JP2007212797A - Radiation-sensitive resin composition for liquid immersion exposure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition for liquid immersion exposure which gives a good pattern profile, excels also in focal depth and ensures a small amount of materials eluting into water with which the composition contacts in liquid immersion exposure. <P>SOLUTION: The radiation-sensitive resin composition for liquid immersion exposure is used in liquid immersion exposure by which a resist film is exposed through water, and contains an alkali-insoluble or slightly alkali-soluble resin which contains a methacrylate unit of norborneol having a lactone ring and becomes alkali-soluble under the action of an acid and a radiation-sensitive acid generator. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiation-sensitive resin composition for immersion exposure used for immersion exposure in which a resist film is exposed through water. More specifically, the present invention relates to a radiation-sensitive resin composition for immersion exposure that has a good pattern shape, excellent depth of focus, and a small amount of eluate in contact with water during immersion exposure.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, a lithography technique 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 the subquarter micron level is extremely difficult with this near ultraviolet rays. Therefore, in order to enable fine processing at a level of 0.20 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 90 nm) will be required in the future. In order to achieve such a pattern formation finer than 90 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, at the time of exposure, a liquid refractive index medium (immersion liquid) such as pure water or fluorine-based inert liquid having a predetermined thickness is interposed between at least the resist film between the lens and the resist film on the substrate. Is. 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 liquid immersion exposure process, the resist film directly contacts with a refractive index liquid (immersion 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.
Therefore, as a resist resin used in the immersion exposure apparatus, for example, resins described in Patent Document 1 and Patent Document 2 have been proposed.
However, even with resists using these resins, the depth of focus is not always sufficient.
In addition, in resists used in immersion exposure apparatuses, it has been eagerly desired to further reduce the amount of eluate in water such as acid generators.

International Publication WO 2004/062422 JP 2005-173474 A

  An object of the present invention is to provide a radiation-sensitive resin composition for immersion exposure that has a good pattern shape, excellent depth of focus, and a small amount of eluate in contact with water during immersion exposure. is there.

As a means for achieving the above object, the invention of claim 1 is a radiation-sensitive resin composition for immersion exposure used for immersion exposure in which a resist film is exposed through water, wherein the following formula ( 1) A liquid comprising the repeating unit represented by 1) as an essential unit and containing an alkali-insoluble or hardly-alkali-soluble resin that becomes alkali-soluble by the action of an acid, and a radiation-sensitive acid generator. A radiation-sensitive resin composition for immersion exposure.

〔一般式（２）において、Ｒは水素原子又はメチル基を示す。各々のＲ^１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し、且つ、Ｒ^１は以下の（１）又は（２）の条件を満たす。
（１）Ｒ^１のうちの少なくとも１つは炭素数４〜２０の１価の脂環式炭化水素基若しくはその誘導体である。
（２）いずれか２つのＲ^１が相互に結合して、それぞれが結合している炭素原子と共に炭素数４〜２０の２価の脂環式炭化水素基若しくはその誘導体を形成し、残りのＲ^１が炭素数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である。〕 The invention of claim 2 is the radiation-sensitive resin composition for immersion exposure according to claim 1, wherein the resin further contains a repeating unit represented by the following general formula (2).

[In General formula (2), R shows a hydrogen atom or a methyl group. Each R ¹ 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, and R 1 ¹ satisfies the following condition (1) or (2).
(1) At least one of R ¹ is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof.
(2) Any two R ^{1 's} are bonded to each other to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof together with the carbon atoms to which each R ¹ is bonded, and the remaining R 1 ¹ is 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. ]

  In the invention of claim 3, the content of the low molecular weight component derived from the monomer used in preparing the resin is 0.1% by mass or less with respect to 100% by mass of the resin in terms of solid content. The radiation-sensitive resin composition for immersion exposure according to claim 1.

  If the radiation-sensitive resin composition for immersion exposure containing a resin containing the specific repeating unit of the present invention is used, the pattern shape obtained is good, the resolution and the depth of focus are excellent, and the water that contacts during immersion exposure The amount of the eluate can be reduced.

Hereinafter, the present invention will be described in detail.
<Resin>
The resin in the present invention contains the repeating unit represented by the above formula (1) (hereinafter referred to as “repeating unit (1)”) as an essential unit, and becomes insoluble or difficult to be alkaline which becomes alkali-soluble by the action of an acid. Soluble resin [hereinafter also referred to as “resin (A)”. ]. The term “alkali insoluble or alkali insoluble” as used herein refers to an alkali development condition employed when a resist pattern is formed from a resist film formed from a radiation-sensitive resin composition containing the resin (A). When a film using only the resin (A) is developed in place of the resist film, it means that 50% or more of the initial film thickness of the film remains after development.

In addition, since the repeating unit (1) has not a acrylate structure but a methacrylic ester structure (because it has —CH ₃ ), the rigidity of the resin (A) in the present invention is increased, and as a result, It is presumed that elution into the water of an acid generator or an acid diffusion controller during immersion exposure is reduced. Further, it is presumed that due to this rigidity, acid diffusibility is suppressed, and there is an allowance in the temperature range of the heat treatment after exposure (hereinafter referred to as “PEB”). Can improve the yield, which is industrially advantageous).

Further, the resin (A) in the present invention may contain a repeating unit other than the repeating unit (1), and the repeating unit represented by the general formula (2) (hereinafter referred to as “repeating unit (2)”). It is preferable to contain.
In the general formula (2), a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms of R ¹ and any two R ¹ bonded to each other to form a divalent hydrocarbon having 4 to 20 carbon atoms. Examples of the alicyclic hydrocarbon group include alicyclic rings derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. A group consisting of these alicyclic rings is, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t -The group etc. which substituted by 1 or more types or 1 or more of C1-C4 linear, branched or cyclic alkyl groups, such as a butyl group, can be mentioned. Among these alicyclic hydrocarbon groups, a group consisting of an alicyclic ring derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane or cyclohexane, or a group consisting of these alicyclic rings is described above. A group substituted with an alkyl group is preferred.

  Examples of the alicyclic hydrocarbon group derivative include hydroxyl group; carboxyl group; oxo group (that is, ═O group); hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1- Hydroxypropyl groups having 1 to 4 carbon atoms such as hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group An alkoxyl group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, a 1-methylpropoxy group and a t-butoxy group; Group: C2-C5 such as cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, 4-cyanobutyl group, etc. A substituent such as Anoarukiru group can include one or more or one or more having groups. Of these substituents, a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, a cyanomethyl group and the like are preferable.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R ¹ include, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and 2-methylpropyl. Group, 1-methylpropyl group, t-butyl group and the like. Of these alkyl groups, a methyl group, an ethyl group, an n-propyl group, and an i-propyl group are preferable.

In addition, the group —COOC (R ¹ ) ₃ in the general formula (2) forms an acid dissociable group that is dissociated by the action of an acid to form a carboxyl group. Hereinafter, the group —COOC (R ¹ ) _{3 is referred} to as “acid-dissociable group (i)”.

  As a preferable acid dissociable group (i), for example, a group represented by the following formula (a), formula (b), formula (c) or formula (d) is preferable.

〔式（ａ）、式（ｂ）、式（ｃ）及び式（ｄ）において、各Ｒ^２は相互に独立に炭素数１〜４の直鎖状若しくは分岐状のアルキル基を示し、ｍは０又は１である。〕

[In Formula (a), Formula (b), Formula (c) and Formula (d), each R ² independently represents a linear or branched alkyl group having 1 to 4 carbon atoms, and m is 0 or 1. ]

In the formula (a), formula (b), formula (c) and formula (d), examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R ² include a methyl group, an ethyl group, Examples include n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like. Of these alkyl groups, a methyl group, an ethyl group, an n-propyl group, and an i-propyl group are preferable.

