JP4710762B2 - Radiation sensitive resin composition - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition, and in particular, fine processing using various types of radiation such as far ultraviolet rays such as KrF excimer laser or ArF excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. The present invention relates to a radiation-sensitive resin composition that can be suitably used as a chemically amplified resist useful in the present invention.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm) or the like is used. There is a need for a lithography technique capable of microfabrication at the same level. As a radiation-sensitive resin composition suitable for irradiation with such an excimer laser, a chemical utilizing the chemical amplification effect by the component having an acid-dissociable functional group and the acid generator which is a component generating an acid by irradiation with radiation. Many amplified radiation-sensitive compositions have been proposed. For example, as a resin component, a polymer compound for a photoresist having a specific structure including a monomer unit having a norbornane ring derivative as a resin component is known (see Patent Documents 1 and 2).
Further, a resist composition using a (meth) acrylic acid copolymer having a repeating unit of an ester of narrowly dispersible (meth) acrylic acid and a specific monocyclohexane or bicycloheptanecarbolactone is known ( (See Patent Document 3).
Further, a repeating unit having a lactone ring in the side chain, a repeating unit having a polycyclic alicyclic hydrocarbon group consisting only of carbon and hydrogen not containing a polar group in the side chain, and an acid dissociable group in the side chain Pattern line edge roughness after development as a chemically amplified resist sensitive to far ultraviolet rays represented by an ArF excimer laser (wavelength 193 nm) using a radiation-sensitive resin composition containing an acrylic polymer containing repeating units It is known that heat treatment dependency after irradiation can be reduced (see Patent Document 4).

JP 2002-201232 A JP 2002-145955 A JP 2003-84436 A JP 2005-68418 A

  However, when a higher degree of integration is required in the semiconductor field, a radiation-sensitive resin composition that is a resist is required to have better resolution. At the same time, as miniaturization progresses, many cases have been seen in which minute defects generated during development become fatal defects in device design. In order to cope with such a situation, there is an urgent need to achieve both the excellent etching resistance as a resist and the property of being excellent in solubility in a developer after exposure. Further, along with miniaturization, excellent etching resistance is required.

  The present invention has been made to cope with the above problems, and by using a resin component containing a specific repeating unit, the transparency to radiation is high, and the sensitivity, resolution, dry etching resistance, pattern shape, etc. An object of the present invention is to provide a radiation-sensitive resin composition that is excellent in basic physical properties as a resist, particularly excellent in solubility in an alkaline developer, and excellent in etching resistance.

〔一般式（１）において、Ｒ^１は水素原子、フッ素原子、炭素数１〜４のアルキル基、炭素数１〜４のフルオロアルキル基を示し、Ｘは、−Ｏ−Ｚ−で表される２価の有機基であり、該Ｚはメチレン基、又は炭素数２〜１０の直鎖状或いは分岐状のアルキレン基を示す。各Ｒ^２は相互に独立に炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基を示し、２つ以上のＲ^２が互いに結合して環を形成していてもよい。〕 As means for solving the above-mentioned problems, the invention according to claim 1 includes (A) a repeating unit having an acid-dissociable group represented by the following general formula (1), and the action of an acid. An alkali-insoluble or alkali-insoluble resin (hereinafter also referred to simply as “resin (A)”) that becomes alkali-soluble when the acid-dissociable group is dissociated, and (B) a radiation-sensitive acid generator (hereinafter, referred to as “resin”). A radiation-sensitive resin composition characterized in that it contains a simple “acid generator (B)”.

[In General Formula (1), R ¹ represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms, and X is represented by —O—Z—. It is a divalent organic group, and Z represents a methylene group or a linear or branched alkylene group having 2 to 10 carbon atoms. Each R ² independently represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and two or more R ² may be bonded to each other to form a ring. ]

〔一般式（２−１）において、Ｒ^３は水素原子又は炭素数１〜４のアルキル基を示す。また、一般式（２−２）において、Ｒ^４は水素原子又は炭素数１〜４のアルキル基を示し、Ｒ^５は水素原子、炭素数１〜４のアルキル基又はトリフルオロメチル基を示し、ｎは１〜４の整数である。〕 The invention according to claim 2 is the invention wherein the resin (A) further contains a repeating unit having at least one lactone skeleton represented by the following general formulas (2-1) and (2-2). The radiation-sensitive resin composition according to 1.

[In General Formula (2-1), R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In the general formula (2-2), R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ⁵ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a trifluoromethyl group, n is an integer of 1-4. ]

  Since the resin component in the radiation sensitive resin composition of the present invention contains a resin containing the repeating unit represented by the general formula (1), the resin component has an adamantane skeleton in the side chain and is separated from the main chain. It has an ester structure at the site. Therefore, the radiation-sensitive resin composition of the present invention has etching resistance based on an adamantane skeleton and is excellent in solubility in a developer after exposure based on an ester structure.

