JP2005206548A - New unsaturated compound and its polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sparingly alkali-soluble resin-containing new polymer having a lactone ring substituted with an ether group, in which a carbon atom constituting the lactone ring forms a polymer main chain and a new unsaturated compound useful as a synthetic raw material, etc., for polymers. <P>SOLUTION: The unsaturated compound is represented by general formula (1) [wherein R<SP>1</SP>is a substituted or unsubstituted 1-14C monovalent non-aromatic hydrocarbon group and R<SP>2</SP>is a hydrogen atom or a 1-14C alkyl group and n is an integer of 1-3] and its polymer has a recurring unit represented by general formula (I) [wherein R<SP>1</SP>, R<SP>2</SP>and n are each as defined above]. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel unsaturated compound having a specific lactone ring and a polymer of the unsaturated compound.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, an excimer laser represented by an ArF excimer laser (wavelength 193 nm) or an F ₂ excimer laser (wavelength 157 nm) is recently used. Therefore, there is a need for a lithography technique capable of microfabrication with radiation having a wavelength of about 200 nm or less. As a radiation-sensitive resin composition applicable to such a lithography technique, a component having an acid-dissociable functional group and radiation Many chemical amplification type radiation sensitive resin compositions using a chemical amplification effect by an acid generator that generates an acid upon irradiation have been proposed.
The chemically amplified radiation sensitive resin composition is protected with a 2-alkyl-2-adamantyl group or a 1-adamantyl-1-alkylethyl group, and is itself insoluble or hardly soluble in an alkaline aqueous solution. A chemically amplified positive resist composition containing a resin that is soluble in an alkaline aqueous solution by the action of an acid and a specific sulfonium salt acid generator (see, for example, Patent Document 1), having a specific lactone ring (meta ) A (meth) acrylic acid ester having a specific lactone ring having a polarity between the two components as a third component in an acid dissociable (meth) acrylic acid ester having a specific alicyclic skeleton and an acrylic acid ester A polymer compound for photoresist (for example, see Patent Document 2), and three types of repeating units having a specific structure having an alicyclic skeleton are specified. Resin containing in a total (e.g., see Patent Document 3.) And the like are known.

JP 2002-156750 A JP 2002-145955 A JP 2002-201232 A

However, in the field of integrated circuit elements, miniaturization is progressing rapidly, and accordingly, a higher degree of integration has been demanded, which is superior to a chemically amplified radiation-sensitive resin composition. A higher resolution is required.
In addition, with the progress of miniaturization, there are many cases where minute defects generated in a resist pattern during development, for example, roughness of a pattern side wall (that is, line edge roughness) has a significant influence on an integrated circuit element.
In order to cope with such a situation, technological development for improving the process margin as a chemically amplified resist such as resolution and exposure dose dependency is underway, but the resin whose line edge roughness is a component is being developed. It is thought to be caused by this, and there is an urgent need to increase the solubility of the resin component used in the resist solvent.
By the way, in the case of (meth) acrylate resins generally used today, rigid side chains hang from a rigid main chain, and (meth) acrylic esters having a lactone ring and other fats. Due to the difference in polymerization rate with the (meth) acrylic acid ester having a cyclic skeleton, the polymer composition becomes non-uniform, and many polymer components having low solubility in the resist solvent are generated. It is considered that problems such as mixing, deterioration of line edge roughness at the time of development, and further deterioration of resolution occur.

On the other hand, it has a repeating unit derived from 2-methylene-3-propanol, 2-methylene-5-pentanolide, 2-methylene-6-hexanolide, 2-methylene-7-heptanolide, 2-methylene-γ-butyrolactone, etc. A chemically amplified radiation-sensitive resin composition containing a polymer having good solubility in a resist solvent and wettability in an alkali developer has been proposed (see, for example, Patent Documents 4 to 6). These compositions are said to be excellent in sensitivity, resolution and dry etching resistance.
However, even if the polymer is included, there are still few synthesis examples of a polymer suitable for a radiation-sensitive resin composition used as a chemically amplified resist in which carbon atoms constituting the lactone ring form the polymer main chain. In the future, the development of new polymers that can provide new radiation-sensitive resin compositions that have excellent solubility in resist solvents, do not deteriorate line edge roughness during development, and have good sensitivity, resolution, etc. It has become an important technical issue from the viewpoint of responding to the progress of miniaturization.

JP 2001-81139 A JP 2002-82441 A JP 2003-131382 A

  The present invention has been made in order to cope with the above-mentioned problems, and the problem thereof is that it has a lactone ring substituted with an ether group, and carbon atoms constituting the lactone ring form a polymer main chain. Another object of the present invention is to provide a novel polymer containing a poorly alkali-soluble resin that is soluble in an alkaline aqueous solution by the action of an acid, and a novel unsaturated compound useful as a raw material for synthesizing the polymer.

The present invention, first,
It consists of a compound represented by the following general formula (1) (hereinafter referred to as “unsaturated compound (1)”).

〔一般式（１）においてＲ¹ は置換もしくは無置換の炭素数１〜１４の１価の非芳香族炭化水素基を示し、Ｒ² は水素原子または炭素数１〜１４の直鎖状、分岐状もしくは環状のアルキル基を示し、ｎは１〜３の整数である。〕

[In the general formula (1), R ¹ represents a substituted or unsubstituted monovalent non-aromatic hydrocarbon group having 1 to 14 carbon atoms, and R ² represents a hydrogen atom or a linear or branched chain having 1 to 14 carbon atoms. A cyclic or cyclic alkyl group, and n is an integer of 1 to 3; ]

The present invention secondly,
A polymer having a repeating unit represented by the following general formula (I) and having a polystyrene-reduced weight average molecular weight of 1,000 to 300,000 by gel permeation chromatography (GPC) (hereinafter referred to as “polymer (α)”) ).

〔一般式（Ｉ）においてＲ¹ は置換もしくは無置換の炭素数１〜１４の１価の非芳香族炭化水素基を示し、Ｒ² は水素原子または炭素数１〜１４の直鎖状、分岐状もしくは環状のアルキル基を示し、ｎは１〜３の整数である。〕

[In general formula (I), R ¹ represents a substituted or unsubstituted monovalent non-aromatic hydrocarbon group having 1 to 14 carbon atoms, and R ² represents a hydrogen atom or a linear or branched group having 1 to 14 carbon atoms. A cyclic or cyclic alkyl group, and n is an integer of 1 to 3; ]

Third, the present invention
It has a repeating unit represented by the general formula (I) and has a polystyrene-equivalent weight average molecular weight of 1,000 to 300,000 by gel permeation chromatography (GPC), and is soluble in an alkaline aqueous solution by the action of an acid. Consisting of an alkali hardly soluble resin (hereinafter referred to as “resin (A)”).
“Alkali poorly soluble” as used herein refers to the alkali development conditions used when forming a resist pattern from a resist film formed using 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.

