JP2006070167A - Manufacturing process of polymer compound for photoresists for immersion exposure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer compound for photoresists for immersion exposure which forms resist films excellent in water resistance. <P>SOLUTION: The manufacturing process of the polymer compound for photoresists for immersion exposure comprises precipitating, using an organic solvent, a polymer containing a monomer unit having a group part of which is eliminated with an acid to show alkaline solubility and re-precipitating, rinsing or re-pulping it using an aqueous solvent. A polymer containing a monomer unit having a group part of which is eliminated with an acid to show alkaline solubility and a monomer unit adhering to a substrate may be used for the polymer subjected to precipitation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a polymer compound for photoresist for immersion exposure used when performing fine processing of a semiconductor, etc., a resin composition for photoresist for immersion exposure comprising a polymer compound obtained by the production method, The present invention also relates to a semiconductor manufacturing method using the photoresist resin composition.

  Resin for photoresist used in the semiconductor manufacturing process has properties such as the property that the irradiated part changes to alkali-soluble when irradiated with light, adhesion to a silicon wafer (substrate), plasma etching resistance, and transparency to the light used. Must-have. The photoresist resin is generally used as a solution containing a main polymer, a photo-oxidant, and several additives for adjusting the above characteristics.

  In order to make a pattern finer, a lithography exposure light source used for manufacturing a semiconductor has become a shorter wavelength year by year. However, since there is a limit to the types of glass materials that transmit light of short wavelengths, the working distance between a substrate such as a wafer and the lens surface closest to the substrate is filled with a liquid that transmits exposure light, There has been proposed an immersion type exposure apparatus that makes an exposure pattern finer by increasing the numerical aperture (for example, Patent Document 1). Such a method of performing exposure under liquid immersion is called a wet exposure method. However, when exposure is performed under immersion, when a conventional photoresist resin composition is used, water may permeate the resist film, or the resist film may swell or have uneven thickness. In addition, a part of the resist component is eluted in water. As a result, there is a problem that it is difficult to obtain a clear and highly accurate pattern.

JP-A-10-303114

Accordingly, an object of the present invention is to provide a photoresist resin composition for immersion exposure capable of forming a resist film having excellent water resistance, and a high resist photoresist for immersion exposure useful as a resin of the resin composition for photoresist. It is to provide a method for producing a molecular compound.
Another object of the present invention is to provide a photoresist resin composition for immersion exposure that can form a fine pattern clearly and accurately, and a semiconductor manufacturing method.

  As a result of intensive studies to achieve the above object, the present inventors have applied a polymer containing a monomer unit having an acid-eliminable group to precipitation using an organic solvent, followed by reprecipitation and rinsing using an aqueous solvent. Or, when subjected to repulping operation, when used as a polymer compound for photoresist for immersion exposure, it can be found that a resist film excellent in water resistance can be formed, and a fine pattern can be formed clearly and accurately, and the present invention completed.

  That is, the present invention is a method in which a polymer containing a monomer unit having a group that exhibits an alkali-soluble function by elimination of a part thereof by an acid is subjected to precipitation with an organic solvent, followed by reprecipitation with an aqueous solvent, rinsing or repulping A method for producing a polymer compound for a photoresist for immersion exposure is provided.

（式中、Ｒ^aは水素原子、ハロゲン原子、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を示す。Ｒ¹及びＲ²は、同一又は異なって、炭素数１〜８の炭化水素基を示し、Ｒ³、Ｒ⁴及びＲ⁵は、同一又は異なって、水素原子、ヒドロキシル基又はメチル基を示す。Ｒ⁶及びＲ⁷は、同一又は異なって、水素原子、ヒドロキシル基又は−ＣＯＯＲ⁸基を示し、Ｒ⁸はｔ−ブチル基、２−テトラヒドロフラニル基、２−テトラヒドロピラニル基又は２−オキセパニル基を示す。Ｒ⁹はメチル基又はエチル基を示し、Ｒ¹⁰及びＲ¹¹は、同一又は異なって、水素原子、ヒドロキシル基又はオキソ基を示す。Ｒ¹²は、式中に示される酸素原子との結合部位に第３級炭素原子を有する、置換基を有していてもよい炭化水素基を示す。Ｒ¹³、Ｒ¹⁴、Ｒ¹⁵、Ｒ¹⁶及びＲ¹⁷は、同一又は異なって、水素原子又はメチル基を示す。Ｒ¹⁸はｔ−ブチル基、２−テトラヒドロフラニル基、２−テトラヒドロピラニル基又は２−オキセパニル基を示す。Ｒ¹⁹、Ｒ²⁰は、同一又は異なって、水素原子、アルキル基又はフルオロアルキル基を示し、Ｒ²¹は水素原子又は有機基を示す。ｍは１〜３の整数を示し、ｎは０又は１を示す）
から選択された少なくとも１種のモノマー単位を用いることができる。 In this production method, the monomer units having a group that is partially eliminated by an acid and exhibits an alkali-soluble function include the following formulas (Ia) to (Ih):

(In the formula, R ^a represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. R ¹ and R ² are the same or different and have 1 to 8 carbon atoms. R ³ , R ⁴ and R ⁵ are the same or different and represent a hydrogen atom, a hydroxyl group or a methyl group, and R ⁶ and R ⁷ are the same or different and represent a hydrogen atom, a hydroxyl group or shows a -COOR ⁸ group, R ⁸ is t- butyl, 2-tetrahydrofuranyl group, .R ⁹ showing a 2-tetrahydropyranyl group or a 2-oxepanyl group represents a methyl group or an ethyl group, R ¹⁰ and R ¹¹ is the same or different and represents a hydrogen atom, a hydroxyl group or an oxo group, and R ¹² has a substituent having a tertiary carbon atom at the bonding site with the oxygen atom shown in the formula. R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are the same or different and each represents a hydrogen atom or a methyl group, and R ¹⁸ represents a t-butyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or a 2-oxepanyl group. R ¹⁹ and R ²⁰ are the same or different and each represents a hydrogen atom, an alkyl group or a fluoroalkyl group, R ²¹ represents a hydrogen atom or an organic group, m represents an integer of 1 to 3, and n represents 0. Or 1)
At least one monomer unit selected from can be used.

  In addition, as the polymer to be subjected to precipitation, a polymer including a monomer unit having a group that is partially eliminated by an acid and exhibiting an alkali-soluble function and a monomer unit having a substrate adhesion function is preferably used.