Hereinafter, embodiments of the present invention will be described in detail.
<Resin (A)>
The resin (A) in the radiation-sensitive resin composition of the present invention is a repeating unit having an acid dissociable group represented by the following general formula (1) (hereinafter also simply referred to as “repeating unit (1)”). It is an alkali-insoluble or alkali-insoluble resin which contains and becomes alkali-soluble when the acid-dissociable group is dissociated by the action of an acid.
The “acid-dissociable group” means a group in which an alkali-soluble site that becomes an anion by the action of an alkali is protected with a protective group, and until the protective group is removed with an acid, A group that is not readily soluble. In the resin (A), the —COOC (R ² ) ₃ portion in the repeating unit (1) is a portion that dissociates by the action of an acid to form a carboxyl group and becomes a readily alkali-soluble portion. By containing the unit, an alkali-insoluble or hardly alkali-soluble resin becomes an alkali-soluble resin by the action of an acid.
In addition, “alkali insoluble or hardly soluble in alkali” means 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) of the present invention. Thus, when a film using only the resin (A) is developed instead of the resist film, it means that 50% or more of the initial film thickness of the film remains after development. Furthermore, “alkali easily soluble” means the property that the film is dissolved by the same treatment and 50% or more of the initial film thickness is lost.

〔一般式（１）において、Ｒ^１は水素原子、フッ素原子、炭素数１〜４のアルキル基、炭素数１〜４のフルオロアルキル基を示し、Ｘは、−Ｏ−Ｚ−で表される２価の有機基であり、該Ｚはメチレン基、又は炭素数２〜１０の直鎖状或いは分岐状のアルキレン基を示す。各Ｒ^２は相互に独立に炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基を示し、２つ以上のＲ^２が互いに結合して環を形成していてもよい。〕

[In General Formula (1), R ¹ represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms, and X is represented by —O—Z—. It is a divalent organic group, and Z represents a methylene group or a linear or branched alkylene group having 2 to 10 carbon atoms. Each R ² independently represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and two or more R ² may be bonded to each other to form a ring. ]

Examples of the alkyl group having 1 to 4 carbon atoms represented by R ¹ in the general formula (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group.
Examples of the fluoroalkyl group having 1 to 4 carbon atoms represented by R ¹ include a trifluoromethyl group and a pentafluoroethyl group.
In the general formula (1), particularly preferred R ¹ is a hydrogen atom or a methyl group.

  Examples of the linear or branched alkylene group having 2 to 10 carbon atoms represented by Z of X in the general formula (1) include an ethylene group, a 1,3-propylene group, and a 1,2-propylene group. Propylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene 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, 2-propylidene group, etc. Can be mentioned.

Moreover, as a C1-C20 linear, branched or cyclic alkyl group represented by R ² in the general formula (1), a methyl group, an ethyl group, an n-propyl group, an i-propyl group, Examples include n-butyl, s-butyl, t-butyl, n-pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and the like.
Furthermore, examples of the cyclic alkyl group formed by bonding two or more R ² together include norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane and the like. Groups composed of alicyclic rings derived from cycloalkanes of the above; groups composed of these alicyclic rings include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, Examples include groups substituted with one or more linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as 2-methylpropyl group, 1-methylpropyl group and t-butyl group. be able to. In particular, when R ² is polycyclic, it is preferable because of excellent etching resistance.

Specific examples of the repeating unit (1) include the following repeating units (1-1) to (1-15). Note that each ^{R 1} in the formula has the same meaning as ^{R 1} in the general formula (1).

Among these, the repeating units (1-1), (1-10), and (1-11) are preferable.
In addition, the said repeating unit (1) may contain only 1 type and may contain 2 or more types.

The resin (A) in the radiation-sensitive resin composition of the present invention contains a repeating unit having a lactone skeleton (hereinafter also referred to as “repeating unit (2)”) in addition to the repeating unit (1). May be.
The structure of the repeating unit (2) is not particularly limited as long as it has a lactone skeleton. Specifically, the repeating unit (2) has at least one lactone skeleton represented by the following general formulas (2-1) and (2-2). Units are preferred.

〔一般式（２−１）において、Ｒ^３は水素原子又は炭素数１〜４のアルキル基を示す。また、一般式（２−２）において、Ｒ^４は水素原子又は炭素数１〜４のアルキル基を示し、Ｒ^５は水素原子、炭素数１〜４のアルキル基を示し、ｍは１〜３、ｎは１〜４の整数である。〕

[In General Formula (2-1), R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In the general formula (2-2), ^{R 4} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, ^{R 5} represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, m is 1 to 3 , N is an integer of 1 to 4. ]

Examples of the alkyl group having 1 to 4 carbon atoms represented by R ³ in the general formula (2-1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group. Particularly preferred R ³ is a hydrogen atom or a methyl group.

