JP2006282686A - Process of manufacturing polymer compound for photoresist and photoresist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently obtain a polymer compound for photoresists containing a minimal amount of residual monomers with a simple means. <P>SOLUTION: The process of manufacturing the polymer compound for photoresists comprises a polymerization step to polymerize with drop polymerization a monomer mixture containing at least a monomer having a group which becomes alkali-soluble with an acid and a monomer having a group which contains a polar-group containing an alicyclic structure and an after step to reduce residual monomers by adding a radical generator after the polymerization step. The process may involve, after the after step, a washing step to wash the solution containing the polymer formed by the polymerization. The monomer solution containing the monomer mixture and the solution of a polymerization initiator may be independently dropped into a medium the temperature of which is elevated to the polymerization temperature. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a photoresist polymer compound useful for preparing a photoresist composition for use in microfabrication of a semiconductor, the photoresist composition containing the photoresist polymer compound, and the photoresist composition. The present invention relates to a method for manufacturing a semiconductor using an object.

  The positive photoresist used in the semiconductor manufacturing process must have properties such as the property that the irradiated part changes to alkali-soluble by light irradiation, adhesion to the silicon wafer, plasma etching resistance, transparency to the light used, etc. Don't be. The positive photoresist is generally used as a solution containing a main polymer, a photoacid generator, and several additives for adjusting the above characteristics. On the other hand, lithography exposure light sources used for semiconductor manufacturing have become shorter in wavelength year by year, and ArF excimer lasers having a wavelength of 193 nm are promising as next-generation exposure light sources. As a resist polymer used in this ArF excimer laser exposure machine, there is a polymer containing a repeating unit containing a group that is partly eliminated by acid and becomes alkali-soluble and a repeating unit containing an alicyclic skeleton having a polar group. Various proposals have been made (for example, Patent Documents 1 and 2).

  Since the monomer used as the raw material for these polymers is opaque to 193 nm far ultraviolet rays, it is desirable that the monomer does not exist at all in the polymer compound for photoresist. However, since it is generally difficult to perform polymerization until the amount of residual monomer is negligible, a method of separating and removing residual monomer from the polymer by reprecipitation or the like has been generally performed (for example, Patent Document 3). ). However, the conventional method for removing monomers by reprecipitation or the like not only reduces the yield, but also the work is complicated, and therefore there is a need for a method that can efficiently produce a polymer with a low residual monomer content by simpler means. It was done.

JP 2000-26446 A JP-A-9-73137 JP 2004-269855 A

Accordingly, an object of the present invention is to provide a method capable of efficiently producing a polymer compound for photoresist having a very small residual monomer content by a simple means.
Another object of the present invention is to provide a photoresist composition capable of accurately forming a desired fine pattern in the production of a semiconductor and a method for producing a semiconductor using the resist composition.

  As a result of intensive studies to achieve the above object, the present inventors have polymerized the monomer mixture by dropwise polymerization and then added a radical generator. The inventors have found that a high molecular weight compound for photoresist with a very small amount of residual monomer can be obtained, and completed the present invention.

  That is, the present invention provides a monomer mixture comprising at least a monomer having a group that is alkali-soluble by an acid and a monomer having a group containing a polar group-containing alicyclic skeleton by a dropping polymerization method. Provided is a method for producing a polymer compound for photoresist, comprising a polymerization step for polymerization and a post-step for adding a radical generator after the polymerization step to reduce residual monomers.

  The said manufacturing method may further include the water washing process of attaching | subjecting the solution containing the polymer produced | generated by superposition | polymerization to a water washing after a post process.

  In the polymerization step, the monomer solution containing the monomer mixture and the polymerization initiator solution containing the polymerization initiator may be dropped independently into the solvent heated to the polymerization temperature. In this case, it is preferable to continue dropping the polymerization initiator solution even after the monomer solution dropping is completed.

  The radical generator used in the subsequent step includes a polymerization initiator having an oxygen atom-containing group or a substituted or unsubstituted amino group in the molecule. Examples of such a polymerization initiator include a polymerization initiator having a hydroxyl group or a carboxyl group.

（式中、環Ｚは置換基を有していてもよい炭素数６〜２０の脂環式炭化水素環を示す。Ｒは水素原子又は置換基を有していてもよい炭素数１〜６のアルキル基を示す。Ｒ¹〜Ｒ³は、同一又は異なって、置換基を有していてもよい炭素数１〜６のアルキル基を示す。Ｒ⁴は環Ｚに結合している置換基であって、同一又は異なって、オキソ基、アルキル基、保護基で保護されていてもよいヒドロキシル基、保護基で保護されていてもよいヒドロキシアルキル基、又は保護基で保護されていてもよいカルボキシル基を示す。但し、ｎ個のＲ⁴のうち少なくとも１つは、−ＣＯＯＲ^a基を示す。前記Ｒ^aは置換基を有していてもよい第３級炭化水素基、テトラヒドロフラニル基、テトラヒドロピラニル基、又はオキセパニル基を示す。ｎは１〜３の整数を示す。Ｒ⁵、Ｒ⁶は、同一又は異なって、水素原子又は置換基を有していてもよい炭素数１〜６のアルキル基を示す。Ｒ⁷は水素原子又は有機基を示す。Ｒ⁵、Ｒ⁶、Ｒ⁷のうち少なくとも２つが互いに結合して隣接する原子とともに環を形成していてもよい）
から選択された少なくとも１種の化合物を使用できる。 Examples of the monomer having a group that becomes alkali-soluble by an acid include the following formulas (1a) to (1d):

(In the formula, ring Z represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms which may have a substituent. R represents a hydrogen atom or an optionally substituted substituent having 1 to 6 carbon atoms. R ^{1 to} R ³ are the same or different and each represents an optionally substituted alkyl group having 1 to 6 carbon atoms, and R ⁴ is a substituent bonded to ring Z. And may be the same or different and may be protected with an oxo group, an alkyl group, a hydroxyl group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, or a protecting group. Represents a carboxyl group, provided that at least one of n R ⁴ groups represents ^a —COOR ^a group, wherein R ^a represents ^a tertiary hydrocarbon group which may have ^a substituent, a tetrahydrofuranyl group, A tetrahydropyranyl group or an oxepanyl group, where n is an integer of 1 to 3. R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms, R ⁷ represents a hydrogen atom or an organic group. ⁵ , R ⁶ , or R ⁷ may be bonded to each other to form a ring with adjacent atoms.
At least one compound selected from can be used.

（式中、Ｒは水素原子又は置換基を有していてもよい炭素数１〜６のアルキル基を示す。Ｒ⁸〜Ｒ¹⁰は、同一又は異なって、水素原子、アルキル基、保護基で保護されていてもよいヒドロキシル基、保護基で保護されていてもよいヒドロキシアルキル基、又は保護基で保護されていてもよいカルボキシル基を示し、Ｖ¹〜Ｖ³は、同一又は異なって、−ＣＨ₂−、−ＣＯ−又は−ＣＯＯ−を示す。但し、（ｉ）Ｖ¹〜Ｖ³のうち少なくとも１つは−ＣＯ−若しくは−ＣＯＯ−であるか、又は（ii）Ｒ⁸〜Ｒ¹⁰のうち少なくとも１つは、保護基で保護されていてもよいヒドロキシル基、保護基で保護されていてもよいヒドロキシアルキル基、又は保護基で保護されていてもよいカルボキシル基である。Ｒ¹¹〜Ｒ¹⁵は、同一又は異なって、水素原子、アルキル基、保護基で保護されていてもよいヒドロキシル基、保護基で保護されていてもよいヒドロキシアルキル基、保護基で保護されていてもよいカルボキシル基を示す。Ｒ¹⁶〜Ｒ²⁴は、同一又は異なって、水素原子、アルキル基、保護基で保護されていてもよいヒドロキシル基、保護基で保護されていてもよいヒドロキシアルキル基、保護基で保護されていてもよいカルボキシル基を示す。Ｒ²⁵〜Ｒ³³は、同一又は異なって、水素原子、アルキル基、保護基で保護されていてもよいヒドロキシル基、保護基で保護されていてもよいヒドロキシアルキル基、保護基で保護されていてもよいカルボキシル基を示す。ｐは０又は１、ｑは１又は２を示す）
から選択された少なくとも１種の化合物を使用できる。 Examples of the monomer having a group containing a polar group-containing alicyclic skeleton include the following formulas (2a) to (2e)

(In the formula, R represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms. R ^{8 to} R ¹⁰ are the same or different and each represents a hydrogen atom, an alkyl group, or a protecting group. A hydroxyl group which may be protected, a hydroxyalkyl group which may be protected with a protecting group, or a carboxyl group which may be protected with a protecting group, V ^{1 to} V ³ are the same or different, and CH _2- , -CO- or -COO-, provided that (i) at least one of V ^{1 to} V ³ is -CO- or -COO-, or (ii) R ^{8 to} R ¹⁰ at least one of the, optionally protected hydroxyl group, a protected or unprotected hydroxyalkyl group with a protecting group, or be protected by a protecting group is also a carboxyl group which .R ¹¹ ~ R ¹⁵ is the same or different and is a hydrogen atom , An alkyl group, a hydroxyl group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, and a carboxyl group that may be protected with a protecting group, R ^{16 to} R ²⁴ represent It is the same or different and represents a hydrogen atom, an alkyl group, a hydroxyl group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, or a carboxyl group that may be protected with a protecting group. R ^{25 to} R ³³ are the same or different and are protected by a hydrogen atom, an alkyl group, a hydroxyl group which may be protected with a protecting group, a hydroxyalkyl group which may be protected with a protecting group, or a protecting group. (P represents 0 or 1, q represents 1 or 2)
At least one compound selected from can be used.

