JP4244755B2 - Radiation sensitive resin composition - Google Patents

Description

  The present invention relates to a radiation sensitive resin composition suitable for fine processing. More particularly, the present invention relates to a positive resist composition suitable for forming a fine pattern using an electron beam or X-ray.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration of integrated circuits, miniaturization of design rules in lithography is progressing rapidly, and microfabrication is performed stably. The development of lithographic processes that can do this is strongly promoted. However, since it is difficult to form a fine pattern of 100 nm or less with high accuracy by the conventional method using a KrF or ArF excimer laser, a method using an electron beam or an X-ray has been proposed.
Various types of resist materials for positive electron beams and X-rays used for such ultrafine processing have been proposed, but each has problems as described below.
(1) A methacrylic main-chain-cut resist such as PMMA (polymethyl methacrylate) is excellent in resolution, but has problems in etching resistance and sensitivity and is difficult to put into practical use. For example, poly-t-butyl α-chloromethylstyrene (see Patent Document 1) having an excellent balance between resolution and sensitivity, and a resin in which atoms (N, O, S) that are easily cut by an electron beam are introduced at the resin terminal (Patent Document 2) ) And the like are known, and improvement in sensitivity is recognized, but sensitivity and etching resistance have not reached a practical level.
(2) Chemically amplified positive resists having polyhydroxystyrene resin (resin for KrF excimer) and novolak (resin for i-line) partially protected with acid-dissociable functional groups and an acid generator have sensitivity and resolution. Excellent balance of etching resistance. For example, a combination of a partially acetal-protected polyhydroxystyrene resin and an acid generator (Patent Document 3), a combination of a fluorine-containing aromatic sulfonic acid-generating onium salt and a fluorine-based or silicon-based surfactant (Patent Document 4), Onium salt (Patent Document 5) having at least one electron-withdrawing group (fluorine atom, cyano group, nitro group) as a cation moiety substituent (Patent Document 5), N-sulfonyloxyimide group Various chemically amplified positive resists including a resin having a low molecular weight (Patent Document 7) and the like are known, but the film surface roughness (hereinafter referred to as roughness), sensitivity, and resolution at the time of forming a fine pattern has not reached a practical level. .

Further, the following various types of resist materials for negative electron beams and X-rays used for such ultrafine processing have been proposed, but there are problems as described below.
(3) Main chain cross-linking resists such as PGMA (polyglycidyl methacrylate) have problems in sensitivity and etching resistance and are difficult to put into practical use. Thereafter, types such as chloromethylated polystyrene with improved sensitivity and etching resistance have been proposed, but have not reached a practical level in terms of resolution and sensitivity.
(4) A chemically amplified negative resist based on a polyhydroxystyrene-based resin (resin for KrF excimer) and novolak (resin for i-line) and an acid generator has an benzodixol structure (Patent Document 8, Patent Document 9), polyhydroxystyrene partially protected with a non-acid dissociable group such as alkyl, aryl, alkenyl, aralkyl ether, etc. (Patent Document 10, Patent Document 11), an unsaturated compound capable of polymerization with an acid or a radical Resins having bonds and low molecular content (Patent Document 12, Patent Document 13, Patent Document 14) and the like are known, but have not reached a practical level in terms of roughness, sensitivity, and resolution when forming a fine pattern.
(5) As a polymer acid generator, a resin having a disulfonyl structure (Patent Document 15), a resin containing a sulfonium salt in a polymer side chain (Non-Patent Document 1), and the like are also known. Roughness, sensitivity, and resolution when forming a fine pattern have not reached a practical level.
JP 2000-147777 A (Claims) JP-A-11-29612 (Claims) JP-A-6-194842 (Claims) JP 2000-187330 A (Claims) Japanese Patent Laid-Open No. 2001-075283 (Claims) JP 2002-072483 A (Claims) JP 2002-107920 A (Claims) JP 2001-142200 A (Claims) JP 2001-174994 A (Claims) JP 2001-242625 A (Claims) JP-A-2002-090986 (Claims) JP 2002-006491 A (Claims) JP 2002-040656 A (Claims) JP 2002-049149 A (Claims) JP 2002-174894 A (Claims) Hengpeng Wu et. Al. Proc.SPIE vol.4345 521-527 (2001)

The problem to be solved is that a radiation-sensitive resin composition that is excellent in roughness, etching resistance, sensitivity, and resolution and that can form a fine pattern with high accuracy and stability cannot be obtained. In the point.
The further subject of this invention exists in the point which cannot obtain the radiation sensitive resin composition used as the chemically amplified positive resist composition suitable for an electron beam, the electron beam which respond | corresponds effectively to an X-ray, and X-rays.

上記式（１）および式（２）において、Ｒ¹は水素原子、ハロゲン原子、シアノ基、炭素数１〜５の直鎖状もしくは分岐状のアルキル基、または、炭素数１〜５の直鎖状もしくは分岐状のハロアルキル基を表し、Ｒ²およびＲ³は相互に独立に、水素原子、置換もしくは非置換された炭素数１〜１０の直鎖状もしくは分岐状のアルキル基、置換もしくは非置換された炭素数１〜１０の直鎖状もしくは分岐状のアルコキシ基、置換もしくは非置換された炭素数１〜１０の直鎖状もしくは分岐状のハロアルキル基、または、置換もしくは非置換された炭素数６〜２０のアリール基を表し、Ａ¹は単結合、エーテル結合、エステル結合、または、アミド結合を表し、Ｘ⁻は陰イオンを表す。

上記式（３）において、Ｒ⁴は水素原子、ハロゲン原子、シアノ基、炭素数１〜５の直鎖状もしくは分岐状のアルキル基、または、炭素数１〜５の直鎖状もしくは分岐状のハロアルキル基を表し、Ｒ⁵は水素原子または１価の有機基を表し、ａおよびｂはそれぞれ１〜４の整数で、（ａ＋ｂ）≦５である。 The radiation-sensitive resin composition of the present invention, repetition of at least one onium salt structure unit selected from iodonium salt structure unit represented by the sulfonium salt structure units and formula represented by the formula (1) (2) 60 to 90 mol% of the repeating unit represented by the formula (3) occupying all repeating units, including a unit, a repeating unit represented by the following formula (3), and a repeating unit having an acid dissociable group It is characterized by being.

In the above formulas (1) and (2), R ¹ is a hydrogen atom, a halogen atom, a cyano group, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear chain having 1 to 5 carbon atoms. Represents a linear or branched haloalkyl group, and R ² and R ³ are independently of each other a hydrogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted Straight or branched alkoxy group having 1 to 10 carbon atoms, substituted or unsubstituted linear or branched haloalkyl group having 1 to 10 carbon atoms, or substituted or unsubstituted carbon number 6 to 20 aryl groups, A ¹ represents a single bond, an ether bond, an ester bond, or an amide bond, and X ⁻ represents an anion.

In the above formula (3), R ⁴ represents a hydrogen atom, a halogen atom, a cyano group, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkyl group having 1 to 5 carbon atoms. Represents a haloalkyl group, R ⁵ represents a hydrogen atom or a monovalent organic group, a and b are each an integer of 1 to 4, and (a + b) ≦ 5.

Further, a repeating unit comprising at least one onium salt structural unit selected from the sulfonium salt structural unit represented by the above formula (1) and the iodonium salt structural unit represented by the above formula (2), and the above formula (3) in the polymer repeating units containing 50-99 mol% represented, Ri name by blending a polymer containing a repeating unit having an acid-dissociable group, a polymer containing a repeating unit having an acid-dissociable group It is characterized by containing 10 to 90% by weight of the total polymer . Moreover, in the polymer containing the repeating unit composed of the onium salt structural unit and the repeating unit represented by the formula (3), the repeating unit represented by the formula (3) is 60 to 90 mol%. Features.

  The radiation-sensitive resin composition of the present invention is a polymer having as a repeating unit at least one onium salt structural unit selected from a sulfonium salt represented by the formula (1) and an iodonium salt represented by the formula (2) Therefore, the positive resist composition is excellent in sensitivity, resolution, and roughness, and in particular, it is possible to suppress deterioration in resolution and roughness at the time of increasing sensitivity, which are problems of EB lithography.