Examples of the alkyl group having 1 to 4 carbon atoms represented by R ⁴ and R ⁵ in the general formula (2-2) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group. Is mentioned.
Particularly preferred R ⁴ is a hydrogen atom or a methyl group, and particularly preferred R ⁵ is a methyl group.

  Specific examples of the repeating unit (2-1) include the following repeating units (2-1-1) and (2-1-2).

Specific examples of the repeating unit (2-2) include the following repeating units (2-2-1) to (2-2-9). Incidentally, each ^{R 4} in the formula has the same meaning as ^{R 4} in the general formula (2-2).

Of these, the repeating units (2-2-1), (2-2-2), and (2-2-8) are preferable.
In addition, the said repeating unit (2) may contain only 1 type and may contain 2 or more types.

  The resin (A) in the radiation-sensitive resin composition of the present invention is not limited to the repeating units (1) and (2), but may be a repeating unit represented by the following general formula (3) (hereinafter referred to as “repeating unit” (3) ") and a repeating unit represented by the following general formula (4) (hereinafter also referred to as" repeating unit (4) ").

〔一般式（３）において、Ｒ^６は水素原子、炭素数が１〜４のアルキル基又はトリフルオロメチル基を表し、Ｒ^７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表し、且つＲ^７の少なくとも１つが該脂環式炭化水素基若しくはその誘導体であるか、或いは何れか２つのＲ^７が相互に結合して、それぞれが結合している炭素原子とともに炭素数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^７が炭素数１〜４の直鎖状若しくは分岐状のアルキル基又は炭素数４〜２０の１価の脂環式炭化水素基若しくはその誘導体を表す。〕

[In General Formula (3), R ⁶ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a trifluoromethyl group, and R ⁷ is a monovalent alicyclic group having 4 to 20 carbon atoms, independently of each other. Represents a hydrocarbon group or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms, and at least one of R ⁷ is the alicyclic hydrocarbon group or a derivative thereof; Two R ⁷ 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 atom to which each R ⁷ is bonded, and the remaining R ⁷ is a group having 1 to 4 a linear or branched alkyl group, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof. ]

〔一般式（４）において、Ｒ^８は水素原子、メチル基、又はトリフルオロメチル基を表し、Ｚは炭素数７〜２０の炭素原子及び水素原子のみからなる多環型脂環式炭化水素基を表す。〕

[In General Formula (4), R ⁸ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and Z represents a polycyclic alicyclic hydrocarbon group consisting of only a carbon atom having 7 to 20 carbon atoms and a hydrogen atom. Represents. ]

Examples of the alkyl group having 1 to 4 carbon atoms in R ⁶ of the general formula (3) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group.
In addition, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms of R ^{7 in} the general formula (3) and a divalent group having 4 to 20 carbon atoms formed by any two R ⁷ bonded to each other. 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 such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, Examples thereof include groups substituted with one or more linear or branched or cyclic alkyl groups having 1 to 4 carbon atoms such as a t-butyl group. 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 ⁷ include 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 and an ethyl group are preferable.

The -COOC ^(R ₇₎ -C in ₃ portions ^(R _{7) 3} portion of the backbone of the general formula (3), for example, the following formula (3-1), the formula (3-2), the formula (3-3 ), A group represented by formula (3-4), formula (3-5), or formula (3-6).

In the above formulas, each R ⁹ independently represents a linear or branched alkyl group having 1 to 4 carbon atoms, and m is 0 to 7. Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, and a 1-methyl group. A propyl group, a t-butyl group, etc. can be mentioned. Of these alkyl groups, a methyl group and an ethyl group are preferable.
In the present invention, preferred —C (R ⁷ ) ₃ moiety skeletons are 1-alkylcycloalkanes, and R ⁹ is a methyl group or an ethyl group.

Moreover, as Z of General formula (4), it has a polycyclic alicyclic hydrocarbon group which consists of a C7-C20 carbon atom and a hydrogen atom in a part of side chain. Preferably, it has a polycyclic alicyclic hydrocarbon group consisting of carbon atoms and hydrogen atoms not containing a polar group having 7 to 20 carbon atoms in a part of the side chain.
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. C1-C4 linear, branched or cyclic alkyl groups such as 1-methylpropyl group and t-butyl group, and skeletons substituted with one or more of hydroxyl groups.

Furthermore, the resin (A) in the radiation sensitive resin composition of the present invention may contain the following other repeating units in addition to the repeating units (1) to (4).
Examples of the other repeating units include the following repeating units (5-1) to (5-7).

The resin (A) of the present invention comprises (i) a copolymer containing the repeating unit (1) and the repeating unit (2), (ii) the repeating unit (1), the repeating unit (2), and the repeating unit. It is preferable that (3) and / or a repeating unit (4) are included.
When the resin (A) is a copolymer containing such a repeating unit, it is excellent in etching resistance and solubility in a developer after exposure.