  The present invention also provides a photoresist composition comprising a polymer compound for photoresist produced by the above method and a photoacid generator.

  The present invention further provides a method for producing a semiconductor, comprising a step of applying the photoresist composition to a substrate or a base material to form a resist coating film.

  According to the method for producing a polymer compound for photoresists of the present invention, the residual monomer can be efficiently reduced after the completion of polymerization, so that the polymer compound for photoresist having a very small residual monomer content by simple purification thereafter. Thus, the process can be simplified and improved in efficiency. In addition, since the photoresist composition prepared from the polymer compound for photoresist thus obtained has an extremely low monomer content, it is possible to accurately form a desired pattern without reducing sensitivity and resolution in semiconductor manufacturing. it can.

  In the present invention, a monomer having a group that is alkali-soluble by an acid (sometimes referred to as “monomer a”) and a monomer having a group containing a polar group-containing alicyclic skeleton (“single” A polymerization step in which a monomer mixture containing at least a monomer b) is polymerized by a dropping polymerization method, and a subsequent step in which a radical generator is added after the polymerization step to reduce residual monomers. Contains.

  Monomer a is a polymerizable compound having a group that is partially dissolved by the action of an acid generated from a photoacid generator upon exposure and introduced into a resin by polymerization and is soluble in an alkaline developer. (Monomer having an acid leaving group) No particular limitation, for example, having an alicyclic hydrocarbon group having 6 to 20 carbon atoms and having a group capable of leaving by the action of an acid (Meth) acrylic acid ester and the like. “A (meth) acrylic acid ester containing a alicyclic hydrocarbon group having 6 to 20 carbon atoms and having a group capable of leaving by the action of an acid” includes an alicyclic group having 6 to 20 carbon atoms. A (meth) acrylic acid ester having a hydrocarbon group and a tertiary carbon atom at the bonding site with an oxygen atom constituting the ester bond of the (meth) acrylic acid ester is included. The alicyclic hydrocarbon group may be directly bonded to an oxygen atom constituting the ester bond of (meth) acrylic acid ester, or may be bonded via a linking group such as an alkylene group. The alicyclic hydrocarbon group having 6 to 20 carbon atoms may be a monocyclic hydrocarbon group or a polycyclic (bridged cyclic) hydrocarbon group. Representative examples of such (meth) acrylic acid esters include compounds represented by the formulas (1a) and (1b).

In addition, “(meth) acrylic acid ester having a group having 6 to 20 carbon atoms and having a group capable of leaving by the action of an acid” includes an aliphatic group having 6 to 20 carbon atoms. A cyclic hydrocarbon group and a -COOR ^a group (R ^a is an optionally substituted tertiary hydrocarbon group, tetrahydrofuranyl group, tetrahydropyranyl group, Or a (meth) acrylic acid ester to which an oxepanyl group is bonded directly or via a linking group. Examples of the tertiary hydrocarbon group in R ^a of the —COOR ^a group include t-butyl, t-amyl, 2-methyl-2-adamantyl, (1-methyl-1-adamantyl) ethyl group, and the like. . Examples of the substituent that the tertiary hydrocarbon group may have include, for example, a halogen atom, an alkyl group (eg, a C _1-4 alkyl group), a hydroxyl group optionally protected by a protecting group, oxo And a carboxyl group which may be protected with a protecting group. The tetrahydrofuranyl group in R ^a includes a 2-tetrahydrofuranyl group, the tetrahydropyranyl group includes a 2-tetrahydropyranyl group, and the oxepanyl group includes a 2-oxepanyl group. Examples of the linking group include an alkylene group (for example, a linear or branched alkyl group having 1 to 6 carbon atoms). The alicyclic hydrocarbon group may be directly bonded to an oxygen atom constituting the ester bond of (meth) acrylic acid ester, or may be bonded via a linking group such as an alkylene group. The alicyclic hydrocarbon group having 6 to 20 carbon atoms may be a monocyclic hydrocarbon group or a polycyclic (bridged cyclic) hydrocarbon group. A typical example of such a (meth) acrylic acid ester is a compound represented by the formula (1c).

  Another example of monomer a is (meth) acrylic acid hemiacetal ester. Specifically, the compound represented by the formula (1d) is exemplified.

  In addition, as monomer a, a (meth) acrylic acid ester containing a lactone ring in which an oxygen atom constituting an ester bond is bonded to the β-position of the lactone ring and has at least one hydrogen atom in the α-position of the lactone ring It is also possible to use. Monomers having a group that becomes alkali-soluble by the acid can be used alone or in combination of two or more.

The monomer a is preferably at least one compound selected from the formulas (1a) to (1d). In formulas (1a) to (1d), the alicyclic hydrocarbon ring having 6 to 20 carbon atoms in ring Z may be a single ring or a polycyclic ring such as a condensed ring or a bridged ring. Typical alicyclic hydrocarbon rings include, for example, cyclohexane ring, cyclooctane ring, cyclodecane ring, adamantane ring, norbornane ring, norbornene ring, bornane ring, isobornane ring, perhydroindene ring, decalin ring, perhydrofluorene ring. (Tricyclo [7.4.0.0 ^3,8 ] tridecane ring), perhydroanthracene ring, tricyclo [5.2.1.0 ^2,6 ] decane ring, tricyclo [4.2.2.1 ^{2, 5} ] Undecane ring, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane ring and the like. The alicyclic hydrocarbon ring includes an alkyl group such as a methyl group (eg, a C _1-4 alkyl group), a halogen atom such as a chlorine atom, a hydroxyl group optionally protected by a protecting group, an oxo group, a protected group It may have a substituent such as a carboxyl group which may be protected with a group. The ring Z is preferably a polycyclic alicyclic hydrocarbon ring (bridged hydrocarbon ring) such as an adamantane ring.

Formula (1a) ~ (1d) in the R, and the formula (1a), (1b), R 1 ~R 3, R 5, R carbon atoms, which may have a substituent at ⁶ in (1d) Examples of the alkyl group having 1 to 6 include linear or branched alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, and hexyl groups. A haloalkyl group having 1 to 6 carbon atoms such as a trifluoromethyl group; R is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, particularly preferably a hydrogen atom or a methyl group. In the formula (1c), examples of the alkyl group represented by R ⁴ include linear or methyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, hexyl, octyl, decyl, and dodecyl groups. Examples include branched chain alkyl groups having about 1 to 20 carbon atoms. Examples of the hydroxyl group that may be protected with a protecting group for R ⁴ include a hydroxyl group and a substituted oxy group (for example, a C _1-4 alkoxy group such as a methoxy, ethoxy, propoxy group, etc.). Examples of the hydroxyalkyl group which may be protected with a protecting group include a group in which a hydroxyl group which may be protected with the protecting group is bonded via an alkylene group having 1 to 6 carbon atoms. Examples of the carboxyl group that may be protected with a protecting group include a —COOR ^b group. R ^b represents a hydrogen atom or an alkyl group, and examples of the alkyl group include linear or branched carbon such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, and hexyl groups. Examples thereof include alkyl groups of 1 to 6. In R ^4, R ^a of -COOR ^a group is the same as above.

Examples of the organic group in R ⁷ 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 ⁷ ) shown in the formula (1d) 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.

At least two of R ⁵ , R ⁶ and R ⁷ may be bonded to each other to form a ring together with adjacent atoms. Examples of the ring include cycloalkane rings such as cyclopropane ring, cyclopentane ring and cyclohexane ring; oxygen-containing rings such as tetrahydrofuran ring, tetrahydropyran ring and oxepane ring; bridged ring and the like.

  In the compounds represented by the formulas (1a) to (1d), stereoisomers may exist, but they can be used alone or as a mixture of two or more.

Although the following compound is mentioned as a typical example of a compound represented by Formula (1a), It is not limited to these.
[1-1] 2- (Meth) acryloyloxy-2-methyladamantane (R = H or CH ₃ , R ¹ = CH ₃ , Z = adamantane ring)
[1-2] 1-hydroxy-2- (meth) acryloyloxy-2-methyladamantane (R = H or CH ₃ , R ¹ = CH ₃ , adamantane ring having a hydroxyl group at the 1-position)
[1-3] 5-hydroxy-2- (meth) acryloyloxy-2-methyladamantane (R = H or CH ₃ , R ¹ = CH ₃ , Z = 5 adamantane ring having a hydroxyl group at the 5-position)
[1-4] 1,3-Dihydroxy-2- (meth) acryloyloxy-2-methyladamantane (R = H or CH ₃ , R ¹ = CH ₃ , Z = 1- and adamantane having hydroxyl groups at the 3-position ring)
[1-5] 1,5-dihydroxy-2- (meth) acryloyloxy-2-methyladamantane (R = H or CH ₃ , R ¹ = CH ₃ , Z = 1- and adamantane having hydroxyl groups at the 5-position ring)
[1-6] 1,3-dihydroxy-6- (meth) acryloyloxy-6-methyladamantane (R = H or CH ₃ , R ¹ = CH ₃ , Z = 1 adamantane having hydroxyl groups at the 1-position and 3-position ring)
[1-7] 2- (Meth) acryloyloxy-2-ethyladamantane (R = H or CH ₃ , R ¹ = CH ₂ CH ₃ , Z = adamantane ring)
[1-8] 1-hydroxy-2- (meth) acryloyloxy-2-ethyladamantane (R = H or CH ₃ , R ¹ = CH ₂ CH ₃ , Z = 1 adamantane ring having a hydroxyl group at the 1-position)
[1-9] 5-hydroxy-2- (meth) acryloyloxy-2-ethyladamantane (R = H or CH ₃ , R ¹ = CH ₂ CH ₃ , Z = 5 adamantane ring having a hydroxyl group at the 5-position)
[1-10] 1,3-Dihydroxy-2- (meth) acryloyloxy-2-ethyladamantane (R = H or CH ₃ , R ¹ = CH ₂ CH ₃ , Z = 1 and hydroxyl groups at the 3-position Has an adamantane ring)
[1-11] 1,5-Dihydroxy-2- (meth) acryloyloxy-2-ethyladamantane (R = H or CH ₃ , R ¹ = CH ₂ CH ₃ , Z = 1 and hydroxyl groups at the 5-position Has an adamantane ring)
[1-12] 1,3-dihydroxy-6- (meth) acryloyloxy-6-ethyladamantane (R = H or CH ₃ , R ¹ = CH ₂ CH ₃ , Z = 1 and hydroxyl groups at the 1 and 3 positions Has an adamantane ring)

  The compound represented by the above formula (1a) is, for example, a conventional esterification method using a corresponding cyclic alcohol and (meth) acrylic acid or a reactive derivative thereof using an acid catalyst, a transesterification catalyst, a base or the like. It can obtain by making it react according to.

Typical examples of the compound represented by the formula (1b) include the following compounds, but are not limited thereto.
[1-13] 1- (1- (Meth) acryloyloxy-1-methylethyl) adamantane (R = H or CH ₃ , R ² = R ³ = CH ₃ , Z = adamantane ring)
[1-14] 1-hydroxy-3- (1- (meth) acryloyloxy-1-methylethyl) adamantane (R = H or CH ₃ , R ² = R ³ = CH ₃ , Z = 1-hydroxyl group at position 1 Adamantane ring)
[1-15] 1- (1-ethyl-1- (meth) acryloyloxy propyl) adamantane (R = H or ^{_{CH 3, R 2 = R 3}} = CH 2 CH 3, Z = adamantane ring)
[1-16] 1-hydroxy-3- (1-ethyl-1- (meth) acryloyloxypropyl) adamantane (R = H or CH ₃ , R ² = R ³ = CH ₂ CH ₃ , Z = 1 position) Adamantane ring having a hydroxyl group)
[1-17] 1- (1- (Meth) acryloyloxy-1-methylpropyl) adamantane (R = H or CH ₃ , R ² = CH ₃ , R ³ = CH ₂ CH ₃ , Z = adamantane ring)
[1-18] 1-hydroxy-3- (1- (meth) acryloyloxy-1-methylpropyl) adamantane (R = H or CH ₃ , R ² = CH ₃ , R ³ = CH ₂ CH ₃ , Z = Adamantane ring having a hydroxyl group at the 1-position)
[1-19] 1- (1- (Meth) acryloyloxy-1,2-dimethylpropyl) adamantane (R = H or CH ₃ , R ² = CH ₃ , R ³ = CH (CH ₃ ) ₂ , Z = Adamantane ring)
[1-20] 1-hydroxy-3- (1- (meth) acryloyloxy-1,2-dimethylpropyl) adamantane (R = H or CH ₃ , R ² = CH ₃ , R ³ = CH (CH ₃ ) ₂ , Z = adamantane ring having a hydroxyl group at the 1-position)
[1-21] 1,3-dihydroxy-5- (1- (meth) acryloyloxy-1-methylethyl) adamantane (R = H or CH ₃ , R ² = R ³ = CH ₃ , Z = 1 position) An adamantane ring having a hydroxyl group at the 3-position)
[1-22] 1- (1-Ethyl-1- (meth) acryloyloxypropyl) -3,5-dihydroxyadamantane (R = H or CH ₃ , R ² = R ³ = CH ₂ CH ₃ , Z = 3 Adamantane ring with hydroxyl groups at the 5 and 5 positions)
[1-23] 1,3-dihydroxy-5- (1- (meth) acryloyloxy-1-methylpropyl) adamantane (R = H or CH ₃ , R ² = CH ₃ , R ³ = CH ₂ CH ₃ , Z = adamantane ring having hydroxyl groups at the 1- and 3-positions)
[1-24] 1,3-dihydroxy-5- (1- (meth) acryloyloxy-1,2-dimethylpropyl) adamantane (R = H or CH ₃ , R ² = CH ₃ , R ³ = CH (CH ₃ ) ₂ , Z = 1 adamantane ring having hydroxyl groups at the 1- and 3-positions)

  The compound represented by the above formula (1b) includes, for example, a methanol derivative having an alicyclic group at the corresponding 1-position and (meth) acrylic acid or a reactive derivative thereof, an acid catalyst, a transesterification catalyst, a base, etc. It can obtain by making it react according to the conventional esterification method using.

Typical examples of the compound represented by the formula (1c) include, but are not limited to, the following compounds.
[1-25] 1-t-Butoxycarbonyl-3- (meth) acryloyloxyadamantane (R = H or CH ₃ , R ⁴ = t-butoxycarbonyl group, n = 1, Z = adamantane ring)
[1-26] 1,3-bis (t-butoxycarbonyl) -5- (meth) acryloyloxyadamantane [R = H or CH ₃ , R ⁴ = t-butoxycarbonyl group, n = 2, Z = adamantane ring ]
[1-27] 1-t-Butoxycarbonyl-3-hydroxy-5- (meth) acryloyloxyadamantane (R = H or CH ₃ , R ⁴ = OH, t-butoxycarbonyl group, n = 2, Z = adamantane ring)
[1-28] 1- (2-Tetrahydropyranyloxycarbonyl) -3- (meth) acryloyloxyadamantane (R = H or CH ₃ , R ⁴ = 2-tetrahydropyranyloxycarbonyl group, n = 1, Z = Adamantane ring)
[1-29] 1,3-bis (2-tetrahydropyranyloxycarbonyl) -5- (meth) acryloyloxyadamantane (R = H or CH ₃ , R ⁴ = 2-tetrahydropyranyloxycarbonyl group, n = 2, Z = adamantane ring)
[1-30] 1-hydroxy-3- (2-tetrahydropyranyloxy carbonyl) -5- (meth) acryloyloxy adamantane (R = H or ^{_{CH 3, R 4 = OH,}} 2- tetrahydropyranyloxy group , N = 2, Z = adamantane ring)

  The compound represented by the above formula (1c) is, for example, a conventional esterification method using a corresponding cyclic alcohol and (meth) acrylic acid or a reactive derivative thereof using an acid catalyst, a transesterification catalyst, a base, or the like. It can obtain by making it react according to.

Typical examples of the compound represented by the formula (1d) include the following compounds, but are not limited thereto.
[1-31] 1-adamantyloxy-1-ethyl (meth) acrylate (R = H or CH ₃ , R ⁵ = CH ₃ , R ⁶ = H, R ⁷ = 1-adamantyl group)
[1-32] 1-adamantylmethyloxy-1-ethyl (meth) acrylate (R = H or CH ₃ , R ⁵ = CH ₃ , R ⁶ = H, R ⁷ = 1-adamantylmethyl group)
[1-33] 2- (1-adamantyl) oxy-1-ethyl (meth) acrylate (R = H or ^{_{CH 3, R 5 = CH 3}} , R 6 = H, R 7 = 1- adamantyl ethyl group)
[1-34] 1-bornyloxy-1-ethyl (meth) acrylate (R = H or CH ₃ , R ⁵ = CH ₃ , R ⁶ = H, R ⁷ = 1-bornyl group)
[1-35] 2-norbornyloxy-1-ethyl (meth) acrylate (R = H or CH ₃ , R ⁵ = CH ₃ , R ⁶ = H, R ⁷ = 2-norbornyl group)
[1-36] 2-Tetrahydropyranyl (meth) acrylate (R = H or CH ₃ , R ⁵ and R ⁷ combine to form a ⁶ -membered ring together with the carbon atom and oxygen atom in the formula, R ⁶ = H )
[1-37] 2-tetrahydrofuranyl (meth) acrylate (R = H or CH ₃ , R ⁵ and R ⁷ combine to form a 5-membered ring with carbon and oxygen atoms in the formula, R ⁶ = H)

  The compound represented by the above formula (1d) can be obtained, for example, by reacting the corresponding vinyl ether compound and (meth) acrylic acid by a conventional method using an acid catalyst. For example, 1-adamantyloxy-1-ethyl (meth) acrylate can be produced by reacting 1-adamantyl-vinyl-ether with (meth) acrylic acid in the presence of an acid catalyst.

The monomer (monomer b) having a group containing a polar group-containing alicyclic skeleton includes (1) an alicyclic hydrocarbon group having 6 to 20 carbon atoms containing a lactone ring [lactone ring and simple group. (Meth) acrylic acid ester (monomer b1) in which a group having a structure in which a ring or a polycyclic (bridged) alicyclic carbocyclic ring is condensed] is bonded to an oxygen atom constituting an ester bond Is included. As a typical example of such a monomer b1, in the formula (2a), at least one of V ^{1 to} V ³ is —COO—, and (2b), (2c), (2d), The compound represented by (2e) is exemplified.

The monomer b includes (2) an alicyclic hydrocarbon group having 6 to 20 carbon atoms having a polar group such as a hydroxyl group, a carboxyl group, or an oxo group (particularly, a bridged cyclic hydrocarbon group). A (meth) acrylic acid ester (monomer b2) bonded to an oxygen atom constituting an ester bond is also included. As a typical example of such a monomer b2, at least one of V ^{1 to} V ^{3 in} the formula (2a) is —CO—, or at least one of R ^{8 to} R ¹⁰ is protected. Examples thereof include a hydroxyl group which may be protected with a group, a hydroxyalkyl group which may be protected with a protecting group, or a carboxyl group which may be protected with a protecting group.

  When the monomer b is introduced into the resin by polymerization, the monomer b provides adhesion to a substrate such as a silicon wafer by a polar group, and imparts dry etching resistance by an alicyclic skeleton. Monomer b can be used alone or in combination of two or more. The monomer b is preferably at least one monomer selected from the formulas (2a) to (2e). Moreover, when the monomer b1 and the monomer b2 are used in combination as the monomer b, a resin having a good balance of properties such as substrate adhesion, dry etching resistance, and solubility in a resist solvent can be obtained. In addition, a great advantage is obtained that the polymer is excellent in homogeneous reactivity during polymerization (a polymer having high uniformity in molecular weight and molecular structure is produced).

R in the formulas (2a) to (2e) is the same as R in the above (1a) to (1c). In formulas (2a) to (2e), examples of the alkyl group represented by R ^{8 to} R ³³ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, hexyl, octyl, decyl, dodecyl group, and the like. And a linear or branched alkyl group having 1 to 13 carbon atoms. Among these, a C1-C4 alkyl group is preferable. Examples of the hydroxyl group that may be protected with a protecting group include a hydroxyl group and a substituted oxy group (for example, a C _1-4 alkoxy group such as a methoxy, ethoxy, and propoxy group). Examples of the hydroxyalkyl group which may be protected with a protecting group include a group in which a hydroxyl group which may be protected with the protecting group is bonded via an alkylene group having 1 to 6 carbon atoms. Examples of the carboxyl group that may be protected with a protecting group include a —COOR ^b group. R ^b is the same as described above.

  In the compounds represented by the formulas (2a) to (2e), stereoisomers may exist, but they can be used alone or as a mixture of two or more.

Although the following compound is mentioned as a typical example of a compound represented by Formula (2a), It is not limited to these.
[2-1] 1- (Meth) acryloyloxy-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-5-one (R = H or CH ₃ , R ⁸ = R ⁹ = R ¹⁰ = H, V ² = —CO—O— (the carbon atom side to which R ⁹ is bonded on the left side), V ¹ = V ³ = —CH ₂ —)
[2-2] 1- (Meth) acryloyloxy-4,7-dioxatricyclo [4.4.1.1 ^3,9 ] dodecane-5,8-dione (R = H or CH ₃ , R ^{8 = R 9 = R 10 = H} , V 1 = -CO-O- ( left bonded to the carbon atom side of the ^{R 8), V 2 = -CO} -O- ( left is bonded to R ⁹ Carbon atom side), V ³ = -CH _2- )
[2-3] 1- (Meth) acryloyloxy-4,8-dioxatricyclo [4.4.1.1 ^3,9 ] dodecane-5,7-dione (R = H or CH ₃ , R ^{8 = R 9 = R 10 = H} , V 1 = -O-CO- ( left bonded to that carbon atom side of the ^{R 8), V 2 = -CO} -O- ( left is bonded to R ⁹ Carbon atom side), V ³ = -CH _2- )
[2-4] 1- (Meth) acryloyloxy-5,7-dioxatricyclo [4.4.1.1 ^3,9 ] dodecane-4,8-dione (R = H or CH ₃ , R ^{8 = R 9 = R 10 = H} , V 1 = -CO-O- ( carbon atoms side the left is attached to ^{R 8), V 2 = -O} -CO- ( left is bonded to R ⁹ Carbon atom side), V ³ = -CH _2- )
[2-5] 1- (meth) acryloyloxy-3-hydroxyadamantane (R = H or ^{_{CH 3, R 8 = OH,}} R 9 = R 10 = H, V 1 = V 2 = V 3 = -CH 2 −)
[2-6] 1- (meth) acryloyloxy-3,5-dihydroxyadamantane (R = H or _{^{CH 3, R 8 = R 9}} = OH, R 10 = H, V 1 = V 2 = V 3 = - CH ₂ −)
[2-7] 1- (Meth) acryloyloxy-3,5,7-trihydroxyadamantane (R = H or CH ₃ , R ⁸ = R ⁹ = R ¹⁰ = OH, V ¹ = V ² = V ³ = —CH ₂ —)
[2-8] 1- (meth) acryloyloxy-3-hydroxy-5,7-dimethyl adamantane (R = H or ^{_{CH 3, R 8 = OH,}} R 9 = R 10 = CH 3, V 1 = V 2 = V ³ = -CH _2- )
[2-9] 1- (meth) acryloyloxy-3-carboxyadamantane (R = H or CH ₃ , R ⁸ = COOH, R ⁹ = R ¹⁰ = H, V ¹ = V ² = V ³ = -CH ₂ −)

  The compound represented by the above formula (2a) is obtained by subjecting a corresponding cyclic alcohol derivative and (meth) acrylic acid or a reactive derivative thereof to a conventional esterification method using an acid catalyst, a transesterification catalyst, a base or the like. It can be obtained by reacting.