As the group represented by the formula (a), a group in which two R ^{2 s} are both methyl groups is particularly preferable. The group represented by the formula (b) is particularly preferably a group in which R ² is a methyl group and a group in which R ² is an ethyl group, an n-propyl group, or an i-propyl group. The group represented by the formula (c) is particularly a group in which m is 0 and R ² is a methyl group, a group in which m is 0 and R ² is an ethyl group, m is 1 and R ² is methyl. A group which is a group, m is 1 and R ² is an ethyl group is preferable. Further, as the group represented by the formula (d), a group in which two R ² are both methyl groups is particularly preferable.

  Examples of the acid dissociable group (i) other than the above include t-butoxycarbonyl group and groups of the following formulas (d-1) to (d-42).

  Moreover, the resin (A) in the present invention may contain two or more of the repeating units (2). The repeating unit (1) and the repeating unit (2) are each a repeating unit derived from a corresponding (meth) acrylic acid derivative (in the specification, “(meth) acrylic acid ester” is acrylic). Both acid ester and methacrylic acid ester).

The resin (A) can further contain one or more repeating units other than the repeating unit (1) and the repeating unit (2) (hereinafter referred to as “other repeating units”).
As other repeating units, repeating units represented by the following general formulas (3) to (6) (hereinafter, the repeating unit of the general formula (3) is referred to as “other repeating unit (3)”, the general formula (4) ) Is the “other repeating unit (4)”, the repeating unit of the general formula (5) is “other repeating unit (5)”, and the repeating unit of the general formula (6) is “other repeating unit (6). And at least one repeating unit selected from repeating units derived from aromatic compounds.

〔一般式（３）において、Ｒは水素原子、メチル基、トリフルオロメチル基、又はヒドロキシメチル基を示し、Ｒ^３は炭素数１〜４の直鎖状又は分岐状のアルキル基を示し、ｑは１〜２の整数である。〕

[In General Formula (3), R represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group, R ³ represents a linear or branched alkyl group having 1 to 4 carbon atoms, q Is an integer of 1-2. ]

〔一般式（４）において、Ｒは水素原子、メチル基、又はトリフルオロメチル基を示し、Ｘは炭素数７〜２０の多環型脂環式炭化水素基であり、この炭素数７〜２０の多環型脂環式炭化水素基は、炭素数１〜４のアルキル基、ヒドロキシル基、シアノ基、炭素数１〜１０のヒドロキシアルキル基で置換されていても、置換されていなくてもよい。〕

[In General formula (4), R shows a hydrogen atom, a methyl group, or a trifluoromethyl group, X is a C7-C20 polycyclic alicyclic hydrocarbon group, and this C7-20 The polycyclic alicyclic hydrocarbon group may be substituted or unsubstituted with an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a cyano group, or a hydroxyalkyl group having 1 to 10 carbon atoms. . ]

〔一般式（５）において、Ｒは水素原子、炭素数１〜４のアルキル基、トリフルオロメチル基、又はヒドロキシメチル基を示し、Ｒ^４は、２価の有機基を示す。〕

In [Formula (5), R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, or a hydroxymethyl group, R ⁴ represents a divalent organic group. ]

〔一般式（６）において、Ｒは水素又はメチル基を表し、Ｘは単結合又は炭素数１〜３の２価の有機基を表し、Ｙは相互に独立に単結合又は炭素数１〜３の２価の有機基を表し、Ｒ^５は相互に独立に水素原子、水酸基、シアノ基、又はＣＯＯＲ^６基を表す（但し、Ｒ^６は水素原子或いは炭素数１〜４の直鎖状若しくは分岐状のアルキル基、又は炭素数３〜２０の脂環式のアルキル基を表す。）。尚、３つのＲ^５のうち少なくとも一つは水素原子でなく、かつＸが単結合のときは、３つのＹのうち少なくとも一つは炭素数１〜３の２価の有機基であることが好ましい。〕

[In General Formula (6), R represents hydrogen or a methyl group, X represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and Y represents a single bond or 1 to 3 carbon atoms independently of each other. R ⁵ represents a hydrogen atom, a hydroxyl group, a cyano group, or a COOR ⁶ group independently of each other (wherein R ⁶ is a hydrogen atom or a linear or branched group having 1 to 4 carbon atoms) Represents an alkyl group in the form of a ring or an alicyclic alkyl group having 3 to 20 carbon atoms.). When at least one of the three R ⁵ is not a hydrogen atom and X is a single bond, at least one of the three Ys is a divalent organic group having 1 to 3 carbon atoms. preferable. ]

  As the other repeating unit (3), a unit (3-1) represented by the following formula is particularly preferable.

〔一般式（３−１）において、Ｒは水素原子、メチル基、トリフルオロメチル基、又はヒドロキシメチル基を示す。〕

[In General Formula (3-1), R represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. ]

X in the other repeating unit (4) represented by the general formula (4) is preferably a polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms. Examples of such polycyclic alicyclic hydrocarbon groups include bicyclo [2.2.1] heptane (4a), bicyclo [2.2.2] octane (4b), Tricyclo [5.2.1.0 ^2,6 ] decane (4c), tetracyclo [6.2.1.1 ^3,6 . And hydrocarbon groups composed of alicyclic rings derived from cycloalkanes such as 0 ^2,7 ] dodecane (4d) and tricyclo [3.3.1.1 ^3,7 ] decane (4e).

  These cycloalkane-derived alicyclic rings may have a substituent, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group. , 1-methylpropyl group, t-butyl group, etc. may be substituted with one or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms. These are represented by the following specific examples, but are not limited to those substituted by these alkyl groups, but are hydroxyl groups, cyano groups, C1-C10 hydroxyalkyl groups, carboxyls. The group may be substituted with oxygen. Moreover, these other repeating units (4) can contain 1 type (s) or 2 or more types.

R in the other repeating unit (5) represented by the general formula (5) represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, or a hydroxymethyl group. Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, and t-butyl group. And the like.
The divalent organic group as R ⁴ of the other repeating unit (5) represented by the general formula (5) is preferably a divalent hydrocarbon group, and preferably a chain among the divalent hydrocarbon groups. A cyclic or cyclic hydrocarbon group is preferable, and may be an alkylene glycol group or an alkylene ester group.
Preferred R ⁴ includes a methylene group, an ethylene group, a propylene group such as a 1,3-propylene group or a 1,2-propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, Nonamethylene group, Decamemethylene group, Undecamethylene group, Dodecamethylene group, Tridecamethylene group, Tetradecamethylene group, Pentacamethylene group, Hexadecamethylene group, Heptadecamethylene group, Octadecamethylene group, Nonadecamethylene group, Insalen group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl- 1,4-butylene group, methylidene group, ethylidene group, propylidene group, or 2-propylidene group Saturated chain hydrocarbon groups such as ethylene groups, cyclobutylene groups such as 1,3-cyclobutylene groups, cyclopentylene groups such as 1,3-cyclopentylene groups, and cyclohexylenes such as 1,4-cyclohexylene groups Group, monocyclic hydrocarbon ring group such as cycloalkylene group having 3 to 10 carbon atoms such as cyclooctylene group such as 1,5-cyclooctylene group, 1,4-norbornylene group or 2,5-norbornylene group Such as norbornylene group, 1,5-adamantylene group, adamantylene group such as 2,6-adamantylene group, etc., bridged cyclic hydrocarbon ring such as 2-4 cyclic hydrocarbon ring group having 4-30 carbon atoms Groups and the like.

In particular, when R ⁴ contains a divalent aliphatic cyclic hydrocarbon group, an alkylene group having 1 to 4 carbon atoms is inserted as a spacer between the bistrifluoromethyl-hydroxy-methyl group and the aliphatic cyclic hydrocarbon group. It is preferable to do.
R ⁴ is preferably a hydrocarbon group containing a 2,5-norbornylene group, a 1,2-ethylene group, or a propylene group.
Particularly preferred other repeating units (5) are the following formulas (5-1) to (5-4).

