable.

The photosensitive resin composition of this Embodiment can add a photosensitizer as (D) component. By adding a photosensitizer, a pattern can be formed with a smaller exposure amount. Here, the photosensitizer is a compound that is excited by absorbing light of a specific wavelength and has an interaction property with the component (B), and includes a coumarin derivative, a benzophenone derivative, a thioxanthone derivative, an anthracene derivative, carbazole. Derivatives, perylene derivatives and the like. Examples of the interaction include energy transfer and electron transfer from the photosensitizer in the excited state.
The molar extinction coefficient of the component (D) with respect to the exposure wavelength is preferably larger than the molar extinction coefficient of the component (B).

Moreover, the resist of this Embodiment can contain well-known additives, such as a coloring agent, an adhesion aid, a storage stabilizer, and an antifoamer, as needed.
Next, the content of each component in the resist of this embodiment will be described.
The content of the polymer component in the component (A) is preferably 5 to 70 parts by weight with respect to 100 parts by weight of the total amount of the polymer component and the component (C) in the component (A), and is preferably 25 to 50 parts by weight. More preferably, it is a part. If this content is less than 5 parts by weight, the coating properties tend to be inferior. On the other hand, if it exceeds 70 parts by weight, the photosensitivity tends to be insufficient.
The content of the component (C) is preferably 30 to 95 parts by weight, and preferably 50 to 75 parts by weight with respect to 100 parts by weight of the total amount of the polymer component and the component (C) in the component (A). Is more preferable. If this content is less than 30 parts by weight, the photosensitivity tends to be insufficient, while if it exceeds 95 parts by weight, the coating properties tend to be inferior.

The total content of the acid generator component in the component (B) and the photosensitizer component in the component (D) is 0.01 with respect to 100 parts by weight of the total amount of the components (A) and (C). It is preferable to set it as -70 weight part, and it is more preferable to set it as 0.1-20 weight part. If the content is less than 0.01 parts by weight, the sensitivity and the resolution tend to decrease. On the other hand, if it exceeds 70 parts by weight, the resist coating property and the pattern shape tend to deteriorate.
The ratio of the photosensitizer in the component (D) to the total amount of the acid generator component in the component (B) and the photosensitizer component in the component (D) is 1 to 90% by weight. Preferably, 5 to 70% by weight is more preferable, and 10 to 50% by weight is particularly preferable. In this case, if the proportion of the sensitizer in the component (D) is less than 1% by weight, the effect of improving the sensitivity tends to be reduced, whereas if it exceeds 90% by weight, it is difficult to form a resist pattern in a rectangular shape. Tend to be.

  When the resist of this embodiment is used, for example, after dissolving in a solvent such that the solid content concentration is 2 to 50% by weight, the resist is filtered with a filter having a pore meter of about 0.1 to 0.2 μm, Prepared as a composition solution. The solvent may be basically anything as long as it can dissolve the component (A) and the component (B), and can be freely selected according to the purpose. For example, ethers, esters, ether esters, Examples include ketones, ketone esters, amides, amide esters, lactams, lactones, (halogenated) hydrocarbons, and the like.

  More specifically, ethylene glycol monoalkyl ethers, diethylene glycol dialkyl ethers, ethylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, acetate esters Hydroxyacetic acid esters, lactic acid esters, alkoxyacetic acid esters, (non-) cyclic ketones, acetoacetic acid esters, pyruvate esters, propionate esters, N, N-dialkylformamides, N, N- Dialkylacetamides, N-alkylpyrrolidones, γ-lactones, (halogenated) aliphatic hydrocarbons, (halogenated) aromatic hydrocarbons and the like can be mentioned. Specific examples of such solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n- Propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene Glycol mono-n-propi Ether acetate, isopropenyl acetate, isopropenyl propionate, toluene, xylene, methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate , Ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl -3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, ethyl acetoacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypro Methyl propionic acid, ethyl 3-ethoxypropionate, N- methylpyrrolidone, N, N- dimethylformamide, N, may be mentioned N- dimethylacetamide. Among these solvents, propylene glycol monomethyl ether acetate (PGMEA), ethyl 2-hydroxypropionate, cyclohexanone and the like are desirable in view of safety. These solvents may be used alone or in combination of two or more.

  Further, the solvent may be benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol as necessary. One or more high-boiling solvents such as benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, and ethylene glycol monophenyl ether acetate can be added.

The resist solution can be applied using a known coating apparatus or method such as a spin coater, a dip coater, or a roller coater. Although the film thickness can be freely set depending on the application, it is usually desirable that the film thickness is 0.1 to 5 μm after pre-baking.
The resist coating film is pre-baked at 80 to 150 ° C., preferably 80 to 110 ° C. For pre-baking, heating means such as a hot plate or a hot air dryer can be used.

  The resist layer coated as described above is usually exposed in an image form via a reticle using a known exposure apparatus. As a light source of the exposure apparatus, a known light source such as a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, a xenon lamp, an Ar ion laser, a semiconductor laser, an excimer laser, visible light, or the like is used. The resist coating film after exposure is heated after exposure at 80 to 150 ° C., preferably 80 to 110 ° C. For the post-exposure heating, a heating means such as a hot plate or a hot air dryer can be used.