Hereinafter, embodiments of the present invention will be described in detail.
The onium salt structural unit that can be used in the present invention is represented by the structural unit containing the sulfonium salt represented by the formula (1), the structural unit containing the iodonium salt represented by the formula (2), or the formula (1). These are structural units each containing a mixed onium salt of a structural unit containing a sulfonium salt and a structural unit containing an iodonium salt represented by the formula (2). An onium salt is preferably contained as a side chain of each structural unit because the monomer is easy to produce and the polymerizability is excellent.
R ¹ in Formula (1) and Formula (2) is a hydrogen atom, a halogen atom, a cyano group, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched group having 1 to 5 carbon atoms. Represents a branched haloalkyl group. Examples of the linear or branched alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. At least one hydrogen atom of these alkyl groups is a halogen atom. Also included are substituted haloalkyl groups. R ¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
Examples of the substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms of R ² and R ³ in formula (1) and formula (2) include a methyl group, an ethyl group, and an n-propyl group. I-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, pentyl group, hexyl group, hydroxymethyl group, hydroxyethyl group, and trifluoromethyl group.
Moreover, the haloalkyl group which substituted at least 1 hydrogen atom of the said alkyl group with the halogen atom is mentioned.
The alkoxy group includes methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, and n-pentyloxy. Group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group and the like.
Examples of the substituted or unsubstituted aryl group having 6 to 20 carbon atoms of R ² and R ³ in formula (1) and formula (2) include a phenyl group and a naphthyl group.
X in the formula (1) and (2) ^- is an alkyl group, an aryl group, an aralkyl group, an alicyclic alkyl group, a halogen-substituted alkyl group, halogen-substituted aryl group, halogen-substituted aralkyl group, an oxygen atom substituted alicyclic alkyl Or an anion containing a halogen-substituted alicyclic alkyl group. Further, X ^- represents an alkyl group, an aryl group, an aralkyl group, an alicyclic alkyl group, a halogen-substituted alkyl group, halogen-substituted aryl group, halogen-substituted aralkyl group, -SO bonded to an oxygen atom substituted alicyclic alkyl group _{of 3} ^- The halogen atom is preferably a fluorine atom.

Specific examples of the repeating unit including the sulfonium salt represented by the formula (1) and the iodonium salt structural unit represented by the formula (2) are shown in the following formulas (4) to (7).

上記式（１−１）および式（２−１）において、Ｒ¹、Ｒ²、Ｒ³、Ａ¹およびＸ⁻は、式（１）および式（２）のそれと同一である。
式（１−１）または式（２−１）で表される単量体は、オニウム塩構造を含むヒドロキシフェニル等を公知の方法でアクリル化することにより製造できる。
また、Ａ¹が単結合の場合、ジフェニルスルオキシドとハロゲン化スチレンのグリニャール反応後、ハロゲン化トリアルキルシランで処理する方法等により製造できる。 The repeating unit containing an onium salt structure represented by the formula (1) or the formula (2) is obtained by polymerizing a monomer represented by the following formula (1-1) or the formula (2-1). It is done.

In the above formula (1-1) and formula (2-1), R ¹ , R ² , R ³ , A ¹ and X ⁻ are the same as those in formula (1) and formula (2).
The monomer represented by Formula (1-1) or Formula (2-1) can be produced by acrylating hydroxyphenyl or the like containing an onium salt structure by a known method.
Further, when A ¹ is a single bond, it can be produced by a method of treating with a halogenated trialkylsilane after a Grignard reaction of diphenylsulfoxide and halogenated styrene.

  The introduction rate of the onium salt structural unit in the polymer having an onium salt structure as a repeating unit cannot be generally defined by the onium salt structural species or other types, but is usually 1 to 50 mol%, preferably 2 to 30 mol%, More preferably, it is 3-20 mol%. If it is less than 1 mol%, the effect of improving the resolution and line edge roughness is small, and if it exceeds 50 mol%, the solubility in a resist solvent deteriorates.

The polymer having an onium salt structural unit as a repeating unit may further contain a repeating unit represented by the formula (3).
In the formula (3), R ⁴ is the same as R ¹ . R ⁵ is a hydrogen atom or a monovalent organic group, and examples thereof include a hydrocarbon group and a heteroatom-containing hydrocarbon group.
Specific examples of the repeating unit of formula (3) include the following.
4-hydroxystyrene, 3-hydroxystyrene, 2-hydroxystyrene, 4-hydroxy-α-methylstyrene, 3-methyl-4-hydroxystyrene, 2-methyl-4-hydroxystyrene, 2-methyl-3-hydroxystyrene , 4-methyl-3-hydroxystyrene, 5-methyl-3-hydroxystyrene, 3,4-dihydroxystyrene, 2,4,6-trihydroxystyrene and the like units having a polymerizable unsaturated bond cleaved.
Of these repeating units, units having a polymerizable unsaturated bond cleaved such as 4-hydroxystyrene, 3-hydroxystyrene, 2-hydroxystyrene, 4-hydroxy-α-methylstyrene are preferred.

For the resin used in the radiation-sensitive resin composition of the present invention, in addition to the onium salt structural unit, a polymer containing a repeating unit of the formula (3) is used alone or in admixture of two or more. be able to.
The introduction rate of the formula (3) in the polymer containing the repeating unit containing an onium salt structure and the repeating unit of the formula (3) cannot be generally defined by the structural type or the type of other copolymer, but is usually 50 to 99 mol%, preferably 60-95 mol%. If the introduction ratio of the formula (3) is less than 50 mol%, the solubility in an alkali developer and the adhesion to the substrate decrease, and if it exceeds 99 mol%, the effects on resist performance such as line edge roughness and resolution become small. .
The polymer containing the onium salt structural unit or the polymer containing the onium salt structural unit and the repeating unit of the formula (3) may further contain a repeating unit having one or more acid-dissociable groups. The introduction rate of the repeating unit having one or more acid-dissociable groups cannot be generally defined, but is usually 1 to 40 mol%, preferably 5 to 30 mol%.

Further, the polymer containing the onium salt structural unit, or the polymer containing the onium salt structural unit and the repeating unit of the formula (3), an acid dissociable group containing a repeating unit having at least one acid dissociable group. It is preferable to further contain a resin containing resin (hereinafter simply referred to as “acid-dissociable group-containing resin”).
Here, the acid dissociable group is a resin having one or more oxygen-containing functional groups such as a phenolic hydroxyl group, an alcoholic hydroxyl group, or a carboxyl group, or the oxygen-containing functional group or sulfur in a resin having a mercapto group. The functional group which can dissociate in presence of an acid which can substitute each hydrogen atom of a containing functional group.
Examples of the acid dissociable group include a substituted methyl group, a 1-substituted ethyl group, a 1-substituted n-propyl group, a 1-branched alkyl group, a silyl group, a germyl group, an alkoxycarbonyl group, an acyl group, and a cyclic acid. Examples include a dissociable group.
Examples of the substituted methyl group include methoxymethyl group, methylthiomethyl group, ethoxymethyl group, ethylthiomethyl group, methoxyethoxymethyl group, benzyloxymethyl group, benzylthiomethyl group, phenacyl group, 4-bromophenacyl group, 4- Methoxyphenacyl group, 4-methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, adamantylmethyl group, 4-bromobenzyl group, 4-nitrobenzyl Group, 4-methoxybenzyl group, 4-methylthiobenzyl group, 4-ethoxybenzyl group, 4-ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, i-propoxy Carbonyl Ethyl group, n- butoxycarbonyl methyl group, t-butoxycarbonyl methyl group, and the like.
Examples of the 1-substituted ethyl group include 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1-diethyl Ethoxyethyl group, 1-phenoxyethyl group, 1-phenylthioethyl group, 1,1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzylthioethyl group, 1-cyclopropyloxyethyl group, 1- Cyclohexyloxyethyl group, 1-phenylethyl group, 1,1-diphenylethyl group, 1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group, 1-i-propoxycarbonylethyl group 1-n-butoxycarbonylethyl group, 1-t-butoxycarbonylethyl group, 1-cyclohexene Oxy carbonyl ethyl group, and the like.
Examples of the 1-substituted-n-propyl group include a 1-methoxy-n-propyl group and a 1-ethoxy-n-propyl group.
Examples of the 1-branched alkyl group include i-propyl group, sec-butyl group, t-butyl group, 1,1-dimethylpropyl group, 1-methylbutyl group, 1,1-dimethylbutyl group, and the like. It is done.
Examples of the silyl group include trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, i-propyldimethylsilyl group, methyldi-i-propylsilyl group, tri-i-propylsilyl group, t -Butyldimethylsilyl group, methyldi-t-butylsilyl group, tri-t-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, triphenylsilyl group and the like.
Examples of the germyl group include trimethylgermyl group, ethyldimethylgermyl group, methyldiethylgermyl group, triethylgermyl group, i-propyldimethylgermyl group, methyldi-i-propylgermyl group, tri- Examples include i-propylgermyl group, t-butyldimethylgermyl group, methyldi-t-butylgermyl group, tri-t-butylgermyl group, phenyldimethylgermyl group, methyldiphenylgermyl group, and triphenylgermyl group. .
Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an i-propoxycarbonyl group, and a t-butoxycarbonyl group.

Examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, a heptanoyl group, a hexanoyl group, a valeryl group, a pivaloyl group, an isovaleryl group, a laurylyl group, a myristoyl group, a palmitoyl group, a stearoyl group, an oxalyl group, and a malonyl group. Succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, canphoroyl group, Benzoyl, phthaloyl, isophthaloyl, terephthaloyl, naphthoyl, toluoyl, hydroatropoyl, atropoyl, cinnamoyl, furoyl, thenoyl, nicotinoyl, Nicotinoyl group, 4-toluenesulfonyl group, mesyl group, and the like.
Furthermore, examples of the cyclic acid dissociable group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a 4-t-butylcyclohexyl group, a 4-methoxycyclohexyl group, a cyclohexenyl group, a norbornyl group, an isobornyl group, and a tricyclodeca group. Nyl group, adamantyl group, tetrahydropyranyl group, tetrahydrofuranyl group, tetrahydrothiopyranyl group, tetrahydrothiofuranyl group, 3-bromotetrahydropyranyl group, 4-methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl Group, 3-tetrahydrothiophene-1,1-dioxide group, methyladamantyl group, ethyladamantyl group, methyltricyclodecanyl group, ethyltricyclodecanyl group, methylcyclopentyl group, ethylcyclopentyl group, methyl Kurohekishiru group, ethyl cyclohexyl group.

Among these acid dissociable groups, t-butoxycarbonylmethyl group, 1-methoxyethyl group, 1-ethoxyethyl group, 1-cyclohexyloxyethyl group, 1-ethoxy-n-propyl group, t-butyl group, 1 , 1-dimethylpropyl group, trimethylsilyl group, t-butoxycarbonyl group, 4-t-butylcyclohexyl group, isobornyl group, tricyclodecanyl group, tetrahydropyranyl group, tetrahydrofuranyl group, tetrahydrothiopyranyl group, tetrahydrothio Furanyl group, 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, methyltricyclodecanyl group, ethyltricyclodecanyl group, methylcyclopentyl group, ethylcyclopentyl group, methylcyclohexyl group, ethylcyclohexyl group Etc. are preferred.
More preferably, a 1-ethoxyethyl group, a t-butyl group, a 2-methyl-2-adamantyl group, and a 2-ethyl-2-adamantyl group are exemplified.

The acid-dissociable group-containing resin containing a repeating unit having at least one kind of acid-dissociable group is an alkali-insoluble or hardly-alkali-soluble resin, and the acid-dissociable group is dissociated by the action of an acid to be easily soluble in alkali. A resin is preferred. The term “alkali-insoluble or alkali-insoluble” as used herein is employed when a resist pattern is formed from a resist film formed using a positive-type radiation-sensitive resin composition containing an acid-dissociable group-containing resin. When a film using only an acid-dissociable group-containing resin instead of the resist film is developed under alkaline development conditions, it means that 50% or more of the initial film thickness of the film remains after development.
The resin containing a repeating unit having at least one acid dissociable group preferably has at least one repeating unit represented by the above formula (3).
Introduction rate of acid-dissociable groups in acid-dissociable group-containing resins (number of acid-dissociable groups relative to the total number of other functional groups and acid-dissociable groups excluding acid-dissociable groups in acid-dissociable group-containing resins) ) Cannot be defined in general depending on the type of the acid dissociable group or the alkali-soluble resin into which the group is introduced, but is preferably 10 to 50%, more preferably 10 to 30%.

  Moreover, when mix | blending acid dissociable group containing resin, it is 1-99 weight% normally with respect to the total resin component amount, Preferably it is 5-95 weight%, More preferably, it is 10-90 weight%.

The polystyrene-converted weight average molecular weight (hereinafter referred to as “Mw”) measured by gel permeation chromatography of a resin having an onium salt structure as a repeating unit is usually 1,000 to 100,000, preferably 3,000 to 50. 5,000, more preferably 5,000 to 25,000. If it is 1,000 or less, the effect on resolution and line edge roughness is small, and if it is 100,000 or more, the solubility in a resist solvent deteriorates.
The ratio (Mw / Mn) of Mw to polystyrene-reduced number average molecular weight (hereinafter referred to as “Mn”) measured by gel permeation chromatography (GPC) is usually 1 to 5, preferably 1 to 3. More preferably, it is 1.0-2.0.

Mw measured by gel permeation chromatography of the acid-dissociable group-containing resin is preferably 1,000 to 50,000, more preferably 3,000 to 30,000, and further preferably 5,000 to 20,000. is there.
In addition, the ratio (Mw / Mn) of the Mw of the acid-dissociable group-containing resin and the polystyrene-equivalent molecular weight (hereinafter referred to as “Mn”) measured by gel permeation chromatography (GPC) is usually 1 to 5. , Preferably 1 to 3, more preferably 1.0 to 2.0.

The acid-dissociable group-containing resin can have one or more repeating units other than those described above.
As other repeating units, for example, styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 4- (2 Vinyl aromatic compounds such as -t-butoxycarbonylethyloxy) styrene;
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, n-pentyl (meth) acrylate, N-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth ) (Meth) acrylic acid esters such as phenyl acrylate and phenethyl (meth) acrylate;
Unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, cinnamic acid;
Carboxyalkyl esters of unsaturated carboxylic acids such as 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate;
Unsaturated nitrile compounds such as (meth) acrylonitrile, α-chloroacrylonitrile, crotonnitrile, maleinnitrile, fumaronitrile;
Unsaturated amide compounds such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleinamide, fumaramide;
Unsaturated imide compounds such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide;
N-vinyl-ε-caprolactam, N-vinyl pyrrolidone, 2-vinyl pyridine, 3-vinyl pyridine, 4-vinyl pyridine, 2-vinyl imidazole, other nitrogen-containing vinyl compounds such as 4-vinyl imidazole, etc. Examples include units in which a saturated bond is cleaved.
Of these other repeating units, styrene, α-methylstyrene, and 4- (2-t-butoxycarbonylethyloxy) styrene units are preferred. The acid dissociable group-containing resins can be used alone or in admixture of two or more.

  In the radiation-sensitive resin composition of the present invention, a compound that generates an acid upon irradiation with an electron beam or radiation (hereinafter abbreviated as an acid generator) can be added to the resin component described above. Examples of the acid generator include (1) onium salt compounds, (2) sulfonimide compounds, (3) diazomethane compounds, (4) halogen-containing compounds, and (5) oxime sulfonate compounds. Examples of these acid generators are shown below.

上記式（８）および式（９）において、Ｒ²、Ｒ³およびＸ⁻は、式（１）および式（２）のそれと同一である。
オニウム塩化合物の具体例としては、
（ａ）スルホニウム塩
トリフェニルスルホニウムトリフルオロメタンスルホネート、トリフェニルスルホニウムノナフルオロ−ｎ−ブタンスルホネート、トリフェニルスルホニウムパーフルオロ−ｎ−オクタンスルホネート、トリフェニルスルホニウム４−トルエンスルホネート、トリフェニルスルホニウムベンゼンスルホネート、トリフェニルスルホニウム１０−カンファースルホネート、トリフェニルスルホニウムｎ−ドデシルベンゼンスルホネート、トリフェニルスルホニウム−２−トルフルオロメチルベンゼンスルホネート、トリフェニルスルホニウム−４−トルフルオロメチルベンゼンスルホネート、トリフェニルスルホニウム−２，４−ジフルオロベンゼンスルホネート、トリフェニルスルホニウムペンタフルオロベンゼンスルホネート、トリフェニルスルホニウム−１−ナフタレンスルホネート、トリフェニルスルホニウム１，１，２，２−テトラフルオロ−２−（ノルボルナン−２−イル）エタンスルホネート、トリフェニルスルホニウム１，１，２，２−テトラフルオロ−２−（テトラシクロ[４．４．０．１^2,5．１^7,10]ドデカン−８−イル）エタンスルホネート、 (1) Onium salt:
Examples of the onium salt compounds include sulfonium salts of the following formula (8), iodonium salts of the formula (9), and phosphonium salts, diazonium salts, ammonium salts, pyridinium salts, and the like.