In the repeating unit (6) represented by the general formula (6), X represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and Y is independently a single bond or 1 to 3 carbon atoms. Although a divalent organic group is represented, a methylene group, an ethylene group, and a propylene group are mentioned as a C1-C3 bivalent organic group represented by X and Y.
R ^{6 of the} —COOR ⁶ group represented by R ⁵ in the repeating unit (6) represented by the general formula (6) is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, or An alicyclic alkyl group having 3 to 20 carbon atoms is represented.
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms in R ⁶ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, Examples thereof include a 1-methylpropyl group and a t-butyl group. Examples of the alicyclic alkyl groups of said 3 to 20 carbon _atoms, -C _{n H 2n-1} cycloalkyl group (n is an integer of 3 to 20) represented by, for example, cyclopropyl group, cyclobutyl group , Cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like, and also polycyclic alicyclic alkyl groups such as bicyclo [2.2.1] heptyl group, tricyclo [5.2.1.0 ^{2]. , 6} ] decyl group, tetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecanyl group, adamantyl group or the like, or one or more of linear, branched or cyclic alkyl groups, and a part of cycloalkyl group or polycyclic alicyclic alkyl group. Examples include substituted groups.

Preferred monomers among the monomers that generate the repeating unit (6) represented by the general formula (6) are listed below.
(Meth) acrylic acid 3-hydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-cyanoadamantane-1- Ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-carboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-methoxycarbonyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxymethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-hydroxymethyladamantan-1-ylmethyl Ester, (meta Acrylic acid 3-cyano-5-hydroxymethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5-carboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5 -Methoxycarbonyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyanoadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dicyanoadamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5-carboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5-methoxycarbonyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyladamantan-1-ylmethyl Ester, (meta Acrylic acid 3,5-dicarboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyl-5-methoxycarbonyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-methoxycarbonyladamantane-1- Ylmethyl ester, (meth) acrylic acid 3,5-dimethoxycarbonyladamantan-1-ylmethyl ester,

  (Meth) acrylic acid 3-hydroxy-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dihydroxy-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5 -Cyano-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5-carboxyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5-methoxycarbonyl- 7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxymethyl-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dihydroxymethyl-7-methyladamantan-1-yl Ester, (meth) acrylic acid 3-hydroxy-5-hydroxymethyl- -Methyladamantan-1-yl ester, (meth) acrylic acid 3-cyano-5-hydroxymethyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxymethyl-5-carboxyl-7-methyl Adamantan-1-yl ester, (meth) acrylic acid 3-hydroxymethyl-5-methoxycarbonyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-cyano-5-methyladamantan-1-yl ester (Meth) acrylic acid 3,5-dicyano-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-cyano-5-carboxyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-cyano-5-methoxycarbonyl-7-methyladamantan-1-y Ester, (meth) acrylic acid 3-carboxyl-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dicarboxyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3- Carboxyl-5-methoxycarbonyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-methoxycarbonyl-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dimethoxycarbonyl-7 -Methyladamantan-1-yl ester,

  (Meth) acrylic acid 3-hydroxy-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxy-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy -5-cyano-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-carboxyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5 -Methoxycarbonyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxymethyl-7- Methyl adamantane-1-ylmethyl ester, (meth) acrylic Acid 3-hydroxy-5-hydroxymethyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5-hydroxymethyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic Acid 3-hydroxymethyl-5-carboxyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5-methoxycarbonyl-7-methyladamantan-1-ylmethyl ester, (meth) Acrylic acid 3-cyano-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dicyano-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5- Carboxyl-7-methyladamantan-1-ylmethyl ester, (Meth) acrylic acid 3-cyano-5-methoxycarbonyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyl-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3 , 5-Dicarboxyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyl-5-methoxycarbonyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-methoxy Carbonyl-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dimethoxycarbonyl-7-methyladamantan-1-ylmethyl ester,

  (Meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxymethyl-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3- Cyano-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-carboxyl-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-methoxycarbonyl-5,7-dimethyl Adamantane-1-yl ester, (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5,7-dimethyladamantan-1-ylmethyl Ester, (meth) acrylic acid 3-cyano-5,7-dimethyladamantane-1 Ylmethyl ester, (meth) acrylic acid 3-carboxyl-5,7-dimethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-methoxycarbonyl-5,7-dimethyladamantan-1-ylmethyl ester, etc. Can be mentioned.

  Among these, particularly preferable monomers include (meth) acrylic acid 3-hydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxyadamantan-1-ylmethyl ester, and (meth) acrylic. Acid 3-cyanoadamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-methyladamantan-1-yl ester, (meth) Acrylic acid 3,5-dihydroxy-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-carboxyl-5 7-dimethyladamantan-1-yl ester, (meth) acrylic acid - hydroxy-5,7-dimethyl-adamantan-1-yl methyl ester, and the like.

Preferred monomers among the monomers that generate repeating units derived from aromatic compounds are listed below.
Styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 4- (2-t-butoxycarbonylethyloxy) styrene 2-hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene, 2-hydroxy-α-methylstyrene, 3-hydroxy-α-methylstyrene, 4-hydroxy-α-methylstyrene, 2-methyl-3-hydroxystyrene 4-methyl-3-hydroxystyrene, 5-methyl-3-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3-methyl-4-hydroxystyrene, 3,4-dihydroxystyrene, 2,4,6- Trihydroxystyrene, 4-t-butoxystyrene, 4-t Butoxy-α-methylstyrene, 4- (2-ethyl-2-propoxy) styrene, 4- (2-ethyl-2-propoxy) -α-methylstyrene, 4- (1-ethoxyethoxy) styrene, 4- ( 1-ethoxyethoxy) -α-methylstyrene, phenyl (meth) acrylate, benzyl (meth) acrylate, acenaphthylene, 5-hydroxyacenaphthylene, 1-vinylnaphthalene, 2-vinylnaphthalene, 2-hydroxy-6 Vinylnaphthalene, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, 1-naphthylmethyl (meth) acrylate, 1-anthryl (meth) acrylate, 2-anthryl (meth) acrylate, 9-anthryl (meth) Acrylate, 9-anthrylmethyl (meth) acrylate, 1-vinyl Lupyrene and the like can be mentioned.

  Examples of the repeating unit other than the repeating units derived from the above formulas (1) to (6) and aromatic include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, (meth ) N-butyl acrylate, 2-methylpropyl (meth) acrylate, 1-methylpropyl (meth) acrylate, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylic 2-hydroxypropyl acid, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-methoxycyclohexyl (meth) acrylate, (meth ) 2-cyclopentyloxycarbonylethyl acrylate, 2-cyclo (meth) acrylate Hexyl oxycarbonyl ethyl, (meth) no bridged hydrocarbon skeleton such as acrylic acid 2- (4-methoxy-cyclohexyl) oxycarbonyl ethyl (meth) acrylate;

  α-hydroxymethyl acrylate esters such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate, n-butyl α-hydroxymethyl acrylate; (meth) acrylonitrile , Α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesaconitrile, citraconitrile, itaconnitrile, and other unsaturated nitrile compounds; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleinamide , Fumaramide, mesaconamide, citraconic amide, itaconic amide, etc .; N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, vinyl Other nitrogen-containing vinyl compounds such as lysine and vinylimidazole; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, etc. Unsaturated carboxylic acids (anhydrides); 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, Carboxyl group-containing esters having no bridged hydrocarbon skeleton of unsaturated carboxylic acid such as (meth) acrylic acid 4-carboxycyclohexyl;

  α- (meth) acryloyloxy-β-methoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-ethoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-n-propoxycarbonyl-γ -Butyrolactone, α- (meth) acryloyloxy-β-i-propoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-n-butoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β -(2-methylpropoxy) carbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β- (1-methylpropoxy) carbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-t-butoxycarbonyl- γ-butyrolactone, α- (meth) acryloyl Oxy-β-cyclohexyloxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β- (4-t-butylcyclohexyloxy) carbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-phenoxycarbonyl- γ-butyrolactone, α- (meth) acryloyloxy-β- (1-ethoxyethoxy) carbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β- (1-cyclohexyloxyethoxy) carbonyl-γ-butyrolactone, α -(Meth) acryloyloxy-β-t-butoxycarbonylmethoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-tetrahydrofuranyloxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-tetrahi B pyranyl butyloxycarbonyl -γ- butyrolactone,

  α-methoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-ethoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-n-propoxycarbonyl-β- (meth) acryloyloxy-γ -Butyrolactone, α-i-propoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-n-butoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α- (2-methylpropoxy) carbonyl -Β- (meth) acryloyloxy-γ-butyrolactone, α- (1-methylpropoxy) carbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-t-butoxycarbonyl-β- (meth) acryloyloxy- γ-butyrolactone, α-cyclohexyloxy Carbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α- (4-t-butylcyclohexyloxy) carbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-phenoxycarbonyl-β- (meth) acryloyl Oxy-γ-butyrolactone, α- (1-ethoxyethoxy) carbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α- (1-cyclohexyloxyethoxy) carbonyl-β- (meth) acryloyloxy-γ-butyrolactone , Α-t-butoxycarbonylmethoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-tetrahydrofuranyloxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-tetrahydropyranyloxycarbonyl-β (Meth) acrylate having an acid dissociable group such as acryloyloxy -γ- butyrolactone (meth) acryloyloxy lactone compounds;

  α- (meth) acryloyloxy-β-fluoro-γ-butyrolactone, α- (meth) acryloyloxy-β-hydroxy-γ-butyrolactone, α- (meth) acryloyloxy-β-methyl-γ-butyrolactone, α- (Meth) acryloyloxy-β-ethyl-γ-butyrolactone, α- (meth) acryloyloxy-β, β-dimethyl-γ-butyrolactone, α- (meth) acryloyloxy-β-methoxy-γ-butyrolactone, α- Fluoro-β- (meth) acryloyloxy-γ-butyrolactone, α-hydroxy-β- (meth) acryloyloxy-γ-butyrolactone, α-methyl-β- (meth) acryloyloxy-γ-butyrolactone, α-ethyl- β- (meth) acryloyloxy-γ-butyrolactone, α, α-dimethyl-β- (meta (Meth) acryloyloxylactone having no acid-dissociable groups such as acryloyloxy-γ-butyrolactone, α-methoxy-β- (meth) acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-δ-mevalonolactone Monofunctional monomers such as compounds,

  1,2-adamantanediol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyl dimethylol di (meth) acrylate, etc. A polyfunctional monomer having a bridged hydrocarbon skeleton;

  Methylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2,5-dimethyl-2,5-hexanediol di ( (Meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,4-bis (2-hydroxypropyl) benzenedi (meth) acrylate, 1,3-bis List units in which a polymerizable unsaturated bond of a polyfunctional monomer such as a polyfunctional monomer having no bridged hydrocarbon skeleton such as (2-hydroxypropyl) benzenedi (meth) acrylate is cleaved Can do.

  Among these repeating units other than the repeating units derived from the above formulas (1) to (6) and aromatics, polymerizable unsaturated bonds of (meth) acrylates having a bridged hydrocarbon skeleton are present. Cleaved units are preferred.

In the resin (A), the content of the repeating unit (1) is usually 10 to 70 mol%, preferably 15 to 65 mol%, more preferably 20 to 60 mol%, based on all repeating units. In this case, if the content of the repeating unit (1) is less than 10 mol%, the resist has poor solubility in an alkaline developer, which may contribute to development defects or deteriorate the exposure margin ( Note that the exposure margin indicates a change in line width with respect to a change in exposure amount. On the other hand, when it exceeds 70 mol%, the solubility of the resist in the solvent is lowered, and the resolution may be lowered.
Moreover, the content rate of a repeating unit (2) is 10-70 mol% normally with respect to all the repeating units, Preferably it is 15-60 mol%, More preferably, it is 20-50 mol%. In this case, if the content of the repeating unit (2) is less than 10 mol%, the resolution as a resist may be lowered. On the other hand, if it exceeds 70 mol%, the exposure margin may be deteriorated.
Moreover, the content rate of a repeating unit (3) is 30 mol% or less normally with respect to all the repeating units, Preferably it is 25 mol% or less. In this case, if the content of the repeating unit (3) exceeds 30 mol%, the top loss of the resist pattern may occur and the pattern shape may be deteriorated.
Moreover, the content rate of a repeating unit (4) is 30 mol% or less normally with respect to all the repeating units, Preferably it is 25 mol% or less. In this case, if the content of the repeating unit (4) exceeds 30 mol%, the resulting resist film may be easily swollen by the alkali developer, or the solubility in the alkali developer may be reduced.
Moreover, the content rate of a repeating unit (5) is 30 mol% or less normally with respect to all the repeating units, Preferably it is 25 mol% or less. In this case, if the content of the repeating unit (5) exceeds 30 mol%, the top loss of the resist pattern may occur and the pattern shape may be deteriorated.
Moreover, the content rate of a repeating unit (6) is 30 mol% or less normally with respect to all the repeating units, Preferably it is 25 mol% or less. In this case, when the content of the repeating unit (6) exceeds 30 mol%, the resulting resist film may be easily swollen by the alkali developer or the solubility in the alkali developer may be reduced.
Moreover, the content rate of the repeating unit derived from an aromatic is 40 mol% or less normally with respect to all the repeating units, Preferably it is 30 mol% or less. In this case, when the content rate of the repeating unit derived from the aromatic exceeds 40 mol%, the radiation transmittance is lowered, and the pattern profile may be deteriorated.
Furthermore, the content of other repeating units is usually 50 mol% or less, preferably 40 mol% or less, based on all repeating units.

  Resin (A) uses, for example, a polymerizable unsaturated monomer corresponding to each repeating unit using a radical polymerization initiator such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. If necessary, it can be produced by polymerization in an appropriate solvent in the presence of a chain transfer agent. 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, dichloroethanes, 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. Moreover, the reaction temperature in the said polymerization is 40-150 degreeC normally, Preferably it is 50-120 degreeC, and reaction time is 1-48 hours normally, Preferably it is 1-24 hours.

  The polystyrene-reduced weight average molecular weight (hereinafter referred to as “Mw”) by gel permeation chromatography (GPC) of the resin (A) is not particularly limited, but is preferably 1000 to 100,000, more preferably 1000 to 30000, and still more preferably. 1000-20000. In this case, if the Mw of the resin (A) is less than 1000, the heat resistance when used as a resist tends to decrease, while if it exceeds 100,000, the developability when used as a resist tends to decrease. The ratio (Mw / Mn) of Mw of the resin (A) to polystyrene-reduced number average molecular weight (hereinafter referred to as “Mn”) by gel permeation chromatography (GPC) is usually 1 to 5, preferably 1. ~ 3.

Moreover, in resin (A) in this invention, content of the low molecular weight component derived from the monomer used when preparing this resin (A) is solid content conversion with respect to 100 mass% of this resin. It is preferable that it is 0.1 mass% or less, More preferably, it is 0.07 mass% or less, More preferably, it is 0.05 mass% or less. When this content is 0.1% by mass or less, it is possible to reduce the amount of the eluate in 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 (A) is so preferable that there are few impurities, such as a halogen and a metal, and, thereby, the sensitivity, resolution, process stability, pattern shape, etc. when it is set as a resist can be improved further. Examples of the purification method of the resin (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. Can be mentioned. In this invention, resin (A) can be used individually or in mixture of 2 or more types.

