JP5343340B2 - Radiation sensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition for immersion lithography which obtains a good pattern shape, is excellent in focal depth, ensures a small amount of eluates in a liquid for immersion lithography, such as water with which the composition contacts in immersion lithography, makes a large backward contact angle between a resist film and the liquid for immersion lithography, such as water, and produces less development defects, and a new polymer for use in the composition. <P>SOLUTION: The radiation-sensitive resin composition includes: a polymer (A) having a weight average molecular weight of 1,000-50,000 as measured by gel permeation chromatography, including 1-40 mol% of a repeating unit (1) containing an OH group as a hydrophilic group and not containing a fluorine atom and 60-99 mol% of a repeating unit (2) containing a fluorine atom, when the entire polymer is considered to be 100 mol%, and not including a repeating unit containing an acid-labile group; a resin (B) containing an acid-labile group; a radiation-sensitive acid generator (C); a nitrogen-containing compound (D); and a solvent (E). <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a radiation sensitive resin composition. More specifically, the present invention relates to a radiation-sensitive resin composition that can be suitably used as an immersion exposure resist used for immersion exposure in which a resist film is exposed through an immersion exposure liquid such as water.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, lithography technology capable of microfabrication at a level of 0.10 μm or less is required. However, in the conventional lithography process, near-ultraviolet rays such as i-rays are generally used as radiation, and it is said that fine processing at a subquarter micron level is extremely difficult with this near-ultraviolet rays. Therefore, in order to enable microfabrication at a level of 0.10 μm or less, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, an X-ray, an electron beam, and the like. Among these, a KrF excimer laser (wavelength 248 nm) is particularly preferable. ) Or ArF excimer laser (wavelength 193 nm) has been attracting attention.
As a resist suitable for irradiation with such an excimer laser, a component having an acid-dissociable functional group and a component that generates acid upon irradiation with radiation (hereinafter referred to as “exposure”) (hereinafter referred to as “acid generator”). )) And a resist utilizing the chemical amplification effect (hereinafter referred to as “chemically amplified resist”) have been proposed. As the chemically amplified resist, for example, a resist containing a resin having a t-butyl ester group of carboxylic acid or a t-butyl carbonate group of phenol and an acid generator has been proposed. In this resist, the t-butyl ester group or t-butyl carbonate group present in the resin is dissociated by the action of an acid generated by exposure, and the resin has an acidic group composed of a carboxyl group or a phenolic hydroxyl group. As a result, the phenomenon that the exposed region of the resist film becomes readily soluble in an alkali developer is utilized.

  In such a lithography process, further fine pattern formation (for example, a fine resist pattern having a line width of about 45 nm) will be required in the future. In order to achieve such fine pattern formation of less than 45 nm, it is conceivable to shorten the light source wavelength of the exposure apparatus and increase the numerical aperture (NA) of the lens as described above. However, a new expensive exposure apparatus is required to shorten the light source wavelength. Further, when the lens has a high NA, the resolution and the depth of focus are in a trade-off relationship. Therefore, there is a problem that the depth of focus decreases even if the resolution is increased.

  Recently, a liquid immersion lithography (liquid immersion lithography) method has been reported as a lithography technique that can solve such problems. In this method, a liquid refractive index medium (immersion exposure liquid) such as pure water or a fluorine-based inert liquid having a predetermined thickness is formed on at least the resist film between the lens and the resist film on the substrate during exposure. It is to intervene. In this method, a light source having the same exposure wavelength can be used by replacing the exposure optical path space, which has conventionally been an inert gas such as air or nitrogen, with a liquid having a higher refractive index (n), such as pure water. Similar to the case of using a light source with a shorter wavelength or the case of using a high NA lens, high resolution is achieved and there is no reduction in the depth of focus. If such immersion exposure is used, it is possible to realize the formation of a resist pattern that is low in cost, excellent in high resolution, and excellent in depth of focus, using a lens mounted on an existing apparatus. It is attracting a lot of attention.

However, in the immersion exposure process described above, the resist film directly comes into contact with an immersion exposure liquid such as water during exposure, so that the acid generator and the like are eluted from the resist film. When the amount of the eluted material is large, there are problems that the lens is damaged, a predetermined pattern shape cannot be obtained, and sufficient resolution cannot be obtained.
In addition, when water is used as the liquid for immersion exposure, if the receding contact angle of water in the resist film is low, water breakage may occur during high-speed scanning exposure, and a watermark (droplet trace) may remain (watermark defect). Because of water penetration into the resist film, the solubility of the film is reduced, and the pattern shape that should originally be resolved cannot achieve sufficient resolution locally, and development of undissolved defects that result in pattern shape defects There is a problem that defects occur.
As a resist resin used in the immersion exposure apparatus, for example, a resin described in Patent Document 1 and Patent Document 2 and an additive described in Patent Document 3 are proposed.
However, even with resists using these resins and additives, the receding contact angle between the resist film and water is not always sufficient, and if the receding contact angle is low, water breakage is poor during high-speed scanning exposure, and watermark defects, etc. Development defects are likely to occur. Moreover, it cannot be said that suppression of the amount of the eluate in water, such as an acid generator, is sufficient.

International Publication WO 2004/062422 JP 2005-173474 A JP 2006-48029 A

  The object of the present invention is that the obtained pattern shape is good, the depth of focus is excellent, the amount of eluate in the immersion exposure liquid such as water that has been contacted during immersion exposure is small, and the resist coating and water or the like An object of the present invention is to provide a radiation-sensitive resin composition for immersion exposure having a large receding contact angle with immersion exposure liquid and few development defects.

〔一般式（１−１）において、Ｒ^１は、水素原子又はメチル基を示し、Ｒ^２及びＲ^５は、それぞれ、メチレン基、炭素数２〜６の直鎖状若しくは分岐状のアルキレン基、又は炭素数４〜１２の脂環式のアルキレン基を示す。〕

〔一般式（２−１）及び（２−２）において、Ｒ^６は、それぞれ、水素原子、メチル基又はトリフルオロメチル基を示し、Ｒ^７は、単結合、メチレン基、炭素数２〜６の直鎖状若しくは分岐状のアルキレン基、又は炭素数４〜１２の脂環式のアルキレン基を示し、Ｒ^８は、少なくとも一つ以上のフッ素原子で置換された炭素数１〜６の直鎖状若しくは分岐状のアルキル基、又は少なくとも一つ以上のフッ素原子で置換された炭素数４〜２０の１価の脂環式炭化水素基若しくはその誘導体を示す。〕
［２］前記重合体（Ａ）の含有量が、本感放射線性樹脂組成物全体を１００質量％とした場合に、０．１〜２０質量％である前記［１］に記載の感放射線性樹脂組成物。
［３］前記樹脂（Ｂ）がラクトン構造を含む繰り返し単位を含有する前記［１］又は［２］に記載の感放射線性樹脂組成物。
［４］前記樹脂（Ｂ）における前記酸不安定基が、単環式構造若しくは多環式構造を有する前記［１］乃至［３］のいずれかに記載の感放射線性樹脂組成物。 The present invention is as follows.
[1] A radiation-sensitive resin composition containing a polymer (A), a resin (B) containing an acid labile group, a radiation-sensitive acid generator (C), a nitrogen-containing compound (D) and a solvent (E) The polymer (A) has a weight average molecular weight of 1,000 to 50,000 as measured by gel permeation chromatography, and does not contain a fluorine atom when the whole polymer is 100 mol%. 1 to 40 mol% of repeating unit (1) containing -OH group as hydrophilic group, 60 to 99 mol% of repeating unit (2) containing fluorine atom, and repeating unit containing acid labile group The repeating unit (1) is a repeating unit represented by the following general formula (1-1), and the repeating unit (2) is represented by the following general formula (2-1). Repeating units and general The radiation-sensitive resin composition, wherein the at least one selected from the repeating units represented by (2-2).