  In addition, as a monomer which produces each said repeating unit contained in resin (A) in this radiation sensitive resin composition, (meth) acrylic acid derivative ester corresponding, respectively is mentioned. In addition, the description with (meth) acrylic acid represents acrylic acid or methacrylic acid.

In the resin (A) contained in the radiation-sensitive resin composition of the present invention, the content of the repeating unit (1) is, when the total of all repeating units constituting the resin (A) is 100 mol%, It is preferable that it is 5-70 mol%, More preferably, it is 10-50 mol%, More preferably, it is 10-40 mol%. If the content of the repeating unit (1) is less than 5 mol%, the resolution tends to deteriorate, and if it exceeds 50 mol%, the solubility in the developer tends to decrease and the developability tends to decrease. .
Moreover, when resin (A) contains repeating unit (2), the content rate of this repeating unit (2) is 10 when the sum total of all the repeating units which comprise resin (A) is 100 mol%. It is preferable that it is -80 mol%, More preferably, it is 20-70 mol%, More preferably, it is 30-60 mol%. When the content of the repeating unit (2) is less than 10 mol%, the solubility in a developing solution as a resist tends to decrease. When the content exceeds 80 mol%, the resolution is deteriorated and the solubility in a solvent is increased. Tend to run out.
Furthermore, when the resin (A) contains the repeating unit (3), the content of the repeating unit (3) is 10 when the total of all repeating units constituting the resin (A) is 100 mol%. It is preferable that it is -80 mol%, More preferably, it is 20-70 mol%, More preferably, it is 30-60 mol%. If the content of the repeating unit (3) is less than 10 mol%, the resolution tends to deteriorate and the desired pattern cannot be accurately resolved. It tends to decrease.
Moreover, when resin (A) contains repeating unit (4), the content rate of this repeating unit (4) is 1 when the sum total of all the repeating units which comprise resin (A) is 100 mol%. It is preferable that it is -40 mol%, More preferably, it is 5-30 mol%, More preferably, it is 10-20 mol%. If the content of the repeating unit (4) is less than 1 mol%, the added effect tends not to be clearly seen. If the content exceeds 30 mol%, the solubility in the developer is insufficient and the pattern is It tends to be impossible to resolve.

Resin (A) is, for example, a mixture of monomers corresponding to each repeating unit, using a radical polymerization initiator such as hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds, etc. Accordingly, it can be produced by polymerization in a suitable solvent in the presence of a chain transfer agent.
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; alkyl lactones such as γ-butyrolactone; alkyl ketones such as 2-butanone, 2-heptanone and methyl isobutyl ketone; cycloalkyl ketones such as cyclohexanone; 2-propanol, propylene glycol monomethyl Examples include alcohols such as ether. These solvents may be used alone or in combination of two or more.
The reaction temperature in the polymerization is usually 40 to 120 ° C, preferably 50 to 100 ° C. The reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

The resin (A) of the present invention is naturally low in impurities such as halogen and metal, and preferably has a residual monomer or oligomer component of a predetermined value or less, for example, 0.1% by mass or the like by HPLC. Thereby, not only can the sensitivity, resolution, process stability, pattern shape and the like as a resist be further improved, but also a radiation-sensitive composition that can be used as a resist that does not change with time such as foreign matter in liquid or sensitivity.
Examples of the purification method of the resin (A) include the following methods. As a method of removing impurities such as metals, the metal is chelated and removed by adsorbing the metal in the resin solution using a zeta potential filter or by washing the resin solution with an acidic aqueous solution such as oxalic acid or sulfonic acid. And the like. In addition, as a method of removing residual monomer and oligomer components below the specified value, liquid-liquid extraction method that removes residual monomer and oligomer components by combining water washing and an appropriate solvent, those with a specific molecular weight or less Purification method in the state of solution such as ultrafiltration that extracts only, and reprecipitation to remove residual monomers by coagulating the polymer in the poor solvent by dropping the polymer solution into the poor solvent There is a purification method in a solid state such as washing with a poor solvent by a method or a filtered polymer slurry. Furthermore, these methods can be combined. The poor solvent used in the reprecipitation method is appropriately selected according to the physical properties of the polymer to be purified.

It is preferable that the polystyrene conversion weight average molecular weight (henceforth "Mw") by the gel permeation chromatography (GPC) of the said resin (A) is 1000-200000, More preferably, it is 2000-50000, More preferably 3000 to 30000. When the Mw of this resin (A) is 1000 to 200000, sufficient heat resistance and developability as a resist can be obtained. In addition, when Mw of resin (A) is too small, there exists a possibility that the heat resistance as a resist may fall, and when Mw is too large, there exists a possibility that the developability as a resist may fall.
Further, the ratio (Mw / Mn) of Mw of the resin (A) to polystyrene-reduced number average molecular weight (hereinafter also referred to as “Mn”) by gel permeation chromatography (GPC) is usually 1 to 7.
In addition, these Mw, Mn, and Mw / Mn can be measured by the method similar to the Example mentioned later.