（式中、Ｒ^aは水素原子、ハロゲン原子、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を示す。Ｒ²²及びＲ²³は、同一又は異なって、水素原子、ヒドロキシル基又はカルボキシル基を示し、Ｒ²⁴はヒドロキシル基、オキソ基又はカルボキシル基を示す。Ｘ¹、Ｘ²及びＸ³は、同一又は異なって、−ＣＨ₂−又は−ＣＯ−Ｏ−を示す。但し、Ｘ¹〜Ｘ³のうち少なくとも１つは−ＣＯ−Ｏ−である。Ｒ²⁵、Ｒ²⁶及びＲ²⁷は、同一又は異なって、水素原子又はメチル基を示す。Ｒ²⁸及びＲ²⁹は、同一又は異なって、水素原子又はメチル基を示す。Ｒ³⁰、Ｒ³¹、Ｒ³²、Ｒ³³及びＲ³⁴は、同一又は異なって、水素原子又はメチル基を示す。Ｒ³⁵は、水素原子、又はヒドロキシル基、ヒドロキシメチル基、カルボキシル基若しくはオキソ基を有する炭素数１〜２０の直鎖状、分岐鎖状、環状若しくは有橋環状炭化水素基を示す。Ｒ³⁶、Ｒ³⁷、Ｒ³⁸及びＲ³⁹は、同一又は異なって、水素原子又はメチル基を示す。Ｒ⁴⁰はヒドロキシル基、ヒドロキシメチル基又はカルボキシル基を示す。ｏ、ｐ、ｑ及びｒは、それぞれ、０又は１を示す）
から選択された少なくとも１種のモノマー単位を用いることができる。 As the monomer unit having the substrate adhesion function, the following formulas (IIa) to (IIh)

(In the formula, R ^a represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. R ²² and R ²³ are the same or different and represent a hydrogen atom or a hydroxyl group. Or a carboxyl group, R ²⁴ represents a hydroxyl group, an oxo group or a carboxyl group, X ¹ , X ² and X ³ are the same or different and represent —CH ₂ — or —CO—O—. At least one of X ^{1 to} X ³ is —CO—O—, R ²⁵ , R ²⁶ and R ²⁷ are the same or different and represent a hydrogen atom or a methyl group, and R ²⁸ and R ²⁹ are the same. R ³⁰ , R ³¹ , R ³² , R ³³ and R ³⁴ are the same or different and each represents a hydrogen atom or a methyl group, and R ³⁵ represents a hydrogen atom or a hydroxyl group. Group, hydroxymethyl group, carboxyl group or o , Straight with a source group, branched chain, .R ³⁶ showing a cyclic or bridged cyclic hydrocarbon group, R ^37, R ³⁸ and R ³⁹ are the same or different, a hydrogen atom or .o .R ⁴⁰ showing a methyl group showing a hydroxyl group, a hydroxymethyl group or a carboxyl group, p, q and r are, respectively, 0 or 1)
At least one monomer unit selected from can be used.

  The present invention also provides a polymer compound for photoresist for immersion exposure obtained by the above production method.

  The present invention further provides a photoresist resin composition for immersion exposure, comprising at least the above-described polymer compound for photoresist for immersion exposure and a photoacid generator.

  In the present invention, the photoresist resin composition for immersion exposure is applied onto a substrate or a substrate to form a resist coating film, and a pattern is formed through exposure and development under immersion. A method of manufacturing a semiconductor including a process is provided.

  According to the present invention, it is possible to form a resist film excellent in water resistance without swelling of the coating film or elution of the resist component into water, so that a fine pattern can be formed with high accuracy by employing the wet exposure method. be able to.

  In the present invention, a polymer containing at least a monomer unit (hereinafter sometimes referred to as “monomer unit 1”) having a group that is partially eliminated by an acid and exhibits an alkali-soluble function is precipitated (reprecipitation) with an organic solvent. And then re-precipitation with an aqueous solvent, rinsing with an aqueous solvent, or repulping with an aqueous solvent. Since the reprecipitation operation with an aqueous solvent is further performed after the precipitation operation with an organic solvent, the water-soluble or water-dispersible components contained in the polymer are efficiently removed. There is no swelling of the resist film or elution of the resist component into water, and fluctuations in coating thickness, uneven thickness, adverse effects on development, etc. can be suppressed or prevented. For this reason, it is possible to form a fine pattern clearly and accurately by developing after immersion exposure.

  The monomer unit having a group that is partially eliminated by an acid and that exhibits an alkali-soluble function is not particularly limited. For example, as a monomer unit having an acid-eliminable group or an alkali-soluble group in a photoresist polymer compound. The well-known monomer unit used can be employ | adopted. The polymer may have one type of these monomer units or two or more types.

  Preferred monomer units having a group that is partially eliminated by an acid and becomes alkali-soluble include monomer units represented by the above formulas (Ia) to (Ih).

R ^a in the formulas (Ia) to (Ih) is the same as described above. In formula (Ia), the hydrocarbon having 1 to 8 carbon atoms in R ¹ and R ² is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, pentyl, isopentyl, 1-methylbutyl, 1-ethyl. C _1-8 alkyl groups such as propyl, hexyl, isohexyl, 1-methylpentyl, 1-ethylbutyl, heptyl, 1-methylhexyl, octyl, 1-methylheptyl group; cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl A C _3-8 cycloalkyl group such as a group; and a phenyl group. Among these, C _1-3 alkyl groups such as methyl, ethyl, and isopropyl groups are preferable.

In the formula (Id), examples of the “hydrocarbon group having a tertiary carbon atom at the bonding site with the oxygen atom represented by the formula” in R ¹² include a t-butyl group and a t-amyl group. It is done. These hydrocarbon groups may have a substituent.

In formula (Ih), the alkyl group in R ¹⁹ and R ²⁰ is a linear or branched alkyl group such as methyl, ethyl, propyl, isopropyl, s-butyl, pentyl, hexyl group (C _1-6 Alkyl group, etc.). The fluoroalkyl group includes a group in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom, such as monofluoromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, tetrafluoro Examples include ethyl, 2,2,3,3,3-tetrafluoropropyl group. R ¹⁹ and R ²⁰ are particularly preferably a hydrogen atom, a C _1-3 alkyl group, a C _1-3 fluoroalkyl group, or the like.

In the formula (Ih), examples of the organic group for R ²¹ include a group containing a hydrocarbon group and / or a heterocyclic group.

The hydrocarbon group includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which two or more of these are bonded. Examples of the aliphatic hydrocarbon group include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, hexyl, and octyl groups (C _{1- 8} alkyl groups); linear or branched alkenyl groups such as allyl groups (C _2-8 alkenyl groups, etc.); linear or branched alkynyl groups such as propynyl groups (C _2-8 alkynyl) Group, etc.). Examples of the alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclopentyl, and cyclohexyl groups (3 to 8 membered cycloalkyl groups); cycloalkenyl groups such as cyclopentenyl and cyclohexenyl groups (3 to 8 members). Cycloalkenyl groups and the like); bridged carbocyclic groups such as adamantyl and norbornyl groups (C _4-20 bridged carbocyclic groups and the like) and the like. Examples of the aromatic hydrocarbon group include C _6-14 aromatic hydrocarbon groups such as phenyl and naphthyl groups. Examples of the group in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded include benzyl and 2-phenylethyl groups.

These hydrocarbon groups, an alkyl group (C _1-4 alkyl group), haloalkyl group (C _1-4 haloalkyl group), a halogen atom, a protected or unprotected hydroxyl group with a protecting group, protected by a protecting group It may have a substituent such as a hydroxymethyl group which may be protected, a carboxyl group which may be protected with a protecting group, or an oxo group. As the protecting group, a protecting group conventionally used in the field of organic synthesis can be used.

  Examples of the heterocyclic group include heterocyclic groups containing at least one heteroatom selected from an oxygen atom, a sulfur atom and a nitrogen atom.

Preferred organic groups include C _1-8 alkyl groups, organic groups containing a cyclic skeleton, and the like. The “ring” constituting the cyclic skeleton includes a monocyclic or polycyclic non-aromatic or aromatic carbocyclic or heterocyclic ring. Of these, monocyclic or polycyclic non-aromatic carbocycles and lactone rings (which may be condensed with non-aromatic carbocycles) are particularly preferable. Examples of the monocyclic non-aromatic carbocycle include a cycloalkane ring having about 3 to 15 members such as a cyclopentane ring and a cyclohexane ring.

Examples of the polycyclic non-aromatic carbocycle (bridged carbocycle) include, for example, an adamantane ring, norbornane ring, norbornene ring, bornane ring, isobornane ring, adamantane ring; norbornane ring, norbornene ring, bornane ring, isobornane ring, tricyclo [5.2.1.0 ^2,6 ] decane ring, tetracyclo [4.4.0.1 ^2,5 . ^1,7,10 ] ring containing norbornane ring or norbornene ring such as dodecane ring; perhydroindene ring, decalin ring (perhydronaphthalene ring), perhydrofluorene ring (tricyclo [7.4.0.0 ^3,8 ] Tridecane ring), a ring in which a polycyclic aromatic condensed ring such as perhydroanthracene ring is hydrogenated (preferably a fully hydrogenated ring); a tricyclo [4.2.2.1 ^2,5 ] undecane ring, etc. And a bridged carbocyclic ring (for example, a bridged carbocyclic ring having about 6 to 20 carbon atoms). Examples of the lactone ring include a γ-butyrolactone ring, 4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-5-one ring, and 4-oxatricyclo [4.2.1.0 ^{3. , 7} ] nonan-5-one ring, 4-oxatricyclo [5.2.1.0 ^2,6 ] decan-5-one ring, and the like.

The ring constituting the cyclic skeleton includes an alkyl group such as a methyl group (eg, a C _1-4 alkyl group), a haloalkyl group such as a trifluoromethyl group (eg, a C _1-4 haloalkyl group), a chlorine atom Or a halogen atom such as a fluorine atom, a hydroxyl group that may be protected with a protective group, a hydroxyalkyl group that may be protected with a protective group, a mercapto group that may be protected with a protective group, or a protective group. It may have a substituent such as a carboxyl group which may be protected, an amino group which may be protected with a protecting group, and a sulfonic acid group which may be protected with a protecting group. As the protecting group, a protecting group conventionally used in the field of organic synthesis can be used.

The ring constituting the cyclic skeleton may be directly bonded to an oxygen atom (oxygen atom adjacent to R ²¹ ) shown in the formula (Ih) or may be bonded via a linking group. . Examples of the linking group include a linear or branched alkylene group such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene group; a carbonyl group; an oxygen atom (ether bond; —O—); an oxycarbonyl group ( An ester bond; —COO—); an aminocarbonyl group (amide bond; —CONH—); and a group in which a plurality of these are bonded.

  The monomer unit represented by the formula (Ia) is desorbed from the carboxylic acid moiety in which the site containing the adamantane skeleton is bonded to the main chain by an acid to generate a free carboxyl group. In the monomer unit represented by the formula (Ib), a carboxyl group protected with a protecting group bonded to an adamantane skeleton is deprotected with an acid to generate a free carboxyl group. In addition, the monomer unit represented by the formula (Ic) generates a free carboxyl group by elimination of the adamantane skeleton from the carboxylic acid moiety bonded to the main chain by an acid. Furthermore, in the monomer units represented by the formulas (Id), (Ie), (If), (Ig), and (Ih), the carboxylic acid ester moiety is decomposed and eliminated by an acid to generate a free carboxyl group.

The monomer units represented by the formulas (Ia), (Ib), (Ic) and (Ig), and the monomer units in which R ²¹ is a group containing a non-aromatic carbocycle in the formula (Ih) are fatty acids. Since it has a cyclic carbon skeleton, it has the characteristics of excellent transparency and extremely high etching resistance. In addition, in the formula (Ia), a monomer unit in which at least one of R ^{3 to} R ⁵ is a hydroxyl group, a monomer unit represented by the formula (If), and a group in which R ^{21 in the} formula (Ih) contains a lactone ring The monomer unit is highly hydrophilic and also has an adhesive function.

  As the polymer to be subjected to precipitation, a polymer containing a monomer unit having a group that is partially eliminated by an acid and exhibiting an alkali-soluble function and a monomer unit having a substrate adhesion function is preferably used. A monomer unit having a substrate adhesion function (hereinafter sometimes referred to as “monomer unit 2”) is generally subjected to copolymerization with a monomer containing a hydrophilic group such as a hydroxyl group, an oxo group, a carboxyl group, or an ester group. Is formed. If such a monomer remains in the polymer in an unreacted state, the resist film swells and a desired film thickness cannot be obtained when exposure is performed under immersion after forming the resist film. The unreacted monomer is eluted in water and adversely affects subsequent processes such as development. Therefore, it becomes difficult to obtain a fine pattern clearly and accurately. According to the present invention, since such components are effectively removed during reprecipitation with water, it is possible to smoothly form a fine pattern with high accuracy. The monomer unit having a substrate adhesion function contained in the polymer may be one type or two or more types.

  Examples of the monomer unit having the substrate adhesion function include monomer units represented by the formulas (IIa) to (IIh).

R ^a in formulas (IIa) to (IIh) is the same as described above. In the formula (IIb), the direction of the —CO—O— group in X ^{1 to} X ³ is not limited. In the formula (IIe), the linear, branched, cyclic or bridged cyclic hydrocarbon group (bridged cyclic group) having 1 to 20 carbon atoms in R ³⁵ is methyl, ethyl, propyl, isopropyl. , Butyl, isobutyl, t-butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl and the like linear or branched aliphatic hydrocarbon groups (particularly alkyl groups) such as cyclopentyl; Cycloalkyl, cycloalkenyl group such as cyclohexyl, cyclooctyl, cyclododecyl group, etc .; perhydroindene ring, perhydrofluorene ring, perhydronaphthalene ring (decalin ring), perhydroanthracene ring, norbornane ring , Norbornene ring, pinane ring, bornane ring, isobornylane ring, tricyclo [5. .1.0 ^2,6] decane ring, tetracyclo [4.4.0.1 ^{2, 5.} 1 ^{7, 10} ] bridged cyclic hydrocarbon group having 6 to 20 carbon atoms (bridged cyclic hydrocarbon group) corresponding to dodecane ring, etc .; tricyclo [5.2.1.0 ^2,6 ] decylmethyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] Dodecylmethyl group, 2-norbornylmethyl group and the like, and the like groups bonded to each of the hydrocarbon groups. These hydrocarbon groups have a hydroxyl group, a hydroxymethyl group, a carboxyl group or an oxo group.