[In General Formula (1-1), R ¹ represents a hydrogen atom or a methyl group, R ² and R ⁵ represent a methylene group, a linear or branched alkylene group having 2 to 6 carbon atoms, Or a C4-C12 alicyclic alkylene group is shown. ]

[In General Formulas (2-1) and (2-2), R ⁶ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁷ represents a single bond, a methylene group, or a carbon number of 2 to 6, respectively. A linear or branched alkylene group, or an alicyclic alkylene group having 4 to 12 carbon atoms, wherein R ⁸ is a linear chain having 1 to 6 carbon atoms substituted with at least one fluorine atom. Or a branched alkyl group, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms substituted with at least one fluorine atom, or a derivative thereof. ]
[2] The radiation sensitive property according to [1], wherein the content of the polymer (A) is 0.1 to 20% by mass when the entire radiation sensitive resin composition is 100% by mass. Resin composition.
[3] The radiation sensitive resin composition according to [1] or [2], wherein the resin (B) contains a repeating unit containing a lactone structure.
[4] The radiation-sensitive resin composition according to any one of [1] to [3], wherein the acid labile group in the resin (B) has a monocyclic structure or a polycyclic structure.

  If the radiation sensitive resin composition for immersion exposure containing the specific polymer of the present invention is used, the pattern shape obtained is good, the depth of focus is excellent, and immersion exposure of water etc. that is in contact during immersion exposure The amount of eluate in the working liquid can be reduced. Furthermore, the receding contact angle between the resist film and the immersion exposure liquid can be made sufficiently high, and development defects (particularly, undissolved defects) can be suppressed.

Hereinafter, the present invention will be described in detail.
The radiation sensitive resin composition in the present invention comprises a polymer (A), a resin (B) containing an acid labile group, a radiation sensitive acid generator (C), a nitrogen-containing compound (D), and a solvent (E). It contains. In addition, this resin composition has a resist pattern including immersion exposure in which a liquid for immersion exposure (for example, water) having a refractive index higher than that of air at a wavelength of 193 nm is irradiated between a lens and a resist film. In the forming method, it is suitably used for forming the resist film.

<Polymer (A)>
The polymer (A) in the present invention does not contain a fluorine atom and contains a repeating unit (1) containing an —OH group as a hydrophilic group [hereinafter simply referred to as “repeating unit (1)”. ] And a repeating unit (2) containing a fluorine atom [hereinafter, simply referred to as “repeating unit (2)”. ] And does not contain a repeating unit containing an acid labile group.

  Since the polymer (A) has a fluorine site in the structure, when it is added as a component of the resist composition, when the resist film is formed, the polymer (A) has an oil repellency characteristic due to its oil repellency. The distribution tends to be higher on the surface of the resist film, and elution of the acid generator, the acid diffusion controller, and the like into water for immersion exposure, such as water, during immersion exposure can be suppressed. Further, due to the water-repellent characteristics of the polymer (A), the receding contact angle between the resist film and the immersion exposure liquid is increased, and high-speed scanning exposure is possible without leaving water droplets. Further, when used together with the conventional upper film for immersion, elution is further reduced, and the resist has high water repellency and can suppress development defects derived from immersion exposure liquids such as watermarks. Furthermore, since the polymer (A) contains a specific amount of the repeating unit (1) as described later, development defects (particularly, undissolved defects) can be sufficiently reduced.

  The repeating unit (1) is a repeating unit represented by the following general formula (1-1) (hereinafter referred to as “repeating unit (1-1)”).

〔一般式（１−１）において、Ｒ^１は、水素原子又はメチル基を示し、Ｒ^２及びＲ^５は、それぞれ、メチレン基、炭素数２〜６の直鎖状若しくは分岐状のアルキレン基、又は炭素数４〜１２の脂環式のアルキレン基を示す。〕

[In General Formula (1-1), R ¹ represents a hydrogen atom or a methyl group, R ² and R ⁵ represent a methylene group, a linear or branched alkylene group having 2 to 6 carbon atoms, Or a C4-C12 alicyclic alkylene group is shown. ]

In the general formula (1-1), the linear or branched alkylene group having 2 to 6 carbon atoms of R ² and R ⁵ is an ethylene group, a 1,3-propylene group, or a 1,2-propylene group. Such as propylene group, tetramethylene group, pentamethylene group, hexamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1 -Saturated chain hydrocarbon groups such as methyl-1,4-butylene group, 2-methyl-1,4-butylene group, methylidene group, ethylidene group, propylidene group, or 2-propylidene group.
Examples of the alicyclic alkylene group having 4 to 12 carbon atoms of R ² and R ⁵ include a cyclobutylene group such as 1,3-cyclobutylene group and a cyclobutylene group such as 1,3-cyclopentylene group. Monocyclic hydrocarbon rings such as cycloalkylene groups having 3 to 10 carbon atoms such as pentylene groups, cyclohexylene groups such as 1,4-cyclohexylene groups, and cyclooctylene groups such as 1,5-cyclooctylene groups Group: 2 to 4 cyclic carbon atoms such as norbornylene group such as 1,4-norbornylene group or 2,5-norbornylene group, adamantylene group such as 1,5-adamantylene group and 2,6-adamantylene group, etc. Examples thereof include bridged cyclic hydrocarbon ring groups such as -12 hydrocarbon ring groups.

  Preferable monomers that give the repeating unit (1-1) include, for example, 2-methacryloyloxyethyl hexahydrophthalate, 3-methacryloyloxypropyl hexahydrophthalate, 4-methacryloyloxybutyl hexahydrophthalate, and the like. Can be mentioned.

The polymer (A) may contain only one type of the repeating unit (1), or may contain two or more types.
In addition, the content of the repeating unit (1) in the polymer (A) is 1 to 40 mol% when the entire polymer [all repeating units in the polymer (A)] is 100 mol%, preferably Is 1 to 30 mol%, more preferably 1 to 25 mol%. When the content rate of this repeating unit (1) is less than 1 mol%, there is a possibility that development defects (particularly, undissolved defects) cannot be suppressed. On the other hand, when it exceeds 40 mol%, water repellency as a polymer may not be sufficiently maintained.

  The repeating unit (2) is represented by a repeating unit represented by the following general formula (2-1) (hereinafter referred to as “repeating unit (2-1)”) and the following general formula (2-2). A repeating unit (hereinafter referred to as “repeating unit (2-2)”).

〔一般式（２−１）及び（２−２）において、Ｒ^６は、それぞれ、水素原子、メチル基又はトリフルオロメチル基を示し、Ｒ^７は、単結合、メチレン基、炭素数２〜６の直鎖状若しくは分岐状のアルキレン基、又は炭素数４〜１２の脂環式のアルキレン基を示し、Ｒ^８は、少なくとも一つ以上のフッ素原子で置換された炭素数１〜６の直鎖状若しくは分岐状のアルキル基、又は少なくとも一つ以上のフッ素原子で置換された炭素数４〜２０の１価の脂環式炭化水素基若しくはその誘導体を示す。〕

[In General Formulas (2-1) and (2-2), R ⁶ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁷ represents a single bond, a methylene group, or a carbon number of 2 to 6, respectively. A linear or branched alkylene group, or an alicyclic alkylene group having 4 to 12 carbon atoms, wherein R ⁸ is a linear chain having 1 to 6 carbon atoms substituted with at least one fluorine atom. Or a branched alkyl group, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms substituted with at least one fluorine atom, or a derivative thereof. ]

Examples of the linear or branched alkylene group having 2 to 6 carbon atoms of R ⁷ in the formula (2-1) include an ethylene group, a 1,3-propylene group, and a 1,2-propylene group. Propylene group, tetramethylene group, pentamethylene group, hexamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl Examples thereof include saturated chain hydrocarbon groups such as -1,4-butylene group, 2-methyl-1,4-butylene group, methylidene group, ethylidene group, propylidene group, and 2-propylidene group.
Examples of the alicyclic alkylene group having 4 to 12 carbon atoms of R ⁷ include a cyclobutylene group such as 1,3-cyclobutylene group and a cyclopentylene group such as 1,3-cyclopentylene group. A monocyclic hydrocarbon ring group such as a cyclohexylene group such as a 1,4-cyclohexylene group, a cycloalkylene group having 3 to 10 carbon atoms such as a cyclooctylene group such as a 1,5-cyclooctylene group, , 4-norbornylene groups or 2,5-norbornylene groups such as norbornylene groups, 1,5-adamantylene groups, adamantylene groups such as 2,6-adamantylene groups, etc. Examples thereof include a crosslinked cyclic hydrocarbon ring group such as a hydrocarbon ring group.