Typical examples of the compound represented by the formula (2b) include the following compounds, but are not limited thereto.
[2-10] 5- (Meth) acryloyloxy-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (= 5- (meth) acryloyloxy-2,6-norbornane (Carbolactone) (R = H or CH ₃ , R ¹¹ = R ¹² = R ¹³ = R ¹⁴ = R ¹⁵ = H)
[2-11] 5- (Meth) acryloyloxy-5-methyl-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (R = H or CH ₃ , R ¹¹ = CH ₃ , R ¹² = R ¹³ = R ¹⁴ = R ¹⁵ = H)
[2-12] 5- (meth) acryloyloxy-1-methyl-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (R = H or CH ₃ , R ¹² = CH ₃ , R ¹¹ = R ¹³ = R ¹⁴ = R ¹⁵ = H)
[2-13] 5- (Meth) acryloyloxy-9-methyl-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (R = H or CH ₃ , R ¹³ = CH ₃ , R ¹¹ = R ¹² = R ¹⁴ = R ¹⁵ = H)
[2-14] 5- (Meth) acryloyloxy-9-carboxy-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (R = H or CH ₃ , R ¹¹ = R ¹² = R ¹⁴ = R ¹⁵ = H, R ¹³ = COOH)
[2-15] 5- (Meth) acryloyloxy-9-methoxycarbonyl-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (R = H or CH ₃ , R ^{11 = R 12 = R 14 = R} 15 = H, R 13 = methoxy group)
[2-16] 5- (Meth) acryloyloxy-9-ethoxycarbonyl-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (R = H or CH ₃ , R ^{11 = R 12 = R 14 = R} 15 = H, R 13 = ethoxycarbonyl group)
[2-17] 5- (meth) acryloyloxy-9-t-butoxycarbonyl-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (R = H or CH ₃ , R ¹¹ = R ¹² = R ¹⁴ = R ¹⁵ = H, R ¹³ = t-butoxycarbonyl group)

  The compound represented by the above formula (2b) is obtained by subjecting a corresponding cyclic alcohol derivative and (meth) acrylic acid or a reactive derivative thereof to a conventional esterification method using an acid catalyst, a transesterification catalyst, a base or the like. Can be obtained by reaction. In addition, the cyclic alcohol derivative used as a raw material in that case is, for example, a corresponding 5-norbornene-2-carboxylic acid derivative or an ester thereof peracid (peracetic acid, m-chloroperbenzoic acid, etc.) or peroxide ( It can be obtained by reaction (epoxidation and cyclization reaction) with hydrogen peroxide, hydrogen peroxide + metal compound such as tungsten oxide or tungstic acid).

Typical examples of the compound represented by the formula (2c) include the following compounds, but are not limited thereto.
[2-18] 8- (Meth) acryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-5-one (R = H or CH ₃ )
[2-19] 9- (Meth) acryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-5-one (R = H or CH ₃ )

  The compound represented by the above formula (2c) is obtained by subjecting a corresponding cyclic alcohol derivative and (meth) acrylic acid or a reactive derivative thereof to a conventional esterification method using an acid catalyst, a transesterification catalyst, a base or the like. It can be obtained by reacting.

Typical examples of the compound represented by the formula (2d) include the following compounds, but are not limited thereto.
[2-20] 4- (Meth) acryloyloxy-6-oxabicyclo [3.2.1] octane-7-one (R = H or CH ₃ , R ¹⁶ = R ¹⁷ = R ¹⁸ = R ¹⁹ = R ^{20 = R 21 = R 22 =} R 23 = R 24 = H)
[2-21] 4- (meth) acryloyloxy-4-methyl-6-oxabicyclo [3.2.1] octan-7-one (R = H or ^{_{CH 3, R 17 = R 18}} = R 19 = R ²⁰ = R ²¹ = R ²² = R ²³ = R ²⁴ = H, R ¹⁶ = CH ₃ )
[2-22] 4- (Meth) acryloyloxy-5-methyl-6-oxabicyclo [3.2.1] octane-7-one (R = H or CH ₃ , R ¹⁶ = R ¹⁸ = R ¹⁹ = R ²⁰ = R ²¹ = R ²² = R ²³ = R ²⁴ = H, R ¹⁷ = CH ₃ )
[2-23] 4- (Meth) acryloyloxy-4,5-dimethyl-6-oxabicyclo [3.2.1] octane-7-one (R = H or CH ₃ , R ¹⁸ = R ¹⁹ = R ^{20 = R 21 = R 22 =} R 23 = R 24 = H, R 16 = R 17 = CH 3)

Typical examples of the compound represented by the formula (2e) include the following compounds, but are not limited thereto.
[2-24] 6- (Meth) acryloyloxy-2-oxabicyclo [2.2.2] octane-3-one (R = H or CH ₃ , R ²⁵ = R ²⁶ = R ²⁷ = R ²⁸ = R ^{29 = R 30 = R 31 =} R 32 = R 33 = H)
[2-25] 6- (Meth) acryloyloxy-6-methyl-2-oxabicyclo [2.2.2] octane-3-one (R = H or CH ₃ , R ²⁵ = R ²⁷ = R ²⁸ = R ²⁹ = R ³⁰ = R ³¹ = R ³² = R ³³ = H, R ²⁶ = CH ₃ )
[2-26] 6- (meth) acryloyloxy-1-methyl-2-oxabicyclo [2.2.2] octan-3-one (R = H or ^{_{CH 3, R 26 = R 27}} = R 28 = R ²⁹ = R ³⁰ = R ³¹ = R ³² = R ³³ = H, R ²⁵ = CH ₃ )
[2-27] 6- (Meth) acryloyloxy-1,6-dimethyl-2-oxabicyclo [2.2.2] octane-3-one (R = H or CH ₃ , R ²⁷ = R ²⁸ = R ^{29 = R 30 = R 31 =} R 32 = R 33 = H, R 25 = R 26 = CH 3)

  The compounds represented by the above formulas (2d) and (2e) are prepared by combining a corresponding cyclic alcohol derivative with (meth) acrylic acid or a reactive derivative thereof using an acid catalyst, a transesterification catalyst, a base or the like. It can be obtained by reacting according to an esterification method.

  In the present invention, a simple substance other than the monomers a and b is used as long as it does not impair properties such as alkali solubility (acid detachability), substrate adhesion, dry etching resistance, and solubility in a resist solvent of the obtained resin. A monomer may be used as a comonomer. Such a monomer is not particularly limited as long as it is a monomer copolymerizable with monomer a and monomer b and does not impair the resist characteristics. Examples thereof include (meth) acrylic acid or a derivative thereof, maleic acid or a derivative thereof, fumaric acid or a derivative thereof, and cyclic olefins. Examples of the (meth) acrylic acid or derivatives thereof include α- (meth) acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-α-methyl-γ-butyrolactone, α- (meth) acryloyloxy- and (meth) acrylic acid esters having a lactone ring (γ-butyrolactone ring, δ-valerolactone ring, etc.) such as γ, γ-dimethyl-γ-butyrolactone. The (meth) acrylic acid ester having this lactone ring can impart substrate adhesion to the polymer.

  The usage-amount of the monomer a is 5-90 mol% with respect to the monomer total amount, Preferably it is 10-80 mol%, More preferably, it is 20-70 mol%. When the amount of monomer a used is less than 5 mol%, when the obtained resin is used as a resin for photoresist, the solubility of the resist film during alkali development becomes insufficient, and the resolution is lowered. It becomes difficult to form a fine pattern with high accuracy. In addition, when the amount of the monomer a used exceeds 90 mol%, when the obtained resin is used as a resin for a photoresist, the substrate adhesion and dry etching resistance are reduced, and the pattern is peeled off by development. The problem of not being easy

  The usage-amount of the monomer b is 10-95 mol%, for example, Preferably it is 20-90 mol%, More preferably, it is 30-80 mol%. When the amount of the monomer b used is less than 10 mol%, the substrate adhesion and dry etching resistance are liable to decrease when the resin is used as a photoresist resin. Therefore, the solubility of the resist film during alkali development tends to be insufficient. When the monomer b1 and the monomer b2 are combined as the monomer b, the ratio of the two is not particularly limited, but generally the former / the latter (molar ratio) = 5/95 to 95/5, preferably 10 / It is about 90 to 90/10, more preferably about 30/70 to 70/30.

  An important feature of the present invention is that a monomer mixture containing at least the monomer a and the monomer b is polymerized by a dropping polymerization method, and a radical generator is added to the system after the completion of the polymerization step. And a post-process for reducing the residual monomer.

  In the polymerization step, drop polymerization is specifically performed by, for example, (i) a monomer solution in which a monomer is previously dissolved in an organic solvent and a polymerization initiator solution in which a polymerization initiator is dissolved in an organic solvent, respectively. A method in which the monomer solution and the polymerization initiator solution are separately dropped from separate containers into an organic solvent prepared and maintained at a constant temperature; and (ii) the monomer and the polymerization initiator are added to the organic solvent. A method of dropping the dissolved mixed solution into an organic solvent maintained at a constant temperature, (iii) a monomer solution in which a monomer is previously dissolved in an organic solvent, and a polymerization initiator solution dissolved in the organic solvent, respectively It is carried out by a method such as a method of dropping a polymerization initiator solution into the monomer solution prepared and kept at a constant temperature. Of these, the method (i) or (ii) is preferred, and the method (i) is particularly preferred.