<Radiosensitive acid generator>
The radiation-sensitive acid generator in the present invention (hereinafter also simply referred to as “acid generator (B)”) is an acid dissociation in a repeating unit present in the resin (A) by the action of an acid generated by exposure. The functional group is dissociated (the protective group is eliminated). As a result, the exposed portion of the resist film becomes readily soluble in an alkali developer, and has a function of forming a positive resist pattern.
The acid generator (B) in the present invention preferably contains a compound represented by the following general formula (7) (hereinafter referred to as “acid generator 1”).

In the general formula (7), R ⁶ is 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 linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms, R ⁷ is a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group, or 1 to 1 carbon atom; 10 represents a linear, branched, or cyclic alkanesulfonyl group, and R ⁸ is independently a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group, or a substituent. A naphthyl group which may be substituted, or two R ⁸ 's bonded to each other to form a divalent group having 2 to 10 carbon atoms, and the divalent group may be substituted Well, k is an integer from 0 to 2 Yes, X ⁻ represents a formula: R ⁹ C _n F _2n SO ₃ ^— (wherein R ⁹ represents a fluorine atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and n represents 1 to Is an integer of 10), and j is an integer of 0 to 10.

In the general formula (7), examples of the linear or branched alkyl group having 1 to 10 carbon atoms of R ⁶ , R ⁷ and R ⁸ include a methyl group, an ethyl group, an n-propyl group, i- Propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2- Examples thereof include an ethylhexyl group, an n-nonyl group, and an n-decyl group. 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 alkoxyl group having 1 to 10 carbon atoms of R ⁶ and R ⁷ include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, 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. 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 ⁶ include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, and n-butoxy. Carbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group, An n-octyloxycarbonyl group, a 2-ethylhexyloxycarbonyl group, an n-nonyloxycarbonyl group, an n-decyloxycarbonyl group, and the like can be given. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

Examples of the linear, branched, and cyclic alkanesulfonyl group having 1 to 10 carbon atoms of R ⁷ include a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a tert. -Butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n-nonanesulfonyl group, n-decanesulfonyl Group, cyclopentanesulfonyl group, cyclohexanesulfonyl group and the like. 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 j, 0-2 are preferable.

In the general formula (7), examples of the optionally substituted phenyl group represented by R ⁸ include a phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,3-dimethylphenyl group, 2 , 4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4 -Substituted with phenyl groups such as ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, 4-fluorophenyl group or linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms. A phenyl group; these phenyl groups or alkyl-substituted phenyl groups can be converted into hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkoxyl groups, alkoxyalkyl groups. And a group substituted with at least one group such as a group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group.

  Among the substituents for the phenyl group and the alkyl-substituted phenyl group, examples of the alkoxyl group include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1- Examples thereof include a linear, branched or cyclic alkoxyl group having 1 to 20 carbon atoms such as a methylpropoxy group, a t-butoxy group, a cyclopentyloxy group and a cyclohexyloxy group.

  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 ⁸ in the general formula (7) 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 ⁸ 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-naphth Tyl 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 that are the above substituents include the groups exemplified for the phenyl group and the alkyl-substituted phenyl group. As the naphthyl group which may be substituted for R ⁸ in the general formula (7), 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 ⁸ to each other is preferably a 5- or 6-membered ring, particularly preferably a 5-membered ring, together with the sulfur atom in the formula (7). A group that forms a ring (that is, a tetrahydrothiophene ring) is 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. The R ⁸ in the general formula (7), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, a 1-naphthyl group, form a tetrahydrothiophene ring structure two R ⁸ are bonded to each other with the sulfur atom A divalent group is preferred.

  Preferred cation sites of the general formula (7) include triphenylsulfonium cation, tri-1-naphthylsulfonium cation, tri-tert-butylphenylsulfonium cation, 4-fluorophenyl-diphenylsulfonium cation, di-4-fluorophenyl- Phenylsulfonium cation, tri-4-fluorophenylsulfonium cation, 4-cyclohexylphenyl-diphenylsulfonium cation, 4-methanesulfonylphenyl-diphenylsulfonium cation, 4-cyclohexanesulfonyl-diphenylsulfonium cation, 1-naphthyldimethylsulfonium cation, 1- Naphthyldiethylsulfonium cation, 1- (4-hydroxynaphthyl) dimethylsulfonium cation, 1- (4- Tylnaphthyl) dimethylsulfonium cation, 1- (4-methylnaphthyl) diethylsulfonium cation, 1- (4-cyanonaphthyl) dimethylsulfonium cation, 1- (4-cyanonaphthyl) diethylsulfonium cation, 1- (3,5-dimethyl -4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxynaphthyl) tetrahydrothiophenium cation, 1- (4-ethoxynaphthyl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthyl) Tetrahydrothiophenium cation, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium cation, 2- (7-methoxynaphthyl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthyl) tetrahydride Thiophenium cation, 2- (7-n- propoxy-naphthyl) tetrahydrothiophenium cation, 2- (7-n- butoxynaphthyl) tetrahydrothiophenium cation, and the like.

Represented by ^R 9 _C n _F with _{^{2n SO 3 - - C n F}} 2n in the anion - X of the general formula (7) group is a perfluoroalkylene group having a carbon number n, said group linear Or branched. Here, n is preferably 1, 2, 4 or 8. The optionally substituted hydrocarbon group having 1 to 12 carbon atoms for R ⁹ is preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, or a bridged alicyclic hydrocarbon group. Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group N-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, norbornyl group, norbornylmethyl group, hydroxynorbornyl group, adamantyl group Etc.

  Preferred anion sites of the general formula (7) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl -1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, and the like.

  In this invention, the acid generator 1 can be used individually or in mixture of 2 or more types.

  Moreover, as a radiation sensitive acid generator (henceforth "other acid generator") other than the said acid generator (B) which can be used as a radiation sensitive acid generator in this invention, it is, for example. Onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, sulfonic acid compounds, and the like. Examples of these other acid generators include the following.

Onium salt compounds:
Examples of the onium salt compound include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.
Specific examples of the onium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta-2. -Yl-1,1,2,2-tetrafluoroethanesulfonate, 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) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2- Te La tetrafluoroethane sulfonate, cyclohexyl 2-oxo-cyclohexyl methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, and 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethanesulfonate, and the like.

Halogen-containing compounds:
Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound.
Specific examples of halogen-containing compounds include (trichloromethyl such as phenylbis (trichloromethyl) -s-triazine, 4-methoxyphenylbis (trichloromethyl) -s-triazine, 1-naphthylbis (trichloromethyl) -s-triazine. ) -S-triazine derivatives and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

Diazo ketone compounds:
Examples of the diazo ketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like.
Specific examples of the diazo ketone include 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2, naphthoquinonediazide of 2,3,4,4′-tetrahydroxybenzophenone. -4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,1,1-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane Examples include 2-naphthoquinonediazide-5-sulfonic acid ester.

Sulfone compounds:
Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds of these compounds.
Specific examples of the sulfone compound include 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and the like.

Sulfonic acid compounds:
Examples of the sulfonic acid compounds include alkyl sulfonic acid esters, alkyl sulfonic acid imides, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates.
Specific examples of the sulfonic acid compounds include benzoin tosylate, pyrogallol tris (trifluoromethanesulfonate), nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethanesulfonylbicyclo [2.2.1] hept- 5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2.2 .1] Hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonylbicyclo [2.2. 1] Hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyl Xyl) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic imide trifluoromethanesulfonate, 1,8-naphthalenedicarboxylic imidononafluoro-n-butanesulfonate, 1,8-naphthalenedicarboxylic Examples include acid imido perfluoro-n-octane sulfonate.

Among these other acid generators, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta- 2-yl-1,1,2,2-tetrafluoroethanesulfonate, 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) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2 -Tetraph Oro ethanesulfonate,
Cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethanesulfonate, dicyclohexyl, 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate,

  Trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide Perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2 , 2-tetrafluoroethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2 1] hept-2-yl-1,1,2,2-tetrafluoroethane sulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate and the like are preferable. The other acid generators can be used alone or in admixture of two or more.