Preferred monomers that give the repeating unit (2-1) include, for example, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester, (Meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl) -2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester, (meth) acrylic acid 2- { [5- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester, (meth) a Acrylic acid 3 - {[8- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] tetracyclo [6.2.1.1 ^{3, 6.} 0 ^2,7 ] dodecyl} ester and the like.

Examples of the linear or branched alkyl group having 1 to 6 carbon atoms substituted with at least one fluorine atom of R ⁸ in the formula (2-2) include a methyl group, an ethyl group, and 1 -Propyl group, 2-propyl group, 1-butyl group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) ) Group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- (2-methyl) And a partially fluorinated or perfluoroalkyl group of a linear or branched alkyl group such as a (rupentyl) group and a 3- (3-methylpentyl) group.

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms substituted with at least one fluorine atom of R ⁸ or a derivative thereof include a cyclopentyl group, a cyclopentylmethyl group, 1- (1- Cyclopentylethyl) group, 1- (2-cyclopentylethyl) group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group , 1- (1-cycloheptylethyl) group, 1- (2-cycloheptylethyl) group, 2-norbornyl group or the like partially fluorinated alkyl group or perfluoroalkyl group.

  Preferred monomers that give the repeating unit (2-2) include trifluoromethyl (meth) acrylic acid ester, 2,2,2-trifluoroethyl (meth) acrylic acid ester, and perfluoroethyl (meth) acrylic. Acid ester, perfluoro n-propyl (meth) acrylic acid ester, perfluoro i-propyl (meth) acrylic acid ester, perfluoro n-butyl (meth) acrylic acid ester, perfluoro i-butyl (meth) acrylic acid ester , Perfluoro t-butyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoropropyl) (meth) acrylate, 1- (2,2,3,3, 4,4,5,5-octafluoropentyl) (meth) acrylic acid ester, perfluorocyclohexylmethyl (Meth) acrylic acid ester, 1- (2,2,3,3,3-pentafluoropropyl) (meth) acrylic acid ester, 1- (3,3,4,4,5,5,6,6,7 , 7,8,8,9,9,10,10,10-heptadecafluorodecyl) (meth) acrylic acid ester, 1- (5-trifluoromethyl-3,3,4,4,5,6, 6,6-octafluorohexyl) (meth) acrylic acid ester and the like.

The polymer (A) may contain only one type of the repeating unit (2), or may contain two or more types.
Further, the content of the repeating unit (2) in the polymer (A) is 60 to 99 mol% when the entire polymer [total repeating units in the polymer (A)] is 100 mol%, preferably Is 70 to 99 mol%, more preferably 75 to 99 mol%. When the content of the repeating unit (2) is less than 60 mol%, the water repellent property cannot be sufficiently obtained, and a development defect may occur due to the immersion liquid soaking. On the other hand, when it exceeds 99 mol%, there is a possibility of causing development defects due to lack of acidic components.

  Moreover, as a repeating unit containing the said acid labile group, the repeating unit (3) and (4) etc. in description of resin (B) mentioned later can be mentioned.

  In addition, the polymer (A) in the present invention includes, for example, a polymerizable unsaturated monomer corresponding to each predetermined repeating unit such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. It can be produced by using a radical polymerization initiator and polymerizing in an appropriate solvent in the presence of a chain transfer agent as required.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, Cycloalkanes such as norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethane, hexamethylene dibromide, chlorobenzene; ethyl acetate Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; tetrahydrofuran, dimethoxyethanes, Ethers such as diethoxyethanes; Methanol, ethanol, 1-propanol, 2-propanol, may be mentioned alcohols such as 4-methyl-2-pentanol. These solvents can be used alone or in admixture of two or more.
The reaction temperature in the polymerization is usually 40 to 150 ° C., preferably 50 to 120 ° C., and the reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

Moreover, the polystyrene conversion weight average molecular weight (henceforth "Mw") by the gel permeation chromatography (GPC) method of the polymer (A) in this invention is 1000-50000, Preferably it is 1000-40000, More preferably Is 1000-30000. When the Mw of the polymer (A) is less than 1000, a sufficient receding contact angle cannot be obtained. On the other hand, when the Mw exceeds 50000, the developability when resist is formed tends to be lowered.
The ratio (Mw / Mn) of the polymer (A) Mw and the polystyrene-equivalent number average molecular weight (hereinafter referred to as “Mn”) by GPC method is usually 1 to 5, preferably 1 to 4. is there.

The polymer (A) is preferably as low as possible in the content of impurities such as halogens and metals, whereby the sensitivity, resolution, process stability, pattern shape, etc. when used as a resist can be further improved.
Examples of the purification method for the polymer (A) include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation. Etc.

  Preferred solvents used for the liquid-liquid extraction include (1) alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, (2) methanol, Examples include alcohols such as ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol; and (3) ketones such as acetone, 2-butanone, 4-methyl-2-pentanone, and 2-heptanone. . Among these, n-hexane, n-heptane, methanol, ethanol, acetone, and 2-butanone are preferable.

Moreover, in this invention, a polymer (A) can be used individually or in mixture of 2 or more types.
The content of the polymer (A) is such that the resist coating ensures a sufficient receding contact angle, and the elution of the acid generator and the like from the resist coating can be sufficiently suppressed. When it is 100 mass%, it is 0.1 mass% or more normally, Preferably it is 0.1-20 mass%, More preferably, it is 0.5-15 mass%. When the content of the polymer (A) is less than 0.1% by mass, the effect (high receding angle and low elution) of the polymer (A) does not appear and the receding contact angle of the resist film is reduced, or the resist There is a tendency that elution of the acid generator and the like from the coating cannot be suppressed. On the other hand, when the content exceeds 20% by mass, the depth of focus of the isolated line may be reduced or a development defect may occur.

<Resin containing acid labile group (B)>
In the resin (B) containing an acid labile group in the present invention (hereinafter, also simply referred to as “resin (B)”), the radiation sensitive resin composition has the effect of the polymer (A) (high receding angle, Although it is not particularly limited to express low elution and development defect suppression, it is preferable to use an alkali-insoluble or alkali-insoluble resin that becomes alkali-soluble by the action of an acid. The term “alkali insoluble or alkali insoluble” as used herein refers to the alkali development conditions employed when forming a resist pattern from a resist film formed from a radiation-sensitive resin composition containing the resin (B). When a film using only the resin (B) is developed instead of the resist film, it means that 50% or more of the initial film thickness of the film remains after development.

  Examples of the resin (B) include a resin having an alicyclic skeleton such as a norbornane ring in a main chain obtained by polymerizing a norbornene derivative or the like, and a main chain obtained by copolymerizing a norbornene derivative and maleic anhydride. A resin having a norbornane ring and a maleic anhydride derivative, a resin having a norbornane ring and a (meth) acryl skeleton mixed in a main chain obtained by copolymerizing a norbornene derivative and a (meth) acrylic compound, a norbornene derivative and maleic anhydride, ( Resin in which norbornane ring, maleic anhydride derivative and (meth) acrylic skeleton are mixed in the main chain obtained by copolymerizing (meth) acrylic compound, main chain obtained by copolymerizing (meth) acrylic compound is (meth) Examples thereof include acrylic skeleton resins. Note that “(meth) acryl” means either “acryl” or “methacryl” or both.

Among the resins (B), preferred examples include those containing a repeating unit containing a lactone skeleton (hereinafter also referred to as “repeating unit (3)”).
Preferable monomers that give this repeating unit (3) include, for example, the following general formulas (3-1) to (3-6).

In formulas (3-1) to (3-6), R ⁹ represents a hydrogen atom or a methyl group, and R ¹⁰ has a hydrogen atom or a substituent having 1 to 4 carbon atoms. R ¹¹ represents a hydrogen atom or a methoxy group. A represents a single bond or a methylene group, and B represents an oxygen atom or a methylene group. Further, l represents an integer of 1 to 3, and m is 0 or 1.
Examples of the alkyl group which may have a substituent having 1 to 4 carbon atoms in R ¹⁰ of the general formula (3-1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, Examples include n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like.