  Examples of the polymerization solvent include glycol solvents, ester solvents, ketone solvents, ether solvents, amide solvents, sulfoxide solvents, monohydric alcohol solvents, hydrocarbon solvents, and mixed solvents thereof. . Examples of glycol solvents include propylene glycol solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene Ethylene glycol solvents such as glycol monobutyl ether and ethylene glycol monobutyl ether acetate are included. Examples of ester solvents include lactic acid ester solvents such as ethyl lactate; propionate solvents such as methyl 3-methoxypropionate; acetate solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate. . Ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclohexanone, and the like. The ether solvent includes diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, dioxane and the like. The amide solvent includes N, N-dimethylformamide and the like. Examples of the sulfoxide solvent include dimethyl sulfoxide. The monohydric alcohol solvent includes methanol, ethanol, propanol, butanol and the like. Hydrocarbon solvents include toluene, xylene, hexane, cyclohexane and the like.

  Preferred polymerization solvents include glycol solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, ester solvents such as ethyl lactate, ketone solvents such as methyl isobutyl ketone and methyl amyl ketone, and mixed solvents thereof. . In particular, a solvent containing at least propylene glycol monomethyl ether acetate, such as a single solvent for propylene glycol monomethyl ether acetate, a mixed solvent of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, a mixed solvent of propylene glycol monomethyl ether acetate and ethyl lactate, etc. preferable.

  The polymerization initiator is not particularly limited. For example, azo, peroxydicarbonate, peroxyester, diacyl peroxide, hydroperoxide, dialkyl peroxide, peroxyketal, ketone peroxide Any polymerization initiator such as can be used. Among these, azo polymerization initiators are particularly preferable. Examples of the azo polymerization initiator include azobisisobutyronitrile, dimethyl 2,2'-azobis (2-methylpropionate), diethyl 2,2'-azobis (2-methylpropionate), and dibutyl. Examples include 2,2'-azobis (2-methylpropionate) and 2,2'-azobisdimethylvaleronitrile. Moreover, as a polymerization initiator, the polymerization initiator which does not have a hydroxyl group, a carboxyl group, and an unsubstituted amino group in a molecule | numerator from a soluble point with respect to an organic solvent is preferable.

  The amount of the polymerization initiator used may be an amount necessary for obtaining a polymer having a desired weight average molecular weight, for example, 0.001 to 1 mol, preferably 0 to 1 mol of the monomer mixture. About 0.01 to 0.1 mol. Further, in order to reduce the residual monomer amount as much as possible, it is more than the above range (for example, 1.05 to 1.4 times, that is, 0.0014 to 1.4 mol, preferably 0 to 1 mol of the monomer mixture). (About .014 to 0.14 mol) may be used. In the latter case, the polymerization initiator solution may be dropped after the monomer solution is dropped. For example, in the case of employing the method (i) in which the monomer solution and the polymerization initiator solution are dropped independently into a solvent heated to the polymerization temperature independently, the polymerization initiator is a polymer having a desired weight average molecular weight. In the case of using more than the amount necessary for obtaining a polymer, a polymerization initiator in an amount necessary for obtaining a polymer having a desired weight average molecular weight is added within the dropping time of the monomer solution (preferably the monomer When the monomer solution is dropped, and then the excess polymerization initiator is dropped into the system, the residual monomer amount is low and the polymer has a desired weight average molecular weight. Can be obtained.

  In the drop polymerization, the ratio of the amount of the solvent (or solution) charged in advance and the total amount of the dropped solution (monomer solution, polymerization initiator solution) takes into consideration productivity, economy, workability, operability, etc. However, it can be appropriately set within the range not impairing the quality of the resin. Generally, the former / the latter (weight ratio) = 5/95 to 90/10, preferably 10/90 to 70/30, more preferably 20 /. It is in the range of 80-60 / 40. The total amount of the polymerization solvent to be used (the amount of the solvent charged in advance or the amount of the solvent in the solution + the amount of the solvent in the solution to be dropped) takes into consideration the workability, operability, reaction efficiency, solubility of the polymer to be produced, etc. Although it can select suitably, generally it is 100-2000 weight part with respect to the total amount of a monomer of 100 weight part, Preferably it is 200-1000 weight part, More preferably, it is about 300-700 weight part.

  The total dropping time of the monomer solution or the polymerization initiator solution varies depending on the polymerization temperature and the kind of the monomer, but is generally 1 to 24 hours, preferably 2 to 12 hours, more preferably about 3 to 8 hours. It is. The polymerization temperature (reaction liquid temperature at the time of dropping) is usually from 50 to 150 ° C, preferably from 60 to 130 ° C. When the polymerization temperature is less than 50 ° C., the polymerization time becomes long and it is not economical. When the polymerization temperature exceeds 130 ° C., the chain transfer reaction becomes remarkable, leading to a decrease in molecular weight.

  In the drop polymerization, it is desirable to control the temperature so as to minimize the fluctuation width of the polymerization temperature (reaction liquid temperature). For example, the polymerization temperature (reaction solution temperature) is within ± 5 ° C. (preferably between 93% or more (preferably between 95% or more) of the total dropping time of the monomer and polymerization initiator solution (preferably between 95% or more). Is preferably controlled within ± 3 ° C.). When the polymerization is carried out in a state where the polymerization temperature deviates from the range of ± 5 ° C. with respect to the set temperature for a period of 7% or more of the total dropping time (a state where the fluctuation width of the polymerization temperature exceeds ± 5%), the molecular weight becomes 40,000. It is easy to increase the polymer content. When the content of the polymer having a molecular weight exceeding 40000 is large, an insoluble matter (turbidity) is generated when the polymer is dissolved in the resist solvent. In particular, at the beginning of the dropping, the dropping solution is usually near room temperature, and since the amount of polymerization heat generated is small at the beginning of the dropping, the polymerization temperature (reaction liquid temperature) once falls greatly below the set temperature of the control system. In many cases, the fluctuation width of the polymerization temperature becomes large. From this, as a method for controlling the polymerization temperature with a small fluctuation width as described above, the temperature (liquid temperature) in the reaction vessel before dropping of the monomer and polymerization initiator solution is set to a temperature higher than the set temperature [ For example, there may be mentioned a method of starting dropping after adjusting to (set temperature + 1 ° C.) to (set temperature + 5 ° C.), preferably (set temperature + 1 ° C.) to (set temperature + 3 ° C.)]. According to this method, when the dropping of the monomer / polymerization initiator solution is started, the temperature inside the system starts to decrease, and when the target set temperature is reached, the set temperature of the control system is gradually set to the set target value. By reducing the temperature to the temperature, the system temperature can be stabilized at the set temperature within a short period of time without significantly lowering the set temperature. As a result, it is possible to suppress the formation of a polymer having a high molecular weight exceeding 40,000, which causes insoluble matter (turbidity) when dissolved in the resist solvent.

  After completion of dropping of the monomer solution and the polymerization initiator solution, an appropriate time (for example, 0.1 to 10 hours, preferably 1 to 6 hours, more preferably about 1 to 4 hours), an appropriate temperature (for example, 60 to Aging at 130 ° C.).

  Polymerization produces a photoresist polymer compound containing at least a repeating unit corresponding to the monomer a and a repeating unit corresponding to the monomer b. The weight average molecular weight (Mw) of the produced polymer is, for example, in the range of 2000 to 20000, preferably 4000 to 17000, and more preferably 6000 to 15000. The molecular weight distribution (Mw / Mn) is, for example, about 1.1 to 3.5, preferably about 1.5 to 3.0. Mn represents the number average molecular weight of the polymer. The repeating units corresponding to the monomers represented by the formulas (1a) to (1d) are represented by the following formulas (Ia) to (Id), respectively. Each code | symbol in a type | formula is the same as that of said Formula (1a)-(1d). The repeating units corresponding to the monomers represented by the formulas (2a) to (2e) are represented by the following formulas (IIa) to (IIe), respectively. Each symbol in the formula is the same as that in the formulas (2a) to (2e).

  An important feature of the present invention is that a step of reducing the residual monomer in the system with a radical generator is provided as a post-process after completion of the polymerization step. The addition timing of the radical generator is preferably the time when the residual monomer concentration in the system does not decrease and becomes almost constant in the previous step. The radical generator used in the subsequent step is not particularly limited as long as it generates radicals by heat or light and the remaining monomer disappears by polymerization. Examples of those that generate radicals by heat include azo, peroxydicarbonate, peroxyester, diacyl peroxide, hydroperoxide, dialkyl peroxide, peroxyketal, and ketone peroxide. Polymerization initiators such as organic peroxides, persulfates, hydrogen peroxide, oxidizers-dimethylaniline, alkylboron, sodium periodate, potassium permanganate, cerium salt, redox It is done. Examples of radicals generated by light include, for example, acetophenone series, benzophenone series, Michler ketone, benzoin series, benzoin ether series, benzyldimethyl ketal series, benzoylbenzoate series, α-acyloxime ester series, tetramethylthiuram monosulfide. And photopolymerization initiators such as thioxanthone series. Among these, azo polymerization initiators are particularly preferable.

  Of the above radical generators, water-soluble or water-dispersible radical generators that can be removed later by washing with water are preferable, and in particular, a polymerization initiator having an oxygen atom-containing group or a substituted or unsubstituted amino group in the molecule. preferable. Examples of the oxygen atom-containing group include a hydroxyl group, a carboxyl group, a substituted oxy group, a substituted oxycarbonyl group, an acyl group, a substituted or unsubstituted carbamoyl group, a hydroxyimino group, a substituted oxyimino group, and a nitro group.

Examples of the substituted oxy group include an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, and a t-butyloxy group (particularly a C _1-4 alkoxy group); an aryloxy group such as a phenoxy group and a naphthyloxy group; Aralkyloxy group such as oxy group; Acyloxy group such as acetoxy group, propionyloxy group, benzoyloxy group (especially C _1-5 aliphatic acyloxy group, aromatic acyloxy group); methoxycarbonyloxy group, ethoxycarbonyloxy group, etc. Alkoxycarbonyloxy groups (particularly C _1-4 alkoxy-carbonyloxy groups); aryloxycarbonyloxy groups such as phenoxycarbonyloxy groups; aralkyloxycarbonyloxy groups such as benzyloxycarbonyloxy groups and the like. Examples of the substituted oxycarbonyl group include an alkoxycarbonyl group such as a methoxycarbonyl group, an ethoxycarbonyl group, and a t-butyloxycarbonyl group (particularly a C _1-4 alkoxy-carbonyl group); an aryloxycarbonyl such as a phenoxycarbonyl group. Group; aralkyloxycarbonyl group such as benzyloxycarbonyl group and the like are included.

Examples of the acyl group include aliphatic acyl groups such as formyl group, acetyl group, propionyl group and hexanoyl group (particularly C _1-6 aliphatic acyl group); aromatic acyl groups such as benzoyl group; cyclohexanecarbonyl group and the like An alicyclic acyl group; a heterocyclic acyl group such as a pyridinecarbonyl group;

Examples of the substituted or unsubstituted carbamoyl group include a carbamoyl group; a mono- or dialkylcarbamoyl group such as a methylcarbamoyl group, an ethylcarbamoyl group, a dimethylcarbamoyl group, and a diethylcarbamoyl group (particularly, a mono- or di-C _1-4 alkylcarbamoyl group). A cyclic aminocarbonyl group such as a 1-pyrrolidinylcarbonyl group, a piperidinocarbonyl group, and a morpholinocarbonyl group; Examples of the substituted oxyimino group include an alkoxyimino group such as a methoxyimino group and an ethoxyimino group (particularly a C _1-4 alkoxyimino group); an aryloxyimino group such as a phenoxyimino group; and an aralkyl such as a benzyloxyimino group. Oxyimino groups and the like are included.

Examples of the substituted or unsubstituted amino group include an amino group; a mono- or dialkylamino group such as a methylamino group, an ethylamino group, a dimethylamino group, and a diethylamino group (particularly, a mono- or di-C _1-4 alkylamino group). A cyclic amino group such as a 1-pyrrolidinyl group, a piperidino group, and a morpholino group;

  Of the above oxygen atom-containing groups and substituted or unsubstituted amino groups, a hydroxyl group, a carboxyl group, and an unsubstituted amino group are particularly preferred.

  As a typical example of the radical generator used in the present invention, for example, 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2 represented by the following formula (3): -Hydroxyethyl] propionamide} [for example, product name “VA-080” manufactured by Wako Pure Chemical Industries, Ltd.], 2,2′-azobis {2-methyl-N- [2] represented by the formula (4) -(Hydroxybutyl)] propionamide} [for example, trade name “VA-085” manufactured by Wako Pure Chemical Industries, Ltd.], 2,2′-azobis [2-methyl-N— represented by the formula (5) (2-hydroxyethyl) propionamide] [for example, trade name “VA-086” manufactured by Wako Pure Chemical Industries, Ltd.], 2,2′-azobis {2- [1- ( 2-hydroxyethyl) -2-imidazolin-2-yl] propane} dihydride Chloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] represented by formula (7), 2,2'-azobis (2- Methyl propionamide oxime), 4,4′-azobis (4-cyanovaleric acid) represented by formula (9) [for example, trade name “ACVA” manufactured by Otsuka Chemical Co., Ltd.] and the like. In equation (7), m represents a natural number.

  Among these initiators, the compounds represented by the formulas (3), (4), (5) and (6) have a hydroxyl group in the molecule [of the formulas (3), (4) and (5). The compound further has a substituted carbamoyl group], the compounds represented by formulas (7) and (9) have a carboxyl group in the molecule [the compound of formula (7) further has a substituted amino group and a hydroxyimino group. The compound represented by formula (8) has an amino group (and a hydroxyimino group) in the molecule.

  The addition amount of the radical generator can be appropriately selected according to the amount of residual monomer in the polymerization solution, but is usually 0.2 mol or more, preferably 0.5 mol, relative to 1 mol of the residual monomer in the polymerization solution. As mentioned above, More preferably, it is 0.7 mol or more. The upper limit of the amount of radical generator added may be within a range that does not impair the quality of the photoresist composition, but is usually 20 mol, preferably 10 mol, more preferably, with respect to 1 mol of the residual monomer in the polymerization solution. About 5 moles.

  The radical generator may be added all at once or sequentially. The radical generator may be used as it is, or may be used in a form dissolved or dispersed in an appropriate solvent. The temperature in the post-process is usually in the range of 50 to 150 ° C., preferably 60 to 130 ° C., may be the same temperature as the polymerization temperature, or may be a different temperature. The post-processing time is, for example, about 5 minutes to 5 hours, preferably about 30 minutes to 3 hours.

  The polymer solution obtained in the subsequent step is usually subjected to a washing step and / or a distillation step, and if necessary, operations such as dilution, concentration, solvent exchange (exchange with a resist solvent), filtration, etc. are performed. Thus, a photoresist polymer solution can be obtained.

  In the water washing step, the solution containing the polymer formed by polymerization is subjected to water washing. When a water-soluble or water-dispersible radical generator is used in the post-process, the radical generator and oligomer (particularly the oligomer generated in the post-process) can be separated and removed in this water-washing process. Further, impurities such as water-soluble or water-dispersible metal components can be removed by washing with water. The object to be treated for the water washing step may be a solution containing a polymer produced by polymerization. The polymer solution at the end of polymerization (polymer dope), and this polymer solution is subjected to appropriate treatment such as dilution, concentration, and filtration. Any of the solutions after the treatment may be used.

In washing with water, an organic solvent may be added in order to improve the liquid separation between the organic solvent layer containing the polymer and the aqueous layer. As the organic solvent, an organic solvent having a specific gravity (20 to 25 ° C.) of 0.95 or less and a solubility parameter (SP value) of 20 MPa ^1/2 or less is preferable. The SP value of the organic solvent is, for example, the method described in “Polymer Handbook”, 4th edition, pages VII-675 to VII-711 [in particular, the formulas (B3) and (B8) on page 676 ]. Further, as the SP value of the organic solvent, the values shown in Table 1 (page VII-683) and Tables 7 to 8 (pages VII-688 to VII-711) of the document can be adopted. For example, when a glycol solvent such as propylene glycol monomethyl ether acetate or an ester solvent such as ethyl lactate is used as a polymerization solvent, these have a specific gravity close to that of water (close to 1), so that they are separated from water. However, when an organic solvent having a specific gravity of 0.95 or less and an SP value of 20 MPa ^1/2 or less (for example, 13 to 20 MPa ^1/2 ) as described above is added, the organic layer and the aqueous layer Separation is extremely easy. The specific gravity of the organic solvent to be added is preferably 0.6 to 0.95, more preferably 0.7 to 0.85 (particularly 0.7 to 0.82). The SP value of the organic solvent to be added is preferably 16 to 19 MPa ^1/2 , more preferably 16.5 to 18.5 MPa ^1/2 (particularly 16.5 to 18 MPa ^1/2 ).

Representative examples of organic solvents having a specific gravity of 0.95 or less and an SP value of 20 MPa ^1/2 or less include, for example, aliphatic hydrocarbons such as hexane, octane, and dodecane; alicyclic hydrocarbons such as cyclohexane; ethylbenzene , P-xylene, toluene, benzene and other aromatic hydrocarbons; ethers such as diisopropyl ether; ketones such as diisobutyl ketone, methyl isobutyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl ethyl ketone and methyl amyl ketone; isopropyl acetate, butyl acetate , Propyl acetate) and the like. Among these solvents, ketones such as diisobutyl ketone, methyl isobutyl ketone, methyl propyl ketone, methyl isopropyl ketone, and methyl amyl ketone are preferable.