The compounds represented by the formulas (IIa), (IIb), (IIc), (IIe) (wherein R ³⁵ is a cyclic or bridged cyclic hydrocarbon group having a hydroxyl group, etc.), (IIg) and (IIh) Since the monomer unit has an alicyclic carbon skeleton, it contributes to improvement of transparency and etching resistance.

  As the polymer, in order to provide various properties as a photoresist in a well-balanced manner, as a monomer unit having a substrate adhesion function, at least one monomer unit selected from the formulas (IIa), (IIe) and (IIh); It preferably has at least one monomer unit selected from the formulas (IIb), (IIc), (IId), (IIf) and (IIg). Further, the polymer may contain monomer units having functions other than the monomer unit 1 and the monomer unit 2.

  In the polymer compound of the present invention, the content of the monomer unit 1 is, for example, 10 to 70 mol%, preferably 20 to 60 mol%, more preferably 25 to 50 mol, based on the entire monomer unit constituting the polymer. %. Moreover, in a preferable polymer compound, the monomer unit 2 is contained in an amount of, for example, 30 to 90 mol%, preferably 40 to 80 mol%, and more preferably about 50 to 75 mol% with respect to the entire monomer units constituting the polymer. .

  The weight average molecular weight (Mw) of the polymer compound is, for example, about 5000 to 50000, preferably about 7000 to 20000, and the molecular weight distribution (Mw / Mn) is, for example, about 1.8 to 3.5. In addition, said Mn shows a number average molecular weight, and both Mn and Mw are values of polystyrene conversion.

  Each of the monomer units represented by the formulas (Ig), (IIf), (IIg) and (IIh) has a corresponding ethylenically unsaturated compound as a (co) monomer, and each of the formulas (Ia) to (If) ), (Ih), and each monomer unit represented by (IIa) to (IIe) is obtained by subjecting the corresponding unsaturated carboxylic acid such as (meth) acrylic acid or its ester as a (co) monomer to polymerization. Can be formed.

[Monomer unit of formula (Ia)]
As typical examples of the monomer corresponding to the monomer unit of the formula (Ia), there may be mentioned the following compounds. 1- (1- (meth) acryloyloxy-1-methylethyl) adamantane, 1-hydroxy-3- (1- (meth) acryloyloxy-1-methylethyl) adamantane, 1- (1-ethyl-1- ( (Meth) acryloyloxypropyl) adamantane, 1-hydroxy-3- (1-ethyl-1- (meth) acryloyloxypropyl) adamantane, 1- (1- (meth) acryloyloxy-1-methylpropyl) adamantane, 1- Hydroxy-3- (1- (meth) acryloyloxy-1-methylpropyl) adamantane, 1- (1- (meth) acryloyloxy-1,2-dimethylpropyl) adamantane, 1-hydroxy-3- (1- ( (Meth) acryloyloxy-1,2-dimethylpropyl) adamantane, 1,3-dihydroxy -5- (1- (meth) acryloyloxy-1-methylethyl) adamantane, 1- (1-ethyl-1- (meth) acryloyloxypropyl) -3,5-dihydroxyadamantane, 1,3-dihydroxy-5 -(1- (meth) acryloyloxy-1-methylpropyl) adamantane, 1,3-dihydroxy-5- (1- (meth) acryloyloxy-1,2-dimethylpropyl) adamantane.

[Monomer unit of formula (Ib)]
As typical examples of the monomer corresponding to the monomer unit of the formula (Ib), there may be mentioned the following compounds. 1-t-butoxycarbonyl-3- (meth) acryloyloxyadamantane, 1,3-bis (t-butoxycarbonyl) -5- (meth) acryloyloxyadamantane, 1-t-butoxycarbonyl-3-hydroxy-5 (Meth) acryloyloxyadamantane, 1- (2-tetrahydropyranyloxycarbonyl) -3- (meth) acryloyloxyadamantane, 1,3-bis (2-tetrahydropyranyloxycarbonyl) -5- (meth) acryloyloxy Adamantane, 1-hydroxy-3- (2-tetrahydropyranyloxycarbonyl) -5- (meth) acryloyloxyadamantane.

[Monomer unit of formula (Ic)]
As typical examples of the monomer corresponding to the monomer unit of the formula (Ic), there may be mentioned the following compounds. 2- (meth) acryloyloxy-2-methyladamantane, 1-hydroxy-2- (meth) acryloyloxy-2-methyladamantane, 5-hydroxy-2- (meth) acryloyloxy-2-methyladamantane, 1,3 -Dihydroxy-2- (meth) acryloyloxy-2-methyladamantane, 1,5-dihydroxy-2- (meth) acryloyloxy-2-methyladamantane, 1,3-dihydroxy-6- (meth) acryloyloxy-6 -Methyl adamantane, 2- (meth) acryloyloxy-2-ethyladamantane, 1-hydroxy-2- (meth) acryloyloxy-2-ethyladamantane, 5-hydroxy-2- (meth) acryloyloxy-2-ethyladamantane 1,3-dihydroxy-2- (meth) ac Liloyloxy-2-ethyladamantane, 1,5-dihydroxy-2- (meth) acryloyloxy-2-ethyladamantane, 1,3-dihydroxy-6- (meth) acryloyloxy-6-ethyladamantane.

[Monomer unit of formula (Id)]
As typical examples of the monomer corresponding to the monomer unit of the formula (Id), there may be mentioned the following compounds. t-Butyl (meth) acrylate.

[Monomer unit of formula (Ie)]
As typical examples of the monomer corresponding to the monomer unit of the formula (Ie), there may be mentioned the following compounds. 2-tetrahydropyranyl (meth) acrylate, 2-tetrahydrofuranyl (meth) acrylate.

[Monomer unit of formula (If)]
As typical examples of the monomer corresponding to the monomer unit of the formula (If), there may be mentioned the following compounds. β- (meth) acryloyloxy-γ-butyrolactone, β- (meth) acryloyloxy-α, α-dimethyl-γ-butyrolactone, β- (meth) acryloyloxy-γ, γ-dimethyl-γ-butyrolactone, β- (Meth) acryloyloxy-α, α, β-trimethyl-γ-butyrolactone, β- (meth) acryloyloxy-β, γ, γ-trimethyl-γ-butyrolactone, β- (meth) acryloyloxy-α, α, β, γ, γ-pentamethyl-γ-butyrolactone.