  In the present invention, the total amount of the acid generator (B) and the other acid generator used is usually 0.1 to 20 with respect to 100 parts by mass of the resin from the viewpoint of ensuring the sensitivity and developability as a resist. Part 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, if it exceeds 20 parts by mass, the transparency to radiation decreases and a rectangular resist pattern is obtained. There is a tendency to become difficult to get. Moreover, the usage-amount of another acid generator is 80 mass% or less normally with respect to the sum total of an acid generator (B) and another acid generator, Preferably it is 60 mass% or less.

<Additives>
In the radiation sensitive resin composition of the present invention, various additives such as an acid diffusion controller, an alicyclic additive, a surfactant, and a sensitizer can be blended as necessary.
The acid diffusion control agent is a component having an action of controlling a diffusion phenomenon of an acid generated from an acid generator upon exposure in a resist film and suppressing an undesirable chemical reaction in a non-exposed region. By blending such an acid diffusion controller, the storage stability of the resulting radiation-sensitive resin composition is improved, the resolution as a resist is further improved, and the process from exposure to heat treatment after exposure is improved. A change in the line width of the resist pattern due to fluctuations in the placement time (PED) can be suppressed, and a composition having extremely excellent process stability can be obtained.
As the acid diffusion controller, a nitrogen-containing organic compound whose basicity is not changed by exposure or heat treatment in the resist pattern forming step is preferable. As such a nitrogen-containing organic compound, for example, a compound represented by the following general formula (8) (hereinafter referred to as “nitrogen-containing compound (i)”), a compound having two nitrogen atoms in the same molecule ( Hereinafter referred to as “nitrogen-containing compound (b)”), polyamino compounds and polymers having 3 or more nitrogen atoms (hereinafter collectively referred to as “nitrogen-containing compound (c)”), amide group-containing compounds, Examples include urea compounds and nitrogen-containing heterocyclic compounds.

〔一般式（８）において、各Ｒ^１０は相互に独立に水素原子、置換若しくは非置換の直鎖状、分岐状若しくは環状のアルキル基、置換若しくは非置換のアリール基又は置換若しくは非置換のアラルキル基を示す。〕

[In the general formula (8), each R ¹⁰ independently represents a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl. Indicates a group. ]

  Examples of the nitrogen-containing compound (i) 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. Di (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, cyclohexyl 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 Aromatic amines such as 2,6-diisopropylaniline are preferred.

Examples of the nitrogen-containing compound (b) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenylether. 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-methylethyl] ben , 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.
As the nitrogen-containing compound (c), for example, polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer 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 Rupiperazine, 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-butoxycarbonyl-1,12-diaminododecane, N N'-di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenyl In addition to Nt-butoxycarbonyl group-containing amino compounds such as benzimidazole, 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 nitrogen-containing heterocyclic compound include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2. -Imidazoles such as methyl-1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenyl Pyridines such as pyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, 2,2 ': 6', 2 "-terpyridine; piperazine, 1- (2-hydroxy In addition to piperazines such as ethyl) piperazine, Pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3 -(N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like are preferable.

  The acid diffusion controller can be used alone or in admixture of two or more. The compounding amount of the acid diffusion controller is usually 15 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less with respect to 100 parts by mass of the copolymer. 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.

Moreover, the said alicyclic additive is a component which shows the effect | action which further improves dry etching tolerance, a pattern shape, adhesiveness with a board | substrate, etc.
Examples of such alicyclic additives include 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α. -Butyrolactone ester, 1,3-adamantane dicarboxylic acid di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2, Adamantane derivatives such as 5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane; t-butyl deoxycholic acid, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid, 2-deoxycholic acid 2- Cyclohexyloxyethyl, deoxy Deoxycholic acid esters such as 3-oxocyclohexyl cholic acid, tetrahydropyranyl deoxycholic acid, mevalonolactone ester of deoxycholic acid; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, Lithocholic acid esters such as lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, din adipate - butyl, alkyl carboxylic acid esters such as adipate t- butyl or 3- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^{2, 5} 1 ^7,10 ] dodecane and the like. These alicyclic additives can be used alone or in admixture of two or more.

The surfactant is a component having an action of improving coating properties, striation, developability and the like.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), Ftop EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd.), Megafax F171, F173 (manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC430, FC431 ( Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-105, SC-106 (Asahi Glass Co., Ltd.) And the like. These surfactants can be used alone or in admixture of two or more.

The sensitizer absorbs radiation energy and transmits the energy to the acid generator (B), thereby increasing the amount of acid produced. The radiation-sensitive resin composition It has the effect of improving the apparent sensitivity.
Examples of such sensitizers include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers can be used alone or in admixture of two or more.
In addition, by blending a dye or pigment, the latent image of the exposed area can be visualized, and the influence of halation during exposure can be alleviated, and by blending an adhesion aid, adhesion to the substrate can be improved. it can. Furthermore, examples of additives other than the above include alkali-soluble resins, low-molecular alkali-solubility control agents having acid-dissociable protecting groups, antihalation agents, storage stabilizers, antifoaming agents, and the like.

<Preparation of composition solution>
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 used for the preparation of the composition solution include 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, and 3-methyl-2- Linear or branched ketones such as pentanone, 3,3-dimethyl-2-butanone, 2-heptanone, 2-octanone; cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2 Cyclic ketones such as 1,6-dimethylcyclohexanone and 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 Propylene glycol monoalkyl ether acetates such as 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-hydroxypropionic acid n-propyl, 2-hydroxypropionic acid i-propyl, 2-hydroxypropionic acid n-butyl, 2-hydroxypropionic acid i-butyl, 2-hydroxypropionic acid sec- Alkyl 2-hydroxypropionates such as butyl and t-butyl 2-hydroxypropionate; methyl 3-methoxypropionate, 3-methoxypropioate Ethyl, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate and the like of 3-alkoxy propionic acid alkyl ethers other,

  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 solvents can be used alone or in admixture of two or more.

<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, an acid-dissociable group in the resin (A) is dissociated by the action of an acid generated from an acid generator by exposure to generate a carboxyl group, and as a result, an alkali in an exposed portion of the resist is obtained. The solubility in the developer is increased, and the exposed portion is dissolved and removed by the alkali developer, and a positive resist pattern is obtained. When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the 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 in some cases, a heat treatment (hereinafter referred to as “PB”) is performed in advance, and then a predetermined resist pattern is formed on the resist film. Exposure. The radiation used at this 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 this PEB, the dissociation reaction of the acid dissociable group in the resin (A) 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, as disclosed in, for example, Japanese Patent Publication No. 6-12458, an organic or inorganic substrate is used. An antireflection film can also be formed, and in order to prevent the influence of basic impurities contained in the environmental atmosphere, as disclosed in, for example, JP-A-5-188598, A protective film can be provided on the substrate, or 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 development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propylamine. , 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, if 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. In addition, an appropriate amount of a surfactant or the like can be added to the developer composed of an 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 Sciences, 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.
^{(3) 13} C-NMR analysis of ¹³ C-NMR analysis the polymer, using a Nippon Denshi Co. "JNM-EX270", was performed using CDCL ₃ as measurement solvent.