  By exposure and post-exposure heating, functional groups that can be silylated only in the exposed areas of the resist of the present invention are generated. For this reason, the surface layer portion of the exposed portion of the resist exposed in the form of an image is selectively silylated by a silylation process described later. The functional group that can be silylated generated in the present invention is a hydroxyl group, a carboxyl group, an amino group, a thiol group, or an amide group.

  The silylation process can be optionally performed by a vapor phase or liquid phase method generally used in the field of semiconductors. As silylating agents, trimethylchlorosilane, hexamethyldisilazane, tetramethyldisilazane, hexamethylcyclotrisilazane, dimethylaminodimethylsilane, dimethylaminoethylsilane, dimethylsilyldimethylamine, trimethylsilyldimethylamine, trimethylsilyldiethylamine, dimethylaminopentamethyl Known compounds such as silane can be used. In the case of gas phase silylation, the resist layer is exposed to vapor of a silylating agent. Liquid phase silylation is performed by immersing the resist layer in a silylating agent solution. These processes are performed at a temperature of 25 to 180 ° C. for about 0.1 to 30 minutes.

  After silylation, dry development is performed using the surface layer portion of the exposed exposed portion as a mask. Dry development is performed by plasma etching using an oxygen-containing gas. By dry development, an unexposed part is removed and a negative resist pattern is formed. Examples of the oxygen-containing gas include oxygen alone, a mixed gas of oxygen and an inert gas such as argon, or a mixed gas of oxygen and carbon monoxide, carbon dioxide, ammonia, dinitrogen monoxide, sulfur dioxide, and the like. Can be used.

  Using the resist pattern formed as described above as a mask, the substrate can be processed by dry etching, wet etching, metal vapor deposition, lift-off or plating, and a desired device can be manufactured.

In the following, the present invention will be described with reference to examples.
The materials shown in Table 1 are blended to obtain a solution.

The resist solution is applied on a silicon substrate and prebaked on a hot plate at 100 ° C. for 60 seconds to form a resist layer having a thickness of 1.0 μm.

Using an i-line stepper (wavelength 365 nm) as an exposure apparatus, exposure is performed in an image form. Post-exposure heating is performed on a hot plate at 100 ° C. for 60 seconds.
The exposed substrate was immersed in a silylation solution consisting of 10% by weight of hexamethylcyclotrisilazane as a silylating agent, 87% by weight of n-decane, and 3% by weight of diethylene glycol dimethyl ether at room temperature for 2 minutes. By rinsing, a silylated layer is selectively formed on the surface layer of the exposed portion. Thereafter, oxygen plasma etching is performed to form a resist pattern.
The resolution is evaluated based on the smallest value of the space width between the generated line widths, which can cleanly remove the unexposed portion by dry development processing and does not cause the line to float or peel off. The evaluation of the resolution is better as the numerical value is smaller. The LER (3σ) is measured using a scanning electron microscope.

Examples 1 to 3 and Comparative Example 1 provide good resolution, but Comparative Example 2 does not have a resolving power of 2.0 μm or less because of low silylated contrast.
Examples 1 to 3 have a smaller LER than Comparative Example 1. The large LER in Comparative Example 1 is due to the non-uniform dispersion of component (B) and the large spatial distribution of oxygen dry etch resistance in the exposed area. Comparative Example 2 having no resolving power of 2.0 μm or less cannot evaluate LER.

Claims (6)

As the component (A), the weight average molecular weight (Mw) is 1,000 to 50,000 in terms of polystyrene, and the molecular weight dispersion (weight average molecular weight / number average molecular weight (Mw / Mn)) is 1.0 to in terms of polystyrene. A polymer that satisfies the condition of 1.5;
(B) a radiation-sensitive acid generator as a component;
(C) at least one functional group of hydroxyl group, carboxyl group, amino group, thiol group, amide group protected with an acid dissociable group as a component;
A photosensitive resin composition comprising:   2. The photosensitive resin according to claim 1, which is a polymer that satisfies the conditions of the component (A) according to claim 1 and does not contain a hydroxyl group, a carboxyl group, an amino group, a thiol group, or an amide group. Composition.   2. The photosensitive resin composition according to claim 1, wherein the polymer satisfying the condition of the component (A) according to claim 1 is polystyrene.   (D) The photosensitive resin composition of Claim 1 which further contains a photosensitizer as a component. A laminating step of laminating the photosensitive resin composition according to any one of claims 1 to 3 on a substrate;
An exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with an actinic ray to form an exposed portion;
Heating the substrate;
Silylating the exposed portion;
A dry development step of removing portions other than the exposed portion of the photosensitive resin composition layer with oxygen plasma;
A method for forming a resist pattern, comprising: Using the resist pattern forming method according to claim 4 to form a resist pattern on a substrate;
A step of performing dry etching, wet etching, metal vapor deposition, lift-off or plating, etc., on the substrate on which the resist pattern is formed by the above-described steps;
A method for processing a substrate, comprising: