JP5798100B2 - Resist material and pattern forming method using the same - Google Patents

Description

  The present invention relates to a resist material having excellent stability and low outgas, particularly a chemically amplified positive resist material, and a pattern forming method using the same.

  With the high integration and high speed of LSI, pattern rule miniaturization is progressing rapidly. In particular, the expansion of the flash memory market and the increase in storage capacity are leading to miniaturization. The fine line for miniaturization is mass production of 65 nm node devices by ArF lithography, and preparation for mass production of 45 nm nodes by next generation ArF immersion lithography is in progress. Next generation 32nm node includes immersion lithography with ultra high NA lens combining liquid with higher refractive index than water, high refractive index lens and high refractive index resist film, vacuum ultraviolet light (EUV) with wavelength of 13.5nm Lithography, double exposure of ArF lithography (double patterning lithography), and the like are candidates and are being studied.

Light elements such as hydrocarbons used in resist materials are hardly absorbed by very short wavelength high energy rays such as electron beams (EB) and X-rays, and polyhydroxystyrene-based resist materials have been studied. ing.
The resist material for EB has been practically used for mask drawing. In recent years, mask manufacturing techniques have become a problem. Reduced projection exposure apparatuses have been used since the light used for exposure was g-line, and the reduction magnification was 1/5. However, both the enlargement of the chip size and the enlargement of the projection lens have a 1/4 magnification. Therefore, the influence of the dimensional deviation of the mask on the dimensional change of the pattern on the wafer has become a problem. It has been pointed out that with the miniaturization of the pattern, the dimensional deviation on the wafer has become larger than the value of the dimensional deviation of the mask. There is a need for a mask error enhancement factor (MEEF) calculated using a mask dimensional change as a denominator and a dimensional change on a wafer as a numerator. It is not uncommon for MEEF to exceed 4 for 45 nm-class patterns. If the reduction ratio is 1/4 and the MEEF is 4, it can be said that the mask production requires an accuracy equivalent to that of a substantially equal magnification mask.

  In order to increase the accuracy of the line width in the mask manufacturing exposure apparatus, an exposure apparatus using an electron beam (EB) has been used from an exposure apparatus using a laser beam. Furthermore, since further miniaturization is possible by increasing the acceleration voltage in the electron gun of EB, 10 keV to 30 keV, and recently 50 keV is the mainstream, and studies of 100 keV are also underway.

  Here, as the acceleration voltage increases, lowering the sensitivity of the resist film has become a problem. When the acceleration voltage is improved, the influence of forward scattering in the resist film is reduced, so that the contrast of the electron drawing energy is improved and the resolution and dimensional controllability are improved. Since it passes, the sensitivity of the resist film decreases. Since the mask exposure machine exposes by direct drawing with a single stroke, a decrease in sensitivity of the resist film leads to a decrease in productivity, which is not preferable. In view of such a demand for higher sensitivity, chemically amplified resist materials have been studied.

With the miniaturization of patterns in mask manufacturing EB lithography, the resist film is becoming thinner in order to prevent pattern collapse during development with a high aspect ratio. In the case of photolithography, the thinning of the resist film greatly contributes to the improvement of the resolution. This is because the planarization of the device has progressed with the introduction of CMP or the like. In the case of mask production, the substrate is flat, and the thickness of the substrate to be processed (for example, Cr, MoSi, SiO ₂ ) is determined for light shielding rate and phase difference control. In order to reduce the thickness, it is necessary to improve the dry etching resistance of the resist film.

  Here, it is generally said that there is a correlation between the carbon density of the resist film and the dry etching resistance. In EB drawing that is not affected by absorption, a resist material based on a novolak polymer having excellent etching resistance has been developed.

  For example, indene copolymerization shown in Patent Document 1 and acenaphthylene copolymer shown in Patent Document 2 not only have a high carbon density, but also show improved etching resistance due to a rigid main chain structure based on a cycloolefin structure.

  So far, it has been reported that the absorption of carbon atoms is small in soft X-ray (EUV) exposure at a wavelength of 5 to 20 nm. Increasing the carbon density is effective not only for improving dry etching resistance but also for improving transmittance in the soft X-ray wavelength region.

  Further, with the progress of miniaturization, image blur due to acid diffusion has become a problem. In order to ensure the resolution in a fine pattern having a dimension size of 45 nm or less, it is proposed that not only improvement of the dissolution contrast conventionally proposed but also control of acid diffusion is important. However, chemically amplified resist materials have increased sensitivity and contrast due to acid diffusion. Therefore, reducing the post-exposure bake temperature (PEB) temperature and time to limit acid diffusion results in sensitivity and contrast. It drops significantly. There is a close relationship between the type of acid labile group and the acid diffusion distance, and development of an acid labile group in which the deprotection reaction proceeds with an extremely short acid diffusion distance is desired.

  Furthermore, a trade-off relationship between sensitivity, edge roughness, and resolution has been reported. Increasing sensitivity degrades edge roughness and resolution, and suppressing acid diffusion improves resolution but decreases edge roughness and sensitivity.

  On the other hand, it is effective to add an acid generator that generates a bulky acid to suppress acid diffusion, but as described above, edge roughness and sensitivity are reduced. Therefore, it has been proposed to copolymerize an onium salt acid generator having a polymerizable olefin in the polymer. Patent Document 3, Patent Document 4, and Patent Document 5 propose sulfonium salts and iodonium salts having a polymerizable olefin that generates a specific sulfonic acid. Photoresists using a base polymer copolymerized with a polymerizable acid generator have low acid diffusion because the acid diffusion is small and the acid generator is uniformly dispersed in the polymer, so both edge resolution and resolution are low. The characteristics can be improved at the same time.

Japanese Patent No. 3865048 JP 2006-169302 A JP-A-4-230645 JP 2005-84365 A JP 2006-045311 A Japanese Patent No. 4771974 Patent 4900603

In EUV lithography, the problem is that the outgas component generated from the resist film during exposure is adsorbed on the surface of the reflection mirror or mask in the exposure apparatus and lowers the reflectivity. It has been proposed to provide a protective film above the resist film. In this case, a coater cup for coating a protective film is required, and in the initial stage of immersion lithography, a protective film has been applied to prevent the acid generator from eluting from the resist film into water.
However, a decrease in throughput and an increase in material cost due to the provision of a protective film have become problems, and the protective film has gradually been discontinued. In consideration of such a background, development of a resist material that reduces outgas without using a protective film is required even in EUV lithography.

  Here, in Patent Document 6 and Patent Document 7, resists to which a copolymer polymer of a styrene derivative and a methacrylate repeating unit having a fluorine atom and a copolymer of vinyl naphthalene and a methacrylate repeating unit having a fluorine atom are added, respectively. Materials have been proposed. In these, a polymer having a styrene unit or a vinylnaphthalene unit is oriented on the surface layer after spin coating, and both water repellency and antireflection properties can be obtained. It also mentions that outgassing during EUV exposure can be suppressed.

  However, copolymerization of methacrylate having fluorine atoms with styrene or vinyl naphthalene units cannot sufficiently suppress the generation of outgas. Therefore, it is desired to develop a resist surface modifying material that can block outgas more effectively.

  The present invention has been made in view of the above problems, and is a mask blank resist material excellent in long-term stability after application and exposure stability in vacuum, an EUV resist material in which generation of outgas in vacuum is reduced, and this An object of the present invention is to provide a pattern forming method using such a material.

  In order to solve the above problems, the present invention provides a polymer compound serving as a base resin whose alkali solubility is improved by an acid, and 1,1,1,3,3,3-hexafluoro-2-propanol as a polymer additive. And a polymer compound containing a repeating unit of indene and / or acenaphthylene having a group.

  Thus, if it is a polymer compound containing a repeating unit of indene and / or acenaphthylene having a 1,1,1,3,3,3-hexafluoro-2-propanol group as a polymer additive, It is possible to prevent the outgas component generated from the inside of the resist film from being released out of the film, and to be excellent in exposure stability in a vacuum.

（一般式（１）中、０≦ｐ≦１．０、０≦ｑ≦１．０、０＜ｐ＋ｑ≦１．０である。） The polymer compound containing the indene and / or acenaphthylene repeating unit having the 1,1,1,3,3,3-hexafluoro-2-propanol group is represented by the following general formula (1): It is preferable that

(In general formula (1), 0 ≦ p ≦ 1.0, 0 ≦ q ≦ 1.0, and 0 <p + q ≦ 1.0.)

  Such a polymeric surfactant containing a repeating unit of indene and / or acenaphthylene having a 1,1,1,3,3,3-hexafluoro-2-propanol group is formed after the photoresist film formation. Orientation on the surface of the photoresist film can improve the stability, reduce the generation of outgas from the resist film, and reduce pattern defects after development.

  The resist material is preferably a chemically amplified positive resist material.

  Even when such a chemically amplified positive resist material is used, generation of outgas from the resist film can be reduced, and pattern defects after development can be reduced.

  The polymer compound as the base resin preferably includes a repeating unit having an acid labile group, and the polymer compound as the base resin further includes at least one of a hydroxy group and a lactone ring. It preferably includes a repeating unit having a functional group.

  Thus, it can be made highly sensitive by having a repeating unit having an acid labile group, and in addition to this, a repeating unit having an adhesive group containing at least one of a hydroxy group and a lactone ring is copolymerized. By doing so, adhesiveness can be improved.

（一般式（２）中、Ｒ^１０、Ｒ^１２はそれぞれ独立に水素原子又はメチル基を表し、Ｒ^１１、Ｒ^１３は酸不安定基を表す。Ｙ_１は単結合、エステル基とラクトン環とフェニレン基とナフチレン基とからなる群のうちいずれか１種又は２種以上を有する炭素数１〜１２の連結基、フェニレン基、及びナフチレン基のいずれかである。Ｙ_２は単結合、エステル基及びアミド基のいずれかである。０≦ａ１≦０．９、０≦ａ２≦０．９、０＜ａ１＋ａ２＜１の範囲である。） The polymer compound as the base resin is a repeating unit a1 according to the following general formula (2) in which a hydrogen atom of a carboxyl group and / or a hydrogen atom of a hydroxyl group of a phenol group is substituted with an acid labile group: Those containing a polymer compound having a weight average molecular weight in the range of 1,000 to 500,000 obtained by copolymerizing any one or more repeating units of a2 are preferred.

(In General Formula (2), R ¹⁰ and R ¹² each independently represent a hydrogen atom or a methyl group, R ¹¹ and R ¹³ each represent an acid labile group. Y ₁ represents a single bond, an ester group and a lactone ring. It is any one of a linking group having 1 to 12 carbon atoms, a phenylene group, and a naphthylene group having one or more of a group consisting of a phenylene group and a naphthylene group, and Y ₂ is a single bond or an ester group. And amide group, 0 ≦ a1 ≦ 0.9, 0 ≦ a2 ≦ 0.9, and 0 <a1 + a2 <1.)

  Thus, the polymer compound as the base resin has a weight average molecular weight of 1,000 to 500, which is obtained by copolymerizing any one or more repeating units of the repeating units a1 and a2 described in the general formula (2). By including a polymer compound in the range of 000, the heat resistance of the resist material and the trailing phenomenon after pattern formation can be suppressed.

（式中、Ｒ^２０、Ｒ^２４、Ｒ^２８は水素原子又はメチル基、Ｒ^２１は単結合、フェニレン基、−Ｏ−Ｒ^３３−、及び−Ｃ（＝Ｏ）−Ｙ−Ｒ^３３−のいずれかである。Ｙは酸素原子又はＮＨ、Ｒ^３３は炭素数１〜６の直鎖状、分岐状又は環状のアルキレン基、フェニレン基及びアルケニレン基のいずれかであり、カルボニル基（−ＣＯ−）、エステル基（−ＣＯＯ−）、エーテル基（−Ｏ−）及びヒドロキシ基のいずれかを含んでいてもよい。Ｒ^２２、Ｒ^２３、Ｒ^２５、Ｒ^２６、Ｒ^２７、Ｒ^２９、Ｒ^３０、Ｒ^３１は同一又は異種の炭素数１〜１２の直鎖状、分岐状又は環状のアルキル基であり、カルボニル基、エステル基及びエーテル基のいずれかを含んでいてもよく、又は炭素数６〜１２のアリール基、炭素数７〜２０のアラルキル基及びチオフェニル基のいずれかを表す。Ｚは単結合、メチレン基、エチレン基、フェニレン基、フッ素化されたフェニレン基、−Ｏ−Ｒ^３２−、及び−Ｃ（＝Ｏ）−Ｚ_１−Ｒ^３２−のいずれかである。Ｚ_１は酸素原子又はＮＨ、Ｒ^３２は炭素数１〜６の直鎖状、分岐状、環状のアルキレン基、フェニレン基及びアルケニレン基のいずれかであり、カルボニル基、エステル基、エーテル基及びヒドロキシ基のいずれかを含んでいてもよい。Ｍ⁻は非求核性対向イオンを表す。０≦ｂ１≦０．３、０≦ｂ２≦０．３、０≦ｂ３≦０．３、０≦ｂ１＋ｂ２＋ｂ３≦０．３の範囲である。） Furthermore, in the polymer compound as the base resin, the repeating units a1 and a2 described in the general formula (2), wherein a hydrogen atom of a carboxyl group and / or a hydrogen atom of a hydroxyl group of a phenol group are substituted with an acid labile group In addition, a polymer compound having a weight average molecular weight in the range of 1,000 to 500,000 obtained by copolymerizing any one or more repeating units of the sulfonium salts b1 to b3 described in the following general formula (3) is included. Those are preferred.

(Wherein R ²⁰ , R ²⁴ and R ²⁸ are a hydrogen atom or a methyl group, R ²¹ is a single bond, a phenylene group, —O—R ³³ —, or —C (═O) —Y—R ³³ —. Y is an oxygen atom or NH, and R ³³ is a linear, branched or cyclic alkylene group having 1 to 6 carbon atoms, a phenylene group or an alkenylene group, and a carbonyl group (—CO—) Any of R ²² , R ²³ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁹ , R ³⁰ , an ester group (—COO—), an ether group (—O—) and a hydroxy group. R ³¹ is the same or different linear, branched or cyclic alkyl group having 1 to 12 carbon atoms and may contain any of carbonyl group, ester group and ether group, or 6 to 6 carbon atoms. 12 aryl groups, 7-20 carbon atoms .Z denote any aralkyl group or thiophenyl group is a single bond, methylene, ethylene, phenylene, fluorinated phenylene group, ^{-O-R 32} -, and -C (= O) -Z ₁ - R ₁ is any one of R ³² , Z ₁ is an oxygen atom or NH, R ³² is any one of a linear, branched or cyclic alkylene group, a phenylene group and an alkenylene group having 1 to 6 carbon atoms; Any of a group, an ester group, an ether group and a hydroxy group, M ⁻ represents a non-nucleophilic counter ion, 0 ≦ b1 ≦ 0.3, 0 ≦ b2 ≦ 0.3, 0 ≦ (B3 ≦ 0.3, 0 ≦ b1 + b2 + b3 ≦ 0.3.)

  As described above, the acid diffusion can be reduced by bonding the acid generator to the polymer main chain, and the resolution can be prevented from being deteriorated due to the acid diffusion blur. Further, the edge roughness (LER, LWR) can be improved by uniformly dispersing the acid generator.

  Furthermore, what contains any one or more of an organic solvent, a basic compound, a dissolution control agent, and surfactant is preferable.

  Thus, by further blending an organic solvent, for example, the coating property of a positive resist composition on a substrate or the like can be improved, and the resolution can be further improved by blending a basic compound. By adding a dissolution control agent, the difference in dissolution rate between the exposed and unexposed areas can be further increased, the resolution can be further improved, and a surfactant can be added. Thus, the coating property of the resist material can be further improved or controlled.

  In addition, the polymer compound serving as a base resin whose alkali solubility is improved by the acid is 100 parts by mass as the polymer additive, 1,1,1,3,3,3-hexafluoro-2-propanol. It is preferable that the high molecular compound containing the repeating unit of indene and / or acenaphthylene having a group is contained in the range of 0.2 to 30 parts by mass.

  With such a blending amount, it can be oriented on the resist surface after coating to reduce the generation of outgas from the resist film, prevent the generation of bridge defects and blob defects, and reduce the LWR.

  The present invention also includes a pattern forming method comprising: a step of applying the resist material onto a substrate; a step of exposing to high energy rays after heat treatment; and a step of developing using a developer. I will provide a.

  With such a pattern formation method, generation of outgas can be suppressed, and a desired pattern having no defects can be stably formed on a substrate, and can be used for integrated circuit manufacturing and the like.

  Further, the present invention provides a pattern forming method in which the high energy ray is any one of a KrF excimer laser having a wavelength of 248 nm, an ArF excimer laser having a wavelength of 193 nm, an electron beam, and a soft X-ray having a wavelength in the range of 3 to 15 nm.

  With such a pattern forming method, generation of outgas can be suppressed, sensitivity, edge roughness, and resolution can be improved, and a fine pattern can be stably obtained.

  As described above, the photoresist film formed using the resist material of the present invention has long-term stability after coating, and can reduce the generation of outgas from the resist film in EUV exposure, for example. The exposure stability in vacuum is excellent, and the edge roughness (LWR) after development can be reduced. Further, by making the resist film surface hydrophilic, the occurrence of blob defects on the resist film after development can be prevented, and the resolution can be improved.

Hereinafter, the present invention will be described in more detail.
As described above, the outgas generation could not be sufficiently suppressed by copolymerization of methacrylate having fluorine atoms with styrene or vinyl naphthalene units. Therefore, it has been desired to develop a resist surface modifying material that can block outgas more effectively.

  Therefore, as a result of intensive studies and studies to solve the above problems, the present inventors have dissolved in an alkali with an acid in order to suppress generation of outgas from the resist film during exposure in a vacuum in EUV exposure. In addition to a normal base polymer, a resist material blended with a polymer compound having a repeating unit of indene and / or acenaphthylene having a 1,1,1,3,3,3-hexafluoro-2-propanol group is used. Devised. In addition, a polymer having a 1,1,1,3,3,3-hexafluoro-2-propanol group-containing indene and / or acenaphthylene repeating unit is soluble in an alkaline developer, It has also been found that there is an effect of reducing bridge defects between resist patterns, and the present invention has been made.

  The resist material of the present invention has a polymer compound serving as a base resin whose alkali solubility is improved by acid, and 1,1,1,3,3,3-hexafluoro-2-propanol group as a polymer additive And a polymer compound containing a repeating unit of indene and / or acenaphthylene.

（一般式（１）中、０≦ｐ≦１．０、０≦ｑ≦１．０、０＜ｐ＋ｑ≦１．０である。） That is, the present invention has a polymer compound serving as a base resin whose alkali solubility is improved by acid, and a 1,1,1,3,3,3-hexafluoro-2-propanol group as a polymer additive. A resist material comprising a polymer compound having a repeating unit of indene and / or acenaphthylene, particularly a polymer compound represented by the following general formula (1).

(In general formula (1), 0 ≦ p ≦ 1.0, 0 ≦ q ≦ 1.0, and 0 <p + q ≦ 1.0.)

  A photoresist film formed using a resist material to which a polymer compound having a repeating unit of the general formula (1) is added has 1,1,1,3,3,3- It is characterized by adding a polymeric surfactant having a repeating unit of indene and / or acenaphthylene having a hexafluoro-2-propanol group. A polymeric surfactant having a repeating unit of indene and / or acenaphthylene having a 1,1,1,3,3,3-hexafluoro-2-propanol group is formed on the photoresist film surface after the photoresist film is formed. Alignment can reduce outgas generation from the resist film, and pattern defects after development can be reduced.

The polymerizable monomer for obtaining the repeating units p and q of indene and / or acenaphthylene having a 1,1,1,3,3,3-hexafluoro-2-propanol group in the general formula (1) is as follows: Specifically, it can be exemplified below.

Indene and / or acenaphthylene repeating units p and q having a 1,1,1,3,3,3-hexafluoro-2-propanol group in the general formula (1), styrenes, vinylnaphthalenes, (meta ) Copolymerizes with acrylates, vinyl ethers, indenes, benzofurans, benzothiophenes, acenaphthylenes, vinylfluorenes, vinylanthracenes, vinylpyrenes, vinylbiphenyls, stilbenes, styrylnaphthalenes, dinaphthylethylenes I can do it.
Styrenes, vinyl naphthalenes, (meth) acrylates, vinyl ethers, indenes, benzofurans, benzothiophenes, acenaphthylenes, vinyl fluorenes, vinyl anthracenes, vinyl pyrenes, vinyl biphenyls, stilbenes, styryl naphthalenes Since dinaphthylethylenes have high carbon density, high transmittance in EUV light, and high density, the outgas generated from the inside of the resist can be suppressed.

Examples of styrenes include the following.

Specific examples of vinyl naphthalenes are shown below.

（ここでＲはメチル基、あるいは水素原子である。） Specific examples of (meth) acrylates include the following.

(Here, R is a methyl group or a hydrogen atom.)

Specific examples of vinyl ethers include the following.

Specific examples of monomers for obtaining stilbenes, styrylnaphthalenes, and dinaphthylethylenes can be given below.

Specific examples of the indene, benzofuran, benzothiophene, acenaphthylene, vinylfluorene, vinylanthracene, vinylpyrene, and vinylbiphenyl monomers are given below.

  At the monomer stage, the hydroxy group can be substituted with an acetyl group, an acetal group or the like, and converted into a hydroxy group by a deprotection reaction after polymerization. When the hydroxy group is substituted with an acetyl group, the acetyl group is deprotected by alkali hydrolysis after polymerization to form a hydroxy group, and the hydroxy group is substituted with an acid labile group such as acetal. Deprotection to the hydroxy group by decomposition.

  As the polymer compound added to the resist material of the present invention, in addition to the repeating units represented by p and q in the general formula (1), the alkali solubility is improved and the hydrophilicity of the resist after development is improved. For the purpose, a repeating unit r having a carboxyl group, a repeating unit s having an α-trifluoromethylhydroxy group and a sulfonamide group can be copolymerized.

Specific examples of the monomer for obtaining the repeating unit r having a carboxyl group include the following.

（ここでＲは水素原子、又はメチル基である。）

(Here, R is a hydrogen atom or a methyl group.)

Specific examples of the repeating unit s having an α-trifluoromethylhydroxy group and a sulfonamide group can be given below.

（式中、Ｒは前述と同様である。）

(In the formula, R is the same as described above.)

The polymer compound as the base resin of the resist material of the present invention is intended to improve adhesion in addition to the repeating unit having an acid labile group represented by (a1) or (a2) in the general formula (2). For repeating unit c having an adhesive group such as hydroxy group, carboxyl group, lactone ring, carbonyl group, carbonate group, ester group, ether group, amide group, sulfonamido group, cyano group, sulfonic acid ester group, lactam Is preferably copolymerized.
In this case, the repeating unit c preferably has a phenolic hydroxyl group that has a sensitizing effect by electron beam and EUV exposure. The repeating unit having a phenolic hydroxyl group is c1 represented by the following general formula (4). It is preferable to be selected from ˜c9.

（式中、Ｙ^１、Ｙ^２、Ｙ^５は単結合、又は−Ｃ（＝Ｏ）−Ｏ−Ｒ^１７−であり、Ｙ^３、Ｙ^４は−Ｃ（＝Ｏ）−Ｏ−Ｒ^１８−であり、Ｒ^１７、Ｒ^１８は単結合、又は炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基であり、エーテル基、エステル基を有していても良い。Ｒ^１６は水素原子、炭素数１〜４の直鎖状又は分岐状のアルキル基、アルコキシ基、シアノ基、アルコキシカルボニル基、アシロキシ基、アシル基であり、Ｒ^１５は同一又は異種の水素原子又はメチル基である。Ｚ^１、Ｚ^２はメチレン基又はエチレン基、Ｚ^３はメチレン基、酸素原子又は硫黄原子、Ｚ^４、Ｚ^５は−ＣＨ又は窒素原子である。ｓ、ｔは１又は２である。）

(In the formula, Y ¹ , Y ² and Y ⁵ are a single bond or —C (═O) —O—R ¹⁷ —, and Y ³ and Y ⁴ are —C (═O) —O—R ¹⁸ —. R ¹⁷ and R ¹⁸ are a single bond or a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, and may have an ether group or an ester group, and R ¹⁶ is hydrogen. An atom, a linear or branched alkyl group having 1 to 4 carbon atoms, an alkoxy group, a cyano group, an alkoxycarbonyl group, an acyloxy group, or an acyl group, and R ¹⁵ is the same or different hydrogen atom or methyl group. Z ¹ and Z ² are a methylene group or an ethylene group, Z ³ is a methylene group, an oxygen atom or a sulfur atom, Z ⁴ and Z ⁵ are —CH or a nitrogen atom, and s and t are 1 or 2.

The monomer for obtaining the repeating units c1 to c9 having the phenolic hydroxyl group can be shown below.

Further, hydroxy groups other than phenolic hydroxyl groups, lactone rings, ether groups, ester groups, carbonyl groups, cyano groups, sulfonic acid ester groups, sulfonamide groups, cyclic —O—C (═O) —S— or —O. Specific examples of the monomer for obtaining the repeating unit c of the adhesive group selected from —C (═O) —NH— can be given below.

  In the case of a monomer having a hydroxy group, the hydroxy group may be replaced with an acetal that can be easily deprotected with an acid such as an ethoxyethoxy group at the time of polymerization, and may be deprotected with a weak acid and water after the polymerization, Substitution with a formyl group, pivaloyl group or the like, and alkali hydrolysis may be performed after polymerization.

（式中、Ｒ^１９は同一、非同一で水素原子、それぞれ炭素数１〜３０のアルキル基、一部又は全てがハロゲン原子で置換されたアルキル基、アルコキシ基、アルカノイル基又はアルコキシカルボニル基、炭素数６〜１０のアリール基、ハロゲン原子、又は１，１，１，３，３，３−ヘキサフルオロ−２−プロパノール基である。Ｚはメチレン基、酸素原子又は硫黄原子である。） The polymer compound serving as the base resin according to the present invention is obtained by further copolymerizing a repeating unit d selected from indene, acenaphthylene, chromone, coumarin, norbornadiene and their derivatives d1 to d5 represented by the following general formula (6). It is preferable to become.

(In the formula, R ¹⁹ is the same or non-identical and is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkyl group partially or entirely substituted with a halogen atom, an alkoxy group, an alkanoyl group or an alkoxycarbonyl group, carbon (It is an aryl group of several 6 to 10, a halogen atom, or a 1,1,1,3,3,3-hexafluoro-2-propanol group. Z is a methylene group, an oxygen atom or a sulfur atom.)

In this case, the monomers for obtaining indene, acenaphthylene, chromone, coumarin, norbornadiene and their derivatives d1 to d5 can be specifically exemplified below.

Furthermore, an onium salt acid generator b having a polymerizable olefin may be copolymerized.
JP-A-4-230645, JP-A-2005-84365, and JP-A-2006-045311 propose sulfonium salts and iodonium salts having a polymerizable olefin that generates a specific sulfonic acid. Japanese Patent Application Laid-Open No. 2006-178317 proposes a sulfonium salt in which a sulfonic acid is directly bonded to the main chain.

（式中、Ｒ^２０、Ｒ^２４、Ｒ^２８は水素原子又はメチル基、Ｒ^２１は単結合、フェニレン基、−Ｏ−Ｒ^３３−、及び−Ｃ（＝Ｏ）−Ｙ−Ｒ^３３−のいずれかである。Ｙは酸素原子又はＮＨ、Ｒ^３３は炭素数１〜６の直鎖状、分岐状又は環状のアルキレン基、フェニレン基及びアルケニレン基のいずれかであり、カルボニル基（−ＣＯ−）、エステル基（−ＣＯＯ−）、エーテル基（−Ｏ−）及びヒドロキシ基のいずれかを含んでいてもよい。Ｒ^２２、Ｒ^２３、Ｒ^２５、Ｒ^２６、Ｒ^２７、Ｒ^２９、Ｒ^３０、Ｒ^３１は同一又は異種の炭素数１〜１２の直鎖状、分岐状又は環状のアルキル基であり、カルボニル基、エステル基及びエーテル基のいずれかを含んでいてもよく、又は炭素数６〜１２のアリール基、炭素数７〜２０のアラルキル基及びチオフェニル基のいずれかを表す。Ｚは単結合、メチレン基、エチレン基、フェニレン基、フッ素化されたフェニレン基、−Ｏ−Ｒ^３２−、及び−Ｃ（＝Ｏ）−Ｚ_１−Ｒ^３２−のいずれかである。Ｚ_１は酸素原子又はＮＨ、Ｒ^３２は炭素数１〜６の直鎖状、分岐状、環状のアルキレン基、フェニレン基及びアルケニレン基のいずれかであり、カルボニル基、エステル基、エーテル基及びヒドロキシ基のいずれかを含んでいてもよい。Ｍ⁻は非求核性対向イオンを表す。０≦ｂ１≦０．３、０≦ｂ２≦０．３、０≦ｂ３≦０．３、０≦ｂ１＋ｂ２＋ｂ３≦０．３の範囲である。） In the present invention, repeating units b1 to b3 having a sulfonium salt represented by the following general formula (3) can be copolymerized.

(Wherein R ²⁰ , R ²⁴ and R ²⁸ are a hydrogen atom or a methyl group, R ²¹ is a single bond, a phenylene group, —O—R ³³ —, or —C (═O) —Y—R ³³ —. Y is an oxygen atom or NH, and R ³³ is a linear, branched or cyclic alkylene group having 1 to 6 carbon atoms, a phenylene group or an alkenylene group, and a carbonyl group (—CO—) Any of R ²² , R ²³ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁹ , R ³⁰ , an ester group (—COO—), an ether group (—O—) and a hydroxy group. R ³¹ is the same or different linear, branched or cyclic alkyl group having 1 to 12 carbon atoms and may contain any of carbonyl group, ester group and ether group, or 6 to 6 carbon atoms. 12 aryl groups, 7-20 carbon atoms .Z denote any aralkyl group or thiophenyl group is a single bond, methylene, ethylene, phenylene, fluorinated phenylene group, ^{-O-R 32} -, and -C (= O) -Z ₁ - R ₁ is any one of R ³² , Z ₁ is an oxygen atom or NH, R ³² is any one of a linear, branched or cyclic alkylene group, a phenylene group and an alkenylene group having 1 to 6 carbon atoms; Any of a group, an ester group, an ether group and a hydroxy group, M ⁻ represents a non-nucleophilic counter ion, 0 ≦ b1 ≦ 0.3, 0 ≦ b2 ≦ 0.3, 0 ≦ (B3 ≦ 0.3, 0 ≦ b1 + b2 + b3 ≦ 0.3.)

Examples of non-nucleophilic counter ions of M ⁻ include halide ions such as chloride ions and bromide ions, triflate, fluoroalkyl sulfonates such as 1,1,1-trifluoroethanesulfonate, nonafluorobutanesulfonate, tosylate, and benzene. Sulfonate, 4-fluorobenzene sulfonate, aryl sulfonate such as 1,2,3,4,5-pentafluorobenzene sulfonate, alkyl sulfonate such as mesylate and butane sulfonate, bis (trifluoromethylsulfonyl) imide, bis (perfluoroethyl) Mention acid such as imide) such as sulfonyl) imide, bis (perfluorobutylsulfonyl) imide, tris (trifluoromethylsulfonyl) methide, tris (perfluoroethylsulfonyl) methide Can do.

  By binding an acid generator to the polymer main chain, acid diffusion can be reduced, and degradation of resolution due to blurring of acid diffusion can be prevented. Further, the edge roughness (LER, LWR) is improved by uniformly dispersing the acid generator.

（一般式（２）中、Ｒ^１０、Ｒ^１２はそれぞれ独立に水素原子又はメチル基を表し、Ｒ^１１、Ｒ^１３は酸不安定基を表す。Ｙ_１は単結合、エステル基とラクトン環とフェニレン基とナフチレン基とからなる群のうちいずれか１種又は２種以上を有する炭素数１〜１２の連結基、フェニレン基、及びナフチレン基のいずれかである。Ｙ_２は単結合、エステル基及びアミド基のいずれかである。０≦ａ１≦０．９、０≦ａ２≦０．９、０＜ａ１＋ａ２＜１の範囲である。） The base resin used in the resist material of the present invention must have a repeating unit having an acid labile group, but is substituted with an acid labile group R ^{11 represented} by the following general formula (2) (meta ) copolymerizing repeating unit a1, the repeating units a2 of hydroxy styrene substituted with an acid labile group R ¹³ of the acrylic acid ester.

(In General Formula (2), R ¹⁰ and R ¹² each independently represent a hydrogen atom or a methyl group, R ¹¹ and R ¹³ each represent an acid labile group. Y ₁ represents a single bond, an ester group and a lactone ring. It is any one of a linking group having 1 to 12 carbon atoms, a phenylene group, and a naphthylene group having one or more of a group consisting of a phenylene group and a naphthylene group, and Y ₂ is a single bond or an ester group. And amide group, 0 ≦ a1 ≦ 0.9, 0 ≦ a2 ≦ 0.9, and 0 <a1 + a2 <1.)

Specific examples of the monomer for obtaining the repeating unit a1 are shown below.

Specific examples of the monomer for obtaining the repeating unit a2 are given below.

The acid labile group (acid labile groups of R ¹¹ and R ^{13 in} the general formula (2)) is variously selected and may be the same or different, and in particular, the following formulas (A-1) to (A- Examples thereof include those represented by the group substituted in 3).

In the formula (A-1), R ^L30 is a tertiary alkyl group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, each alkyl group is a trialkylsilyl group having 1 to 6 carbon atoms, and 4 to 20 carbon atoms. An oxoalkyl group or a group represented by the above general formula (A-3) is shown. Specific examples of the tertiary alkyl group include a tert-butyl group, a tert-amyl group, a 1,1-diethylpropyl group, and 1-ethyl. Cyclopentyl group, 1-butylcyclopentyl group, 1-ethylcyclohexyl group, 1-butylcyclohexyl group, 1-ethyl-2-cyclopentenyl group, 1-ethyl-2-cyclohexenyl group, 2-methyl-2-adamantyl group, etc. Specific examples of the trialkylsilyl group include a trimethylsilyl group, a triethylsilyl group, and a dimethyl-tert-butylsilyl group. Specific examples of the oxoalkyl group include a 3-oxocyclohexyl group, a 4-methyl-2-oxooxan-4-yl group, and a 5-methyl-2-oxooxolan-5-yl group. A1 is an integer of 0-6.

In the formula (A-2), R ^L31 and R ^L32 represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, specifically a methyl group, Examples thereof include an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a cyclopentyl group, a cyclohexyl group, a 2-ethylhexyl group, and an n-octyl group. R ^L33 represents a monovalent hydrocarbon group which may have a hetero atom such as an oxygen atom having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, a linear, branched or cyclic alkyl group, Examples include those in which a part of hydrogen atoms are substituted with a hydroxyl group, an alkoxy group, an oxo group, an amino group, an alkylamino group, and the like, and specific examples include the following substituted alkyl groups.

R ^L31 and R ^L32 , R ^L31 and R ^L33 , R ^L32 and R ^L33 may be combined to form a ring with the carbon atom to which they are bonded, and if a ring is formed, it is involved in the formation of the ring R ^L31 , R ^L32 , and R ^L33 each represent a linear or branched alkylene group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and preferably the ring has 3 to 10 carbon atoms, particularly 4 to 10 carbon atoms. is there.

  Specific examples of the acid labile group of the above formula (A-1) include tert-butoxycarbonyl group, tert-butoxycarbonylmethyl group, tert-amyloxycarbonyl group, tert-amyloxycarbonylmethyl group, 1,1 -Diethylpropyloxycarbonyl group, 1,1-diethylpropyloxycarbonylmethyl group, 1-ethylcyclopentyloxycarbonyl group, 1-ethylcyclopentyloxycarbonylmethyl group, 1-ethyl-2-cyclopentenyloxycarbonyl group, 1-ethyl Examples include 2-cyclopentenyloxycarbonylmethyl group, 1-ethoxyethoxycarbonylmethyl group, 2-tetrahydropyranyloxycarbonylmethyl group, 2-tetrahydrofuranyloxycarbonylmethyl group and the like.

Furthermore, the substituent shown by following formula (A-1) -1-(A-1) -10 can also be mentioned.

Here, R ³⁷ is the same or different from each other, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms, R ³⁸ is a hydrogen atom, or 1 to 1 carbon atoms. 10 linear, branched or cyclic alkyl groups.
R ³⁹ is a linear, branched or cyclic alkyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms, which are the same or different from each other. A1 is an integer of 0-6.

Of the acid labile groups represented by the above formula (A-2), examples of the linear or branched groups include those of the following formulas (A-2) -1 to (A-2) -35. be able to.

  Among the acid labile groups represented by the above formula (A-2), the cyclic ones include tetrahydrofuran-2-yl group, 2-methyltetrahydrofuran-2-yl group, tetrahydropyran-2-yl group, 2- Examples thereof include a methyltetrahydropyran-2-yl group.

Further, the base resin may be intermolecularly or intramolecularly crosslinked by an acid labile group represented by the general formula (A-2a) or (A-2b).

In the formula, R ⁴⁰ and R ⁴¹ represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms. Alternatively, R ⁴⁰ and R ⁴¹ may be bonded to form a ring together with the carbon atom to which they are bonded, and when forming a ring, R ⁴⁰ and R ⁴¹ involved in the formation of the ring have 1 to 8 carbon atoms. A linear or branched alkylene group. R ⁴² is a straight, branched or cyclic alkylene group having 1 to 10 carbon atoms, B1, D1 is 0 or 1 to 10, preferably 0 or an integer of 1 to 5, the C1 is an integer from 1 to 7 . A represents a (C1 + 1) -valent aliphatic or alicyclic saturated hydrocarbon group having 1 to 50 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, and these groups may intervene a hetero atom, Alternatively, a part of hydrogen atoms bonded to the carbon atom may be substituted with a hydroxyl group, a carboxyl group, a carbonyl group, or a fluorine atom. B represents —CO—O—, —NHCO—O— or —NHCONH—.

  In this case, preferably, A is a divalent to tetravalent C1-20 linear, branched or cyclic alkylene group, an alkyltriyl group, an alkyltetrayl group, or an arylene group having 6 to 30 carbon atoms. In these groups, a hetero atom may be interposed, and a part of hydrogen atoms bonded to the carbon atom may be substituted with a hydroxyl group, a carboxyl group, an acyl group, or a halogen atom. C1 is preferably an integer of 1 to 3.

Specific examples of the crosslinked acetal groups represented by the general formulas (A-2a) and (A-2b) include those represented by the following formulas (A-2) -36 to (A-2) -43.

Next, in the formula (A-3), R ³⁴ , R ³⁵ , and R ³⁶ are monovalent hydrocarbon groups such as a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, such as oxygen, sulfur, Hetero atoms such as nitrogen and fluorine may be contained, and R ³⁴ and R ³⁵ , R ³⁴ and R ³⁶ , R ³⁵ and R ³⁶ are bonded to each other, and together with the carbon atom to which they are bonded, a ring having 3 to 20 carbon atoms May be formed.

  As the tertiary alkyl group represented by the formula (A-3), a tert-butyl group, a triethylcarbyl group, a 1-ethylnorbornyl group, a 1-methylcyclohexyl group, a 1-ethylcyclopentyl group, 2- (2- A methyl) adamantyl group, a 2- (2-ethyl) adamantyl group, a tert-amyl group, and the like.

Specific examples of the tertiary alkyl group include the following formulas (A-3) -1 to (A-3) -18.

In formulas (A-3) -1 to (A-3) -18, R ⁴³ is the same or different, linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, or 6 to 20 carbon atoms. An aryl group such as a phenyl group or a naphthyl group is shown. R ⁴⁴ and R ⁴⁶ represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. R ⁴⁵ represents an aryl group such as a phenyl group having 6 to 20 carbon atoms.

（上記式（Ａ−３）−１９、（Ａ−３）−２０中、Ｒ^４３は前述と同様、Ｒ^４７は炭素数１〜２０の直鎖状、分岐状もしくは環状のアルキレン基、又はフェニレン基等のアリーレン基を示し、酸素原子や硫黄原子、窒素原子などのヘテロ原子を含んでいてもよい。ｅ１は１〜３の整数である。） Further, as shown in the following formulas (A-3) -19 and (A-3) -20, the polymer contains a divalent or higher valent alkylene group and R ⁴⁷ which is an arylene group, and the polymer within or between the molecules is crosslinked. May be.

(In the formulas (A-3) -19 and (A-3) -20, R ⁴³ is the same as described above, and R ⁴⁷ is a linear, branched or cyclic alkylene group having 1 to 20 carbon atoms, or phenylene. An arylene group such as a group, and may contain a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and e1 is an integer of 1 to 3)

（式中、Ｒ^１０は前述の通り、Ｒ^ｃ３は炭素数１〜８の直鎖状、分岐状又は環状のアルキル基又は炭素数６〜２０の置換されていてもよいアリール基を示す。Ｒ^ｃ４〜Ｒ^ｃ９及びＲ^ｃ１２、Ｒ^ｃ１３はそれぞれ独立に水素原子又は炭素数１〜１５のヘテロ原子を含んでもよい１価の炭化水素基を示し、Ｒ^ｃ１０、Ｒ^ｃ１１は水素原子を示す。あるいは、Ｒ^ｃ４とＲ^ｃ５、Ｒ^ｃ６とＲ^ｃ８、Ｒ^ｃ６とＲ^ｃ９、Ｒ^ｃ７とＲ^ｃ９、Ｒ^ｃ７とＲ^ｃ１３、Ｒ^ｃ８とＲ^ｃ１２、Ｒ^ｃ１０とＲ^ｃ１１又はＲ^ｃ１１とＲ^ｃ１２は互いに環を形成していてもよく、その場合には炭素数１〜１５のヘテロ原子を含んでもよい２価の炭化水素基を示す。またＲ^ｃ４とＲ^ｃ１３、Ｒ^ｃ１０とＲ^ｃ１３又はＲ^ｃ６とＲ^ｃ８は隣接する炭素に結合するもの同士で何も介さずに結合し、二重結合を形成してもよい。また、本式により、鏡像体も表す。） In particular, the acid labile group of the formula (A-3) is preferably a repeating unit of a (meth) acrylic acid ester having an exo structure represented by the following formula (A-3) -21.

(.R shown wherein, R ¹⁰ is as defined above, R ^c3 represents a linear 1 to 8 carbon atoms, branched or cyclic alkyl or optionally substituted aryl group having 6 to 20 carbon atoms ^{c4 to} R ^c9 and R ^c12 and R ^c13 each independently represent a hydrogen atom or a monovalent hydrocarbon group that may contain a heteroatom having 1 to 15 carbon atoms, and R ^c10 and R ^{c11 each} represent a hydrogen atom. R ^c4 and R ^c5 , R ^c6 and R ^c8 , R ^c6 and R ^c9 , R ^c7 and R ^c9 , R ^c7 and R ^c13 , R ^c8 and R ^c12 , R ^c10 and R ^c11, or R ^c11 and R ^c12 A divalent hydrocarbon group which may form a ring and may contain a hetero atom having 1 to 15 carbon atoms, R ^c4 and R ^c13 , R ^c10 and R ^c13, or R ^c6 ; R ^c8 is bonded to adjacent carbon. They may be combined with each other without any intervention to form a double bond.

Here, an ester monomer for obtaining a repeating unit having an exo structure represented by the general formula (A-3) -21 is disclosed in JP-A No. 2000-327633. Specific examples include the following, but are not limited thereto.

（式中、Ｒ^１０は前述の通りである。Ｒ^ｃ１４、Ｒ^ｃ１５はそれぞれ独立に炭素数１〜１０の直鎖状、分岐状又は環状の１価炭化水素基を示す。又は、Ｒ^ｃ１４、Ｒ^ｃ１５は互いに結合してこれらが結合する炭素原子と共に脂肪族炭化水素環を形成してもよい。Ｒ^ｃ１６はフランジイル、テトラヒドロフランジイル又はオキサノルボルナンジイルから選ばれる２価の基を示す。Ｒ^ｃ１７は水素原子又はヘテロ原子を含んでもよい炭素数１〜１０の直鎖状、分岐状又は環状の１価炭化水素基を示す。） Next, as the acid labile group represented by the formula (A-3), the acid resistance of (meth) acrylic acid ester having frangyl, tetrahydrofurandiyl or oxanorbornanediyl represented by the following formula (A-3) -22 is used. Mention may be made of stabilizing groups.

(In the formula, R ¹⁰ is as described above. R ^c14 and R ^c15 each independently represent a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms, or R ^c14 , R ^c15 may be bonded to each other to form an aliphatic hydrocarbon ring together with the carbon atom to which they are bonded, R ^c16 represents a divalent group selected from ^flangedyl , tetrahydrofurandiyl or ^{oxanorbornanediyl.} Represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms which may contain a hydrogen atom or a hetero atom.)

Monomers for obtaining repeating units substituted with acid labile groups having frangyl, tetrahydrofuraniyl or oxanorbornanediyl are exemplified below. Ac represents an acetyl group and Me represents a methyl group.

  A polymer compound containing a repeating unit of indene and / or acenaphthylene having a 1,1,1,3,3,3-hexafluoro-2-propanol group described in the general formula (1) and a compound described in the general formula (2) In order to synthesize a base polymer having an acid labile group, one method includes synthesizing a desired monomer among monomers giving repeating units p, q, r and a to d, a radical polymerization initiator in an organic solvent. In addition, a polymer compound of a copolymer can be obtained by performing heat polymerization.

  Examples of the organic solvent used at the time of polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, dioxane and the like. As polymerization initiators, 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropionate) ), Benzoyl peroxide, lauroyl peroxide and the like, and preferably polymerized by heating to 50 to 80 ° C. The reaction time is 2 to 100 hours, preferably 5 to 20 hours.

  Ammonia water, triethylamine, etc. can be used as the base during the alkali hydrolysis. The reaction temperature is −20 to 100 ° C., preferably 0 to 60 ° C., and the reaction time is 0.2 to 100 hours, preferably 0.5 to 20 hours.

Here, the ratio of the repeating units p, q, r, and s is as follows.
p is 0 ≦ p ≦ 1.0, q is 0 ≦ q ≦ 1.0, 0 <p + q ≦ 1.0, preferably 0.2 ≦ p + q ≦ 1.0, more preferably 0.3 ≦ p + q ≦ 1.0. r is 0 ≦ r <1.0, preferably 0 ≦ r ≦ 0.8, and more preferably 0 ≦ r ≦ 0.7. s is 0 ≦ s <1.0, preferably 0 ≦ s ≦ 0.8, and more preferably 0 ≦ s ≦ 0.7.

Here, the ratio of the repeating units a to d is as follows.
a is 0 ≦ a1 ≦ 0.9, 0 ≦ a2 ≦ 0.9, 0 <a1 + a2 <1, preferably 0 ≦ a1 ≦ 0.8, 0 ≦ a2 ≦ 0.8, 0.1 ≦ a1 + a2 ≦ 0 .8, more preferably 0 ≦ a1 ≦ 0.7, 0 ≦ a2 ≦ 0.7, 0.2 ≦ a1 + a2 ≦ 0.7.
b is preferably in the range of 0 ≦ b1 ≦ 0.3, 0 ≦ b2 ≦ 0.3, 0 ≦ b3 ≦ 0.3, and more preferably 0 ≦ b1 + b2 + b3 ≦ 0.3.
c is 0 ≦ c <1.0, preferably 0 ≦ c ≦ 0.9, more preferably 0 ≦ c ≦ 0.8, and d is 0 ≦ d ≦ 0.5, preferably 0 ≦ d ≦ 0. 4, more preferably 0 ≦ d ≦ 0.3, 0.5 ≦ a1 + a2 + b1 + b2 + b3 + c ≦ 1.0, particularly preferably 0.5 ≦ a1 + a2 + b1 + b2 + b3 + c ≦ 1.0, and a1 + a2 + b1 + b2 + b3 + c + d = 1.
For example, a + b + c = 1 means that in a polymer compound containing repeating units a, b, and c, the total amount of repeating units a, b, and c is 100 mol% with respect to the total amount of all repeating units. A + b + c <1 means that the total amount of the repeating units a, b and c is less than 100 mol% with respect to the total amount of all the repeating units and has other repeating units in addition to a, b and c. It shows that.

The polymer compound used in the resist material of the present invention has a weight average molecular weight of 1,000 to 500,000, preferably 2,000 to 30,000. If the weight average molecular weight is 1,000 or more, the resist material has heat resistance. If the weight average molecular weight is 500,000 or less, the alkali solubility does not decrease and the trailing phenomenon does not occur after pattern formation.
The weight average molecular weight (Mw) is a measured value in terms of polystyrene using gel permeation chromatography (GPC).

Further, in the polymer compound used in the resist material of the present invention, when the molecular weight distribution (Mw / Mn) of the multi-component copolymer is wide, there is a low molecular weight or high molecular weight polymer. Foreign matter may be seen on top or the shape of the pattern may deteriorate. Therefore, since the influence of such molecular weight and molecular weight distribution tends to increase as the pattern rule becomes finer, in order to obtain a resist material suitably used for fine pattern dimensions, the multi-component copolymer to be used is obtained. The molecular weight distribution is preferably from 1.0 to 2.0, particularly preferably from 1.0 to 1.5 and narrow dispersion.
It is also possible to blend two or more polymers having different resist base polymer composition ratios, molecular weight distributions, and molecular weights.

  The present invention has, for example, p, q, r, and s as repeating units, and reduces the generation of outgas from the resist film by orienting on the resist surface after coating, thereby preventing the occurrence of bridge defects and blob defects. Blending an alkali-soluble polymer additive for reducing LWR and a polymer that is soluble in an alkaline developer by an acid having, for example, a1, a2, b1, b2, b3, c, d as repeating units Based on the finished resin. The blend ratio of the surface-aligning polymer additive is 0.1 to 50 parts by weight, preferably 0.2 to 30 parts by weight, more preferably 0.2 to 20 parts per 100 parts by weight of the acid labile group-containing polymer. Part by mass. The single alkali dissolution rate of the surface-oriented polymer additive is in the range of 0.1 to 100,000 nm / s, preferably 1 to 50,000 nm / s, more preferably 10 to 20,000 nm / s.

The resist material of the present invention may contain an acid generator for causing the chemically amplified positive resist material used in the pattern forming method of the present invention to function, for example, a compound that generates an acid in response to actinic rays or radiation. (Photoacid generator) may be contained. The component of the photoacid generator may be any compound that generates an acid upon irradiation with high energy rays. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, and the like. These can be used alone or in admixture of two or more.
Specific examples of the acid generator are described, for example, in paragraphs [0122] to [0142] of JP-A-2008-111103.

The resist material of the present invention can further contain any one or more of an organic solvent, a basic compound, a dissolution controller, a surfactant, and acetylene alcohols.
Specific examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, and methyl-2-n-amyl ketone described in paragraphs [0144] to [0145] of JP-A-2008-111103, 3-methoxybutanol, Alcohols such as 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether , Ethers such as propylene glycol dimethyl ether and diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, lactic acid Esters such as chill, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono tert-butyl ether acetate, γ-butyrolactone, etc. Lactones and mixed solvents thereof, and basic compounds include primary, secondary, and tertiary amine compounds described in paragraphs [0146] to [0164], particularly hydroxy groups, ether groups, ester groups, Examples include amine compounds having a lactone ring, a cyano group, and a sulfonic acid ester group, the surfactants are paragraphs [0165] to [0166], and the dissolution control agent is paragraph [0155] of JP-A-2008-122932. To [0178], and acetylene alcohols are described in paragraph [017 9] to [0182]. A polymer-type quencher described in JP-A-2008-239918 can also be added. This enhances the rectangularity of the patterned resist by being oriented on the coated resist surface. The polymer quencher also has an effect of preventing pattern film loss and pattern top rounding when a protective film for immersion exposure is applied.

  In addition, it is preferable that the compounding quantity of an acid generator shall be 0.01-100 mass parts with respect to 100 mass parts of base resins, especially 0.1-80 mass parts, and the compounding quantity of an organic solvent is 100 mass of base resins. The amount is preferably 50 to 10,000 parts by mass, particularly 100 to 5,000 parts by mass with respect to parts. Moreover, 0-100 mass parts, especially 0-40 mass parts, a basic compound are 0-100 mass parts with respect to 100 mass parts of base resins, especially 0.001-50 mass parts, surfactant is a surfactant. The blending amount is preferably 0 to 10 parts by mass, particularly 0.0001 to 5 parts by mass.

  Resist materials of the present invention, for example, chemically amplified positive resist materials containing an organic solvent, a polymer compound represented by general formulas (1) and (2), an acid generator, and a basic compound, are used for various integrated circuit manufacture. When used, it is not particularly limited, but a known lithography technique can be applied.

For example, the resist material of the present invention is applied to a substrate for manufacturing an integrated circuit (Si, SiO ₂ , SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflection film, etc.) or a substrate for manufacturing a mask circuit (Cr, CrO). , CrON, MoSi, spin-coated on the SiO _2, etc.), roll coating, flow coating, dip coating, spray coating, as the coating film by a suitable coating method such as doctor coating becomes 0.1~2.0μm Apply. This is pre-baked on a hot plate at 60 to 150 ° C. for 10 seconds to 30 minutes, preferably 80 to 120 ° C. for 30 seconds to 20 minutes. Next, a target pattern is passed through a predetermined mask with a light source selected from high energy rays such as ultraviolet rays, far ultraviolet rays, electron beams, X-rays, excimer lasers, γ rays, synchrotron radiation, and vacuum ultraviolet rays (soft X-rays). Direct exposure is performed. It is preferable to expose so that the exposure amount is about 1 to 200 mJ / cm ² , preferably 10 to 100 mJ / cm ² , or 0.1 to 100 μC, preferably about 0.5 to 50 μC. Next, post-exposure baking (PEB) is performed on a hot plate at 60 to 150 ° C. for 10 seconds to 30 minutes, preferably 80 to 120 ° C. for 30 seconds to 20 minutes.

  Furthermore, 0.1 to 10% by weight, preferably 2 to 10% by weight, especially 2 to 8% by weight of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH) 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, using a developing solution of an alkaline aqueous solution such as tetrabutylammonium hydroxide (TBAH), dip method, paddle method, spray method By developing by a conventional method such as the above, a portion irradiated with light is dissolved in the developer, and a portion not exposed is not dissolved, and a desired positive pattern is formed on the substrate. The resist material of the present invention is particularly suitable for fine patterning by KrF excimer laser, ArF excimer laser, electron beam, vacuum ultraviolet ray (soft X-ray), X-ray, γ-ray, and synchrotron radiation among high energy rays. .

TEAH, TPAH, and TBAH having a longer alkyl chain than the TMAH aqueous solution that is generally widely used have the effect of reducing the swelling during development and preventing pattern collapse. In Japanese Patent No. 3429592, a repeating unit having an alicyclic structure such as adamantane methacrylate is copolymerized with a repeating unit having an acid labile group such as t-butyl methacrylate, and has no hydrophilic group and is water repellent. An example using an aqueous TBAH solution for the development of high polymer is presented.
As the tetramethylammonium hydroxide (TMAH) developer, an aqueous solution of 2.38% by mass is most widely used. This corresponds to 0.26N, and it is preferable that the TEAH, TPAH, and TBAH aqueous solutions have the same normality. The masses of TEAH, TPAH, and TBAH that are 0.26N are 3.84 mass%, 5.31 mass%, and 6.78 mass%, respectively.
In a pattern of 32 nm or less that is resolved by EB or EUV, a phenomenon occurs in which lines are twisted, the lines are stuck together, or the stuck lines are tilted. This is thought to be because the lines swollen and swollen in the developer are stuck together. Since the swollen line is soft like a sponge containing a developer, it tends to collapse due to the stress of rinsing. For this reason, the developer having a long alkyl chain has the effect of preventing swelling and preventing pattern collapse.

  A negative pattern can also be obtained by organic solvent development. As the developer, 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, Isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, phenyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonic acid, ethyl crotonic acid, methyl propionate, Ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate 1 selected from methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate More than seeds can be mentioned.

  At the end of development, rinse is performed. As the rinsing liquid, a solvent which is mixed with the developer and does not dissolve the resist film is preferable. As such a solvent, alcohols having 3 to 10 carbon atoms, ether compounds having 8 to 12 carbon atoms, alkanes having 6 to 12 carbon atoms, alkenes, alkynes, and aromatic solvents are preferably used.

Specifically, as the alkane having 6 to 12 carbon atoms, hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane. Is mentioned. Examples of the alkene having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, alkyne having 6 to 12 carbon atoms, hexene, heptin, octyne and the like. As the alcohol of several 3 to 10, n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-amyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3- Xanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2 -Methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1- Examples include pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, and 1-octanol.
Examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, and di-t-amyl. One or more kinds of solvents selected from ether and di-n-hexyl ether are exemplified.
In addition to the aforementioned solvents, aromatic solvents such as toluene, xylene, ethylbenzene, isopropylbenzene, t-butylbenzene, mesitylene and the like can also be used.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited by these description.
[Preparation of polymer compound]
As a polymer compound (polymer additive) added to the resist material, each monomer is combined and subjected to a copolymerization reaction in a methyl ethyl ketone solvent, crystallized in hexane, and further washed with hexane, then isolated and dried. Thus, a polymer compound having the following composition was obtained. The composition of the obtained polymer compound was confirmed by ¹ H-NMR, and the molecular weight and dispersity were confirmed by gel permeation chromatography.

Polymer 1 (Polymer 1)
Molecular weight (Mw) = 8,100
Dispersity (Mw / Mn) = 1.85

Polymer 2
Molecular weight (Mw) = 9,900
Dispersity (Mw / Mn) = 1.98

Polymer 3 (Polymer 3)
Molecular weight (Mw) = 7,200
Dispersity (Mw / Mn) = 1.98

Polymer 4 (Polymer 4)
Molecular weight (Mw) = 8,600
Dispersity (Mw / Mn) = 1.88

Polymer 5 (Polymer 5)
Molecular weight (Mw) = 6,100
Dispersity (Mw / Mn) = 1.64

Polymer 6 (Polymer 6)
Molecular weight (Mw) = 6,100
Dispersity (Mw / Mn) = 1.84

Polymer 7 (Polymer 7)
Molecular weight (Mw) = 6,100
Dispersity (Mw / Mn) = 1.69

Polymer 8 (Polymer 8)
Molecular weight (Mw) = 6,100
Dispersity (Mw / Mn) = 1.69

Polymer 9 (Polymer 9)
Molecular weight (Mw) = 6,100
Dispersity (Mw / Mn) = 1.69

Polymer 10 (Polymer 10)
Molecular weight (Mw) = 7,100
Dispersity (Mw / Mn) = 1.69

Polymer 11 (Polymer 11)
Molecular weight (Mw) = 7,900
Dispersity (Mw / Mn) = 1.88

Comparative polymer 1 (Reference Polymer 1)
Molecular weight (Mw) = 8,200
Dispersity (Mw / Mn) = 1.69

[Preparation of resist material]
EUV Evaluation Using the above polymer additive obtained by normal radical polymerization and the following resist polymer, a solution dissolved in the composition shown in Table 1 below is filtered through a 0.2 μm size filter to obtain a resist material. Was prepared.
The obtained resist material was applied onto a Si-containing SOG film SHB-A940 made by Shin-Etsu Chemical Co., Ltd., which was laminated with a film thickness of 35 nm on a Si substrate having a diameter of 4 inches (100 mm), and on a hot plate, Pre-baking was performed at 110 ° C. for 60 seconds to produce a 35 nm resist film. EUV exposure using NA0.3, Pseudo PSM, PEB is performed under the temperature conditions shown in Table 2, baked with 0.20N tetrabutylammonium hydroxide (TBAH) aqueous solution for 30 seconds, rinsed with pure water and spin-dried Thus, a resist pattern was formed. The sensitivity for forming the 20 nm line and space, the limit resolution of the minimum dimension resolved at this time, and the edge roughness (LWR) were measured by SEM. The results are shown in Table 2.

ＰＧＭＥＡ：プロピレングリコールモノメチルエーテルアセテート
ＰＧＭＥ：プロピレングリコールモノメチルエーテル
ＦＣ−４４３０：フッ素系界面活性剤、住友３Ｍ社製

PGMEA: Propylene glycol monomethyl ether acetate PGME: Propylene glycol monomethyl ether FC-4430: Fluorosurfactant, manufactured by Sumitomo 3M

[result]

  From the results of Table 2 above, the resist film using the resist material of the present invention has the effect of reducing the LWR after development and improving the resolution as a result of the reduction of outgas generation from the resist film in EUV exposure. It was done.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Claims (10)

Polymer compound as base resin whose alkali solubility is improved by acid, and indene and / or acenaphthylene having 1,1,1,3,3,3-hexafluoro-2-propanol group as polymer additive A resist material comprising a polymer compound containing a unit ,
The polymer compound serving as a base resin whose alkali solubility is improved by the acid is based on 1,1,1,3,3,3-hexafluoro-2-propanol group as the polymer additive with respect to 100 parts by mass. A resist material comprising a polymer compound containing a repeating unit of indene and / or acenaphthylene in an amount of 0.2 to 30 parts by mass. The polymer compound containing a repeating unit of indene and / or acenaphthylene having the 1,1,1,3,3,3-hexafluoro-2-propanol group is represented by the following general formula (1). The resist material according to claim 1.

(In general formula (1), 0 ≦ p ≦ 1.0, 0 ≦ q ≦ 1.0, and 0 <p + q ≦ 1.0.)   The resist material according to claim 1, wherein the resist material is a chemically amplified positive resist material.   The resist material according to claim 1, wherein the polymer compound as the base resin contains a repeating unit having an acid labile group.   5. The polymer compound as the base resin includes a repeating unit having an adhesive group containing at least one of a hydroxy group and a lactone ring. 6. Resist material. In the polymer compound as the base resin, repeating units a1 and a2 represented by the following general formula (2) in which a hydrogen atom of a carboxyl group and / or a hydrogen atom of a hydroxyl group of a phenol group are substituted with an acid labile group 6. The polymer composition according to claim 1, comprising a polymer compound having a weight average molecular weight in the range of 1,000 to 500,000 obtained by copolymerizing any one or more repeating units. The resist material described in 1.

(In General Formula (2), R ¹⁰ and R ¹² each independently represent a hydrogen atom or a methyl group, R ¹¹ and R ¹³ each represent an acid labile group. Y ₁ represents a single bond, an ester group and a lactone ring. It is any one of a linking group having 1 to 12 carbon atoms, a phenylene group, and a naphthylene group having one or more of a group consisting of a phenylene group and a naphthylene group, and Y ₂ is a single bond or an ester group. And amide group, 0 ≦ a1 ≦ 0.9, 0 ≦ a2 ≦ 0.9, and 0 <a1 + a2 <1.) In addition to the repeating units a1 and a2 described in the general formula (2), the polymer compound as the base resin has a hydrogen atom of a carboxyl group and / or a hydrogen atom of a hydroxyl group of a phenol group substituted with an acid labile group And a polymer compound having a weight average molecular weight in the range of 1,000 to 500,000 obtained by copolymerizing one or more repeating units of the sulfonium salts b1 to b3 described in the following general formula (3). The resist material according to claim 6.

(Wherein R ²⁰ , R ²⁴ and R ²⁸ are a hydrogen atom or a methyl group, R ²¹ is a single bond, a phenylene group, —O—R ³³ —, or —C (═O) —Y—R ³³ —. Y is an oxygen atom or NH, and R ³³ is a linear, branched or cyclic alkylene group having 1 to 6 carbon atoms, a phenylene group or an alkenylene group, and a carbonyl group (—CO—) Any of R ²² , R ²³ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁹ , R ³⁰ , an ester group (—COO—), an ether group (—O—) and a hydroxy group. R ³¹ is the same or different linear, branched or cyclic alkyl group having 1 to 12 carbon atoms and may contain any of carbonyl group, ester group and ether group, or 6 to 6 carbon atoms. 12 aryl groups, 7-20 carbon atoms .Z denote any aralkyl group or thiophenyl group is a single bond, methylene, ethylene, phenylene, fluorinated phenylene group, ^{-O-R 32} -, and -C (= O) -Z ₁ - R ₁ is any one of R ³² , Z ₁ is an oxygen atom or NH, R ³² is any one of a linear, branched or cyclic alkylene group, a phenylene group and an alkenylene group having 1 to 6 carbon atoms; Any of a group, an ester group, an ether group and a hydroxy group, M ⁻ represents a non-nucleophilic counter ion, 0 ≦ b1 ≦ 0.3, 0 ≦ b2 ≦ 0.3, 0 ≦ (B3 ≦ 0.3, 0 ≦ b1 + b2 + b3 ≦ 0.3.)   The resist material according to any one of claims 1 to 7, further comprising any one or more of an organic solvent, a basic compound, a dissolution controller, and a surfactant. . A step of applying the resist material according to any one of claims 1 to 8 on a substrate, a step of exposing to high energy rays after heat treatment, and a step of developing using a developer. The pattern formation method characterized by the above-mentioned. The pattern formation according to claim 9 , wherein the high energy beam is any one of a KrF excimer laser having a wavelength of 248 nm, an ArF excimer laser having a wavelength of 193 nm, an electron beam, and a soft X-ray having a wavelength in the range of 3 to 15 nm. Method.