[Monomer unit of formula (Ig)]
As typical examples of the monomer corresponding to the monomer unit of the formula (Ig), there may be mentioned the following compounds. 5-t-butoxycarbonylnorbornene, 9-t-butoxycarbonyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 5- (2-tetrahydropyranyloxycarbonyl) norbornene, 9- (2-tetrahydropyranyloxycarbonyl) tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene.

[Monomer unit of formula (Ih)]
As typical examples of the monomer corresponding to the monomer unit of the formula (Ih), there may be mentioned the following compounds. 1- (adamantan-1-yloxy) ethyl (meth) acrylate, 1- (adamantan-1-ylmethoxy) ethyl (meth) acrylate, 1- [2- (adamantan-1-yl) ethoxy] ethyl (meth) acrylate, 1- (3-hydroxyadamantan-1-yloxy) ethyl (meth) acrylate, 1- (norbornan-2-yloxy) ethyl (meth) acrylate, 1- (norbornan-2-ylmethoxy) ethyl (meth) acrylate, 1- (2-methylnorbornan-2-yloxy) ethyl (meth) acrylate, 1- [1- (norbornan-2-yl) -1-methylethoxy] ethyl (meth) acrylate, 1- (3-methylnorbornane-2- Ylmethoxy) ethyl (meth) acrylate, 1- (bornyloxy) ) Ethyl (meth) acrylate, 1- (isobornyloxycarbonyl) ethyl (meth) acrylate; 1- [1- (meth) acryloyloxy ethoxy] -4-oxa-tricyclo [4.3.1.1 ^{3, 8} ] Undecan-5-one, 2- [1- (meth) acryloyloxyethoxy] -4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one, 8- [1- (meta ) Acrylyloxyethoxy] -4-oxatricyclo [5.2.1.0 ^2,6 ] decan-5-one, 9- [1- (meth) acryloyloxyethoxy] -4-oxatricyclo [5. 2.1.0 ^2,6 ] decan-5-one, α- [1- (meth) acryloyloxyethoxy] -γ, γ-dimethyl-γ-butyrolactone, 3- [1- (meth) acryloyloxyethoxy] -2-oxo-1- Oxaspiro [4.5] decane, α- [1- (meth) acryloyloxyethoxy] -γ-butyrolactone, α- [1- (meth) acryloyloxyethoxy] -α, γ, γ-trimethyl-γ-butyrolactone, α- [1- (Meth) acryloyloxyethoxy] -β, β-dimethyl-γ-butyrolactone.

[Monomer unit of formula (IIa)]
Typical compounds of the monomer corresponding to the monomer unit of the formula (IIa) include the following compounds. 1-hydroxy-3- (meth) acryloyloxyadamantane, 1,3-dihydroxy-5- (meth) acryloyloxyadamantane, 1-carboxy-3- (meth) acryloyloxyadamantane, 1,3-dicarboxy-5 (Meth) acryloyloxyadamantane, 1-carboxy-3-hydroxy-5- (meth) acryloyloxyadamantane, 1- (meth) acryloyloxy-4-oxoadamantane, 3-hydroxy-1- (meth) acryloyloxy-4 -Oxoadamantane, 7-hydroxy-1- (meth) acryloyloxy-4-oxoadamantane.

[Monomer unit of formula (IIb)]
As typical examples of the monomer corresponding to the monomer unit of the formula (IIb), there may be mentioned the following compounds. 1- (meth) acryloyloxy-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-5-one, 1- (meth) acryloyloxy-4,7-dioxatricyclo [4. 4.1.1 ^3,9 ] dodecane-5,8-dione, 1- (meth) acryloyloxy-4,8-dioxatricyclo [4.4.1.1 ^3,9 ] dodecane-5,7 -Dione, 1- (meth) acryloyloxy-5,7-dioxatricyclo [4.4.1.1 ^3,9 ] dodecane-4,8-dione.

[Monomer unit of formula (IIc)]
Typical examples of the monomer that forms the monomer unit of the formula (IIc) include the following compounds. 2- (Meth) acryloyloxy-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one, 2- (meth) acryloyloxy-2-methyl-4-oxatricyclo [4 .2.1.0 ^3,7 ] nonan-5-one.

[Monomer unit of formula (IId)]
Typical examples of the monomer forming the monomer unit of the formula (IId) include the following compounds. α- (meth) acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-α-methyl-γ-butyrolactone, α- (meth) acryloyloxy-β, β-dimethyl-γ-butyrolactone, α- (meta ) Acrylyloxy-α, β, β-trimethyl-γ-butyrolactone, α- (meth) acryloyloxy-γ, γ-dimethyl-γ-butyrolactone, α- (meth) acryloyloxy-α, γ, γ-trimethyl- γ-butyrolactone, α- (meth) acryloyloxy-β, β, γ, γ-tetramethyl-γ-butyrolactone, α- (meth) acryloyloxy-α, β, β, γ, γ-pentamethyl-γ-butyrolactone .

[Monomer unit of formula (IIe)]
Typical examples of the monomer forming the monomer unit of the formula (IIe) include the following compounds. (Meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, decahydro (meth) acrylate Naphthyl, norbornyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dimethyladamantyl (meth) acrylate, tricyclo [5.2.1.0 ^2,6 ] decyl (meth) acrylate , Tetracyclo (meth) acrylate [4.4.0.1 ^2,5 . 1 ^7,10] in groups corresponding to R ³⁷ of dodecyl, hydroxy group, a hydroxymethyl group, compounds in which the carboxyl group or oxo group is bonded.

[Monomer unit of formula (IIf)]
The monomer forming the monomer unit of the formula (IIf) includes maleic anhydride.

[Monomer unit of formula (IIg)]
Typical examples of the monomer that forms the monomer unit of the formula (IIg) include the following compounds. 4-oxatricyclo [5.2.1.0 ^2,6 ] decan-8-en-5-one, 3-oxatricyclo [5.2.1.0 ^2,6 ] decan-8-ene- 4-one, 5-oxatricyclo [6.2.1.0 ^2,7 ] undecan-9-en-6-one, 4-oxatricyclo [6.2.1.0 ^2,7 ] undecane- 9-en-5-one, 4-oxapentacyclo [6.5.1.1 ^9,12 . 0 ^2,6 . 0 ^8,13 ] pentadecan-10-en-5-one, 3-oxapentacyclo [6.5.1.1 ^9,12 . 0 ^2,6 . 0 ^8,13] pentadecane-10-en-4-one, 5-oxa penta cyclo [6.6.1.1 ^{10, 13.} 0 ^2,7 . 0 ^9,14] hexadecane-11-en-6-one, 4-oxa-penta cyclo [6.6.1.1 ^{10, 13.} 0 ^2,7 . 0 ^9,14 ] Hexadecan-11-en-5-one.

[Monomer unit of formula (IIh)]
Representative examples of the monomer that forms the monomer unit of the formula (IIh) include 5-hydroxy-2-norbornene.