Hereinafter, the present invention will be described in detail.
Unsaturated compound (1)
In the general formula (1), as the unsubstituted monovalent non-aromatic hydrocarbon group having 1 to 14 carbon atoms of R ¹ , for example,
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, t-pentyl group, n- Directly such as hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, t-dodecyl group, n-tridecyl group, n-tetradecyl group, etc. A chain or branched alkyl group;
A cyclic alkyl group of cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group;

Groups consisting of alicyclic rings derived from bridged alicyclic hydrocarbons such as bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, tricyclodecane, tetracyclododecane, adamantane;
An ethyl group in which two hydrogen atoms at the 1-position are substituted with a methyl group and a group consisting of the cycloalkyl group or alicyclic ring;
An ethyl group in which two hydrogen atoms at the 1-position are substituted with a group consisting of the cycloalkyl group or alicyclic ring;
Examples thereof include a group in which the cycloalkyl group or the group comprising an alicyclic ring is bonded to an oxygen atom via a C2-C8 alkylene group such as a methylene group, an ethylene group, or a propylene group.

Examples of the substituent for the monovalent non-aromatic hydrocarbon group include a linear or branched alkyl group having 1 to 14 carbon atoms (for example, 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, etc.), linear or branched alkoxyl group having 1 to 8 carbon atoms (for example, methoxy group, ethoxy group) Group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, etc.), linear or branched alkoxy having 2 to 8 carbon atoms Alkyl groups (for example, methoxymethyl group, ethoxymethyl group, t-butoxymethyl group, etc.), linear or branched alkoxyalkoxyl groups having 2 to 8 carbon atoms (for example, methoxymethone) Si group, ethoxymethoxy group, t-butoxymethoxy group, etc.), linear or branched alkylcarbonyloxy group having 2 to 8 carbon atoms (for example, methylcarbonyloxy group, ethylcarbonyloxy group, t-butylcarbonyloxy group) Group), linear or branched alkoxycarbonyl group having 2 to 8 carbon atoms (for example, methoxycarbonyl group, ethoxycarbonyl group, t-butoxycarbonyl group, etc.), linear or branched group having 2 to 14 carbon atoms. -Like cyanoalkyl group (for example, cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, 4-cyanobutyl group, etc.), C1-C14 linear or branched fluoroalkyl group (for example, fluoromethyl group) Group, trifluoromethyl group, pentafluoroethyl group, etc.).
Two or more of these substituents may be present in the substituted derivative, or a plurality of substituents may be bonded to each other to form a ring structure.

In the general formula (1), R ¹ is a non-acid dissociable group such as a methyl group, an ethyl group, an n-propyl group, or an n-butyl group; a t-butyl group, a t-pentyl group, or a 1-methylcyclopentyl group. 1-ethylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-methylcycloheptyl group, 1-ethylcycloheptyl group, 2-methylnorbornan-2-yl group, 2-ethylnorbornane-2- Yl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, 1- (bicyclo [2.2.1] heptan-2-yl) -1-methylethyl group, 1- ( Adamantane-1-yl) -1-methylethyl group, methoxymethyl group, ethoxymethyl group, 1-methoxyethyl group, 1-ethoxyethyl group, tetrahydrofuranyl Preferably acid-labile group such as tetrahydropyranyl group, especially, a methyl group, an ethyl group, a methoxymethyl group is preferable.
When R ¹ is an acid dissociable group, the acid dissociable group is eliminated by irradiation with radiation or heating after irradiation to generate a hydroxyl group, so that the dissolution contrast in an alkali developer can be increased.

In the general formula (1), examples of the linear, branched or cyclic alkyl group having 1 to 14 carbon atoms represented by R ² include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n- Butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, Examples include n-undecyl group, n-dodecyl group, t-dodecyl group, n-tridecyl group, n-tetradecyl group, cyclopentyl group, cyclohexyl group and the like.

In the general formula (1), R ² is preferably a hydrogen atom, a methyl group or the like, and particularly preferably a hydrogen atom.
Moreover, as n, 1 is particularly preferable.

  Preferred examples of the unsaturated compound (1) include compounds represented by the following general formula (1-a) or general formula (1-b), and particularly preferred are those represented by the general formula (1-a). (Hereinafter referred to as “unsaturated compound (1-a)”).

〔ここで、Ｒ¹ は一般式（１）におけるＲ¹ と同義であり、Ｒ² は炭素数１〜１４の直鎖状、分岐状もしくは環状のアルキル基を示す。〕

[Wherein R ¹ has the same meaning as R ¹ in formula (1), and R ² represents a linear, branched or cyclic alkyl group having 1 to 14 carbon atoms. ]

As preferred unsaturated compounds (1-a), R ¹ is methyl, ethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornane, bicyclo [2.2.2] octane, tri A compound which is a group consisting of an alicyclic ring derived from alicyclic hydrocarbons such as cyclodecane, tetracyclododecane and adamantane; R ¹ is a t-butyl group, a t-pentyl group, a 1-methylcyclopentyl group, 1 -Ethylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-methylcycloheptyl group, 1-ethylcycloheptyl group, 2-methylbicyclo [2.2.1] heptan-2-yl group, 2 -Ethylbicyclo [2.2.1] heptan-2-yl group, 2-methyladamantan-2-yl group, 2-ethyladama Ntan-2-yl group, 1- (bicyclo [2.2.1] heptan-2-yl) -1-methylethyl group, 1- (adamantan-1-yl) -1-methylethyl group, methoxymethyl group , ethoxymethyl group, 1-methoxyethyl group, 1-ethoxyethyl group, tetrahydrofuranyl group, and a compound such as an acid dissociable group such as a tetrahydropyranyl group, especially R ¹ is a methyl group, an ethyl group Or the compound which is a methoxymethyl group is preferable from a polar and polymeric viewpoint.

  Specific examples of the preferable unsaturated compound (1) include compounds represented by the following formulas (1-1) to (1-23).

The unsaturated compound (1) can be synthesized, for example, as follows.
That is, according to the method described in Non-Patent Document 1, the corresponding 4-hydroxymethyl-γ-butyrolactone is reacted with sodium hydride to convert it to an alkoxide, which is reacted with an alkylating agent such as an alkyl halide. To synthesize methoxymethyl-γ-butyrolactone corresponding to the compound of formula (1-1), and synthesize other corresponding alkoxymethylated lactone according to this, and then obtain the resulting alkoxymethyllactone. In the presence of sodium hydride, after formylation with formic acid ester, it is dehydrated by reduction with Raney nickel or the like (for example, see Non-Patent Document 2), or in the presence of sodium ethylate with diethyl oxalate A method of reacting formaldehyde after the reaction (for example, see Non-patent Document 3); α-bromo By the action of zinc chill acrylate and α- alkoxy acetaldehyde, a method of synthesizing via a Reformatsky toss Qiao (Reformarsky) reaction (e.g., Non-Patent Document 4 reference.) Can be synthesized by such.

J. et al. Org. Chem. , 50, p. 2764 (1985) J. et al. Chem. Soc. , Chem. Commun. , P. 531 (1985) J. et al. Org. Chem. , 42, p. 1180 (1977) J. et al. Med. Chem. , 23, p. 1031 (1980)

The unsaturated compound (1) can be used particularly suitably as a raw material for synthesizing the following polymer (α), and is also useful as a raw material or an intermediate for synthesizing other related compounds.
Since the unsaturated compound (1) is excellent in copolymerizability with other polymerizable unsaturated compounds, even when copolymerized, the resulting polymer (α) does not become non-uniform in composition, A repeating unit having a lactone ring that exhibits preferable characteristics can be introduced into the polymer (α).