In the above formula (8) and formula (9), R ² , R ³ and X ⁻ are the same as those in formula (1) and formula (2).
As a specific example of the onium salt compound,
(A) sulfonium salt triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 4-toluenesulfonate, triphenylsulfoniumbenzenesulfonate, triphenyl Sulfonium 10-camphorsulfonate, triphenylsulfonium n-dodecylbenzenesulfonate, triphenylsulfonium-2-trifluoromethylbenzenesulfonate, triphenylsulfonium-4-trifluoromethylbenzenesulfonate, triphenylsulfonium-2,4-difluorobenzenesulfonate , Triphenylsulfonium pentafluorobenzenesulfur Phonate, triphenylsulfonium-1-naphthalenesulfonate, triphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate, triphenylsulfonium 1,1,2,2-tetrafluoro 2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecane-8-yl) ethanesulfonate,

Diphenyl-2,4,6-trimethylphenylsulfonium trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium perfluoro-n- Octanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium 4-toluenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium 10-camphorsulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-4-toluene Fluoromethylbenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate , Diphenyl-2,4,6-trimethylphenyl sulfonium 1,1,2,2-tetrafluoro-2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecane-8-yl ) Ethane sulfonate,

Diphenyl-4-fluorophenylsulfonium trifluoromethanesulfonate, diphenyl-4-fluorophenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4-fluorophenylsulfonium perfluoro-n-octanesulfonate, diphenyl-4-fluorophenylsulfonium 4- Toluenesulfonate, diphenyl-4-fluorophenylsulfonium-10-camphorsulfonate, diphenyl-4-fluorophenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate, diphenyl-4- Fluorophenylsulfonium 1,1,2,2-tetrafluoro-2- (tetracyclo [4.4.0.1 ^2,5 .1, ^7,10 ] dodecan-8-yl) ethanesulfo Nate,

Diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4-hydroxyphenylsulfonium perfluoro-n-octanesulfonate, diphenyl-4-hydroxyphenylsulfonium 4- Toluenesulfonate, diphenyl-4-hydroxyphenylsulfonium-10-camphorsulfonate, diphenyl-4-hydroxyphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate, diphenyl-4- Hydroxyphenylsulfonium 1,1,2,2-tetrafluoro-2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] dodecan-8-yl ) Ethane sulfonate,

Diphenyl-4-t-butoxyphenylsulfonium trifluoromethanesulfonate, diphenyl-4-t-butoxyphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4-t-butoxyphenylsulfonium perfluoro-n-octanesulfonate, diphenyl-4 -T-butoxyphenylsulfonium 4-toluenesulfonate, diphenyl-4-t-butoxyphenylsulfonium-10-camphorsulfonate, diphenyl-4-t-butoxyphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornane) -2-yl) ethanesulfonate, diphenyl-4-t-butoxyphenylsulfonium 1,1,2,2-tetrafluoro-2- (tetracyclo [4.4.0.1 ^2,5 .1, ^7,10 ] De Can-8-yl) ethanesulfonate, tris (4-fluorophenyl) sulfonium trifluoromethanesulfonate, tris (4-hydroxyphenyl) sulfonium trifluoromethanesulfonate, and the like.

(B) iodonium salt bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro- n-octanesulfonate, bis (4-t-butylphenyl) 4-toluenesulfonate, bis (4-t-butylphenyl) iodoniumbenzenesulfonate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, bis (4 -T-butylphenyl) iodonium-2-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium-4-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium -2,4 difluorobenzenesulfonate, bis (4-t-butylphenyl) iodonium pentafluorobenzenesulfonate, bis (4-t-butylphenyl) iodonium 1,1,2,2-tetrafluoro-2- (tetracyclo [4 .4.0.1 ^2,5 .1 ^7,10] dodecane-8-yl) ethanesulfonate, bis (4-t- butylphenyl) iodonium 1,1,2,2-tetrafluoro-2- (tetracyclo [ 4.4.0.1 ^2,5 .1 ^7,10] dodecane-8-yl) ethanesulfonate,

Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 4-toluenesulfonate, diphenyliodoniumbenzenesulfonate, diphenyliodonium 10-camphorsulfonate, diphenyliodonium-2- Trifluoromethylbenzenesulfonate, diphenyliodonium-4-trifluoromethylbenzenesulfonate, diphenyliodonium-2,4difluorobenzenesulfonate, diphenyliodonium pentafluorobenzenesulfonate, diphenyliodonium1,1,2,2-tetrafluoro-2- ( tetracyclo [4.4.0.1 ^2,5 1 ^7,10] dodecane-8-yl) ethanesulfonate, diphenyliodonium 1,1,2,2-tetrafluoro-2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecane - 8-yl) ethanesulfonate, and the like.

上記式（１０）において、Ｙはアルキレン基、アリーレン基、アルコキシレン基等の２価の基を表し、Ｒ⁶はアルキル基、アリール基、ハロゲン置換アルキル基、ハロゲン置換アリール基等の１価の基を表す。
スルホンイミド化合物の具体例としては、
Ｎ−（トリフルオロメチルスルホニルオキシ）スクシンイミド、Ｎ−（トリフルオロメチルスルホニルオキシ）フタルイミド、Ｎ−（トリフルオロメチルスルホニルオキシ）ジフェニルマレイミド、Ｎ−（トリフルオロメチルスルホニルオキシ）ビシクロ［２．２．１］ヘプト−５−エン−２，３−ジカルボキシイミド、Ｎ−（トリフルオロメチルスルホニルオキシ）−７−オキサビシクロ［２．２．１］ヘプト−５−エン−２，３−ジカルボキシイミド、Ｎ−（トリフルオロメチルスルホニルオキシ）ビシクロ［２．２．１］ヘプタン−５，６−オキシ−２，３−ジカルボキシイミド、Ｎ−（トリフルオロメチルスルホニルオキシ）ナフチルイミド、 (2) Sulfonimide compound:
Examples of the sulfonimide compound include the following formula (10).

In the above formula (10), Y represents a divalent group such as an alkylene group, an arylene group, or an alkoxylen group, and R ⁶ represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group, or a halogen-substituted aryl group. Represents a group.
As a specific example of the sulfonimide compound,
N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1 ] Hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthylimide,

N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) phthalimide, N- (nonafluoro-n-butanesulfonyloxy) diphenylmaleimide, N- (nonafluoro-n-butanesulfonyloxy) ) Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5 Ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (nonafluoro- n-butanesulfonyloxy) naphthylimide,
N- (10-camphorsulfonyloxy) succinimide, N- (10-camphorsulfonyloxy) phthalimide, N- (10-camphorsulfonyloxy) diphenylmaleimide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1 ] Hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (10-camphorsulfonyloxy) naphthylimide,

N- (n-octanesulfonyloxy) succinimide, N- (n-octanesulfonyloxy) phthalimide, N- (n-octanesulfonyloxy) diphenylmaleimide, N- (n-octanesulfonyloxy) bicyclo [2.2.1 ] Hept-5-ene-2,3-dicarboximide, N- (n-octanesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (n-octanesulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (n-octanesulfonyloxy) naphthylimide,
N- (4-toluenesulfonyloxy) succinimide, N- (4-toluenesulfonyloxy) phthalimide, N- (4-toluenesulfonyloxy) diphenylmaleimide, N- (4-toluenesulfonyloxy) bicyclo [2.2.1 ] Hept-5-ene-2,3-dicarboximide, N- (4-toluenesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-toluenesulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (4-toluenesulfonyloxy) naphthylimide,
N- (4-trifluoromethylbenzenesulfonyloxy) succinimide, N- (4-trifluoromethylbenzenesulfonyloxy) phthalimide, N- (4-trifluoromethylbenzenesulfonyloxy) diphenylmaleimide, N- (4-trifluoro Methylbenzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-trifluoromethylbenzenesulfonyloxy) -7-oxabicyclo [2.2.1 ] Hept-5-ene-2,3-dicarboximide, N- (4-trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide N- (4-Trifluoromethylbenzenesulfonyloxy) naphthylimi ,

  N- (benzenesulfonyloxy) succinimide, N- (benzenesulfonyloxy) phthalimide, N- (benzenesulfonyloxy) diphenylmaleimide, N- (benzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2 , 3-dicarboximide, N- (benzenesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (benzenesulfonyloxy) bicyclo [2 2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (benzenesulfonyloxy) naphthylimide, N- (1,1,2,2-tetrafluoro-2- (norbornane- 2-yl) ethylsilphonyloxy) -5-norbornene-2,3-dicarboximide and the like.

上記式（１１）において、Ｒ⁷およびＲ⁸は相互に独立にアルキル基、アリール基、ハロゲン置換アルキル基、ハロゲン置換アリール基等の１価の基を表す。
ジアゾメタン化合物の具体例としては、ビス（トリフルオロメチルスルホニル）ジアゾメタン、ビス（シクロヘキシルスルホニル）ジアゾメタン、ビス（フェニルスルホニル）ジアゾメタン、ビス（４−トルエンスルホニル）ジアゾメタン、ビス（２，４−ジメチルベンゼンスルホニル）ジアゾメタン、メチルスルホニル・４−トルエンスルホニルジアゾメタン、ビス（４−ｔ−ブチルフェニルスルホニル）ジアゾメタン、ビス（４−クロロベンゼンスルホニル）ジアゾメタン、シクロヘキシルスルホニル・４−トルエンスルホニルジアゾメタン、１−シクロヘキシルスルホニル・１，１−ジメチルエチルスルホニルジアゾメタン、ビス（１，１−ジメチルエチルスルホニル）ジアゾメタン、ビス（１−メチルエチルスルホニル）ジアゾメタン、ビス（３，３−ジメチル−１，５−ジオキサスピロ[５．５]ドデカン−８−スルホニル）ジアゾメタン、ビス（１，４−ジオキサスピロ[４.５]デカン−７−スルホニル）ジアゾメタン等が挙げられる。 (3) Diazomethane compound:
As a diazomethane compound, the compound represented by following formula (11) is mentioned, for example.