Hereinafter, each synthesis example will be described.
<Synthesis Example 1-1>
The following compound (M-1) 53.93 g (50 mol%), compound (M-2) 10.69 g (10 mol%), compound (M-3) 35.38 g (40 mol%) was added to 2-butanone 200 g. And a monomer solution charged with 5.58 g of dimethyl 2,2′-azobis (2-methylpropionate) was prepared, and a 1000 ml three-necked flask charged with 100 g of 2-butanone was charged with nitrogen for 30 minutes. Purged. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. 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 on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (74 g, yield 74%). . This polymer has Mw of 6900, Mw / Mn of 1.70, and as a result of ¹³ C-NMR analysis, each repeating unit derived from compound (M-1), compound (M-2), and compound (M-3) Was a copolymer having a content of 53.0: 9.8: 37.2 (mol%). This polymer is referred to as “acrylic polymer (A-1)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.03 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 1-2>
The monomer solution was mixed with 48.22 g (48 mol%) of the following compound (M-1), 40.25 g (38 mol%) of the compound (M-4), 11.53 g (14 mol%) of the compound (M-3). Is dissolved in 200 g of 2-butanone, and a resin is synthesized in the same manner as in Synthesis Example 1-1 except that 3.71 g of 2,2′-azobis (isobutyronitrile) is added. This resin has a molecular weight of 5200 and Mw / Mn of 1.62, and as a result of ¹³ C-NMR analysis, each resin is derived from compound (M-1), compound (M-4) and compound (M-3). The copolymer had a unit content of 50.0: 37.0: 13.0 (mol%). This polymer is referred to as “resin (A-2)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.03 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 1-3>
The monomer solution was prepared by the following compound (M-1) 43.64 g (45 mol%), compound (M-5) 15.47 g (15 mol%), compound (M-4) 40.90 g (40 mol%). Is dissolved in 200 g of 2-butanone, and a resin is synthesized in the same manner as in Synthesis Example 1-1 except that 5.02 g of dimethyl 2,2′-azobis (2-methylpropionate) is added. did. This resin has a molecular weight of 5000 and Mw / Mn of 1.60. As a result of ¹³ C-NMR analysis, each resin is derived from compound (M-1), compound (M-5), and compound (M-4). The copolymer had a unit content of 47.3: 15.8: 36.9 (mol%). This polymer is referred to as “resin (A-3)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.05 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 1-4>
The monomer solution was 54.51 g (50 mol%) of the following compound (M-1), 9.72 g (10 mol%) of the compound (M-6), 35.76 g (40 mol%) of the compound (M-3). Was dissolved in 200 g of 2-butanone, and a resin was synthesized in the same manner as in Synthesis Example 1-1 except that 5.65 g of dimethyl 2,2′-azobis (2-methylpropionate) was added. did. This resin has a molecular weight of 8100 and Mw / Mn of 1.69, and as a result of ¹³ C-NMR analysis, each resin is derived from compound (M-1), compound (M-6), and compound (M-3). The copolymer had a unit content of 53.6: 9.8: 36.6 (mol%). This polymer is referred to as “resin (A-4)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.04 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 1-5>
The following compound (M-1) 55.77 g (50 mol%) and the following compound (M-3) 36.59 g (40 mol%) were dissolved in 200 g of 2-butanone, and dimethyl 2,2′-azobis (2 -Methylpropionate) A monomer solution charged with 5.78 g was prepared. The following compound (M-7) 7.64 g (10 mol%) and 2-butanone 100 g were put into a 1000 ml three-necked flask and stirred to obtain a homogeneous solution. The flask was purged with nitrogen for 30 minutes, and then the flask was stirred. While heating to 80 ° C., the monomer solution was dropped from the dropping funnel over 3 hours. After completion of dropping, the reaction solution was stirred for 3 hours while heating at 80 ° C. 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 on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (79 g, yield 79%). . This resin has a molecular weight of 6100 and Mw / Mn of 1.62, and as a result of ¹³ C-NMR analysis, each repeat derived from the compound (M-1), the compound (M-7) and the compound (M-3) The copolymer had a unit content of 53.6: 9.8: 36.6 (mol%). This polymer is referred to as “resin (A-5)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.03 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 1-6>
40.27 g (42 mol%) of the following compound (M-1) and 40.44 g (40 mol%) of the following compound (M-4) are dissolved in 200 g of 2-butanone, and further dimethyl 2,2′-azobis (2 -Methylpropionate) A monomer solution charged with 4.97 g was prepared. In a 1000 ml three-necked flask, 19.29 g (18 mol%) of the following compound (18 mol%) and 100 g of 2-butanone were added and stirred to obtain a homogeneous solution. After purging the flask with nitrogen for 30 minutes, the flask was stirred. While heating to 80 ° C., the monomer solution was dropped from the dropping funnel over 3 hours. After completion of dropping, the reaction solution was stirred for 3 hours while heating at 80 ° C. 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 on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (70 g, yield 70%). . This resin has a molecular weight of 8200 and Mw / Mn of 1.78. As a result of ¹³ C-NMR analysis, each resin is derived from compound (M-1), compound (M-4), and compound (M-8). The copolymer had a unit content of 50.0: 36.9: 13.1 (mol%). This polymer is referred to as “resin (A-6)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.03 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 2-1>
The following compound (M-1) 55.44 g (50 mol%), compound (M-2) 11.99 g (10 mol%), compound (M-9) 33.57 g (40 mol%) were added to 2-butanone 200 g A monomer solution containing 5.74 g of dimethyldimethyl 2,2′-azobis (2-methylpropionate) was prepared, and a 1000 ml three-necked flask charged with 100 g of 2-butanone was added for 30 minutes. Nitrogen purged. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. 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 on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (72 g, yield 72%). . This polymer has Mw of 6300 and Mw / Mn of 1.58. As a result of ¹³ C-NMR analysis, each polymer derived from compound (M-1), compound (M-2), and compound (M-9) It was a copolymer having a content of repeating units of 51.0: 10.8: 38.2 (mol%). This polymer is referred to as “acrylic polymer (A′-1)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.03 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 2-2>
The monomer solution was prepared by the following compound (M-1) 48.65 g (48 mol%), compound (M-4) 40.61 g (38 mol%), compound (M-9) 10.74 g (14 mol%). Was dissolved in 200 g of 2-butanone, and a resin was synthesized in the same manner as in Synthesis Example 2-1, except that 5.25 g of dimethyl 2,2′-azobis (2-methylpropionitrile) was added. did. This resin has a molecular weight of 5800 and Mw / Mn of 1.63, and as a result of ¹³ C-NMR analysis, each resin is derived from compound (M-1), compound (M-4) and compound (M-9). The copolymer had a unit content of 50.0: 36.0: 14.0 (mol%). This polymer is referred to as “resin (A′-2)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.04 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 2-3>
57.39 g (50 mol%) of the following compound (M-1) and 34.75 g (40 mol%) of the following compound (M-9) were dissolved in 200 g of 2-butanone, and further dimethyl 2,2′-azobis (2 -Methylpropionate) A monomer solution charged with 5.95 g was prepared. In a 1000 ml three-necked flask, 7.86 g (10 mol%) of the following compound (100 mol%) and 100 g of 2-butanone were stirred to obtain a homogeneous solution, and the flask was purged with nitrogen for 30 minutes, and then the flask was stirred. While heating to 80 ° C., the monomer solution was dropped from the dropping funnel over 3 hours. After completion of dropping, the reaction solution was stirred for 3 hours while heating at 80 ° C. 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 on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (78 g, yield 78%). . This resin has a molecular weight of 7100 and Mw / Mn of 1.70. As a result of ¹³ C-NMR analysis, each resin is derived from compound (M-1), compound (M-7), and compound (M-9). The copolymer had a unit content of 50.5: 10.3: 39.2 (mol%). This polymer is referred to as “resin (A′-3)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.03 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 3-1>
The monomer solution was composed of 36.55 g (40 mol%) of the following compound (M-6), 23.70 g (20 mol%) of compound (M-5), and 39.75 g (40 mol%) of compound (M-3). Was dissolved in 200 g of 2-butanone, and a resin was synthesized in the same manner as in Synthesis Example 1-1 except that 5.77 g of dimethyl 2,2′-azobis (2-methylpropionate) was added. did. This resin has a molecular weight of 5400 and Mw / Mn of 1.84, and as a result of ¹³ C-NMR analysis, each resin is derived from compound (M-6), compound (M-5), and compound (M-3). The copolymer had a unit content of 38.6: 23.1: 38.3 (mol%). This polymer is referred to as “resin (a-1)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.05 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 3-2>
The monomer solution was the following compound (M-10) 21.77 g (25 mol%), compound (M-5) 36.27 g (30 mol%), compound (M-3) 41.96 g (45 mol%). Is dissolved in 200 g of 2-butanone, and a resin is synthesized in the same manner as in Synthesis Example 1-1 except that 5.89 g of dimethyl 2,2′-azobis (2-methylpropionate) is added. did. This resin has a molecular weight of 6900 and Mw / Mn of 1.93. As a result of ¹³ C-NMR analysis, each resin is derived from the compound (M-10), the compound (M-5) and the compound (M-3). The unit content was 31.4: 28.5: 40.1 (mol%). This polymer is referred to as “resin (a-2)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.08 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 3-3>
The monomer solution was prepared by the following compound (M-11) 52.30 g (50 mol%), compound (M-2) 11.07 g (10 mol%), compound (M-3) 36.63 g (40 mol%). Was dissolved in 200 g of 2-butanone, and a resin was synthesized in the same manner as in Synthesis Example 1-1 except that 5.78 g of dimethyl 2,2′-azobis (2-methylpropionate) was added. did. This resin has a molecular weight of 8000 and Mw / Mn of 1.78. As a result of ¹³ C-NMR analysis, each resin is derived from compound (M-11), compound (M-2), and compound (M-3). The copolymer had a unit content of 49.8: 10.3: 39.9 (mol%). This polymer is referred to as “resin (a-3)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.05 mass% with respect to 100 mass% of this polymer.