Polymer (α)
The polymer (α) has a repeating unit represented by the general formula (I) (hereinafter referred to as “repeating unit (I)”), and has a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC). Consists of 1,000 to 300,000 polymers.
The repeating unit (I) in the polymer (α) is a unit in which the polymerizable carbon / carbon double bond of the unsaturated compound (1) is cleaved.
In the polymer (α), the repeating unit (I) may be present alone or in combination of two or more.
The unsaturated compound (1) giving the repeating unit (I) is excellent in copolymerizability with other polymerizable unsaturated compounds, so that the composition of the resulting polymer (α) is poor even when copolymerized. It is possible to introduce the repeating unit (I) having a lactone ring without causing homogenization, and since the repeating unit (I) has good affinity with a general resist solvent, the polymer ( When α) is used as a resin (A) in a radiation-sensitive resin composition used as a chemically amplified resist, the contamination of the resist film as described in the background art, the line edge roughness during development, Problems such as deterioration and resolution reduction can be solved.

The polymer (α) can have a repeating unit other than the repeating unit (I) (hereinafter referred to as “other repeating unit”).
Preferable other repeating units include, for example, repeating units represented by the following general formula (II) (hereinafter referred to as “repeating units (II)”).

〔一般式（II）において、Ｒ³ は置換もしくは無置換の炭素数３〜１４の１価の酸解離性基を示し、Ｒ⁴ は水素原子またはメチル基を示す。〕

[In the general formula (II), R ³ represents a substituted or unsubstituted monovalent acid-dissociable group having 3 to 14 carbon atoms, and R ⁴ represents a hydrogen atom or a methyl group. ]

In the general formula (II), the unsubstituted C 3-14 monovalent acid-dissociable group for R ³ is preferably a tertiary alkyl group such as a t-butyl group or a t-pentyl group; A group in which the 1-position of a cyclic alkyl group such as a cyclopentyl group or a cyclohexyl group is substituted with a linear or branched alkyl group having 1 to 4 carbon atoms; bonded to the carbonyloxy group in the general formula (II) Bridged alicyclic ring such as norbornane, bicyclo [2.2.2] octane, tricyclodecane, tetracyclododecane, adamantane, etc., in which the carbon atom is substituted with a linear or branched alkyl group having 1 to 4 carbon atoms A group comprising an alicyclic ring derived from a hydrocarbon of the formula; an ethyl group in which two hydrogen atoms at the 1-position thereof are substituted with a methyl group and a group comprising the cycloalkyl group or alicyclic ring; Two hydrogen atoms Ethyl group substituted with a group consisting of the cycloalkyl group or an alicyclic ring;
Acetal groups such as methoxymethyl group, ethoxymethyl group, 1-methoxyethyl group, 1-ethoxyethyl group, tetrahydrofuranyl group, tetrahydropyranyl group and the like can be mentioned.

Examples of the substituent for the monovalent acid dissociable group include a hydroxyl group, a carboxyl group, an oxo group (═O), a cyano group, a halogen atom (for example, a fluorine atom, a chlorine atom, etc.), a carbon number of 1 To 14 linear or branched alkyl groups (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.), linear or branched alkoxyl groups having 1 to 8 carbon atoms (for example, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, etc.), linear or branched alkoxyalkyl groups having 2 to 8 carbon atoms (for example, methoxymethyl group, ethoxymethyl group, t-buto group) Dimethyl group), a linear or branched alkoxyalkoxyl group having 2 to 8 carbon atoms (for example, methoxymethoxy group, ethoxymethoxy group, t-butoxymethoxy group, etc.), straight chain having 2 to 8 carbon atoms or Branched alkylcarbonyloxy group (for example, methylcarbonyloxy group, ethylcarbonyloxy group, t-butylcarbonyloxy group, etc.), linear or branched alkoxycarbonyl group having 2 to 8 carbon atoms (for example, methoxycarbonyl) Group, ethoxycarbonyl group, t-butoxycarbonyl group, etc.), C2-C14 linear or branched cyanoalkyl group (for example, cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, 4-cyanobutyl group) Group), a linear or branched fluoroalkyl group having 1 to 14 carbon atoms (for example, Fluoromethyl group, trifluoromethyl group, pentafluoroethyl group and the like) and the like.
Two or more of these substituents may be present in the substituted derivative.

As preferable monovalent acid dissociable groups for R ³ , for example, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 2-methylbicyclo [2.2.1]. ] Heptan-2-yl group, 2-ethylbicyclo [2.2.1] heptan-2-yl group, 8-methyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 8-ethyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 4-methyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 4-ethyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 2-methyladamantan-2-yl group, 2-methyl-3-hydroxyadamantan-2-yl group, 2-ethyladamantan-2-yl group, 2-ethyl- 3-hydroxyadamantan-2-yl group, 2-n-propyladamantan-2-yl group, 2-n-propyl-3-hydroxyadamantan-2-yl group, 2-i-propyladamantan-2-yl group, 2-i-propyl-3-hydroxyadamantan-2-yl group, 1- (bicyclo [2.2.1] heptan-2-yl) -1-methylethyl group, 1- (tricyclo [5.2.1] .0 ^2,6 ] decan-8-yl) -1-methylethyl group, 1- (tetracyclo [6.2.1.1 ^3,6 .0 ^2,7 ] decan-4-yl) -1-methyl Ethyl group, 1- (adamantan-1-y ) -1-methylethyl group, 1- (3-hydroxyadamantan-1-yl) -1-methylethyl group, 1,1-dicyclohexylethyl group, 1,1-di (bicyclo [2.2.1] heptane -2-yl) ethyl group, 1,1-di (tricyclo [5.2.1.0 ^2,6 ] decan-8-yl) ethyl group, 1,1-di (tetracyclo [6.2.1. 1 ^3,6 .0 ^2,7 ] dodecan-4-yl) ethyl group, 1,1-di (adamantan-1-yl) ethyl group, and the like.

Among these preferable monovalent acid dissociable groups, in particular, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 2-methyladamantan-2-yl group, 2 -Ethyladamantan-2-yl group, 2-n-propyl adamantan-2-yl group, 2-i-propyladamantan-2-yl group, 1- (adamantan-1-yl) -1-methylethyl group and the like Is preferred.
In the polymer (a), the repeating unit (II) may be present alone or in combination of two or more.

Moreover, as other preferable repeating units other than the repeating unit (II), for example, compounds of the following formulas (2-a) to (2-c), (meth) acrylic acid 4-oxoadamantan-1-yl, 2- (Meth) acryloyloxy-5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonane, 2- (meth) acryloyloxy-9-methoxycarbonyl-5-oxo-4- Oxatricyclo [4.2.1.0 ^3,7 ] nonane, 4- (meth) acryloyloxy-7-oxo-6-oxabicyclo [3.2.1] octane, 4- (meth) acryloyloxy- 2-methoxycarbonyl-7-oxo-6-oxabicyclo [3.2.1] octane, 8- (meth) acryloyloxy-3-oxo-4-oxatricyclo [5.2.1.0 ^2,6 ] Deccan, 9 (Meth) acryloyloxy-3-oxo-4-oxa-tricyclo [5.2.1.0 ^{2, 6]} decane, 2- (meth) acryloyloxy-5- (1,1,1-fluoro-2 -Trifluoromethyl-2-hydroxypropyl) bicyclo [2.2.1] heptan-2-yl, a unit in which a polymerizable carbon / carbon double bond is cleaved.

（ここで、各Ｒ⁵ は相互に独立に水素原子またはメチル基を示す。）

(Here, each R ⁵ independently represents a hydrogen atom or a methyl group.)

  Furthermore, as another repeating unit other than the above, for example, (meth) acrylic acid; (meth) acrylic acid ester having no bridged hydrocarbon skeleton such as methyl (meth) acrylate and ethyl (meth) acrylate (Meth) acrylic acid esters having a bridged hydrocarbon skeleton such as norbornyl (meth) acrylate, isonorbornyl (meth) acrylate, tricyclodecanyl (meth) acrylate; Saturated nitrile compounds; unsaturated amide compounds such as (meth) acrylamide and N, N-dimethyl (meth) acrylamide; other nitrogen-containing compounds such as N- (meth) acryloylmorpholine, N-vinylpyrrolidone, vinylpyridine and vinylimidazole Saturated compounds: α- (meth) acryloyloxy-γ-butyrolactone, β- (meth) Acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-β, β-dimethyl-γ-butyrolactone, δ- (meth) acryloyloxy-β, β-dimethyl-γ-valerolactone, β- (meth) (Meth) acryloyloxy group-containing lactone compounds such as acryloyloxy-β-methyl-δ-valerolactone; polymerizable carbon / carbon double bonds such as compounds of the following formulas (3-a) to (3-d) are cleaved Units.

（ここで、各Ｒ⁶ は相互に独立に水素原子またはメチル基を示す。）
繰り返し単位（II）以外の前記他の繰り返し単位は、単独でまたは２種以上が存在することができる。

(Here, each R ⁶ independently represents a hydrogen atom or a methyl group.)
The other repeating units other than the repeating unit (II) may be used alone or in combination of two or more.

Although the content rate of each repeating unit in a polymer ((alpha)) can be suitably selected according to the intended use, in the radiation sensitive resin composition used as a chemically amplified resist as resin (A). When used for the resin component, it is preferable that the repeating unit (I) and the repeating unit (II) are the main components.
In the resin (A), the total content of the repeating unit (I) and the repeating unit (II) is preferably 20 to 100 mol%, more preferably 35 to 100 mol%.
The content of the repeating unit (I) is usually 5 to 70 mol%, preferably 5 to 60 mol%, and the content of the repeating unit (II) is usually 20 to 60 mol%, preferably 30 to 45 mol%. In this case, when the content of the repeating unit (I) is less than 5 mol%, the line edge roughness as a resist tends to decrease. On the other hand, when the content exceeds 70 mol%, the resolution as a resist and the dissolution in a resist solvent are present. Tend to decrease. Further, when the content of the repeating unit (II) is less than 20 mol%, the resolution as a resist tends to be lowered, whereas when it exceeds 60 mol%, the developability as a resist tends to be lowered.

  Moreover, when resin (A) has other repeating units other than repeating unit (I), repeating unit (II), and repeating unit (II), the content rate of each repeating unit is about 5 repeating unit (I). It is preferable that the repeating unit (II) is about 5 to about 60 mol%, and other repeating units other than the repeating unit (II) are the remainder.

The weight average molecular weight (hereinafter referred to as “Mw”) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer (α) is 1,000 to 300,000, preferably 2,000 to 200,000, and more preferably. Is 3,000-100,000. In this case, when the Mw of the polymer (α) is less than 1,000, the heat resistance as a resist tends to decrease, and when it exceeds 300,000, the developability as a resist tends to decrease.
Further, the ratio (Mw / Mn) of Mw of the polymer (α) to the polystyrene-equivalent number average molecular weight (hereinafter referred to as “Mn”) by gel permeation chromatography (GPC) is usually 1 to 5, preferably 1-3.

The polymer (α) is, for example, a monomer corresponding to each repeating unit using a radical polymerization initiator such as hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, and the like. In the presence of a chain transfer agent in a suitable solvent.
Examples of the solvent used for the polymerization include cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane; ethyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate, propylene glycol monomethyl ether. Saturated carboxylic acid esters such as acetate; lactones such as γ-butyrolactone; linear or branched ketones such as 2-butanone, 2-heptanone and methyl isobutyl ketone; cyclic ketones such as cyclohexanone; Examples include alcohols such as propanol and propylene glycol monomethyl ether.
These solvents can be used alone or in admixture of two or more.
Moreover, as for the reaction conditions in the said superposition | polymerization, reaction temperature is 40-120 degreeC normally, Preferably it is 50-100 degreeC, and reaction time is 1 to 48 hours normally, Preferably it is 1 to 24 hours.

The polymer (α) is naturally low in impurities such as halogen and metal, but the residual monomer or oligomer component is below a specified value, for example, a value measured by HPLC (high performance liquid chromatography) is 0.1 weight. % Or less is preferable, so that not only can the sensitivity, resolution, process stability, pattern shape, etc. as a resist be further improved, but also used as a chemically amplified resist that does not change with time, such as foreign matter in liquid or sensitivity. A radiation-sensitive resin composition that can be obtained can be obtained.
Examples of the method for purifying the polymer (α) include the following methods.
As a method for removing impurities such as metals, a method in which a metal in a resin solution is adsorbed using a zeta potential filter; a metal solution is chelated by washing the resin solution with an acidic aqueous solution such as oxalic acid or sulfonic acid. The method of removing etc. can be mentioned.
In addition, as a method of lowering the residual monomer and oligomer components below the specified value, as a purification method in a solution state, a water washing method, a liquid extraction method by an appropriate solvent combination, an ultrafiltration method, etc .; in a solid state Examples of the purification method include a reprecipitation method in which a polymer solution is dropped into a poor solvent to solidify the polymer, a method of washing the polymer as a slurry in the poor solvent, and a combination of these methods. .

The polymer (α) uses various kinds of radiation such as deep ultraviolet rays such as KrF excimer laser and ArF excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams, particularly as the resin (A). It can be used very suitably as a resin component of a radiation sensitive resin composition useful as a chemically amplified resist used for fine processing.
Below, this radiation sensitive resin composition is demonstrated.

Radiation-sensitive resin composition The radiation-sensitive resin composition contains a resin (A) and a radiation-sensitive acid generator that generates acid upon irradiation with radiation (hereinafter referred to as “acid generator (B)”). .
In the radiation-sensitive resin composition, the resin (A) can be used alone or in admixture of two or more. If desired, the resin (A) can be used together with the resin (A) to become alkali-soluble by the action of an acid. One or more alkali-soluble resins may be used in combination.
Examples of the other hardly alkali-soluble resins include resins having one or more repeating units (II) and optionally further including one or more other repeating units other than the repeating unit (II). Can do.