Specific examples of a preferable monomer that gives the repeating unit (3) include (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl. Ester, (meth) acrylic acid-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid-5-oxo -4-oxa-tricyclo [5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic acid-10-methoxycarbonyl-5-oxo-4-oxa-tricyclo [5.2. 1.0 ^3,8 ] non-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-4 -Methoxycarbonyl-6- Xo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (Meth) acrylic acid-4-methoxycarbonyl-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic acid-2-oxotetrahydropyran-4-yl ester , (Meth) acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-ethyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4 -Propyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic Luric acid-2,2-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2-oxo Tetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5,5-dimethyl-2-oxotetrahydrofuran-3-yl ester , (Meth) acrylic acid-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-3,3-dimethyl-5-oxotetrahydrofuran -2-ylmethyl ester, (meth) acrylic acid-4,4-dimethyl 5-oxo tetrahydrofuran-2-yl methyl ester.

The said resin (B) may contain only 1 type of this repeating unit (3), and may contain 2 or more types.
The content of the repeating unit (3) is preferably from 5 to 85 mol%, more preferably from 10 to 70 mol%, even more preferably when all the repeating units in the resin (B) are 100 mol%. Is 15 to 60 mol%. When the content of the repeating unit (3) is less than 5 mol%, developability and exposure margin tend to be deteriorated. On the other hand, when this content rate exceeds 85 mol%, there exists a tendency for the solubility to the solvent of resin (B) to deteriorate, and the resolution to deteriorate.

  In addition to the repeating unit (3), the resin (B) contains a repeating unit having an acid labile group represented by the following general formula (4) (hereinafter referred to as “repeating unit (4)”). It is preferable. In addition, resin (B) may contain only 1 type of this repeating unit (4), and may contain 2 or more types.

〔一般式（４）において、Ｒ^１２は水素原子、メチル基又はトリフルオロメチル基を示す。各々のＲ^１３は相互に独立に炭素数４〜２０の１価の脂環式炭化水素基若しくはその誘導体、又は炭素数１〜４の直鎖状若しくは分岐状のアルキル基を示す。〕

In [Formula (4), R ¹² represents a hydrogen atom, a methyl group or a trifluoromethyl group. Each R ¹³ independently represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms. ]

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms in R ¹³ of the general formula (4) include cyclohexane such as norbornane, adamantane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. Groups composed of alicyclic rings derived from alkanes and the like; groups composed of these alicyclic rings are, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2- Examples include groups substituted with one or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as methylpropyl group, 1-methylpropyl group and t-butyl group. it can. Moreover, any two R < ¹³ > may couple | bond together and may form a bivalent alicyclic hydrocarbon group or its derivative with the carbon atom which each has couple | bonded.
Of these alicyclic hydrocarbon groups, a group consisting of an alicyclic ring derived from adamantane, cyclopentane or cyclohexane, a group obtained by substituting a group consisting of these alicyclic rings with the alkyl group, and the like are preferable.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms in R ¹³ of the general formula (4) include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n- A butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like can be mentioned.

In the general formula (4), preferred examples of —C (R ¹³ ) ₃ include t-butyl group, 1-n- (1-ethyl-1-methyl) propyl group, 1-n- (1,1- Dimethyl) propyl group, 1-n- (1,1-dimethyl) butyl group, 1-n- (1,1-dimethyl) pentyl group, 1- (1,1-diethyl) propyl group, 1-n- ( 1,1-diethyl) butyl group, 1-n- (1,1-diethyl) pentyl group, 1- (1-methyl) cyclopentyl group, 1- (1-ethyl) cyclopentyl group, 1- (1-methyl) Cyclohexyl group, 1- (1-ethyl) cyclohexyl group, 1- {1-methyl-1- (1-adamantyl)} ethyl group, 1- (1-methyl) adamantyl group, 1- (1-ethyl) adamantyl group Or a group consisting of these alicyclic rings such as methyl , Ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, etc. Examples include a group substituted with one or more cyclic alkyl groups or one or more.

  A preferred monomer that gives the repeating unit (4) preferably has a monocyclic structure or a polycyclic structure. Specifically, 2-methyladamantyl-2- (meth) acrylate is preferable. Yl ester, (meth) acrylic acid 2-ethyladamantyl-2-yl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl ester, (meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic Acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid 1-ethyl-1-cyclohexyl ester, and the like.

  The content of the repeating unit (4) is usually 10 to 70 mol%, preferably 15 to 60 mol%, more preferably 20 to 50 mol, when the total repeating units in the resin (B) are 100 mol%. Mol%. When the content of the repeating unit (4) is less than 10 mol%, the resolution as a resist may be lowered. On the other hand, if the content exceeds 70 mol%, the developability and exposure margin may be deteriorated.

  The resin (B) in the present invention may contain one or more repeating units other than the repeating units (3) and (4).

  In addition, the resin (B) in the present invention includes, for example, a polymerizable unsaturated monomer corresponding to each predetermined repeating unit as a radical such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. It can manufacture by superposing | polymerizing in a suitable solvent using a polymerization initiator in presence of a chain transfer agent as needed.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, Cycloalkanes such as norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethane, hexamethylene dibromide, chlorobenzene; ethyl acetate Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; tetrahydrofuran, dimethoxyethanes, Ethers such as diethoxyethanes It can be mentioned. These solvents can be used alone or in admixture of two or more.
The reaction temperature in the polymerization is usually 40 to 150 ° C., preferably 50 to 120 ° C., and the reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

Moreover, although Mw by GPC method of resin (B) in this invention is not specifically limited, Preferably it is 1000-100000, More preferably, it is 1000-30000, More preferably, it is 1000-20000. When the Mw of the resin (B) is less than 1000, the heat resistance when used as a resist tends to decrease. On the other hand, if the Mw exceeds 100,000, the developability when used as a resist tends to decrease.
Moreover, ratio (Mw / Mn) of Mw of resin (B) and Mn by GPC method is normally 1-5, Preferably it is 1-3.

Moreover, in resin (B), content of the low molecular-weight component derived from the monomer used when preparing this resin (B) is 0.1 with respect to 100 mass% of this resin in conversion of solid content. It is preferably at most mass%, more preferably at most 0.07 mass%, still more preferably at most 0.05 mass%. When this content is 0.1% by mass or less, it is possible to reduce the amount of the eluate in the immersion exposure liquid such as water that is in contact with the immersion exposure. Furthermore, foreign matters are not generated in the resist during resist storage, and coating unevenness does not occur during resist application, and the occurrence of defects during resist pattern formation can be sufficiently suppressed.
Examples of the low molecular weight component derived from the monomer include a monomer, a dimer, a trimer, and an oligomer, and can be a component having an Mw of 500 or less. The components having an Mw of 500 or less can be removed by, for example, chemical purification methods such as washing with water and liquid-liquid extraction, or a combination of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. it can. Moreover, it can analyze by the high performance liquid chromatography (HPLC) of resin.
In addition, resin (B) is so preferable that there is little content of impurities, such as a halogen and a metal, Thereby, the sensitivity at the time of setting it as a resist, resolution, process stability, a pattern shape, etc. can be improved further.
Examples of the purification method for the resin (B) include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation. Can be mentioned.

  Moreover, in this invention, resin (B) can be used individually or in mixture of 2 or more types.

<Radiosensitive acid generator (C)>
The radiation-sensitive acid generator (C) in the present invention (hereinafter also simply referred to as “acid generator (C)”) generates an acid upon exposure, and the resin generated by the action of the acid generated upon exposure. The acid dissociable group of the repeating unit (4) present in the component is dissociated (the protecting group is eliminated), so that the exposed portion of the resist film becomes readily soluble in an alkali developer, and a positive resist pattern is formed. It has an action to form.
As such an acid generator (C), what contains the compound (henceforth "the acid generator 1") represented by following General formula (5) is preferable.