In the above formula (11), R ⁷ and R ⁸ each independently represent a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group, or a halogen-substituted aryl group.
Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (4-toluenesulfonyl) diazomethane, and bis (2,4-dimethylbenzenesulfonyl). Diazomethane, methylsulfonyl · 4-toluenesulfonyldiazomethane, bis (4-t-butylphenylsulfonyl) diazomethane, bis (4-chlorobenzenesulfonyl) diazomethane, cyclohexylsulfonyl · 4-toluenesulfonyldiazomethane, 1-cyclohexylsulfonyl · 1,1- Dimethylethylsulfonyldiazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, bis (1-methylethylsulfonyl) diazometa Bis (3,3-dimethyl-1,5-dioxaspiro [5.5] dodecan-8-sulfonyl) diazomethane, bis (1,4-dioxaspiro [4.5] decan-7-sulfonyl) diazomethane, and the like. .

(4) Halogen-containing compounds:
As the halogen compound, for example, a haloalkyl group-containing hydrocarbon compound, a haloalkyl group-containing heterocyclic compound and the like are preferably used.
Specific examples of the halogen-containing compound include tris (2,3-dibromopropyl) isocyanurate, α, α, α-tribromomethylphenylsulfone, tribromoneopentyl alcohol, 2,2-bis (bromomethyl) -1, 3-propanediol, pentaerythritol tetrabromide, 2- (bromomethyl) -2- (hydroxymethyl) -1,3-propanediol, hexabromohexane, hexabromoheptane, hexabromocyclododecane, tetrabromo-o-cresol, tetra Bromine compounds such as bromobisphenol A bishydroxyethyl ether, 2,4-dibromo-2,4-dimethyl-3-pentanone, pentaerythritol tetrachloride, phenyl-bis- (trichloromethyl) -s-triazine, methoxyphenyl-bis (G (Trichloromethyl) -s-triazine derivatives such as chloromethyl) -s-triazine, naphthyl-bis (trichloromethyl) -s-triazine, and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane And the like, and iodine compounds such as hexaiodohexane and 4-diiodobenzene.

(5) Oxime sulfonate compound:
Specific examples of the oxime sulfonate compound include α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (propylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- ( And methylsulfonyloxyimino) -4-bromophenylacetonitrile.

Of the acid generators described above, onium salts are preferred. Moreover, the acid generator in this invention can be used individually or in mixture of 2 or more types.
In this invention, the compounding quantity of the acid generator in a radiation sensitive resin composition is 0-30 weight with respect to 100 weight part of total amounts of the polymer which has an onium salt structural unit as a repeating unit, and acid dissociable group containing resin. Parts, preferably 0 to 10 parts by weight.

The radiation-sensitive resin composition of the present invention can contain other components such as an alkali dissolution controller, an acid diffusion controller, and a surfactant. Each component is dissolved in a solvent.
Alkali dissolution control agent:
In the radiation sensitive resin composition of the present invention, the following alkali dissolution controlling agent can be blended depending on the case. Examples of the alkali dissolution control agent include compounds in which a hydrogen atom of an acidic functional group such as a phenolic hydroxyl group or a carboxyl group is substituted with an acid dissociable group or a t-butoxycarbonylmethyl group. Examples of the acid dissociable group include a substituted methyl group, a 1-substituted ethyl group, a 1-substituted n-propyl group, a 1-branched alkyl group, a silyl group, a germyl group, an alkoxycarbonyl group, an acyl group, and a cyclic group. Examples include acid dissociable groups.
Examples of the alkali dissolution inhibitor in the radiation-sensitive resin composition of the present invention include steroids (bile acids) such as cholic acid, deoxycholic acid, and lithocholic acid, and alicyclic compounds such as adamantane carboxylic acid and adamantane dicarboxylic acid. A compound in which a hydrogen atom of a carboxyl group in a carboxylic acid compound having a ring or an aromatic ring is substituted with the acid dissociable group or t-butoxycarbonylmethyl group is preferable.
The compounding amount of the alkali solubility control agent in the radiation-sensitive resin composition is 0.5 to 50 parts by weight, preferably 1 to 30 parts by weight, more preferably 2 to 20 parts by weight with respect to 100 parts by weight of the polymer. . Moreover, an alkali solubility control agent can be used individually or in mixture of 2 or more types.

上記式（２１）において、各Ｒ⁹は相互に独立に水素原子、アルキル基、アリール基またはアラルキル基を示し、これらの基は例えばヒドロキシ基等の官能基で置換されていてもよい。 Acid diffusion control agent:
The radiation-sensitive resin composition of the present invention has an acid diffusion control function that controls the diffusion phenomenon of an acid generated from an acid generator upon exposure in a resist film and suppresses an undesirable chemical reaction in a non-exposed region. It is preferable to mix an agent.
By using such an acid diffusion control agent, the storage stability of the composition is improved, the resolution is improved as a resist, and due to fluctuations in the holding time (PED) from exposure to heat treatment after exposure. Changes in the line width of the resist pattern can be suppressed, and the process stability is extremely excellent.
As the acid diffusion controller, a nitrogen-containing organic compound whose basicity does not change by exposure or heat treatment in the resist pattern forming step is preferable.
Examples of such a nitrogen-containing organic compound include a compound represented by the following formula (12) (hereinafter referred to as a nitrogen-containing compound (α)) and a diamino compound having two nitrogen atoms in the same molecule (hereinafter referred to as “containing”). Nitrogen compounds (β)), diamino polymers having 3 or more nitrogen atoms (hereinafter referred to as nitrogen-containing compounds (γ)), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

In the above formula (21), each R ⁹ independently represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and these groups may be substituted with a functional group such as a hydroxy group.

  Examples of the nitrogen-containing compound (α) include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; di-n-butylamine, di-n- Dialkylamines such as pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine; triethylamine, tri-n-propylamine, Trialkylamines such as tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine Aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methyl Ruanirin, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, aromatic amines such as 1-naphthylamine, and the like.

Examples of the nitrogen-containing compound (β) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 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 Zen, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, and the like.
Examples of the nitrogen-containing compound (γ) include polymers of polyethyleneimine, polyallylamine, dimethylaminoethylacrylamide, and the like.

Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. Can be mentioned.
Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea and the like. .
Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole; pyridine, 2-methylpyridine, 4-methylpyridine. Pyridine such as 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, acridine , Pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, phenanthroline And the like.

  Moreover, the nitrogen-containing compound which has an acid dissociable group can also be used as a nitrogen-containing organic compound. Examples of the nitrogen-containing compound having an acid-dissociable group include N- (t-butoxycarbonyl) piperidine, N- (t-butoxycarbonyl) imidazole, N- (t-butoxycarbonyl) benzimidazole, N- (t- Butoxycarbonyl) 2-phenylbenzimidazole, N- (t-butoxycarbonyl) dioctylamine, N- (t-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine, etc. Is mentioned.

Of these nitrogen-containing organic compounds, nitrogen-containing compounds (α), nitrogen-containing compounds (β), nitrogen-containing heterocyclic compounds, nitrogen-containing compounds having an acid-dissociable group, and the like are preferable.
The acid diffusion control agents can be used alone or in admixture of two or more.
The compounding amount of the acid diffusion controller is usually 10 parts by weight or less, preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts per 100 parts by weight of the total resin in the radiation-sensitive resin composition. Parts by weight. In this case, when the compounding amount of the acid diffusion controller exceeds 10 parts by weight, the sensitivity as a resist and the developability of the exposed part tend to be lowered. If the blending amount of the acid diffusion controller is less than 0.01 parts by weight, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

Surfactant:
A surfactant exhibiting an effect of improving the coating property and striation of the radiation-sensitive resin composition of the present invention, the developability as a resist, and the like can be blended.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenol ether, polyoxyethylene n-nonylphenol ether, polyethylene glycol dilaurate, polyethylene glycol dilaurate. Examples of commercially available products include F-top EF301, EF303, EF352 (manufactured by Tochem Products), Megafax F171, F173 (above, Dainippon Ink & Chemicals, Inc.) )), Fluorad FC430, FC431 (above, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, the SC105, the SC106 (manufactured by Asahi Glass Co., Ltd.), KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.).
These surfactants can be used alone or in admixture of two or more.
The blending amount of the surfactant is preferably 2 parts by weight or less per 100 parts by weight of the total resin.

solvent:
The radiation-sensitive resin composition of the present invention was uniformly dissolved in a solvent so that the concentration of the total solid content was usually 0.1 to 50% by weight, preferably 1 to 30% by weight, when used. Thereafter, it is prepared as a composition solution by, for example, filtering with a filter having a pore size of about 0.2 μm.
Examples of the solvent used for preparing the composition solution include ethylene glycol such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, and ethylene glycol mono-n-butyl ether acetate. Monoalkyl ether acetates;
Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether;
Propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether, propylene glycol di-n-butyl ether;
Propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-n-butyl ether acetate;
Lactate esters such as methyl lactate, ethyl lactate, n-propyl lactate, i-propyl lactate;
N-amyl formate, i-amyl formate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, i-propyl propionate Aliphatic carboxylic acid esters such as n-butyl propionate and i-butyl propionate;
Ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxy Methyl propionate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutyl butyrate, Other esters such as methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate;
Aromatic hydrocarbons such as toluene and xylene;
Ketones such as methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone;
Amides such as N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone;
Examples include lactones such as γ-butyrolacun.
These solvents can be used alone or in admixture of two or more.