Examples of the acid generator (B) include onium salt compounds such as sulfonium salts and iodonium salts, imide sulfonate compounds, organic halogen compounds, and sulfone compounds such as disulfones and diazomethane sulfones.
As a preferable acid generator (B), for example,
Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2- (bicyclo [2.2.1] heptan-2-yl)- 1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] dodecan-3-yl) -1,1-difluoroethanesulfonate Triphenylsulfonium salt compounds such as triphenylsulfonium N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, triphenylsulfonium 10-camphorsulfonate;

4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2- (bicyclo [2 2.1] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2- (tetracyclo [4.4.0.1 ^2,5 .1 ^{7, 10]} dodecane-3-yl) -1,1-difluoroethanesulfonate, 4-cyclohexyl-phenyl diphenyl sulfonium N, N'-bis (nonafluoro -n- butanesulfonyl) imidate 4-cyclohexyl-phenyl diphenyl sulfonium salt compounds such as 4-cyclohexyl-phenyl diphenyl sulfonium 10-camphorsulfonate;

4-t-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-t-butylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-t-butylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-t-butylphenyl Diphenylsulfonium 2- (bicyclo [2.2.1] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-t-butylphenyldiphenylsulfonium 2- (tetracyclo [4.4. 0.1 ^{2,5 .1,7,10} ] dodecan-3-yl) -1,1-difluoroethanesulfonate, 4-t-butylphenyldiphenylsulfonium N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, 4-t-butylphenyl 4-t-butylphenyl diphenyl sulfonium salt compounds such as triphenylsulfonium 10-camphorsulfonate;

Tris (4-t-butylphenyl) sulfonium trifluoromethanesulfonate, tris (4-t-butylphenyl) sulfonium nonafluoro-n-butanesulfonate, tris (4-t-butylphenyl) sulfonium perfluoro-n-octanesulfonate, Tris (4-t-butylphenyl) sulfonium 2- (bicyclo [2.2.1] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, tris (4-t-butylphenyl) sulfonium 2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecane-3-yl) -1,1-difluoroethanesulfonate, tris (4-t- butylphenyl) sulfonium N, N ' -Bis (nonafluoro-n-butanesulfonyl) imidate, tris (4-t-butyl) Eniru) tris (4-t-butylphenyl, such as sulfonium 10-camphorsulfonate) sulfonium salt compounds;

Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2- (bicyclo [2.2.1] heptan-2-yl) -1,1, 2,2-tetrafluoroethane sulfonate, diphenyliodonium 2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecane-3-yl) -1,1-difluoroethanesulfonate, diphenyliodonium N, Diphenyliodonium salt compounds such as N′-bis (nonafluoro-n-butanesulfonyl) imidate, diphenyliodonium 10-camphorsulfonate;

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] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium 2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecane-3-yl) -1,1-difluoroethanesulfonate, bis (4-t- butylphenyl) iodonium N, N ' -Bis (nonafluoro-n-butanesulfonyl) imidate, bis (4-t-butylphenyl) io Iodonium 10-camphorsulfonate, etc. bis (4-t- butylphenyl) iodonium salt compounds;

1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (bicyclo [2.2 .1] Heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (tetracyclo [4.4. 0.1 ^2,5 .1 ^7,10] dodecane-3-yl) -1,1-difluoroethanesulfonate 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothio 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium salt compounds such as phenium 10-camphorsulfonate;

1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (3,5-Dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (bicyclo [2.2 .1] Heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (tetracyclo [4.4. 0.1 ^2,5 .1 ^7,10] dodecane-3-yl) -1,1-Jifuruo Ethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, 1- (3,5-dimethyl-4-hydroxyphenyl) ) 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium salt compounds such as tetrahydrothiophenium 10-camphorsulfonate;

N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- [2- (bicyclo [2.2.1] ] Heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonyloxy] succinimide, N- [2- (tetracyclo [4.4.0.1 ^2,5 .1, ^7,10 ] dodecane- Succinimide compounds such as 3-yl) -1,1-difluoroethanesulfonyloxy] succinimide, N- (10-camphorsulfonyloxy) succinimide;

N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept -5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- [ 2- (Bicyclo [2.2.1] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonyloxy] bicyclo [2.2.1] hept-5-ene-2,3- dicarboximide, N- [2- (tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecane-3-yl) -1,1-difluoroethane sulfonyloxy] bicyclo [2.2.1 ] Hep Bicyclo [2.2 such as -5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide. .1] hept-5-ene-2,3-dicarboximide compounds and the like.
These acid generators (B) can be used alone or in admixture of two or more.

  The amount of the acid generator (B) used is usually 0.1 to 30 parts by weight, preferably 0.1 to 100 parts by weight of the resin (A), from the viewpoint of ensuring the sensitivity and developability as a resist. ~ 20 parts by weight. In this case, if the amount of the acid generator (B) used is less than 0.1 parts by weight, the sensitivity and developability tend to decrease. On the other hand, if it exceeds 30 parts by weight, the transparency to radiation decreases and the rectangular shape is reduced. It tends to be difficult to obtain a resist pattern.

If necessary, the radiation-sensitive resin composition contains various additives such as an acid diffusion controller, an alicyclic additive that may have an acid-dissociable group, a surfactant, and a sensitizer. can do.
The acid diffusion controlling agent is a component having an action of controlling an undesired chemical reaction in a non-irradiated region by controlling a diffusion phenomenon of an acid generated from the acid generator (B) by irradiation of radiation in a resist film.
By blending such an acid diffusion control agent, the storage stability of the resulting radiation-sensitive resin composition is improved, the resolution as a resist is further improved, and the holding time from irradiation to development processing ( The change in the line width of the resist pattern due to the variation in PED) can be suppressed, and a composition having excellent process stability can be obtained.

The acid diffusion controller is preferably a nitrogen-containing organic compound whose basicity does not change by irradiation or heat treatment during the resist pattern formation process.
Examples of such nitrogen-containing organic compounds include tertiary amine compounds, amide group-containing compounds, quaternary ammonium hydroxide compounds, and nitrogen-containing heterocyclic compounds.
Examples of the tertiary amine compound include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n- Tri (cyclo) alkylamines such as octylamine, tri-n-nonylamine, tri-n-decylamine, cyclohexyldimethylamine, dicyclohexylmethylamine, tricyclohexylamine; N, N-dimethylaniline, N, N-dimethyl-4 -Methylaniline, N, N-dimethyl-4-nitroaniline, N, N-dimethyl-2,6-dimethylaniline, N, N-dimethyl-2,6-di-i-propylaniline, triphenylamine, etc. Aromatic amines; Alkaline such as triethanolamine, diethanolaniline N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, bis (2-N, N-dimethylaminoethyl) Examples include ether and bis (2-N, N-diethylaminoethyl) ether.

Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, and Nt. -Butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4'-diaminodiphenylmethane, N -T-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycal Bonyl-N-methyl-1-adamantylamine,
N, N′-di-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, N, N, N ′, N′-tetra In addition to Nt-butoxycarbonyl group-containing amino compounds such as t-butoxycarbonylhexamethylenediamine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide , Propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like.

Examples of the quaternary ammonium hydroxide compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, and tetra-n-butylammonium hydroxide.
Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, 4-methylimidazole, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, and 2-phenylbenzimidazole; Pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, In addition to pyridines such as quinoline, 4-hydroxyquinoline, 8-oxoquinoline and acridine; piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, - piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, and 1,4-diazabicyclo [2.2.2] octane.

Of these nitrogen-containing organic compounds, tertiary amine compounds, amide group-containing compounds, and nitrogen-containing heterocyclic compounds are preferred, and among the amide group-containing compounds, Nt-butoxycarbonyl group-containing amino compounds are more preferred, Among the nitrogen-containing heterocyclic compounds, imidazoles are more 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 weight or less, preferably 10 parts by weight or less, and more preferably 5 parts by weight or less with respect to 100 parts by weight of the resin (A). In this case, when the compounding amount of the acid diffusion controller exceeds 15 parts by weight, the sensitivity and developability as a resist tend to be lowered. If the amount of the acid diffusion controller is less than 0.001 part by weight, the pattern shape and dimensional fidelity may be lowered depending on the process conditions.

The alicyclic additive that may have an acid dissociable group is a component that has an effect of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like.
Examples of such alicyclic additives include 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid butyrolactone, 1,3-adamantane dicarboxylic acid di-t. -Butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantanediacetate di-t-butyl, 2,5-dimethyl-2,5-di (adamantylcarbonyloxy) Adamantane derivatives such as hexane; deoxycholic acid t-butyl, deoxycholic acid t-butoxycarbonylmethyl, deoxycholic acid 2-ethoxyethyl, deoxycholic acid 2-cyclohexyloxyethyl, deoxycholic acid 3-oxocyclohexyl, deoxycholic Acid tetrahi Deoxycholic acid esters such as lopyranyl and deoxycholic acid mevalonolactone; tert-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid, Lithocholic acid esters such as tetrahydropyranyl lithocholic acid and mevalonolactone lithocholic acid; alkyl such as dimethyl adipate, diethyl adipate, di-n-propyl adipate, di-n-butyl adipate, di-t-butyl adipate Examples thereof include carboxylic acid esters.
These alicyclic additives can be used alone or in admixture of two or more.

  The compounding quantity of an alicyclic additive is 50 parts weight or less normally with respect to 100 weight part of resin (A), Preferably it is 30 parts weight or less. In this case, when the compounding amount of the alicyclic additive exceeds 50 parts by weight, the heat resistance as a resist tends to decrease.

The surfactant is a component having an action of improving coating properties, striations, 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.), F-top EF301, EF303, EF352 (manufactured by Tochem Products), Megafax F171, F173 (manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( Asahi Glass Co., Ltd.).
These surfactants can be used alone or in admixture of two or more.
The compounding quantity of surfactant is 2 parts weight or less normally with respect to 100 weight part of resin (A).

The sensitizer absorbs radiation energy and transmits the energy to the acid generator (B), thereby increasing the amount of acid generated, and the apparent radiation-sensitive resin composition. It is a component which shows the effect | action which improves a sensitivity.
Examples of such a sensitizer include carbazoles, benzophenones, rose bengals, anthracenes, phenols and the like.
These sensitizers can be used alone or in admixture of two or more.
The blending amount of the sensitizer is usually 50 parts by weight or less with respect to 100 parts by weight of the resin (A). Furthermore, examples of additives other than those mentioned above include antihalation agents, adhesion assistants, storage stabilizers, antifoaming agents, and the like.

The radiation-sensitive resin composition is usually dissolved in a solvent so that the total solid content is usually 3 to 50% by weight, preferably 5 to 25% by weight. A composition solution is prepared by filtering with a filter of about 2 m.
Examples of the solvent used for the preparation of the composition solution include linear or branched ketones such as 2-pentanone, 2-hexanone, 2-heptanone, and 2-octanone; cyclopentanone, cyclohexanone, and the like. Cyclic ketones; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; 2-hydroxypropionate alkyls such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate; In addition to alkyl 3-alkoxypropionates such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate and ethyl 3-ethoxypropionate, ethylene glycol mono Chill ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, n-butyl acetate, methyl pyruvate, pyruvate Examples thereof include ethyl, N-methylpyrrolidone, and γ-butyrolactone.

  These solvents can be used alone or in admixture of two or more, but 2-heptanone, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl 2-hydroxypropionate, ethyl 3-ethoxypropionate, propylene glycol It is preferable to contain at least one selected from monomethyl ether and γ-butyrolactone. However, cyclohexanone is an effective solvent from the viewpoint of solubility, but it is preferable to avoid its use from the viewpoint of toxicity.

Formation of Resist Pattern Here, a method for forming a resist pattern using the radiation sensitive resin composition will be described.
In forming the resist pattern, the acid dissociable group in the resin (A) is dissociated by the action of the acid generated from the acid generator (B) by irradiation with radiation (hereinafter referred to as “exposure”). A hydroxyl group and / or a carboxyl group are generated. As a result, the solubility of the exposed portion of the resist in the alkaline developer is increased, and the exposed portion is dissolved and removed by the alkaline developer, whereby a positive resist pattern is obtained.
When forming a resist pattern from a radiation-sensitive resin composition, the composition solution is applied by appropriate coating means such as spin coating, cast coating, roll coating, etc., for example, a silicon wafer, a wafer coated with aluminum, etc. Then, a heat treatment (hereinafter referred to as “PB”) is optionally performed to form a resist film.

Next, the resist film is exposed to form a predetermined resist pattern.
Examples of radiation used at this time include ultraviolet rays, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), EUV (extreme ultraviolet light, wavelength 13 nm, etc.), etc. X-rays such as deep ultraviolet rays and synchrotron radiation, and charged particle beams such as electron beams can be appropriately selected and used. Of these, far ultraviolet rays and electron beams are preferred.
Moreover, exposure conditions, such as exposure amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition, the kind of each additive, etc.
In order to stably form a high-precision fine pattern, it is preferable to perform heat treatment (hereinafter referred to as “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 order to maximize the potential of the radiation-sensitive resin composition, an organic or inorganic antireflection film is formed on the substrate to be used, for example, as disclosed in Patent Document 7. In order to prevent the influence of basic impurities and the like contained in the environmental atmosphere, a protective film can be provided on the resist film as disclosed in Patent Document 8, for example. Can also be used together.

Japanese Examined Patent Publication No. 6-12458 JP-A-5-188598

Next, the exposed resist film is developed using an alkali developer to form a predetermined resist pattern.
As the alkaline developer, for example, an alkaline aqueous solution in which tetramethylammonium hydroxide is dissolved is preferable.
The concentration of the alkaline developer is usually 10% by weight or less. In this case, if the concentration of the alkali developer exceeds 10% by weight, the unexposed area may be dissolved in the alkali developer, which is not preferable.
An appropriate amount of a surfactant or the like can also be added to the alkaline developer. In addition, after developing with an alkali developing solution, it is generally washed with water and dried.