（各式中、Ｒ^１８は、互いに独立して、フッ素原子を有し、且つ、炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、又は、２つのＲ^１８が互いに結合して、フッ素原子を有し、且つ、炭素数２〜１０の２価の有機基であり、該２価の有機基は置換基を有してもよい。）〕 In the general formula (5), R ¹⁴ represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched alkoxyl having 1 to 10 carbon atoms. A straight chain or branched alkoxycarbonyl group having 2 to 11 carbon atoms; R ¹⁵ represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms. Further, R ¹⁶ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group or an optionally substituted naphthyl group, or two R ¹⁶ is bonded to each other to form a divalent group having 2 to 10 carbon atoms, the divalent group may be substituted, k is an integer of 0 to 2, and X ⁻ is Formula: R ¹⁷ C _n F _2n SO ₃ ⁻ , R ¹⁷ SO ₃ ⁻ (wherein R ¹⁷ represents a fluorine atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and n is 1 Or an anion represented by the following general formula (6-1) or (6-2), and r is an integer of 0 to 10.

(In each formula, R ¹⁸ are independently of each other a fluorine atom and a linear or branched alkyl group having 1 to 10 carbon atoms, or two R ¹⁸ are bonded to each other, It is a divalent organic group having 2 to 10 carbon atoms and having a fluorine atom, and the divalent organic group may have a substituent.

In the general formula (5), examples of the linear or branched alkyl group having 1 to 10 carbon atoms of R ¹⁴ , R ¹⁵ and R ¹⁶ include a methyl group, an ethyl group, an n-butyl group, 2- A methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group and the like can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

^Examples of the linear or branched alkoxy group having 1 to 10 carbon atoms of ^{R 14} and ^{R 15,} for example, a methoxy group, an ethoxy group, n- propoxy group, i- propoxy, n- butoxy group, A 2-methylpropoxy group, a 1-methylpropoxy group, a t-butoxy group, and the like can be given. Of these alkoxyl groups, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.

Examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms of R ¹⁴ include, for example, methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-butoxy. A carbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group and the like can be exemplified. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

Examples of the linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms of R ¹⁵ include, for example, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a tert. -A butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, etc. can be mentioned. Of these alkanesulfonyl groups, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable.

  Moreover, as r, 0-2 are preferable.

In the general formula (5), examples of the optionally substituted phenyl group represented by R ¹⁶ include a phenyl group, a 4-ethylphenyl group, a 4-t-butylphenyl group, a 4-cyclohexylphenyl group, and 4-fluorophenyl. A phenyl group such as a group or a phenyl group substituted with a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms; these phenyl group or alkyl-substituted phenyl group can be a hydroxyl group, a carboxyl group, a cyano group; , A nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, a group substituted with one or more groups such as an alkoxycarbonyloxy group.

  Among the substituents for the phenyl group and the alkyl-substituted phenyl group, examples of the alkoxyl group include 1 carbon atom such as a methoxy group, an ethoxy group, an n-propoxy group, a t-butoxy group, a cyclopentyloxy group, and a cyclohexyloxy group. -20 linear, branched or cyclic alkoxyl groups can be exemplified.

Examples of the alkoxyalkyl group include 2 to 21 carbon atoms such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, and a 2-ethoxyethyl group. And linear, branched or cyclic alkoxyalkyl groups.
Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, a 2-methylpropoxycarbonyl group, and a 1-methylpropoxycarbonyl group. , T-butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like, and straight chain, branched or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms.

Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, Examples thereof include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as cyclopentyloxycarbonyl group and cyclohexyloxycarbonyl.
Examples of the optionally substituted phenyl group represented by R ¹⁵ in the general formula (5) include a phenyl group, a 4-cyclohexylphenyl group, a 4-t-butylphenyl group, a 4-methoxyphenyl group, and a 4-t-butoxyphenyl group. Etc. are preferred.

Examples of the optionally substituted naphthyl group for R ¹⁶ include 1-naphthyl group, 2-methyl-1-naphthyl group, 3-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 5-methyl-1-naphthyl group, 6-methyl-1-naphthyl group, 7-methyl-1-naphthyl group, 8-methyl-1-naphthyl group, 2,3-dimethyl -1-naphthyl group, 2,4-dimethyl-1-naphthyl group, 2,5-dimethyl-1-naphthyl group, 2,6-dimethyl-1-naphthyl group, 2,7-dimethyl-1-naphthyl group, 2,8-dimethyl-1-naphthyl group, 3,4-dimethyl-1-naphthyl group, 3,5-dimethyl-1-naphthyl group, 3,6-dimethyl-1-naphthyl group, 3,7-dimethyl- 1-naphthyl group, 3,8-dimethyl-1-na Butyl group, 4,5-dimethyl-1-naphthyl group, 5,8-dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group 2-naphthyl group, 1-methyl-2-naphthyl group, 3-methyl A naphthyl group substituted with a naphthyl group such as a 2-naphthyl group or 4-methyl-2-naphthyl group or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms; these naphthyl group or alkyl Examples include a group in which a substituted naphthyl group is substituted with at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Can do.

  Examples of the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group and alkoxycarbonyloxy group as the substituent include the groups exemplified for the phenyl group and the alkyl-substituted phenyl group.

Examples of the optionally substituted naphthyl group of R ¹⁶ in the general formula (5) include 1-naphthyl group, 1- (4-methoxynaphthyl) group, 1- (4-ethoxynaphthyl) group, 1- (4- n-propoxynaphthyl) group, 1- (4-n-butoxynaphthyl) group, 2- (7-methoxynaphthyl) group, 2- (7-ethoxynaphthyl) group, 2- (7-n-propoxynaphthyl) group , 2- (7-n-butoxynaphthyl) group and the like are preferable.

In addition, the divalent group having 2 to 10 carbon atoms formed by bonding two R ¹⁶ to each other is preferably a 5-membered or 6-membered ring, particularly preferably 5 together with the sulfur atom in the general formula (5). Groups that form member rings (ie, tetrahydrothiophene rings) are desirable.

Examples of the substituent for the divalent group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxy group exemplified as the substituent for the phenyl group and the alkyl-substituted phenyl group. Examples thereof include a carbonyl group and an alkoxycarbonyloxy group.
As R ¹⁶ in the general formula (5), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, a 1-naphthyl group, and two R ¹⁶ are bonded to each other to form a tetrahydrothiophene ring structure together with a sulfur atom. A divalent group is preferred.

X ⁻ in the general formula (5) is R ¹⁷ C _n F _2n SO ₃ ⁻ , R ¹⁷ SO ₃ ⁻ or an anion represented by the general formula (6-1) or (6-2). The —C _n F _2n — group in the case where X ⁻ is R ¹⁷ C _n F _2n SO ₃ ^— is a perfluoroalkylene group having n carbon atoms, but this group may be linear. However, it may be branched. Here, n is preferably 1, 2, 4 or 8.
As the hydrocarbon group which carbon atoms which may have 1 to 12 substituents of R ^17, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a bridged alicyclic hydrocarbon group.
Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, norbornyl group, norbornylmethyl group, hydroxy A norbornyl group, an adamantyl group, etc. can be mentioned.

In addition, R ¹⁸ in the case where X ⁻ is an anion represented by the general formula (6-1) or (6-2) has fluorine atoms independent of each other, and has 1 to 10 carbon atoms. May be a linear or branched alkyl group, or two R ¹⁸ may be bonded to each other to have a fluorine atom and be a divalent organic group having 2 to 10 carbon atoms. In that case, the divalent organic group may have a substituent.
In General Formula (6-1) or (6-2), when R ¹⁸ is a linear or branched alkyl group having 1 to 10 carbon atoms, a trifluoromethyl group, a pentafluoroethyl group, or a heptafluoro group. A propyl group, a nonafluorobutyl group, a dodecafluoropentyl group, a perfluorooctyl group, etc. are mentioned.
When R ¹⁸ is a divalent organic group having 2 to 10 carbon atoms, a tetrafluoroethylene group, a hexafluoropropylene group, an octafluorobutylene group, a decafluoropentylene group, an undecafluorohexylene group, etc. Can be mentioned.

Accordingly, preferred anions X ⁻ in the general formula (5) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hepta. 2-yl-1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, the following formula (7-1) Examples include anions represented by (7-7).