  When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution prepared as described above is applied by appropriate coating means such as spin coating, cast coating, roll coating, etc. Then, it is applied onto a substrate such as a silicon wafer or a wafer coated with aluminum, and in some cases, a heat treatment (hereinafter referred to as “PB”) is performed at a temperature of about 70 ° C. to 160 ° C. to form a resist film. After that, drawing is performed by irradiating with radiation, preferably electron beam. The drawing conditions are appropriately selected according to the composition of the radiation sensitive resin composition, the type of each additive, and the like.

In the present invention, in order to stably form a high-precision fine pattern, a heat treatment (hereinafter referred to as “PEB”) is performed at a temperature of 50 to 200 ° C., preferably 70 to 160 ° C. for 30 seconds or more after exposure. ) Is preferable. In this case, when the temperature of the PEB is less than 50 ° C., there is a possibility that the variation in sensitivity depending on the type of the substrate is widened.
Then, a predetermined resist pattern is formed by developing with an alkali developer usually at 10 to 50 ° C. for 10 to 200 seconds, preferably at 15 to 30 ° C. for 15 to 100 seconds.
Examples of the alkali developer include alkali metal hydroxide, aqueous ammonia, mono-, di- or tri-alkylamines, mono-, di- or tri-alkanolamines, heterocyclic amines, and tetraalkyls. Alkaline compounds such as ammonium hydroxides, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3.0] -5-nonene are usually used. An alkaline aqueous solution dissolved so as to have a concentration of 1 to 10% by weight, preferably 1 to 5% by weight, particularly preferably 1 to 3% by weight is used.
In addition, a water-soluble organic solvent such as methanol or ethanol or a surfactant can be appropriately added to the developer composed of an alkaline aqueous solution.
In forming the resist pattern, a protective film or an antistatic film can be provided on the resist film in order to prevent the influence of basic impurities contained in the environmental atmosphere and the charge in the film.

Hereinafter, the present invention will be described in more detail with reference to examples and synthesis examples of monomers and resins used in these examples.
Synthesis Example 1: Synthesis of monomer having onium salt structure 80 g of diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate and 8.0 g of sodium hydroxide were dissolved in 200 ml of methanol and stirred at room temperature for 1 hour. The reaction solution was concentrated under reduced pressure to remove methanol, and then redissolved in 80 ml of acetone. The insoluble matter in the acetone solution was removed by filtration, the filtrate was concentrated under reduced pressure to remove acetone, and then redissolved in 300 ml of acetonitrile. To the acetonitrile solution, excess acrylic acid chloride was slowly added dropwise with stirring at room temperature, and the reaction was performed at room temperature for 12 hours after the completion of the addition. The precipitate in the reaction solution was filtered, purified by reprecipitation with a large amount of ether, and vacuum-dried to obtain 72 g of (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate.

Synthesis Example 2: Synthesis of monomer having onium salt structure 80 g of diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate was converted to diphenyl-4-hydroxyphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornane-2) -Yl) Synthesis was carried out in the same manner as in Synthesis Example 1 except that 108 g of ethanesulfonate was changed to (4-acryloyloxyphenyl) -diphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ) 95 g of ethanesulfonate was obtained.

Synthesis Example 3: Synthesis of monomer having onium salt structure Similar to Synthesis Example 1 except that 80 g of diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate was changed to 95 g of diphenyl-4-hydroxyphenylsulfonium-10-camphorsulfonate. Synthesis was carried out to obtain 82 g of (4-acryloyloxyphenyl) -diphenylsulfonium-10-camphorsulfonate.

Synthesis Example 4: Synthesis of monomer having onium salt structure Synthesis was performed in the same manner as in Synthesis Example 1 except that acrylic acid chloride was changed to methacrylic acid chloride, and (4-methacryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate. 70 g was obtained.

Synthesis Example 5: Synthesis of monomer having onium salt structure Synthesis was performed in the same manner as in Synthesis Example 1 except that 80 g of diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate was changed to 100 g of 4-hydroxyphenyl-phenyliodonium trifluoromethanesulfonate. Then, 85 g of (4-acryloyloxyphenyl) -phenyliodonium trifluoromethanesulfonate was obtained.

Synthesis Example 6: Synthesis of resin (A-1) having onium salt structure 4-acetoxystyrene 100 g, (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate 33.1 g, azobisisobutyronitrile 5.6 g , 1.7 g of t-dodecyl mercaptan and 133 g of propylene glycol monomethyl ether were put into a separable flask and stirred at room temperature to obtain a uniform solution. Under a nitrogen atmosphere, the reaction temperature was raised to 80 ° C., and polymerization was carried out for 10 hours with stirring. After completion of the polymerization, the reaction solution was purified by reprecipitation with a large amount of methanol, and 120 g of the resulting polymer was dissolved in 800 g of propylene glycol monomethyl ether, and this was concentrated under reduced pressure.
Next, about 300 g of a polymerization solution, 60 g of toluethylamine, 10 g of ion-exchanged water, and 300 g of methanol were charged into a separable flask, and a hydrolysis reaction was performed under stirring and refluxing. Thereafter, the hydrolyzed solution is concentrated under reduced pressure, purified by reprecipitation with a large amount of ion-exchanged water, and vacuum-dried at 50 ° C. to give 4-hydroxystyrene / (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethane. 90 g of sulfonate (molar ratio 90/10) copolymer (Mw 10,000, Mw / Mn; 1.60) was obtained. This compound is referred to as “onium salt-containing resin (A-1)”.

Synthesis Example 7: Synthesis of resin (A-2) having onium salt structure 33.1 g of (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate was converted to (4-acryloyloxyphenyl) -diphenylsulfonium 1,1,2 , 2-Tetrafluoro-2- (norbornan-2-yl) ethanesulfonate Except for changing to 41.8 g, synthesis was performed in the same manner as in Synthesis Example 6, and 4-hydroxystyrene / (4-acryloyloxyphenyl) -diphenylsulfonium. 100 g of 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate (molar ratio 90/10) copolymer (Mw 10,500, Mw / Mn; 1.65) was obtained. . This compound is referred to as “onium salt-containing resin (A-2)”.

Synthesis Example 8: Synthesis of resin (A-3) having onium salt structure 33.1 g of (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate was converted to (4-acryloyloxyphenyl) -diphenylsulfonium-10-camphorsulfonate. Synthesis was conducted in the same manner as in Synthesis Example 6 except that the amount was changed to 38.7 g, and a 4-hydroxystyrene / (4-acryloyloxyphenyl) -diphenylsulfonium-10-camphorsulfonate (90/10 in molar ratio) copolymer ( Mw 9,800, Mw / Mn; 1.55) 95 g was obtained. This compound is referred to as “onium salt-containing resin (A-3)”.

Synthesis Example 9 Synthesis of Resin (A-4) Having Onium Salt Structure 33.1 g of (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate was converted to (4-methacryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate 34 Synthesis was conducted in the same manner as in Synthesis Example 6 except that the amount was changed to 1 g, and a 4-hydroxystyrene / (4-methacryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate (90/10 molar ratio) copolymer (Mw11, 000, Mw / Mn; 1.55) 90 g was obtained. This compound is referred to as “onium salt-containing resin (A-4)”.

Synthesis Example 10: Synthesis of resin (A-5) having onium salt structure 33.1 g of (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate was changed to 42 g of (4-acryloyloxyphenyl) -phenyliodonium trifluoromethanesulfonate. Synthesis was performed in the same manner as in Synthesis Example 6 except for changing, and 4-hydroxystyrene / (4-acryloyloxyphenyl) -phenyliodonium trifluoromethanesulfonate (90/10 in molar ratio) copolymer (Mw11,000, Mw / 90 g of Mn; 1.55) was obtained. This compound is referred to as “onium salt-containing resin (A-5)”.