  In addition, in the radiation sensitive resin composition of this invention, resin (A) may be used independently and may be used in mixture of 2 or more types.

<Radiation sensitive acid generator (B)>
Examples of the acid generator (B) in the radiation-sensitive resin composition of the present invention include onium salts such as sulfonium salts and iodonium salts, organic halogen compounds, and sulfone compounds such as disulfones and diazomethane sulfones.
Preferred examples of the acid generator (B) include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2 .2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2- (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} Dodecanyl) -1,1-difluoroethanesulfonate, triphenylsulfonium N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, triphenylsulfonium salt compounds such as triphenylsulfonium camphorsulfonate;

4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2. 2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexyl-phenyl diphenyl sulfonium 2- (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7, 10]} dodecanyl) -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 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] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-t-butylphenyldiphenylsulfonium 2- (3-tetracyclo [4.4. 0.1 ^2,5 .1 ^7,10] dodecanyl) -1,1-difluoroethanesulfonate, 4-t-butylphenyl diphenyl sulfonium N, N'-bis (nonafluoro -n- butanesulfonyl) imidate, 4-t- Butylphenyl 4-t-butylphenyl diphenyl sulfonium salt compounds such as triphenylsulfonium camphorsulfonate;

Tri (4-t-butylphenyl) sulfonium trifluoromethanesulfonate, tri (4-t-butylphenyl) sulfonium nonafluoro-n-butanesulfonate, tri (4-t-butylphenyl) sulfonium perfluoro-n-octanesulfonate, Tri (4-t-butylphenyl) sulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, tri (4-t-butylphenyl) sulfonium 2 - (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, tri (4-t- butylphenyl) sulfonium N, N'-bis (nonafluoro -N-butanesulfonyl) imidate, tri (4-t-butylphenyl) sulfur Bromide tri (4-t- butylphenyl) such as camphorsulfonate sulfonium salt compound;

Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2, 2-tetrafluoroethane sulfonate, diphenyliodonium 2- (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, diphenyliodonium N, N'-bis Diphenyliodonium salt compounds such as (nonafluoro-n-butanesulfonyl) imidate, diphenyliodonium 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] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium 2 - (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, bis (4-t- butylphenyl) iodonium N, N'-bis (nonafluoro -N-butanesulfonyl) imidate, bis (4-t-butylphenyl) io Bis (4-t- butylphenyl) such as camphorsulfonate 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] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (3-tetracyclo [4.4. 0.1 ^2,5 .1 ^7,10 ] dodecanyl) -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 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] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (3-tetracyclo [4.4. 0.1 ^2,5 .1 ^7,10 ] dodecanyl) -1,1-difluoro 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 camphorsulfonate;

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, N- (2- (3- tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) Succinimide compounds such as -1,1-difluoroethanesulfonyloxy) succinimide and N- (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] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxy imide, N- (2- (3- tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethane-sulfonyloxy) bicyclo [2.2.1] hept Bicyclo [2.2.1] such as -5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide. And hept-5-ene-2,3-dicarboximide compounds.

In this invention, an acid generator (B) may be used independently and may be used in mixture of 2 or more types.
Moreover, the usage-amount of an acid generator (B) is 0.1-30 mass parts normally with respect to 100 mass parts of resin (A) from a viewpoint of ensuring the sensitivity and developability as a resist, Preferably it is 0. .1 to 20 parts by mass. In this case, when the amount of the acid generator (B) used is less than 0.1 parts by mass, the sensitivity and developability tend to decrease. On the other hand, when the amount exceeds 30 parts by mass, the transparency to radiation decreases and the rectangular shape is reduced. It tends to be difficult to obtain a resist pattern.

<Additives>
In the radiation sensitive resin composition of the present invention, an acid diffusion controller, an alicyclic additive having an acid dissociable group, an alicyclic additive not having an acid dissociable group, and a surfactant are included as necessary. Various additives such as a sensitizer can be blended.
The acid diffusion control 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 an acid generator upon irradiation 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; aniline, N-methylaniline, N, N-dimethylaniline, Aromatic amines such as 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, 2,6-dimethylaniline, 2,6-diisopropylaniline, diphenylamine, triphenylamine, naphthylamine; triethanol Amines, Alkanolamines such as ethanolaniline; N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- ( 4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, 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] benzene, bis (2-dimethylamino) Chill) ether, bis (2-diethylaminoethyl) ether.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, N -T-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-1-adamantyl Amine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylene Diamine, N, N, N ′, N′-tetra-t-butoxycarbonylhexamethyl Tylenediamine, 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-phenylbenz Imidazole, Nt-butoxycarbonyl-pyrrolidine, Nt-butoxycarbonyl-piperidine, Nt-butoxycarbo In addition to Nt-butoxycarbonyl group-containing amino compounds such as nyl-4-hydroxy-piperidine, Nt-butoxycarbonyl-morpholine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N- Examples thereof include 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 , Pyridines such as quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine; piperazines such as piperazine, 1- (2-hydroxyethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidin , 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane.