  The polymer can be obtained by subjecting the monomer mixture to a conventional polymerization method used for producing an acrylic polymer or the like, such as solution polymerization, bulk polymerization, suspension polymerization, bulk-suspension polymerization, and emulsion polymerization. In particular, solution polymerization is preferred, and drop polymerization is preferred among solution polymerizations. Specifically, for example, (i) a monomer solution previously dissolved in an organic solvent and a polymerization initiator solution dissolved in an organic solvent are prepared in an organic solvent kept at a constant temperature. A method in which the monomer solution and the polymerization initiator solution are respectively dropped, and (ii) a method in which a mixed solution in which the monomer and the polymerization initiator are dissolved in an organic solvent is dropped into an organic solvent maintained at a constant temperature. (Iii) A monomer solution previously dissolved in an organic solvent and a polymerization initiator solution dissolved in the organic solvent are respectively prepared, and the polymerization initiator solution is dropped into the monomer solution maintained at a constant temperature. It is performed by a method or the like.

  As the polymerization solvent, a known solvent can be used. For example, ether (chain ether such as diethyl ether, propylene glycol monomethyl ether, etc., chain ether such as tetrahydrofuran, dioxane, etc.), ester (methyl acetate, ethyl acetate, Glycol ether esters such as butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), amides (N, N-dimethylacetamide, N, N-dimethylformamide, etc.) ), Sulfoxide (dimethylsulfoxide, etc.), alcohol (methanol, ethanol, propanol, etc.), hydrocarbon (aromatic hydrocarbons such as benzene, toluene, xylene, etc.) Aliphatic hydrocarbons such as hexane, and alicyclic hydrocarbons such as cyclohexane), and mixtures of these solvents. Moreover, a well-known polymerization initiator can be used as a polymerization initiator. The polymerization temperature can be appropriately selected within a range of about 30 to 150 ° C., for example.

  In the present invention, the polymer obtained by polymerization is subjected to a precipitation operation with an organic solvent, and further purified by reprecipitation with an aqueous solvent, rinsing or repulping operation. Most of impurities such as unreacted monomer and polymerization initiator are removed by precipitation with an organic solvent, and then a slight amount of water-soluble components and components having hydrophilic groups are removed by reprecipitation with water, etc. Therefore, the water resistance of the polymer is dramatically improved. The reprecipitation with the aqueous solvent, the rinsing with the aqueous solvent, and the repulping operation with the aqueous solvent may be performed singly or in combination of two or more operations.

  Examples of the organic solvent include hydrocarbons (aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene); Halogenated hydrocarbons (halogenated aliphatic hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene), nitro compounds (nitromethane, nitroethane, etc.), nitriles (acetonitrile, Benzonitrile, etc.), ethers (chain ethers such as diethyl ether, diisopropyl ether, dimethoxyethane; cyclic ethers such as tetrahydrofuran, dioxane), ketones (acetone, methyl ethyl ketone, diisobutyl ketone, etc.) , Ester (ethyl acetate, butyl acetate, etc.), carbonate (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, etc.), alcohol (methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.), carboxylic acid (acetic acid, etc.), these And the like. The precipitation operation with an organic solvent may be repeated using the same solvent or different solvents.

  Among the organic solvents, a solvent containing at least a hydrocarbon (particularly an aliphatic hydrocarbon such as hexane) is preferable. In such a solvent containing at least hydrocarbon, the ratio of hydrocarbon (for example, aliphatic hydrocarbon such as hexane) and other solvent is, for example, the former / the latter (volume ratio; 25 ° C.) = 10/90 to 99 / 1, preferably the former / the latter (volume ratio; 25 ° C.) = 30/70 to 98/2, more preferably the former / the latter (volume ratio; 25 ° C.) = 50/50 to 97/3.

  Examples of the aqueous solvent used in the reprecipitation, rinsing, or repulping operation include water; a mixed solvent of water and a water-soluble organic solvent such as acetonitrile, tetrahydrofuran, dioxane, acetone, methanol, ethanol, and acetic acid. There is no restriction | limiting in particular as a method of reprecipitation operation, For example, it can carry out by dropping the solution which melt | dissolved the polymer in the water soluble organic solvent in water or the mixed solvent of water and a water soluble organic solvent. Also, rinsing and repulping operations can be performed by conventional methods. The amount of the aqueous solvent used for reprecipitation varies depending on the type of polymer, but is generally 10 to 1000 parts by weight, preferably 50 to 800 parts by weight, more preferably 100 to 500 parts by weight with respect to 1 part by weight of the polymer. Degree. Moreover, although the quantity of the aqueous solvent used for a rinse or a repulp changes also with the kind of polymer, generally 1-1000 weight part with respect to 1 weight part of polymers, Preferably it is 5-800 weight part, More preferably, it is 10-10 weight part. About 500 parts by weight. The temperature at the time of performing reprecipitation, rinse, or repulping operation is not specifically limited, For example, it is performed in 0-100 degreeC. The polymer precipitated by reprecipitation or the polymer subjected to rinsing or repulping is subjected to, for example, filtration or centrifugation, and, if necessary, an appropriate solvent [for example, the above organic solvent (nitrile, ether, ketone, alcohol, etc. It can be isolated by rinsing with a water-soluble or hydrophilic organic solvent or the like and drying.

  In the method of the present invention, other purification means are used before the precipitation operation with the organic solvent, between the precipitation operation with the organic solvent and the reprecipitation operation with the aqueous solvent, or after the reprecipitation operation with the aqueous solvent. Purification steps may be provided.

  The polymer purified in this way has an extremely small amount of water-soluble components, and the formed resist film has high water resistance. Therefore, it is extremely useful as a polymer compound for photoresist for immersion exposure.

  The photoresist resin composition of the present invention contains a polymer purified by the above-described method, that is, a polymer compound for photoresist for immersion exposure, and a photoacid generator.

  Examples of the photoacid generator include conventional or known compounds that efficiently generate acid upon exposure, such as diazonium salts, iodonium salts (for example, diphenyliodohexafluorophosphate), sulfonium salts (for example, triphenylsulfonium hexafluoroantimony). Nates, triphenylsulfonium hexafluorophosphate, triphenylsulfonium methanesulfonate, etc.), sulfonate esters [eg 1-phenyl-1- (4-methylphenyl) sulfonyloxy-1-benzoylmethane, 1,2,3-tri Sulfonyloxymethylbenzene, 1,3-dinitro-2- (4-phenylsulfonyloxymethyl) benzene, 1-phenyl-1- (4-methylphenylsulfonyloxymethyl) -1-hydroxy-1-benzo Rumetan etc.], oxathiazole derivatives, s- triazine derivatives, disulfone derivatives (diphenyl sulfone) imide compound, an oxime sulfonate, a diazonaphthoquinone, and benzoin tosylate. These photoacid generators can be used alone or in combination of two or more.

  The amount of the photoacid generator used can be appropriately selected according to the strength of the acid generated by light irradiation, the ratio of each monomer unit (repeating unit) in the polymer, and the like, for example, with respect to 100 parts by weight of the polymer compound It can be selected from the range of 0.1 to 30 parts by weight, preferably 1 to 25 parts by weight, more preferably about 2 to 20 parts by weight.