The unsaturated compound (1) of the present invention can be used particularly suitably as a raw material for synthesizing the polymer (α).
Especially the polymer ((alpha)) of this invention can be used very suitably as a resin component of the radiation sensitive resin composition used as a chemically amplified resist as resin (A).
Resin (A) of this invention can be used very suitably as a resin component of the said radiation sensitive resin composition.
The radiation-sensitive resin composition, when used in a chemically amplified resist, has high transparency to radiation, excellent basic physical properties as a resist such as sensitivity and resolution, and solubility in a resist solvent. It has an excellent effect that the line edge roughness after development can be remarkably reduced.

Hereinafter, the embodiments of the present invention will be described more specifically with reference to examples and comparative examples. Synthesis Example 1 (Synthesis of unsaturated compound (1))
A 100 ml three-necked flask equipped with a dropping funnel and a septum is charged with 3.03 g of sodium hydride (purity 60% by weight) and 40 ml of N, N-dimethylformamide. After cooling in a saturated saline-ice cooling bath at 0 ° C., a solution of 6.81 g of 5-hydroxymethyldihydrofuran-2-one dissolved in 10 ml of N, N-dimethylformamide was added dropwise over 15 minutes. Thereafter, the cooling bath was removed, and the contents were stirred until hydrogen gas bubbling ceased. The flask was cooled again with a saturated saline-ice bath, and 25 g of methyl iodide was added dropwise over 15 minutes. Thereafter, the cooling bath was removed and the reaction was allowed to proceed at room temperature for 1 hour, and then the reaction solution was put into 100 ml of a 10 wt% ammonium chloride aqueous solution. Thereafter, the reaction solution was extracted four times with 40 ml of chloroform, and then the extract was washed twice with 20 ml of 10 wt% hydrochloric acid and twice with 20 ml of saturated saline solution in this order. By distilling off the solvent using an evaporator, 4.1 g of 5-methoxymethyldihydrofuran-2-one was obtained.

  Next, into another 100 ml three-necked flask equipped with a dropping funnel and a septum, 1.16 g of sodium ethoxide and 10 ml of ethanol were added to dissolve the sodium ethoxide, and then the flask was saturated with brine-ice. After cooling with a cooling bath, 2.34 g of diethyl oxalate was added. Thereafter, a solution of 2.05 g of 5-methoxymethyldihydrofuran-2-one dissolved in 10 ml of ethanol was added dropwise over 30 minutes, stirred at 0 ° C. for 1 hour, and then allowed to react overnight at room temperature. It was. Thereafter, 6 g of 10 wt% hydrochloric acid was added to acidify the reaction solution, and 40 g of water was further added. Thereafter, ethanol was distilled off using a rotary evaporator. Thereafter, the reaction solution was extracted four times with 20 ml of methylene chloride, and then the extract was dried over magnesium sulfate, and the desiccant was filtered off. Then, 3.1 g of ethyl (5-methoxymethyl-2-oxotetrahydrofuran-3-yl) oxoacetate represented by the following formula (4) was obtained by distilling off the solvent using a rotary evaporator.

Next, after adding 0.44 g of sodium hydride (purity 60% by weight) and 20 ml of tetrahydrofuran to another 100 ml three-necked flask equipped with a dropping funnel and a partition wall, -Methoxymethyl-2-oxotetrahydrofuran-3-yl) A solution of 3.1 g of ethyl oxoacetate in 20 ml of tetrahydrofuran was slowly added dropwise. Thereafter, the reaction was continued with stirring for about 1 hour until no foaming of hydrogen gas disappeared. Thereafter, 1.95 g of paraformaldehyde was added, the temperature was raised to 65 ° C. over about 30 minutes, and the mixture was left for 5 hours. Thereafter, the reaction solution was returned to room temperature, and insolubles were filtered off using celite. Thereafter, the reaction solution was concentrated using a rotary evaporator and dissolved in 50 ml of dichloromethane, and then 50 ml of saturated aqueous sodium hydrogen carbonate solution was added and stirred for 30 minutes. Thereafter, the aqueous layer is removed, the organic layer is dried over sodium sulfate, filtered, and then the solvent is distilled off using a rotary evaporator, followed by drying, whereby 5-methoxymethyl of the above formula (1-1) is obtained. 1.3 g of -3-methylenetetrahydrofuran-2-one (hereinafter referred to as “unsaturated compound (1-1)”) was obtained as a colorless liquid.
This product was subjected to ¹ H-NMR analysis and found to have a chemical shift (δ) of 6.23 (1H), 5.65 (1H), 4.64 (1H), 3.53 (2H), 3 79 (3H) and 2.91 (2H).

Example 1 (Synthesis of polymer (α))
157.1 g of 2-methyladamantan-2-yl methacrylate and 142.9 g of unsaturated compound (1-1) were dissolved in 600 g of 2-butanone, and 7.0 g of dimethyl-2,2′-azoisobutyronitrile was further dissolved. A monomer solution charged with was prepared.
Separately, 300 g of 2-butanone was charged into a 1,000 ml three-necked flask equipped with a dropping funnel, purged with nitrogen for 30 minutes, and then the contents were heated to 80 ° C. with stirring. Thereafter, the monomer solution was added dropwise over 3 hours, and polymerization was started for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the reaction solution was cooled with water and cooled to 30 ° C. or lower, poured into 6000 g of n-hexane, and the precipitated white powder was separated by filtration. Thereafter, the white powder was mixed with 1200 g of n-hexane and washed in a slurry state twice, and then filtered and dried under vacuum at 50 ° C. for 17 hours to obtain 225 g of a white powder polymer (yield). 75% by weight). This polymer has Mw of 10,300, and as a result of ¹³ C-NMR analysis, the molar ratio of each repeating unit derived from 2-methyladamantan-2-yl methacrylate and the unsaturated compound (1-1) is 37. 4: 62.6 polymer. This polymer is referred to as “polymer (α-1)”.

  Mw of the polymer (α-1) and the following polymers (α-2) to (α-4) are GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation. Measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of a flow rate of 1.0 ml / min, an elution solvent tetrahydrofuran, and a column temperature of 40 ° C.

Example 2 (Synthesis of polymer (α))
As monomers, 157.10 g of 1-ethylcyclopentyl methacrylate, 39.80 g of a compound of the following formula (5) (hereinafter referred to as “unsaturated compound (5)”) and 128. 245 g (yield 82% by weight) of a white powder polymer was obtained in the same manner as in Example 1 except that 45 g was used. This polymer has Mw of 9,400, and as a result of ¹³ C-NMR analysis, the moles of each repeating unit derived from 1-ethylcyclopentyl methacrylate, unsaturated compound (5) and unsaturated compound (1-1). It was a polymer with a ratio of 35.4: 12.6: 52.0. This polymer is referred to as “polymer (α-2)”.