  Further, preferred specific examples of the general formula (5) include triphenylsulfonium trifluoromethanesulfonate, tri-tert-butylphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyl-diphenyl. Sulfonium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate,

  Triphenylsulfonium perfluoro-n-butanesulfonate, tri-tert-butylphenylsulfonium perfluoro-n-butanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium perfluoro-n-butanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium per Fluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-butanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro- n-butanesulfonate,

  Triphenylsulfonium perfluoro-n-octane sulfonate, tri-tert-butylphenylsulfonium perfluoro-n-octane sulfonate, 4-cyclohexylphenyl-diphenylsulfonium perfluoro-n-octane sulfonate, 4-methanesulfonylphenyl-diphenylsulfonium per Fluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro- n-octane sulfonate,

  Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, tri-tert-butylphenylsulfonium 2- (bicyclo [2.2 .1] Hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl)- 1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoro Ethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (bicyclo [2.2. ] Hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2 '-Yl) -1,1,2,2-tetrafluoroethanesulfonate,

尚、本発明において、酸発生剤１は、一種単独でも又は２種以上を混合しても使用することができる。 Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, tri-tert-butylphenylsulfonium 2- (bicyclo [2.2.1] hepta-2 '-Yl) -1,1-difluoroethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 4-methanesulfonylphenyl -Diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- ( Bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfur 1- (4-n-butoxynaphthyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, represented by the following formulas C1-C15 And the like.

In the present invention, the acid generator 1 can be used singly or in combination of two or more.

  Examples of the radiation sensitive acid generator (C) other than the acid generator 1 include onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, sulfonic acid compounds and the like (hereinafter referred to as “other acid generators”). ")". These other acid generators can be used alone or in admixture of two or more.

In this invention, the total usage-amount of the acid generator 1 and another acid generator is with respect to a total of 100 mass parts of a polymer (A) and resin (B) from a viewpoint of ensuring the sensitivity and developability as a resist. Usually, it is 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass. In this case, if the total amount used is less than 0.1 parts by mass, the sensitivity and developability tend to decrease. On the other hand, when the total amount used exceeds 20 parts by mass, the transparency to radiation is lowered, and it tends to be difficult to obtain a rectangular resist pattern.
Moreover, the usage-amount of other acid generators is 80 mass% or less normally with respect to 100 mass% of the sum total of the acid generator 1 and another acid generator, Preferably it is 60 mass% or less.

<Nitrogen-containing compound (D)>
The nitrogen-containing compound (D) is a component that controls the diffusion phenomenon of the acid generated from the acid generator upon exposure in the resist film and suppresses an undesirable chemical reaction in the non-exposed region. By mix | blending such an acid diffusion control agent, the storage stability of the radiation sensitive resin composition obtained improves. In addition, the resolution as a resist is further improved, and it is possible to suppress changes in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to post-exposure heat treatment, and an extremely excellent process stability. A thing is obtained.

Examples of the nitrogen-containing compound (D) include tertiary amine compounds, other amine compounds, amide group-containing compounds, urea compounds, and other nitrogen-containing heterocyclic compounds.
Examples of the tertiary amine compounds include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n-butylamine Di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. (Cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, Tri-n-nonylamine, tri-n-decylamine, cyclohex Tri (cyclo) alkylamines such as dimethylamine, methyldicyclohexylamine, tricyclohexylamine; substituted alkylamines such as 2,2 ′, 2 ″ -nitrotriethanol; aniline, N-methylaniline, N, N— Dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-tert-butyl-N-methylaniline, N- Phenyldiethanolamine, 2,6-diisopropylaniline and the like are preferable.

  Examples of the other amine compounds include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methyl ester Benzene], bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′ , N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and the like are preferable.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt -Butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)- (-)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxy Piperidine, Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbo Lupiperazine, Nt-butoxycarbonylpiperidine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt- Butoxycarbonyl-4,4'-diaminodiphenylmethane, N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra-t-butoxycarbonylhexamethylenediamine, N, N'- Di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycal Nyl-1,12-diaminododecane, N, N′-di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole Nt-butoxycarbonyl group-containing amino compounds such as Nt-butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N , N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric acid tris (2-hydroxyethyl) and the like are preferable.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butyl. Thiourea and the like are preferable.

  Examples of the other nitrogen-containing heterocyclic compounds include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl- Imidazoles such as 2-methyl-1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4- Pyridines such as phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, 2,2 ′: 6 ′, 2 ″ -terpyridine; piperazine, 1- (2 Piperazine such as -hydroxyethyl) piperazine In addition, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetyl Preferred are morpholine, 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like.

The nitrogen-containing compound (D) can be used singly or in combination of two or more.
The amount of the acid diffusion controller [nitrogen-containing compound (D)] is usually 15 parts by mass or less, preferably 10 parts by mass or less, with respect to 100 parts by mass in total of the polymer (A) and the resin (B). More preferably, it is 5 parts by mass or less. In this case, when the compounding amount of the acid diffusion controller exceeds 15 parts by mass, the sensitivity as a resist tends to decrease. If the amount of the acid diffusion controller is less than 0.001 part by mass, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

<Solvent (E)>
The radiation-sensitive resin composition of the present invention is usually dissolved in a solvent so that the total solid content concentration is usually 1 to 50% by mass, preferably 1 to 25% by mass. A composition solution is prepared by filtering with a filter having a pore size of about 0.2 μm.

  Examples of the solvent (E) include 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3- Linear or branched ketones such as dimethyl-2-butanone, 2-heptanone, 2-octanone; cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, Cyclic ketones such as isophorone; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl Propylene glycol monoalkyl ether acetates such as ether acetate, propylene glycol mono-i-butyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-t-butyl ether acetate; methyl 2-hydroxypropionate, 2-hydroxypropionic acid Ethyl, 2-hydroxypropionate n-propyl, 2-hydroxypropionate i-propyl, 2-hydroxypropionate n-butyl, 2-hydroxypropionate i-butyl, 2-hydroxypropionate sec-butyl, 2-hydroxy Alkyl 2-hydroxypropionates such as t-butyl propionate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxy Methyl propionate, other 3-alkoxy propionic acid alkyl such as ethyl 3-ethoxypropionate,

  n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclohexanol, 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 , Propylene glycol monoethyl Ether, propylene glycol mono-n-propyl ether, toluene, xylene, 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-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, Ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol Cole monoethyl ether, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, etc. Can do.

Among these, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, γ-butyrolactone and the like are preferable. .
These solvent (E) can be used individually or in mixture of 2 or more types.

<Additives>
Various additives, such as an alicyclic additive, surfactant, and a sensitizer, can be mix | blended with the radiation sensitive resin composition of this invention as needed.

<Method for forming resist pattern>
The radiation sensitive resin composition of the present invention is particularly useful as a chemically amplified resist. In the chemically amplified resist, the acid-dissociable group in the resin component [mainly resin (B)] is dissociated by the action of the acid generated from the acid generator by exposure to generate a carboxyl group, and as a result, The solubility of the exposed portion of the resist in the alkaline developer is increased, and the exposed portion is dissolved and removed by the alkaline developer to obtain a positive resist pattern.
When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the resin composition solution is coated with, for example, a silicon wafer or aluminum by an appropriate application means such as spin coating, cast coating, or roll coating. A resist film is formed by coating on a substrate such as a wafer, and this resist is formed so that a predetermined resist pattern is formed after a heat treatment (hereinafter referred to as “PB”) in some cases. Expose the coating. The radiation used at that time is appropriately selected from visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams, etc., depending on the type of acid generator used. ArF excimer laser Far ultraviolet rays represented by (wavelength 193 nm) or KrF excimer laser (wavelength 248 nm) are preferable, and ArF excimer laser (wavelength 193 nm) is particularly preferable.
Moreover, exposure conditions, such as exposure amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition, the kind of additive, etc. In the present invention, it is preferable to perform heat treatment (PEB) after exposure. By PEB, the dissociation reaction of the acid dissociable group in the resin component proceeds smoothly. The heating condition of PEB varies depending on the composition of the radiation sensitive resin composition, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  In the present invention, in order to maximize the potential of the radiation-sensitive resin composition, for example, as disclosed in Japanese Patent Publication No. 6-12252 (Japanese Patent Laid-Open No. 59-93448), etc. An organic or inorganic antireflection film may be formed on the substrate to be formed. Further, in order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film can be provided on the resist film as disclosed in, for example, JP-A-5-188598. Further, in order to prevent the acid generator and the like from flowing out of the resist film in immersion exposure, a liquid immersion protective film is provided on the resist film as disclosed in, for example, JP-A-2005-352384. You can also. These techniques can be used in combination.