  The resin composition for photoresist includes alkali-soluble components such as alkali-soluble resins (for example, novolak resins, phenol resins, imide resins, carboxyl group-containing resins), colorants (for example, dyes), organic solvents (for example, Hydrocarbons, halogenated hydrocarbons, alcohols, esters, amides, ketones, ethers, cellosolves, carbitols, glycol ether esters, mixed solvents thereof, etc.) .

  The photoresist resin composition is applied onto a substrate or a substrate, dried, and then exposed to light through a predetermined mask through a predetermined mask (or further exposed). A fine pattern can be formed with high accuracy by baking and forming a latent image pattern and then developing.

  Examples of the base material or the substrate include a silicon wafer, metal, plastic, glass, and ceramic. The application of the photoresist resin composition can be performed using a conventional application means such as a spin coater, a dip coater, or a roller coater. The thickness of a coating film is 0.01-1 micrometer, for example, Preferably it is about 0.02-0.5 micrometer.

For exposure, various wavelengths of light such as ultraviolet rays and X-rays can be used. For semiconductor resists, g-line, i-line, and excimer lasers (eg, XeCl, KrF, KrCl, ArF, ArCl, F) are generally used. ₂ , Kr ₂ , KrAr, Ar ₂ etc.). The exposure energy is, for example, about 0.1 to 100 mJ / cm ² . In the present invention, since the resist film has high water resistance, exposure can be performed under immersion using an immersion type exposure apparatus. Therefore, it is possible to further advance the pattern miniaturization.

  An acid is generated from the photoacid generator by light irradiation, and this acid causes a protective group (leaving group) such as a carboxyl group of a monomer unit (alkali-soluble unit) having an acid leaving group of the polymer compound. Is rapidly eliminated, and carboxyl groups and the like that contribute to solubilization are generated. Therefore, a predetermined pattern can be accurately formed by development with water or an alkali developer.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

還流管、撹拌子、滴下ロートを備えた１００ｍｌ丸底フラスコに、窒素雰囲気下、テトラヒドロフラン（ＴＨＦ）１０ｍｌを入れ、６０℃に加熱し、撹拌下に、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン１．３８ｇ（６．２２ミリモル）、１−（１−メタクリロイルオキシ−１−メチルエチル）アダマンタン２．１６ｇ（８．２４ミリモル）、１−メタクリロイルオキシ−３−ヒドロキシアダマンタン１．４６ｇ（６．１９ミリモル）、及び開始剤（和光純薬工業製、商品名「Ｖ−６５」）０．５０ｇをＴＨＦ１６ｇに溶解させた溶液を２時間かけて滴下した。さらに６時間、同温度で熟成後、反応液をヘキサンと酢酸エチルの９：１（体積比；２５℃）混合液５００ｍｌに落とし、生じた沈殿物を濾別することで精製を行った。回収した沈殿を減圧乾燥後、再度ＴＨＦ１６ｇに溶解させ、上述の沈殿精製操作を繰り返すことにより、樹脂３．５５ｇを得た。さらに、得られ樹脂をＴＨＦ１６ｇに溶解させ、得られた溶液を蒸留水５００ｍｌに落とし、生じた沈殿を濾過後、イソプロピルアルコール１０ｍｌでリンスし、その後沈殿を回収し、減圧乾燥させて、所望の樹脂３．０ｇを得た。回収したポリマーをＧＰＣ（ゲルパーミエーションクロマトグラフィー）分析したところ、重量平均分子量（Ｍｗ）が７８００、分子量分布（Ｍｗ／Ｍｎ）が２．０であった。 Example 1
Synthesis of resin with the following structure

In a 100 ml round bottom flask equipped with a reflux tube, a stirrer, and a dropping funnel, 10 ml of tetrahydrofuran (THF) was placed in a nitrogen atmosphere, heated to 60 ° C., and stirred with 5-methacryloyloxy-2,6-norbornanecarbox. Lactone 1.38 g (6.22 mmol), 1- (1-methacryloyloxy-1-methylethyl) adamantane 2.16 g (8.24 mmol), 1-methacryloyloxy-3-hydroxyadamantane 1.46 g (6.2. 19 mmol) and an initiator (trade name “V-65”, manufactured by Wako Pure Chemical Industries, Ltd.) 0.50 g in THF 16 g were added dropwise over 2 hours. After further aging at the same temperature for 6 hours, the reaction solution was dropped into 500 ml of a 9: 1 (volume ratio; 25 ° C.) mixture of hexane and ethyl acetate, and the resulting precipitate was purified by filtration. The recovered precipitate was dried under reduced pressure and then dissolved again in 16 g of THF, and the above precipitation purification operation was repeated to obtain 3.55 g of a resin. Further, the obtained resin is dissolved in 16 g of THF, the obtained solution is dropped into 500 ml of distilled water, the resulting precipitate is filtered, rinsed with 10 ml of isopropyl alcohol, and then the precipitate is recovered and dried under reduced pressure to obtain a desired resin. 3.0 g was obtained. When the collected polymer was analyzed by GPC (gel permeation chromatography), the weight average molecular weight (Mw) was 7800, and the molecular weight distribution (Mw / Mn) was 2.0.

還流管、撹拌子、滴下ロートを備えた１００ｍｌ丸底フラスコに、窒素雰囲気下、テトラヒドロフラン（ＴＨＦ）１０ｍｌを入れ、６０℃に加熱し、撹拌下に、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン１．３８ｇ（６．２２ミリモル）、１−（１−メタクリロイルオキシ−１−メチルエチル）アダマンタン２．１６ｇ（８．２４ミリモル）、１−メタクリロイルオキシ−３−ヒドロキシアダマンタン１．４６ｇ（６．１９ミリモル）、及び開始剤（和光純薬工業製、商品名「Ｖ−６５」）０．５０ｇをＴＨＦ１６ｇに溶解させた溶液を２時間かけて滴下した。さらに６時間、同温度で熟成後、反応液をヘキサンと酢酸エチルの９：１（体積比；２５℃）混合液５００ｍｌに落とし、生じた沈殿物を濾別することで精製を行った。回収した沈殿を減圧乾燥後、再度ＴＨＦ１６ｇに溶解させ、上述の沈殿精製操作を繰り返すことにより、樹脂３．５ｇを得た。回収したポリマーをＧＰＣ（ゲルパーミエーションクロマトグラフィー）分析したところ、重量平均分子量（Ｍｗ）が７８００、分子量分布（Ｍｗ／Ｍｎ）が２．０であった。 Comparative Example 1
Synthesis of resin with the following structure