Among the nitrogen-containing heterocyclic compounds, tertiary amine compounds, amide group-containing compounds, and nitrogen-containing heterocyclic compounds are preferable.
Among the tertiary amine compounds, alkanolamines are preferable. Among the amide group-containing compounds, Nt-butoxycarbonyl group-containing amino compounds are preferable. Among nitrogen-containing heterocyclic compounds, imidazoles are preferable.

  The acid diffusion controller may be used alone or in combination of two or more. Moreover, the compounding quantity of an acid diffusion control agent is 15 mass parts or less normally with respect to 100 mass parts of resin (A), Preferably it is 10 mass parts or less, More preferably, it is 5 mass parts or less. In this case, the compounding amount of the acid diffusion control agent exceeds 15 parts by mass, and the sensitivity as a resist and the developability of the radiation-irradiated part tend 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.

In addition, an alicyclic additive having an acid dissociable group or an alicyclic additive not having an acid dissociable group is a component that further improves dry etching resistance, pattern shape, adhesion to a substrate, and the like. It is.
Examples of such alicyclic additives include 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α-butyrolactone ester, 1,3-adamantane dicarboxylic acid diester. -T-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantanediacetate di-t-butyl, 2,5-dimethyl-2,5-di (adamantylcarbonyl) Adamantane derivatives such as oxy) hexane; deoxycholate t-butyl, deoxycholate t-butoxycarbonylmethyl, deoxycholate 2-ethoxyethyl, deoxycholate 2-cyclohexyloxyethyl, deoxycholate 3-oxocyclohexyl, Deoxychol Deoxycholic acid esters such as tetrahydropyranyl, deoxycholic acid mevalonolactone ester; lithocholic acid t-butyl, lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid Lithocholic acid esters such as 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, di-t-butyl adipate, etc. And alkyl carboxylic acid esters. These alicyclic additives can be used alone or in admixture of two or more.
The compounding amount of the alicyclic additive is usually 50 parts by mass or less, preferably 30 parts by mass or less with respect to 100 parts by mass of the resin (A). When the blending amount of the alicyclic additive exceeds 50 parts by mass, the heat resistance as a resist tends to decrease.

Further, the surfactant as an additive is a component having an effect of improving coating property, 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), Megafax F171, F173 (manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (Sumitomo 3M Co., Ltd.), 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 this surfactant is 2 mass parts or less normally with respect to 100 mass parts of resin (A).

Further, the sensitizer as an additive has an action of absorbing radiation energy and transmitting the energy to the acid generator, thereby increasing the amount of acid generated. The radiation-sensitive resin composition It has the effect of improving the apparent sensitivity.
Examples of such sensitizers include carbazoles, benzophenones, rose bengals, anthracenes, phenols and the like. These sensitizers can be used alone or in admixture of two or more.
It is preferable that the compounding quantity of this sensitizer is 50 mass parts or less with respect to 100 mass parts of resin (A).

  Further, additives other than those mentioned above include antihalation agents, adhesion assistants, storage stabilizers, antifoaming agents and the like.

When the radiation-sensitive resin composition of the present invention is used, it is dissolved in a solvent so that the total solid content is usually 3 to 50% by mass, preferably 5 to 25% by mass. It is prepared as a composition solution by filtering with a filter of about 2 μm.
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 monomethyl 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 , Ethyl pyruvate, N-methylpyrrolidone, γ-butyrolactone and the like.

Among these, it contains at least one selected from propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclohexanone, γ-butyrolactone, ethyl 2-hydroxypropionate and ethyl 3-ethoxypropionate. preferable.
In addition, these solvents can be used individually or in mixture of 2 or more types.

The radiation sensitive resin composition of the present invention is particularly useful as a chemically amplified resist. In particular, it is useful as a positive resist having etching resistance and excellent solubility in a developer after exposure.
In a chemically amplified resist, the acid-dissociable group in the resin is dissociated by the action of the acid generated from the acid generator by radiation irradiation to generate a carboxyl group. The solubility becomes high, and the irradiated portion is dissolved and removed by an 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. Irradiate. Examples of radiation used in this case 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.) Far ultraviolet rays, charged particle beams such as electron beams, and X-rays such as synchrotron radiation can be appropriately selected and used. Of these, far ultraviolet rays and electron beams are preferred. Moreover, irradiation conditions, such as irradiation amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition, the kind of each additive, etc.
In the present invention, in order to stably form a high-precision fine pattern, it is preferable to heat (hereinafter also referred to as “PEB”) a substrate provided with the exposed resist film. By this PEB, the dissociation reaction of the acid dissociable organic group in the resin proceeds smoothly. The heating conditions for PEB vary depending on the composition of the radiation sensitive resin composition, but are 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 irradiated 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 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 non-irradiated part may be dissolved in the developer, which is not preferable.
In addition, an appropriate amount of a surfactant or the like can be added to the alkaline aqueous solution. In addition, after developing with an alkaline developer, it is generally washed with water and dried.