  Next, the exposed resist film is developed to form a predetermined resist pattern. Examples of the developer used for this development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propyl. Amine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo -An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is usually 10% by mass or less. In this case, if the concentration of the alkaline aqueous solution exceeds 10% by mass, the unexposed area may be dissolved in the developer, which is not preferable.

In addition, for example, an organic solvent can be added to the developer composed of the alkaline aqueous solution. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol, and n-propyl. Alcohols such as alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane Esters such as ethyl acetate, n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone and dimethylformamide. These organic solvents can be used alone or in admixture of two or more. The amount of the organic solvent used is preferably 100% by volume or less with respect to the alkaline aqueous solution. In this case, when the amount of the organic solvent used exceeds 100% by volume, the developability is lowered, and there is a possibility that the remaining development in the exposed area increases. An appropriate amount of a surfactant or the like can be added to the developer composed of the alkaline aqueous solution.
In addition, after developing with the developing solution which consists of alkaline aqueous solution, generally it wash | cleans with water and dries.

  Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Here, the part is based on mass unless otherwise specified.

Each measurement and evaluation in each of the following synthesis examples was performed in the following manner.
(1) Mw and Mn
Gel permeation based on monodisperse polystyrene using GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation under the analysis conditions of flow rate 1.0 ml / min, elution solvent tetrahydrofuran, column temperature 40 ° C. It was measured by an association chromatography (GPC). Further, the degree of dispersion Mw / Mn was calculated from the measurement results.
(2) Amount of low molecular weight component derived from monomer Using an Intersil ODS-25 μm column (4.6 mmφ × 250 mm) manufactured by GL Science, a flow rate of 1.0 ml / min, elution solvent acrylonitrile / 0.1% phosphoric acid aqueous solution Measurement was performed by high performance liquid chromatography (HPLC) under the analysis conditions described above.
A result shows the mass% of the low molecular weight with respect to it when the whole resin is 100 mass%.

Hereinafter, each synthesis example will be described.
Each monomer used for the synthesis of each polymer (A) and resin (B) is shown below as formulas (M-1) to (M-10).

<Synthesis of Polymers (A-1) to (A-12)>
First, a monomer solution in which a combination shown in Table 1 and a monomer having a mass% to be charged and an initiator (MAIB; dimethyl-2,2′-azobisisobutyrate) are dissolved in 50 g of methyl ethyl ketone are prepared. Got ready. The total amount of monomers at the time of preparation was adjusted to 50 g. In addition, mol% of each monomer represents mol% with respect to the total amount of monomer, and mol% of initiator represents mol% with respect to the total amount of monomer and initiator.
On the other hand, 50 g of ethyl methyl ketone was added to a 500 ml three-necked flask equipped with a thermometer and a dropping funnel, and a nitrogen purge was performed for 30 minutes. Then, it heated so that it might become 80 degreeC, stirring the inside of a flask with a magnetic stirrer.
Subsequently, the monomer solution was dropped into the flask over 3 hours using a dropping funnel. After dropping, the mixture was aged for 3 hours, and then cooled to 30 ° C. or lower to obtain a copolymer solution.
Then, after transferring the obtained copolymer solution to a 2 L separatory funnel, the polymer solution was uniformly diluted with 150 g of n-hexane (solvent A), and 600 g of methanol (solvent B) was added. Mixed. Next, 30 g of distilled water was added, and the mixture was further stirred and allowed to stand for 30 minutes. Thereafter, the lower layer was collected to obtain a propylene glycol monomethyl ether acetate solution. The Mw, Mw / Mn, yield, and residual low molecular weight of each copolymer thus obtained were measured. The results are shown in Table 2.

<Synthesis of Resin (B-1)>
Monomer (M-4) 53.93 g (50 mol%), monomer (M-2) 35.38 g (40 mol%), and monomer (M-5) 10.69 g (10 mol) %) Was dissolved in 200 g of 2-butanone, and a monomer solution containing 5.58 g of dimethyl 2,2′-azobis (2-methylpropionate) was prepared, and 100 g of 2-butanone was added. A 500 ml three-necked flask was purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or lower, poured into 2000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 400 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (74 g, yield 74%). .
This polymer had Mw of 6900 and Mw / Mn = 1.70. This polymer is referred to as “resin (B-1)”. In addition, content of the low molecular weight component derived from each monomer in resin (B-1) was 0.03 mass% with respect to 100 mass% of this polymer.

<Synthesis of Resin (B-2)>
Monomer (M-4) 55.44 g (50 mol%), monomer (M-3) 33.57 g (40 mol%), and monomer (M-5) 11.99 g (10 mol) %) Was dissolved in 200 g of 2-butanone, and a monomer solution containing 5.74 g of dimethyl 2,2′-azobis (2-methylpropionate) was further prepared, and 100 g of 2-butanone was added. A 500 ml three-necked flask was purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or lower, poured into 2000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 400 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (72 g, yield 72%). .
This polymer had Mw of 9100 and Mw / Mn = 1.56. This polymer is referred to as “resin (B-2)”. In addition, content of the low molecular weight component derived from each monomer in resin (B-2) was 0.02 mass% with respect to 100 mass% of this polymer.

<Preparation of radiation-sensitive resin composition>
In the ratio shown in Table 3, the polymer (A), the resin (B), the acid generator (C), the nitrogen-containing compound (D) and the solvent (E) were mixed, and Examples 1 to 12 and Comparative Example 1, 2 radiation sensitive resin composition was prepared.

The details of the acid generator (C), nitrogen-containing compound (D) and solvent (E) shown in Table 3 are shown below. In the table, “part” is based on mass unless otherwise specified.
<Acid generator (C)>
(C-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (C-2): 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro-n-butanesulfonate (C-3): 4 -Cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate (C-4): Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoro Ethanesulfonate (C-5): 1- (4-n-butoxynaphthyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetra Fluoroethanesulfonate
<Nitrogen-containing compound (D)>
(D-1): Nt-butoxycarbonyl-4-hydroxypiperidine
<Solvent (E)>
(E-1): Propylene glycol monomethyl ether acetate (E-2): Gamma-butyrolactone (E-3): Ethyl lactate (E-4): Cyclohexanone

<Evaluation of radiation-sensitive resin composition>
About each radiation sensitive resin composition of Examples 1-12 and Comparative Examples 1 and 2, following (1)-(5) various evaluation was performed as follows. These evaluation results are shown in Table 4.

Each evaluation method is as follows.
(1) Measurement of Elution Amount As shown in FIG. 1, an 8-inch silicon wafer that has been subjected to HMDS (hexamethyldisilazane) 31 treatment (100 ° C., 60 seconds) in advance in CLEAN TRACK ACT8 (manufactured by Tokyo Electron Limited). A silicon rubber sheet 4 (manufactured by Kureha Elastomer Co., Ltd., thickness: 1.0 mm, shape: square with a side of 30 cm) was placed on the center of 3. Next, 10 ml of ultrapure water 5 was filled in the hollowed-out portion at the center of the silicon rubber using a 10 mL hole pipette.
Thereafter, a lower layer antireflection film (“ARC29A”, manufactured by Brewer Science) 61 having a film thickness of 77 nm is formed in advance by CLEAN TRACK ACT8, and then the resist composition shown in Table 3 is applied to the lower layer in CLEAN TRACK ACT8. The silicon wafer 6 on which the resist film 62 having a film thickness of 205 nm is formed by spin coating on the antireflection film 61 and baking (115 ° C., 60 seconds) so that the resist coating surface is in contact with the ultrapure water 5. In addition, the ultrapure water 5 was placed on the silicon rubber sheet 4 so as not to leak from the silicon rubber 4.
And it kept for 10 seconds with the state. Thereafter, the 8-inch silicon wafer 6 was removed, and ultrapure water 5 was collected with a glass syringe, which was used as a sample for analysis. The recovery rate of ultrapure water after the experiment was 95% or more.
Subsequently, the peak intensity of the anion part of the photoacid generator in the ultrapure water obtained above was calculated by LC-MS (liquid chromatograph mass spectrometer, LC part: SERIES1100 manufactured by AGILENT, MS part: Perseptive Biosystems, Inc. (Manufactured by Mariner) was measured under the following measurement conditions. At that time, each of the peak intensities of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the photoacid generator was measured under the measurement conditions to prepare a calibration curve, and the elution amount was calculated from the peak intensity using the calibration curve. Similarly, each peak intensity of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the acid diffusion control agent is measured under the measurement conditions to prepare a calibration curve, and the calibration curve is used to calculate the acid diffusion control agent from the peak intensity. The amount of elution was calculated. When the elution amount was 5.0 × 10 ⁻¹² mol / cm ² / sec or more, it was judged as “bad”, and when it was below, it was judged as “good”.