<Synthesis Example 3-4>
The monomer solution was 53.82 g (50 mol%) of the following compound (M-11), 11.39 g (10 mol%) of the compound (M-2), 34.79 g (40 mol%) of the compound (M-9). Was dissolved in 200 g of 2-butanone, and a resin was synthesized in the same manner as in Synthesis Example 1-1 except that 5.95 g of dimethyl 2,2′-azobis (2-methylpropionate) was added. did. This resin has a molecular weight of 7500 and Mw / Mn of 1.65, and as a result of ¹³ C-NMR analysis, each resin is derived from compound (M-11), compound (M-2), and compound (M-9). The copolymer had a unit content of 49.4: 10.5: 40.1 (mol%). This polymer is referred to as “resin (a-4)”. In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.05 mass% with respect to 100 mass% of this polymer.

<< Evaluation of radiation sensitive resin composition >>
Various evaluations were performed on each composition composed of the components shown in Table 1. The evaluation results regarding elution are shown in Table 2, and the exposure conditions and other evaluation results are shown in Table 3. The components other than the resin shown in Table 1 are as follows. In the table, “parts” are based on mass unless otherwise specified.
<Acid generator (B)>
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate
<Acid diffusion inhibitor (C)>
(C-1): Triethanolamine
<Solvent (D)>
(D-1): Propylene glycol monomethyl ether acetate (D-2): γ-butyrolactone

The evaluation method is as follows.
Evaluation method (1) Elution amount (acid generator elution amount and acid diffusion control agent elution amount):
As shown in FIG. 2, in the center on the 8-inch silicon wafer 3 that has been subjected to HMDS (hexamethyldisilazane) 31 treatment (100 ° C., 60 seconds) in advance in CLEAN TRACK ACT8 (manufactured by Tokyo Electron Ltd.) 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 which was cut into a circular shape having a diameter of 11.3 cm. 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 antireflection film (“ARC29A”, manufactured by Brewer Science) 61 having a film thickness of 77 nm is formed in advance by CLEAN TRACK ACT8, and the resist composition shown in Table 1 is then applied to the lower layer by 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 comes into contact with the ultrapure water 5 is formed. 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.
Next, the peak intensity of the anion part of the photoacid generator in the ultrapure water obtained above was calculated using 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 peak intensity of 1 ppb, 10 ppb, and 100 ppb aqueous solutions of triphenylsulfonium nonafluoro-n-butanesulfonate was measured under the above measurement conditions to prepare a calibration curve, and the amount eluted from the peak intensity using this calibration curve. Was calculated. 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.

(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) Sensitivity:
As the substrate, a 12-inch silicon wafer having a 77 nm-thick lower layer antireflection film (“ARC29A”, manufactured by Brewer Science) on the surface was used. For the formation of this antireflection film, “CLEAN TRACK ACT12” (manufactured by Tokyo Electron Limited) was used.
Subsequently, the resist composition of Table 1 was spin-coated on the said board | substrate in the said CLEAN TRACK ACT12, and PB was performed on the conditions of Table 2, and the resist film with a film thickness of 150 nm was formed. This resist film was exposed through a mask pattern by an ArF excimer laser exposure apparatus (“TWIN SCAN XT1250i”, manufactured by ASML, certification condition: NA 0.85 sigma 0.93 / 0.69). Thereafter, PEB was performed under the conditions shown in Table 3, 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.
(3) Cross-sectional shape of pattern:
The cross-sectional shape of the 90 nm line and space pattern was observed with “S-4800” manufactured by Hitachi High-Technologies Corporation. As shown in FIG. 1, the line width Lb in the middle of the resist pattern and the upper part of the film The line width La was measured, and the range of 0.9 ≦ (La−Lb) /Lb≦1.1 was evaluated as “◯”, and the others were evaluated as “×”.
(4) Depth of focus:
When the depth of focus is changed in increments of 0.1 μm in the range from −1.0 μm to +1.0 μm, exposure is performed with an optimum exposure amount, and a resist pattern is formed, the lines of the line-and-space pattern to be formed The range of the depth of focus where the line width is 81 nm or more and 99 nm or less was measured using a scanning electron microscope (“S-9380”, manufactured by Hitachi High-Technologies Corporation).

As is apparent from Tables 2 and 3, when the radiation-sensitive resin composition for immersion exposure of the present invention is used, the pattern shape obtained is good, the focal depth is excellent, and the contact during immersion exposure is achieved. The amount of eluate in the water was found to be small.
Further, in the present invention, Examples 1 and 7 containing the repeating unit (1) having a methacrylic ester structure and the same repeating unit except that the methacrylic ester structure is an acrylate structure. From the results of Comparative Examples 3 and 4, due to the presence of the repeating unit (1) having a methacrylic ester structure, the pattern shape obtained is good, the depth of focus is excellent, and elution into water that is in contact during immersion exposure It was found that a radiation-sensitive resin composition for immersion exposure with a small amount of product was obtained.

It is a schematic diagram explaining the cross-sectional shape of a resist pattern. It is a schematic diagram explaining the method of producing the sample for a measurement of the elution amount.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Underlayer antireflection film, 2; Resist pattern, 3; Silicon wafer, 31; HMDS, 4; Silicon rubber sheet, 5; Ultrapure water, 6; Silicon wafer, 61;

Claims (3)

A radiation-sensitive resin composition for immersion exposure used for immersion exposure for exposing a resist film through water,
It contains a repeating unit represented by the following formula (1) as an essential unit, and contains an alkali-insoluble or alkali-insoluble resin that becomes alkali-soluble by the action of an acid, and a radiation-sensitive acid generator. A radiation-sensitive resin composition for immersion exposure.

The radiation sensitive resin composition for immersion exposure according to claim 1, wherein the resin further contains a repeating unit represented by the following general formula (2).

[In General formula (2), R shows a hydrogen atom or a methyl group. Each R ¹ 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, and R 1 ¹ satisfies the following condition (1) or (2).
(1) At least one of R ¹ is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof.
(2) Any two R ^{1 's} are bonded to each other to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof together with the carbon atoms to which each R ¹ is bonded, and the remaining R 1 ¹ is 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. ]   The content of a low molecular weight component derived from a monomer used when preparing the resin is 0.1% by mass or less with respect to 100% by mass of the resin in terms of solid content. A radiation-sensitive resin composition for immersion exposure.

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