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

[1] Synthesis of resin (A)
<Synthesis Example 1>
Monomer (M-1) 34.64 g (50 mol%) and monomer (M-2-1) 65.36 g (50 mol%) represented by the following formulas were converted into 2-butanone 200 g. Dissolve and prepare a monomer solution charged with 3.00 g of azobisisobutyronitrile. A 1000 ml three-necked flask charged with 100 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (70 g, yield 70%). ). This copolymer had Mw of 13000 and Mw / Mn of 1.96. This copolymer is referred to as “resin (A-1)”.

<Synthesis Example 2>
49.18 g (50 mol%) of monomer (M-1) represented by the following formulas, 18.56 g (10 mol%) of monomer (M-2-1), monomer (M- 3-1) A monomer solution prepared by dissolving 32.27 g (40 mol%) in 200 g of 2-butanone and further adding 4.25 g of azobisisobutyronitrile is prepared, and 100 g of 2-butanone is added. The 1000 ml three neck flask was purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (66 g, yield 66%). ). This copolymer had Mw of 7200 and Mw / Mn of 1.65. This copolymer is referred to as “resin (A-2)”.

<Synthesis Example 3>
43.40 g (50 mol%) of monomer (M-1) represented by the following formulas, 24.56 g (15 mol%) of monomer (M-2-1), monomer (M- 4) A monomer solution in which 32.03 g (35 mol%) was dissolved in 200 g of 2-butanone and 3.75 g of azobisisobutyronitrile was further prepared, and 1000 ml of 100 g of 2-butanone was added. The three-neck flask is purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (76 g, yield 76%). ). This copolymer had Mw of 7200 and Mw / Mn of 1.90. This copolymer is referred to as “resin (A-3)”.

<Synthesis Example 4>
Monomer (M-1) 36.44 g (50 mol%), monomer (M-2-1) 55.00 g (40 mol%) represented by the following formulas, monomer (M- 5) A monomer solution prepared by dissolving 8.57 g (10 mol%) in 200 g of 2-butanone and further adding 3.15 g of azobisisobutyronitrile was prepared, and 1000 ml of 100 g of 2-butanone was added. The three-neck flask is purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (85 g, 85% yield). ). This copolymer had Mw of 11000 and Mw / Mn of 2.19. This copolymer is referred to as “resin (A-4)”.

<Synthesis Example 5>
28.56 g (30 mol%) of monomer (M-1) represented by the following formulas, 53.88 g (30 mol%) of monomer (M-2-1), monomer (M- 3-1) A monomer solution in which 17.57 g (40 mol%) was dissolved in 200 g of 2-butanone and 3.09 g of azobisisobutyronitrile was further prepared, and 100 g of 2-butanone was added. A 1000 ml three neck flask is purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (67 g, 67% yield). ). This copolymer had Mw of 10,000 and Mw / Mn of 1.98. This copolymer is referred to as “copolymer (A-5)”.

<Synthesis Example 6>
Monomer (M-1) 33.90 g (50 mol%) and monomer (M-2-2) 66.10 g (50 mol%) represented by the following formulas were converted into 2-butanone 200 g. A monomer solution in which 2.93 g of azobisisobutyronitrile is dissolved is added, and a 1000 ml three-necked flask charged with 100 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (82 g, yield 82%). ). This copolymer had Mw of 13000 and Mw / Mn of 2.00. This copolymer is referred to as “resin (A-6)”.

<Synthesis Example 7>
Monomer (M-1) 36.26 g (50 mol%), monomer (M-2-2) 56.55 g (40 mol%) represented by the following formulas, monomer (M- 6-1) A monomer solution prepared by dissolving 7.19 g (10 mol%) in 200 g of 2-butanone and further adding 3.76 g of dimethyl 2,2′-azobis (2-methylpropionate) is prepared. Then, a 1000 ml three-necked flask charged with 100 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (78 g, yield 78%). ). This copolymer had Mw of 8900 and Mw / Mn of 1.78. This copolymer is referred to as “resin (A-7)”.

<Synthesis Example 8>
Monomer (M-1) 50.11 g (50 mol%) represented by the following formulas, monomer (M-2-2) 19.54 g (10 mol%), monomer (M- 3-2) A monomer solution prepared by dissolving 30.35 g (40 mol%) in 200 g of 2-butanone and adding 5.19 g of dimethyl 2,2′-azobis (2-methylpropionate) is prepared. Then, a 1000 ml three-necked flask charged with 100 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (81 g, 81% yield). ). This copolymer had Mw of 8800 and Mw / Mn of 1.73. This copolymer is referred to as “resin (A-8)”.