Synthesis Example 11: Synthesis of resin (A-6) having onium salt structure 4-acetoxystyrene 80 g, 4-t-butoxystyrene 31.0 g, (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate 17.0 g , 5.8 g of azobisisobutyronitrile, 1.8 g of t-dodecyl mercaptan, and 133 g of propylene glycol monomethyl ether were charged into a separable flask and stirred at room temperature to obtain a uniform solution. Under a nitrogen atmosphere, the reaction temperature was raised to 80 ° C., and polymerization was carried out for 10 hours with stirring. After completion of the polymerization, the reaction solution was purified by reprecipitation with a large amount of methanol, and 115 g of the resulting polymer was dissolved in 800 g of propylene glycol monomethyl ether, and this was concentrated under reduced pressure.
Next, about 300 g of the polymerization solution, 50 g of toluethylamine, 10 g of ion-exchanged water, and 300 g of methanol were charged into a separable flask, and a hydrolysis reaction was performed under stirring and refluxing. Thereafter, the hydrolyzed solution is concentrated under reduced pressure, purified by reprecipitation with a large amount of ion-exchanged water, and vacuum-dried at 50 ° C. to give 4-hydroxystyrene / 4-t-butoxystyrene / (4-acryloyloxyphenyl). ) -Diphenylsulfonium trifluoromethanesulfonate (molar ratio 70/25/5) copolymer (Mw 10,000, Mw / Mn; 1.55) 90 g was obtained. This compound is referred to as “onium salt-containing resin (A-6)”.

Synthesis Example 12: Synthesis of resin (A-7) having onium salt structure 31.0 g of 4-t-butoxystyrene was added to 23.5 g of 2-methyl-2-adamantyl acrylate and (4-acryloyloxyphenyl) -diphenylsulfonium. Synthesis example except that 17.0 g of trifluoromethanesulfonate is changed to 19.3 g of (4-acryloyloxyphenyl) -diphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate 11 and 4-hydroxystyrene / 2-methyl-2-adamantyl acrylate / (4-acryloyloxyphenyl) -diphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornane-2) -Yl) ethanesulfonate (78/17/5 in molar ratio) ) 90 g of a copolymer (Mw 11,000, Mw / Mn; 1.65) was obtained. This compound is referred to as “onium salt-containing resin (A-7)”.

Synthesis Example 13: Synthesis of resin (A-8) having onium salt structure 23.5 g of 2-methyl-2-adamantyl acrylate was converted to 25.0 g of 2-ethyl-2-adamantyl acrylate and (4-acryloyloxyphenyl) Except for changing 19.3 g of diphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate to 15.8 g of (4-methacryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate Was synthesized in the same manner as in Synthesis Example 12, 4-hydroxystyrene / 2-ethyl-2-adamantyl acrylate / (4-methacryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate (78/17/5 in molar ratio) Copolymer (Mw 11,500, M w / Mn; 1.60) 95 g was obtained. This compound is referred to as “onium salt-containing resin (A-8)”.

Synthesis Example 14: Synthesis of resin (A-9) having onium salt structure 31.0 g of 4-t-butoxystyrene was added to 23.5 g of 2-methyl-2-adamantyl acrylate and (4-acryloyloxyphenyl) -diphenylsulfonium toluol. Synthesis was carried out in the same manner as in Synthesis Example 11 except that 17.0 g of fluoromethanesulfonate was changed to 17.6 g of (4-acryloyloxyphenyl) -phenyliodonium trifluoromethanesulfonate, and 4-hydroxystyrene / 2-methyl-2 acrylate 95 g of adamantyl / (4-acryloyloxyphenyl) -phenyliodonium trifluoromethanesulfonate (molar ratio 78/17/5) copolymer (Mw 11,000, Mw / Mn; 1.60) was obtained. This compound is referred to as “onium salt-containing resin (A-9)”.

Synthesis Example 15: Synthesis of resin having onium salt structure (A- 10 ) 20 g of 4-isopropenylphenol, 72 g of (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate, 2.5 g of azobisisobutyronitrile, 100 g of propylene glycol monomethyl ether was put into a separable flask and stirred at room temperature to obtain a uniform solution. Under a nitrogen atmosphere, the reaction temperature was raised to 80 ° C., and polymerization was carried out for 10 hours with stirring. After completion of the polymerization, the reaction solution was purified by reprecipitation with a large amount of hexane, followed by vacuum drying at 50 ° C. to give 4-isopropenylphenol / (4-acryloyloxyphenyl) -diphenylsulfonium trifluoromethanesulfonate (molar ratio). 50/50) copolymer (Mw; 10,000, Mw / Mn; 1.55) 55 g was obtained. This compound is referred to as “onium salt-containing resin (A-10)”.

Synthesis Example 16: Synthesis of acid dissociable resin (B-1) 4-acetoxystyrene 100 g, styrene 4.6 g, pt-butoxystyrene 38.8 g, azobisisobutyronitrile 7.2 g, t-dodecyl mercaptan 2.0 g and 145 g of propylene glycol monomethyl ether were put into a separable flask and stirred at room temperature to obtain a uniform solution. Under a nitrogen atmosphere, the reaction temperature was raised to 80 ° C., and polymerization was carried out for 10 hours with stirring. After completion of the polymerization, the reaction solution was purified by reprecipitation with a large amount of methanol, and 130 g of the resulting polymer was dissolved in 800 g of propylene glycol monomethyl ether, and this was concentrated under reduced pressure.
Next, about 300 g of the polymer solution, 60 g of triethylamine, 10 g of ion-exchanged water, and 300 g of methanol were charged into a separable flask and subjected to a hydrolysis reaction with stirring and reflux. Thereafter, the hydrolyzed solution was concentrated under reduced pressure, purified by reprecipitation with a large amount of ion-exchanged water, and vacuum-dried at 50 ° C. to obtain p-hydroxystyrene / styrene / pt-butoxystyrene (molar ratio of 70 / 5/25) 100 g of a copolymer (Mw; 10,000, Mw / Mn; 1.55) was obtained. This compound is referred to as “acid-labile group-containing resin (B-1)”.

Synthesis Example 17 Synthesis of Acid Dissociable Resin (B-2) 100 g of 4-acetoxystyrene, 40.6 g of 2-methyl-2-adamantyl acrylate, 6.5 g of azobisisobutyronitrile, t-dodecyl mercaptan 7 g and 141 g of propylene glycol monomethyl ether were put into a separable flask and stirred at room temperature to obtain a uniform solution. Under a nitrogen atmosphere, the reaction temperature was raised to 80 ° C., and polymerization was carried out for 10 hours with stirring. After completion of the polymerization, the reaction solution was purified by reprecipitation with a large amount of methanol, and 130 g of the resulting polymer was dissolved in 800 g of propylene glycol monomethyl ether, and this was concentrated under reduced pressure.
Next, about 300 g of the polymer solution, 60 g of triethylamine, 10 g of ion-exchanged water, and 300 g of methanol were charged into a separable flask, and a hydrolysis reaction was performed under stirring and reflux. Thereafter, the hydrolyzed solution was concentrated under reduced pressure, purified by reprecipitation with a large amount of ion-exchanged water, and vacuum-dried at 50 ° C. to give 4-hydroxystyrene / 2-methyl-2-adamantyl acrylate (in molar ratio). 77/23) 102 g of a copolymer (Mw; 9500, Mw / Mn; 1.52) was obtained. This compound is referred to as “acid-labile group-containing resin (B-2)”.

Synthesis Example 18 Synthesis of Acid Dissociable Resin (B-3) 100 g of 4-acetoxystyrene, 43 g of 2-ethyl-2-adamantyl acrylate, 6.5 g of azobisisobutyronitrile, and 1.8 g of t-dodecyl mercaptan Then, 141 g of propylene glycol monomethyl ether was put into a separable flask and stirred at room temperature to obtain a uniform solution. Under a nitrogen atmosphere, the reaction temperature was raised to 80 ° C., and polymerization was carried out for 10 hours with stirring. After completion of the polymerization, the reaction solution was purified by reprecipitation with a large amount of methanol, and 132 g of the resulting polymer was dissolved in 800 g of propylene glycol monomethyl ether, and concentrated under reduced pressure.
Next, about 300 g of the polymer solution, 60 g of triethylamine, 10 g of ion-exchanged water, and 300 g of methanol were charged into a separable flask, and a hydrolysis reaction was performed under stirring and reflux. Thereafter, the hydrolyzed solution is concentrated under reduced pressure, purified by reprecipitation with a large amount of ion-exchanged water, and vacuum-dried at 50 ° C. to give 4-hydroxystyrene / 2-ethyl-2-adamantyl acrylate (in molar ratio). 77/23) 104 g of a copolymer (Mw; 9600, Mw / Mn; 1.49) was obtained. This compound is referred to as “acid-labile group-containing resin (B-3)”.