Example 3 (Synthesis of polymer (α))
As monomers, 130.4 g of 2-methyladamantan-2-yl methacrylate, 56.4 g of a compound of the following formula (2-1) (hereinafter referred to as “unsaturated compound (2-1)”) and unsaturated Except for using 113.15 g of compound (1-1), 219 g (yield 73 wt%) of a white powder polymer was obtained in the same manner as in Example 1. This polymer has Mw of 11,200 and is derived from 2-methyladamantan-2-yl methacrylate, unsaturated compound (2-1) and unsaturated compound (1-1) as a result of ¹³ C-NMR analysis. The molar ratio of each repeating unit was 33.6: 16.2: 50.2. This polymer is referred to as “polymer (α-3)”.

Example 4 (Synthesis of polymer (α))
As monomers, 97.62 g of 1-ethylcyclopentyl methacrylate, 33.71 g of unsaturated compound (5), a compound of the following formula (3-1) (hereinafter referred to as “unsaturated compound (3-1)”). Except for using 124.50 g and 32.63 g of unsaturated compound (1-1), 213 g (yield 71 wt%) of a white powder polymer was obtained in the same manner as in Example 1. This polymer has Mw of 9,200, and as a result of ¹³ C-NMR analysis, 1-ethylcyclopentyl methacrylate, unsaturated compound (4-1), unsaturated compound (3-1) and unsaturated compound (1 The molar ratio of each repeating unit derived from -1) was 32.1: 11.2: 40.2: 16.5. This polymer is referred to as “polymer (α-4)”.

Comparative Example 1
Example, except that 123.1 g of 2-methyladamantan-2-yl methacrylate, 31.0 g of unsaturated compound (2-1) and 145.9 g of unsaturated compound (3-1) were used as monomers. In the same manner as in Example 1, 204 g (yield 68% by weight) of a white powder polymer was obtained. This polymer has Mw of 8,900 and is derived from 2-methyladamantan-2-yl methacrylate, unsaturated compound (2-1) and unsaturated compound (3-1) as a result of ¹³ C-NMR analysis. The molar ratio of each repeating unit was 35.9: 12.0: 52.1. This polymer is referred to as “polymer (a-1)”.

Comparative Example 2
Except that 106.0 g of 1-ethylcyclopentyl methacrylate and 194.0 g of unsaturated compound (3-1) were used as monomers, 210 g of a white powder polymer (yield) was obtained in the same manner as in Example 1. 70% by weight). This polymer has an Mw of 8,700, and as a result of ¹³ C-NMR analysis, the molar ratio of each repeating unit derived from 1-ethylcyclopentyl methacrylate and the unsaturated compound (3-1) is 37.1: 62. .9 polymer. This polymer is referred to as “polymer (a-2)”.

For each of the polymers obtained in Evaluation Examples 1-4 and Comparative Examples 1-2, a propylene glycol monomethyl ether acetate (PGMEA) solution having a concentration of 5% by weight, 10% by weight or 15% by weight was prepared. Was visually observed to evaluate the solubility in propylene glycol monomethyl ether acetate. The evaluation criteria were “good” when the precipitate was not observed and transparent, and “bad” when the precipitate was observed. The evaluation results are shown in Table 1.

Application examples 1 to 4 and comparative application example 1
Each polymer obtained in Examples 1 to 4 and Comparative Example 1, the acid generator (B), the acid diffusion controller and the solvent shown below are the proportions shown in Table 2 (parts are based on weight). It mix | blended and the composition solution of each radiation sensitive resin composition was prepared, and it evaluated in the following way. The evaluation results are shown in Table 4.
Acid generator (B)
B-1: Triphenylsulfonium nonafluoro-n-butanesulfonate
Acid diffusion controller C-1: Triethanolamine
Solvent S-1: Propylene glycol monomethyl ether acetate S-2: Cyclohexanone

Evaluation Procedure (1) Radiation Transmittance A resist film having a film thickness of 0.34 m formed by applying each composition solution onto quartz glass by spin coating and performing PB on a hot plate under the conditions shown in Table 3. The radiation transmittance was calculated from the absorbance at a wavelength of 193 nm and used as a measure of transparency in the deep ultraviolet region.
(2) Sensitivity Each composition solution is spin-coated on a silicon wafer (indicated as “ARC29” in Table 3) on which a “ARC29” (trade name, manufactured by Brewer Science) film having a film thickness of 780 Å is formed on the surface. Then, PB is performed on the hot plate under the conditions shown in Table 3 to form a resist film having a film thickness of 0.34 m. A Nikon ArF excimer laser exposure apparatus (numerical aperture of 0.00) is formed on each resist film. 55), and the exposure amount was changed through the mask pattern. Thereafter, PEB is performed under the conditions shown in Table 3, and then developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 25 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. did. At this time, the exposure amount for forming a line-and-space pattern (1L1S) having a line width of 0.16 m in a one-to-one line width was defined as the optimum exposure amount, and this optimum exposure amount was defined as the sensitivity.

(3) Resolution:
The dimension of the smallest line and space pattern (1L1S) that can be resolved with the optimum exposure amount was taken as the resolution.
(4) Line edge roughness (LER):
A line-and-space pattern (1L1S) with a line width of 160 nm resolved with an optimum exposure dose is observed from above the pattern with a scanning electron microscope “Measurement SEM: S9220” (trade name) manufactured by Hitachi, Ltd. When the line width of the line pattern is measured at a plurality of measurement points and the “variation” is expressed by the 3 sigma method, the case where the “variation” is less than 10 nm is “good”, and the case where the “variation” is 10 nm or more. Rated as “bad”.

Claims (5)

A compound represented by the following general formula (1).

[In the general formula (1), R ¹ represents a substituted or unsubstituted monovalent non-aromatic hydrocarbon group having 1 to 14 carbon atoms, and R ² represents a hydrogen atom or a linear or branched chain having 1 to 14 carbon atoms. A cyclic or cyclic alkyl group, and n is an integer of 1 to 3; ] A polymer having a repeating unit represented by the following general formula (I) and having a polystyrene-reduced weight average molecular weight of 1,000 to 300,000 by gel permeation chromatography (GPC).

[In general formula (I), R ¹ represents a substituted or unsubstituted monovalent non-aromatic hydrocarbon group having 1 to 14 carbon atoms, and R ² represents a hydrogen atom or a linear or branched group having 1 to 14 carbon atoms. A cyclic or cyclic alkyl group, and n is an integer of 1 to 3; ] The polymer according to claim 2, wherein in the general formula (I), R ² is a hydrogen atom and n is 1. The polymer according to claim 2 or 3, further comprising a repeating unit represented by the following general formula (II).

[In General Formula (II), R ³ represents a substituted or unsubstituted monovalent acid-dissociable group having 3 to 14 carbon atoms, and R ⁴ represents a hydrogen atom or a methyl group. ]   It has a repeating unit represented by the general formula (I) according to claim 2, optionally further having a repeating unit represented by the general formula (II) according to claim 4, and gel permeation chromatography ( GPC) has a polystyrene-reduced weight average molecular weight of 1,000 to 300,000, and is an alkali hardly soluble resin that is soluble in an alkaline aqueous solution by the action of an acid.