<Synthesis Example 9>
Monomer (M-1) 48.59 g (50 mol%), monomer (M-4) 20.67 g (30 mol%) represented by the following formulas and monomer (M-6) 2) A monomer solution prepared by dissolving 30.74 g (30 mol%) in 200 g of 2-butanone and further adding 4.03 g of dimethyl 2,2′-azobis (2-methylpropionate) was prepared. Purge 1000 ml 3-neck flask charged with butanone with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off. 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 copolymer (74 g, yield 74%). ). This copolymer had Mw of 9800 and Mw / Mn of 1.93. This copolymer is referred to as “resin (R-1)”.

  In addition, the measurement of Mw, Mn, and Mw / Mn in each said synthesis example was performed in the following way. In addition, Table 1 summarizes the monomer charge ratio in each synthesis example, and the Mw, Mw / Mn, and yield of the obtained copolymer.

<Mw and Mn>
Tosoh Co., Ltd. high-speed GPC device (model “HLC-8120”) and Tosoh Co., Ltd. GPC column (trade name “G2000H _XL ”; two, “G3000H _XL ”; one, “G4000H _XL ”; 1 This was measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of a flow rate of 1.0 ml / min, an elution solvent tetrahydrofuran, and a column temperature of 40 ° C. Further, the degree of dispersion Mw / Mn was calculated from the measurement results.

[2] Preparation Examples 1 to 14 and Comparative Example 1 of Radiation Sensitive Resin Composition
Each resin obtained in Synthesis Examples 1 to 9, the acid generator (B) shown below, the acid diffusion controller (C), and the solvent (D) were blended in the proportions shown in Table 2, and then carried out. Each radiation sensitive resin composition of Examples 1-14 and Comparative Example 1 was prepared.

<Acid generator (B)>
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (B-2): Triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2- Tetrafluoroethanesulfonate (B-3): 4-n-butoxy-1-naphthyltetrahydrothiophenium, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoro Ethanesulfonate
<Acid diffusion controller (C)>
(C-1): tert-butyl 4-hydroxy-1-piperidinecarboxylate (C-2): phenylbenzimidazole
<Solvent (D)>
(D-1): Propylene glycol monomethyl ether acetate (D-2): Cyclohexanone

[3] Evaluation of Examples The following various evaluations were performed using the radiation-sensitive resin compositions of Examples 1 to 14 and Comparative Example 1. The evaluation results are shown in Table 3.
<Evaluation method>
(1) Sensitivity When exposure is performed with an ArF light source, a silicon wafer (ARC29) having a 77 nm thick ARC29 [(Brewer Science)] film formed on the wafer surface is used. Using a Nikon ArF excimer laser exposure device (numerical aperture of 0.78) on a resist film with a film thickness of 200 nm formed by spin coating and PB on a hot plate at 120 ° C. for 1 minute. And exposure through a mask pattern. Thereafter, PEB is performed at 120 ° C. for 1 minute, and then developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 25 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. Formed. 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.
(2) Resolution The minimum line-and-space pattern dimension that can be resolved with the optimum exposure dose is taken as the resolution.
(3) Line edge roughness (LER)
When observing the 100nm 1L / 1S pattern resolved at the optimal exposure dose, the line width is observed at an arbitrary point when observing from the top of the pattern with Hitachi SEM: S9260, and the measurement variation is expressed in 3 sigma. In this case, the case where the value was 10 nm or more was judged “bad”, and the case where the value was less than 10 nm was judged “good”.

  Since the radiation sensitive resin composition of the present invention is excellent in etching resistance and solubility in an alkaline developer, it is extremely useful as a chemically amplified resist for semiconductor device production, which is expected to be further refined from now on. is there.

Claims (2)

(A) An alkali-insoluble or alkali-insoluble material that contains a repeating unit having an acid-dissociable group represented by the following general formula (1) and becomes alkali-soluble when the acid-dissociable group is dissociated by the action of an acid. A radiation-sensitive resin composition comprising: (B) a radiation-sensitive acid generator.

[In General Formula (1), R ¹ represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms, and X is represented by —O—Z—. It is a divalent organic group, and Z represents a methylene group or a linear or branched alkylene group having 2 to 10 carbon atoms. Each R ² independently represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and two or more R ² may be bonded to each other to form a ring. ] The radiation-sensitive resin composition according to claim 1, wherein the resin further contains a repeating unit having at least one lactone skeleton represented by the following general formulas (2-1) and (2-2).

[In General Formula (2-1), R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In the general formula (2-2), R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ⁵ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a trifluoromethyl group, n is an integer of 1-4. ]