Synthesis Example 19 Synthesis of Acid Dissociable Resin (B-4) 100 g of 4-t-butoxystyrene, 4.7 g of azobisisobutyronitrile, 1.5 g of t-dodecyl mercaptan, and 100 g of propylene glycol monomethyl ether are separable. The solution was put into a flask and stirred at room temperature to obtain a uniform solution. Under a nitrogen atmosphere, the reaction temperature was raised to 80 ° C., and polymerization was carried out for 10 hours with stirring. After completion of the polymerization, the reaction solution was purified by reprecipitation with a large amount of methanol, and 90 g of the resulting polymer was dissolved in 500 g of propylene glycol monomethyl ether, and this was concentrated under reduced pressure.
Next, about 250 g of the polymer solution and 40 g of 10% sulfuric acid aqueous solution were charged into a separable flask, and a hydrolysis reaction was performed under stirring and reflux. Then, it reprecipitated with a large amount of ion-exchanged water, purified, and vacuum dried at 50 ° C. to obtain 60 g of 4-hydroxystyrene polymer (Mw; 10800, Mw / Mn; 1.58).
Next, 60 g of 4-hydroxystyrene and 500 g of propylene glycol monomethyl ether acetate were put into a separable flask and concentrated under reduced pressure. To this was added 1.0 g of pyridinium-4-toluenesulfonic acid to obtain a homogeneous solution, and 20 g of vinylcyclohexyl ether was added dropwise to the reaction solution, followed by stirring at room temperature for 10 hours. The reaction solution was purified by reprecipitation of triethylamine with a large amount of ion-exchanged water and vacuum-dried at 50 ° C., whereby a polymer having a hydroxy group of 28 mol% cyclohexyloxyethylated (Mw; 12000, Mw / Mn1 .75) 70 g were obtained. This compound is referred to as “acid-labile group-containing resin (B-4)”.

  Each measurement and evaluation in Examples and Comparative Examples was performed by the following methods.

(1) Mw and Mw / Mn
Tosoh Co., Ltd. high-speed GPC device (model “HLC-8120”) is equipped with Tosoh Co., Ltd. GPC columns (trade name “G2000HXL”; 2, “G3000HXL”; 1, “G4000HXL”; 1). It was measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of a flow rate of 1.0 ml / min, an elution solvent tetrahydrofuran, and a column temperature of 40 ° C.
(2) Sensitivity When a resist film formed on a silicon wafer is irradiated with an electron beam, immediately subjected to PEB, developed with alkali, washed with water and dried to form a resist pattern. The irradiation dose for forming the space pattern (1L1S) with a one-to-one line width was set as the optimum dose, and the sensitivity was evaluated based on this optimum dose.
(3) Resolution The minimum dimension (nm) of the line-and-space pattern (1L1S) resolved when irradiated with the optimal dose of (2) was taken as the resolution.
(4) Roughness (LER)
For a line and space pattern (1L1S) having a design line width of 120 nm, the cross-sectional dimension of the line pattern is measured by a scanning electron microscope, the minimum dimension is Lin, the maximum dimension is Lout (Lout-Lin) is Ld, and Ld The following criteria were evaluated according to the value of:
×: Ld exceeds 10.0 nm Δ: Ld exceeds 7.0 nm and less than 10.0 nm ○: Ld exceeds 5.0 and less than 7.0 nm A: Less than 5.0 nm

Examples 1-14 and Comparative Examples 1-3
Each component shown in Table 1 (where parts are based on weight) was mixed to obtain a uniform solution, and then filtered through a membrane filter having a pore size of 0.2 μm to remove foreign matters, thereby preparing a resist solution. Thereafter, these resist solutions were spin-coated on a 6-inch silicon wafer to form a resist film having a thickness of 200 nm. Subsequently, the resist film was irradiated with an electron beam using a simple electron beam drawing apparatus (manufactured by Hitachi, model “HL700D-M, output: 50 KeV, current density: 4.5 amperes). PEB was performed under the conditions shown, followed by development using an aqueous solution containing 2.38% by weight of tetramethylammonium hydroxide by the paddle method at 23 ° C. for 60 seconds, followed by washing with water for 30 seconds and drying. A positive resist pattern was formed, and the evaluation results of the obtained resist pattern are shown in Table 2.

The material used for Examples 1-14 and Comparative Examples 1-3 is shown below.
(A) Onium salt-containing resin A-1; Resin A-2 obtained in Synthesis Example 6; Resin A-3 obtained in Synthesis Example 7; Resin A-4 obtained in Synthesis Example 8; Synthesis Example 9 Resin A-5 obtained in Synthesis Example 10; Resin A-6 obtained in Synthesis Example 10; Resin A-7 obtained in Synthesis Example 11; Resin A-8 obtained in Synthesis Example 12; Obtained in Synthesis Example 13 Resin A-9; Resin A-10 obtained in Synthesis Example 14; Resin obtained in Synthesis Example 15

(B) Acid-labile group-containing resin B-1; Resin B-2 obtained in Synthesis Example 16; Resin B-3 obtained in Synthesis Example 17; Resin B-4 obtained in Synthesis Example 18; Resin (C) acid generator C-1 obtained in Example 19; triphenylsulfonium trifluoromethanesulfonate C-2: triphenylsulfonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) Ethanesulfonate C-3: Diphenyliodonium 1,1,2,2-tetrafluoro-2- (norbornan-2-yl) ethanesulfonate (D) Acid diffusion controller D-1: Tri-n-octylamine D-2 : 2-phenylbenzimidazole (E) solvent E-1; ethyl lactate E-2; propylene glycol monomethyl ether acetate

  As shown in Table 2, in each Example, a radiation sensitive resin composition excellent in resolution and roughness (LER) characteristics is obtained.

  The positive resist composition of the present invention is excellent in sensitivity, resolution, and roughness, and is particularly effective for resolution deterioration and roughness deterioration at the time of increasing sensitivity, which is a problem of EB lithography. It is extremely useful as a chemically amplified resist for manufacturing semiconductor devices.

Claims (4)

A repeating unit composed of at least one onium salt structural unit selected from a sulfonium salt structural unit represented by the formula (1) and an iodonium salt structural unit represented by the formula (2), and represented by the following formula (3): A radiation-sensitive resin composition comprising a repeating unit and a repeating unit having an acid dissociable group, wherein the repeating unit represented by the formula (3) occupies 60 to 90 mol% of all repeating units. object.

(In Formula (1) and Formula (2), R ¹ is a hydrogen atom, a halogen atom, a cyano group, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear chain having 1 to 5 carbon atoms. Represents a linear or branched haloalkyl group, and R ² and R ³ are independently of each other a hydrogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted Straight or branched alkoxy group having 1 to 10 carbon atoms, substituted or unsubstituted linear or branched haloalkyl group having 1 to 10 carbon atoms, or substituted or unsubstituted carbon number Represents an aryl group of 6 to 20, A ¹ represents a single bond, an ether bond, an ester bond, or an amide bond, and X ⁻ represents an anion.)

(In Formula (3), R ⁴ represents a hydrogen atom, a halogen atom, a cyano group, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkyl group having 1 to 5 carbon atoms. Represents a haloalkyl group, R ⁵ represents a hydrogen atom or a monovalent organic group, a and b are each an integer of 1 to 4, and (a + b) ≦ 5. A repeating unit comprising at least one onium salt structural unit selected from a sulfonium salt structural unit represented by the following formula (1) and an iodonium salt structural unit represented by the following formula (2); A polymer containing a repeating unit having an acid-dissociable group in a polymer containing 50 to 99 mol% of the repeating unit represented by the formula (3) in all repeating units. Ri Na formulated, the radiation-sensitive resin composition, wherein the polymer containing a repeating unit contains 10 to 90 wt% of the total polymer with the acid-dissociable group.

(In Formula (1) and Formula (2), R ¹ is a hydrogen atom, a halogen atom, a cyano group, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear chain having 1 to 5 carbon atoms. Represents a linear or branched haloalkyl group, and R ² and R ³ are independently of each other a hydrogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted Straight or branched alkoxy group having 1 to 10 carbon atoms, substituted or unsubstituted linear or branched haloalkyl group having 1 to 10 carbon atoms, or substituted or unsubstituted carbon number Represents an aryl group of 6 to 20, A ¹ represents a single bond, an ether bond, an ester bond, or an amide bond, and X ⁻ represents an anion.)

(In Formula (3), R ⁴ represents a hydrogen atom, a halogen atom, a cyano group, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkyl group having 1 to 5 carbon atoms. Represents a haloalkyl group, R ⁵ represents a hydrogen atom or a monovalent organic group, a and b are each an integer of 1 to 4, and (a + b) ≦ 5.   In the polymer containing the repeating unit composed of the onium salt structural unit and the repeating unit represented by the formula (3), the repeating unit represented by the formula (3) is 60 to 90 mol%. The radiation sensitive resin composition according to claim 2.   The radiation sensitive resin composition according to claim 1, 2, or 3, wherein an electron beam or an X-ray is used as radiation to be irradiated.