In a 100 ml round bottom flask equipped with a reflux tube, a stirrer, and a dropping funnel, 10 ml of tetrahydrofuran (THF) was placed in a nitrogen atmosphere, heated to 60 ° C., and stirred with 5-methacryloyloxy-2,6-norbornanecarbox. Lactone 1.38 g (6.22 mmol), 1- (1-methacryloyloxy-1-methylethyl) adamantane 2.16 g (8.24 mmol), 1-methacryloyloxy-3-hydroxyadamantane 1.46 g (6.2. 19 mmol) and an initiator (trade name “V-65”, manufactured by Wako Pure Chemical Industries, Ltd.) 0.50 g in THF 16 g were added dropwise over 2 hours. After further aging at the same temperature for 6 hours, the reaction solution was dropped into 500 ml of a 9: 1 (volume ratio; 25 ° C.) mixture of hexane and ethyl acetate, and the resulting precipitate was purified by filtration. The recovered precipitate was dried under reduced pressure, then dissolved again in 16 g of THF, and the above precipitation purification operation was repeated to obtain 3.5 g of a resin. When the collected polymer was analyzed by GPC (gel permeation chromatography), the weight average molecular weight (Mw) was 7800, and the molecular weight distribution (Mw / Mn) was 2.0.

Evaluation test 1
About each polymer obtained by the said Example and comparative example, 1.5 g of this polymer was melt | dissolved in 8.5 g of cyclohexanone, 10 g solution was prepared, and it spin-coated on the silicon wafer. The film thickness of the obtained coating film was measured at 5 points by ellipsometry. The silicon wafer on which the coating film was formed was immersed in water at room temperature for 10 minutes and air blown, and then the thickness of the coating film was measured again by the above method. The results are shown in Table 1. In Table 1, the increase value is a value (nm) obtained by subtracting the average value of the film thickness before water immersion from the average value of the film thickness after water immersion.

  As is apparent from Table 1, when the polymer of Example 1 was used, it was found that even when immersed in water, there was almost no variation in the thickness of the coating film and the water resistance was excellent. Therefore, the polymer of Example 1 is useful as a resist for immersion exposure. On the other hand, when the polymer of Comparative Example 1 is used, when it is immersed in water, it swells and the thickness of the coating film increases greatly.

Evaluation test 2
For each of the polymers obtained in the above Examples and Comparative Examples, 100 parts by weight of polymer and 10 parts by weight of triphenylsulfonium hexafluoroantimonate were mixed with propylene glycol monomethyl ether acetate (PGMEA) as a solvent to obtain a polymer concentration. A resin composition for photoresist of 17% by weight was prepared. This composition was applied on a silion wafer by a spin coating method to form a photosensitive layer having a thickness of 0.4 μm. After pre-baking on a hot plate at a temperature of 100 ° C. for 150 seconds, using a KrF excimer laser with a wavelength of 247 nm, exposure was performed at a dose of 30 mJ / cm ² through a mask, followed by post-baking at a temperature of 100 ° C. for 60 seconds. Subsequently, it developed for 60 second with 0.3M tetramethylammonium hydroxide aqueous solution, and rinsed with the pure water. As a result, a 0.20 μm line and space pattern was obtained.

Claims (7)

  A polymer containing a monomer unit having a group that expresses an alkali-soluble function by partial elimination by an acid is subjected to precipitation with an organic solvent, and then subjected to reprecipitation with an aqueous solvent, rinsing or repulping operation. A method for producing a polymer compound for photoresist for immersion exposure. Monomer units having a group that is partially eliminated by an acid and exhibits an alkali-soluble function are represented by the following formulas (Ia) to (Ih):

(In the formula, R ^a represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. R ¹ and R ² are the same or different and have 1 to 8 carbon atoms. R ³ , R ⁴ and R ⁵ are the same or different and represent a hydrogen atom, a hydroxyl group or a methyl group, and R ⁶ and R ⁷ are the same or different and represent a hydrogen atom, a hydroxyl group or shows a -COOR ⁸ group, R ⁸ is t- butyl, 2-tetrahydrofuranyl group, .R ⁹ showing a 2-tetrahydropyranyl group or a 2-oxepanyl group represents a methyl group or an ethyl group, R ¹⁰ and R ¹¹ is the same or different and represents a hydrogen atom, a hydroxyl group or an oxo group, and R ¹² has a substituent having a tertiary carbon atom at the bonding site with the oxygen atom shown in the formula. R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ are the same or different and each represents a hydrogen atom or a methyl group, and R ¹⁸ represents a t-butyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or a 2-oxepanyl group. R ¹⁹ and R ²⁰ are the same or different and each represents a hydrogen atom, an alkyl group or a fluoroalkyl group, R ²¹ represents a hydrogen atom or an organic group, m represents an integer of 1 to 3, and n represents 0. Or 1)
2. The method for producing a polymer compound for photoresist for immersion exposure according to claim 1, wherein the monomer unit is at least one monomer unit selected from the group consisting of:   The liquid immersion according to claim 1 or 2, wherein the polymer to be subjected to precipitation is a polymer comprising a monomer unit having a group that exhibits an alkali-soluble function when part of it is eliminated by an acid and a monomer unit having a substrate adhesion function. A method for producing a polymer compound for photoresist for exposure. Monomer units having a substrate adhesion function are represented by the following formulas (IIa) to (IIh):

(In the formula, R ^a represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. R ²² and R ²³ are the same or different and represent a hydrogen atom or a hydroxyl group. Or a carboxyl group, R ²⁴ represents a hydroxyl group, an oxo group or a carboxyl group, X ¹ , X ² and X ³ are the same or different and represent —CH ₂ — or —CO—O—. At least one of X ^{1 to} X ³ is —CO—O—, R ²⁵ , R ²⁶ and R ²⁷ are the same or different and represent a hydrogen atom or a methyl group, and R ²⁸ and R ²⁹ are the same. R ³⁰ , R ³¹ , R ³² , R ³³ and R ³⁴ are the same or different and each represents a hydrogen atom or a methyl group, and R ³⁵ represents a hydrogen atom or a hydroxyl group. Group, hydroxymethyl group, carboxyl group or o , Straight with a source group, branched chain, .R ³⁶ showing a cyclic or bridged cyclic hydrocarbon group, R ^37, R ³⁸ and R ³⁹ are the same or different, a hydrogen atom or .o .R ⁴⁰ showing a methyl group showing a hydroxyl group, a hydroxymethyl group or a carboxyl group, p, q and r are, respectively, 0 or 1)
4. The method for producing a polymer compound for photoresist for immersion exposure according to claim 3, wherein the monomer unit is at least one monomer unit selected from the group consisting of:   The high molecular compound for photoresists for immersion exposure obtained by the manufacturing method in any one of Claims 1-4.   A resin composition for a photoresist for immersion exposure, comprising at least the polymer compound for a photoresist for immersion exposure according to claim 5 and a photoacid generator. A semiconductor comprising a step of applying a photoresist resin composition for immersion exposure according to claim 6 on a substrate or a substrate to form a resist coating film, and forming a pattern through exposure and development under immersion. Manufacturing method.