(Column condition)
Column used: “CAPCELL PAK MG”, manufactured by Shiseido Co., Ltd., 1 flow rate: 0.2 ml / min Outflow solvent: water / methanol (3/7) with 0.1% by mass of formic acid Measurement temperature: 35 ℃

(2) Measurement of receding contact angle The receding contact angle was measured immediately after creating a substrate (wafer) on which a coating film of each radiation sensitive resin composition was formed using “DSA-10” manufactured by KRUS. , Room temperature: 23 ° C., humidity: 45%, measured under the normal pressure as follows.
<1> Adjust the wafer stage position.
<2> Set the wafer on the stage.
<3> Inject water into the needle.
<4> Finely adjust the needle position.
<5> Water is discharged from the needle to form 25 μL water droplets on the wafer.
<6> Pull the needle out of the water drop.
<7> Pull the needle down again to the position adjusted in <4> above.
<8> A water droplet is sucked from the needle at a speed of 10 μL / min for 90 seconds. At the same time, the contact angle is measured every second (total 90 times).
<9> From the time when the contact angle is stabilized, an average value is calculated for the contact angles of a total of 20 points and set as the receding contact angle.

(3) Sensitivity A 12-inch silicon wafer having a 77 nm-thick lower layer antireflection film (“ARC29A”, manufactured by Brewer Science Co., Ltd.) formed on the surface was used as the substrate. For the formation of this antireflection film, “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Limited) was used.
Next, the resist composition of Table 3 was spin-coated on the substrate by the CLEAN TRACK ACT8, and baked (PB) under the conditions of Table 4 to form a resist film having a thickness of 205 nm. This resist film was exposed through a mask pattern by an ArF excimer laser exposure apparatus (“NSR S306C”, manufactured by Nikon, illumination conditions: NA 0.78 sigma 0.93 / 0.69). Thereafter, PEB was performed under the conditions shown in Table 4, and then developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 30 seconds, washed with water, and dried to form a positive resist pattern. did. At this time, an exposure amount for forming a line-and-space pattern (1L1S) having a line width of 90 nm in a one-to-one line width was defined as an optimum exposure amount, and this optimum exposure amount was defined as sensitivity. A scanning electron microscope (“S-9380”, manufactured by Hitachi High-Technologies Corporation) was used for this length measurement.

(4) Cross-sectional shape of pattern The cross-sectional shape of the 90 nm line and space pattern in (3) was observed with “S-4800” manufactured by Hitachi High-Technologies Corporation, and as shown in FIG. The line width Lb in the middle of the film and the line width La at the top of the film are measured, and the case of 0.9 ≦ (La−Lb) /Lb≦1.1 is determined to be “good”, In some cases, it was judged as “bad”.

(5) Number of Defects A 12-inch silicon wafer having a 77 nm-thick lower layer antireflection film (“ARC29A”, manufactured by Brewer Science) on the surface was used as the substrate. For the formation of this antireflection film, “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Limited) was used.
Subsequently, the resist composition of Table 3 was spin-coated on the said board | substrate in the said CLEAN TRACK ACT8, and the resist film with a film thickness of 120 nm was formed by performing baking (PB) on the conditions of Table 4. Thereafter, rinsing was performed with pure water for 90 seconds. This resist film was exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“NSR S306C”, manufactured by NIKON) at NA = 0.75, σ = 0.85, and 1/2 Annular. After exposure, rinsing was again performed with pure water for 90 seconds, and PEB was performed under the conditions shown in Table 4, followed by development with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, followed by washing with water. And dried to form a positive resist pattern. At this time, an exposure amount for forming a hole pattern having a width of 1000 nm was set as an optimal exposure amount, and a hole pattern having a width of 1000 nm was formed on the entire surface of the wafer with the optimal exposure amount, and used as a wafer for defect inspection. A scanning electron microscope (“S-9380”, manufactured by Hitachi High-Technologies Corporation) was used for this length measurement.
Thereafter, the number of defects on the hole pattern having a width of 1000 nm was measured using “KLA2351” manufactured by KLA-Tencor. Furthermore, the defects measured by “KLA2351” were observed using a scanning electron microscope (“S-9380”, manufactured by Hitachi High-Technologies Corporation), and those derived from resist and foreign materials derived from outside It was classified as what seems to be. Then, the case where the total number of defects considered to be derived from the resist was 100 / wafer or more was determined as “bad”, and the case where it was less than 100 / wafer was determined as “good”.
In addition, the defect seen from the resist is a residue-like defect derived from the undissolved residue at the time of development, a protruding defect derived from the resin undissolved in the resist solvent, etc. It is a type of defect that is not related to the resist, such as dust, uneven coating, and bubbles derived from the dust inside.

  As is apparent from Table 4, when the radiation-sensitive resin composition for immersion exposure to which the polymer (A) of the present invention was added was used, the amount of eluate in water contacted during immersion exposure was Less, high receding contact angle is given, pattern shape is good, and the number of defects is small. Therefore, it is considered to work suitably in lithography that will be miniaturized in the future.

It is a schematic diagram explaining the method of producing the sample for a measurement of the elution amount. It is a figure which shows the cross-sectional shape of a line and space pattern.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Substrate, 2; Pattern, 3; Silicon wafer, 31; HMDS, 4; Silicon rubber sheet, 5; Ultrapure water, 6; Silicon wafer, 61; Antireflection film, 62;

Claims (4)

A radiation-sensitive resin composition comprising a polymer (A), a resin (B) containing an acid labile group, a radiation-sensitive acid generator (C), a nitrogen-containing compound (D) and a solvent (E). And
The polymer (A) has a weight average molecular weight of 1000 to 50000 as measured by gel permeation chromatography, and when the entire polymer is 100 mol%, it does not contain a fluorine atom and serves as a hydrophilic group. 1 to 40 mol% of repeating unit (1) containing OH group, 60 to 99 mol% of repeating unit (2) containing fluorine atom, and no repeating unit containing acid labile group ,
The repeating unit (1) is a repeating unit represented by the following general formula (1-1):
The repeating unit (2) is at least one selected from repeating units represented by the following general formula (2-1) and repeating units represented by the following general formula (2-2). Radiation sensitive resin composition.

[In General Formula (1-1), R ¹ represents a hydrogen atom or a methyl group, R ² and R ⁵ represent a methylene group, a linear or branched alkylene group having 2 to 6 carbon atoms, Or a C4-C12 alicyclic alkylene group is shown. ]

[In General Formulas (2-1) and (2-2), R ⁶ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁷ represents a single bond, a methylene group, or a carbon number of 2 to 6, respectively. A linear or branched alkylene group, or an alicyclic alkylene group having 4 to 12 carbon atoms, wherein R ⁸ is a linear chain having 1 to 6 carbon atoms substituted with at least one fluorine atom. Or a branched alkyl group, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms substituted with at least one fluorine atom, or a derivative thereof. ]   2. The radiation-sensitive resin composition according to claim 1, wherein the content of the polymer (A) is 0.1 to 20 mass% when the entire radiation-sensitive resin composition is 100 mass%.   The radiation sensitive resin composition of Claim 1 or 2 in which the said resin (B) contains the repeating unit containing a lactone structure.   The radiation sensitive resin composition according to any one of claims 1 to 3, wherein the acid labile group in the resin (B) has a monocyclic structure or a polycyclic structure.

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