  The amount of the organic solvent to be added for improving the liquid separation property can be appropriately selected in consideration of extraction efficiency, operability, etc., but is usually 10 to 100 parts by weight of the polymer solution after the post-process. The amount is about 300 parts by weight, preferably about 20 to 200 parts by weight.

  The amount of water used in the water washing can be appropriately selected in consideration of extraction efficiency, operability, etc. Usually, the total amount of the polymer solution after the post-process and the organic solvent used for improving the liquid separation is 100 wt. The amount is about 5 to 300 parts by weight, preferably about 10 to 200 parts by weight per part.

  The washing operation can be carried out by a conventional method, and may be carried out by any of batch, semi-batch and continuous methods. The washing operation may be repeated a plurality of times (for example, about 2 to 10 times). The washing temperature can be appropriately selected in consideration of operability and solubility, and is, for example, about 0 to 100 ° C., preferably about 25 to 50 ° C.

  In the distillation step, the organic solvent solution containing the polymer after washing with water is usually subjected to distillation (for example, flash distillation or the like). By this distillation, water and other low-boiling components (such as the organic solvent used in the water washing) contained in the organic solvent solution can be separated and removed. Distillation can be carried out at any pressure such as normal pressure or reduced pressure, but vacuum distillation is preferred in view of thermal decomposition and the like. The pressure is, for example, about 500 to 1 torr (66.5 to 0.133 kPa), preferably about 400 to 5 torr (53.2 to 0.665 kPa). The distillation may be simple distillation or distillation using a distillation column. Further, as the distillation tower, a packed tower, a plate tower, or the like can be used.

  According to the method of the present invention, a photoresist polymer solution having a residual monomer amount of 0.5% by weight or less (preferably 0.3% by weight or less) based on the polymer is obtained without performing precipitation and reprecipitation operations. Obtainable.

  In the method of the present invention, since the amount of residual monomer in the polymer is extremely small, normal precipitation and reprecipitation operations are unnecessary, but they may be performed if necessary. Since the amount of residual monomer in the polymer is small, the yield does not decrease so much even if precipitation and reprecipitation operations are performed. Precipitation and reprecipitation can be performed by a known or conventional method using a poor solvent such as an aliphatic hydrocarbon such as hexane or heptane. Moreover, you may give a rinse process and a repulp process with respect to the isolated polymer after precipitation and reprecipitation. A polymer solution for photoresist can be obtained by re-dissolving the polymer thus obtained in a solvent for resist.

  The photoresist composition of the present invention includes a photoresist polymer compound produced by the production method of the present invention, a photoacid generator, and a resist solvent. The resin composition for photoresist can be prepared, for example, by adding a photoacid generator to the polymer solution for photoresist obtained as described above.

  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 use amount of the photoacid generator can be appropriately selected according to the strength of the acid generated by light irradiation, the ratio of each repeating unit in the polymer (resin for photoresist), and the like. It can be selected from a range of about 1 to 30 parts by weight, preferably 1 to 25 parts by weight, and more preferably about 2 to 20 parts by weight.

  Examples of the resist solvent include glycol solvents, ester solvents, ketone solvents, and mixed solvents exemplified as the polymerization solvent. Among these, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, methyl isobutyl ketone, methyl amyl ketone, and a mixed solution thereof are preferable, and in particular, propylene glycol monomethyl ether acetate alone solvent, propylene glycol monomethyl ether acetate and A solvent containing at least propylene glycol monomethyl ether acetate such as a mixed solvent of propylene glycol monomethyl ether and a mixed solvent of propylene glycol monomethyl ether acetate and ethyl lactate is preferably used.

  The polymer concentration in the photoresist composition is, for example, about 10 to 40% by weight. The photoresist composition may contain an alkali-soluble component such as an alkali-soluble resin (for example, a novolac resin, a phenol resin, an imide resin, a carboxyl group-containing resin), a colorant (for example, a dye), and the like.

  The photoresist composition thus obtained is applied onto a substrate or a substrate, dried, and then exposed to light on a coating film (resist film) through a predetermined mask (or further subjected to post-exposure baking). By forming the latent image pattern and then developing it, a fine pattern can be formed with high accuracy.

  Examples of the base material or the substrate include a silicon wafer, metal, plastic, glass, and ceramic. The photoresist composition can be applied using a conventional application means such as a spin coater, a dip coater, or a roller coater. The thickness of the coating film is, for example, about 0.1 to 20 μm, preferably about 0.3 to 2 μm.

For exposure, light of various wavelengths such as ultraviolet rays and X-rays can be used. For semiconductor resists, g-rays, i-rays, and excimer lasers (eg, XeCl, KrF, KrCl, ArF, ArCl, etc.) are usually used. Etc. are used. The exposure energy is, for example, about 1 to 1000 mJ / cm ² , preferably about 10 to 500 mJ / cm ² .

  An acid is generated from the photoacid generator by light irradiation, and this acid, for example, a carboxyl group of a repeating unit (a repeating unit having an acid-eliminating group) that becomes alkali-soluble by the action of the acid of the photoresist polymer compound. And the like, a protecting group (leaving group) such as succinctly desorbs to generate a carboxyl group and the like that contribute to solubilization. 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.

撹拌機、温度計、還流冷却管、滴下ロート及び窒素導入管を備えたセパラブルフラスコに、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）を１３０ｇ導入し、８７℃に昇温後、１−メタクリロイルオキシ−３−ヒドロキシアダマンタン（ＨＭＡ）７．１ｇ（３０ミリモル）、５−メタクリロイルオキシ−２，６−ノルボルニルカルボラクトン（ＭＮＢＬ）１１．４ｇ（５０ミリモル）、２−メタクリロイルオキシ−２−メチルアダマンタン（２ＭＭＡ）１６．７ｇ（７０ミリモル）をプロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）７０ｇに溶解したモノマー溶液と、ジメチル−２，２´−アゾビス（２−メチルプロピオネート）（重合開始剤；和光純薬工業製、商品名「Ｖ−６０１」）１．５ｇをプロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）３０ｇに溶解した重合開始剤溶液とを、別々の容器から、それぞれ一定の速度で滴下した。モノマー溶液の滴下時間は５時間、重合開始剤溶液の滴下時間は５．５時間であった。モノマー溶液及び重合開始剤溶液を滴下開始すると徐々に温度が下がり、８５℃となった。以後、反応液温度を８５℃に制御した。重合開始剤溶液の滴下終了後、同温度で２時間熟成した。この時点の残存モノマー量はポリマーに対して約３重量％であった。熟成終了後、２，２′−アゾビス｛２−メチル−Ｎ−［２−（１−ヒドロキシブチル）］プロピオンアミド｝［ラジカル発生剤；和光純薬（株）製、商品名「ＶＡ−０８５」］１．４ｇ（４．１ミリモル；残存モノマー量に対して等モル）をテトラヒドロフラン１０ｇに溶解した溶液を系内に添加し、同温度で２時間撹拌した。得られた反応溶液（ポリマードープ）を冷却後、これにメチルイソブチルケトン（ＭＩＢＫ）２４０ｇを加えて混合し、さらに水２４０ｇを添加し、よく撹拌を行った後、３０分静置して分液させた。得られた有機層に対し、再度同様にして水洗を行った。得られた有機層中の残存モノマー量はポリマーに対して０．２重量％であった。前記有機層をフラッシュ蒸留に付して水及びメチルイソブチルケトンを留去することにより、ポリマー濃度２５重量％のフォトレジスト用ポリマー溶液（残存モノマー量：ポリマーに対して０．２重量％）を得た。ポリマーの重量平均分子量は８８００、分子量分布は２．０１であった。 Example 1
Preparation of photoresist polymer solution containing polymer compound for photoresist with the following structure

130 g of propylene glycol monomethyl ether acetate (PGMEA) was introduced into a separable flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel, and a nitrogen introduction tube, heated to 87 ° C., and then 1-methacryloyloxy-3 -Hydroxyadamantane (HMA) 7.1 g (30 mmol), 5-methacryloyloxy-2,6-norbornylcarbolactone (MNBL) 11.4 g (50 mmol), 2-methacryloyloxy-2-methyladamantane (2MMA) ) Monomer solution prepared by dissolving 16.7 g (70 mmol) in 70 g of propylene glycol monomethyl ether acetate (PGMEA) and dimethyl-2,2′-azobis (2-methylpropionate) (polymerization initiator; Wako Pure Chemical Industries, Ltd.) Product name "V-601") 1.5g B and propylene glycol monomethyl ether acetate (PGMEA) a polymerization initiator was dissolved in 30g solution, from separate containers, were added dropwise each at a constant speed. The dropping time of the monomer solution was 5 hours, and the dropping time of the polymerization initiator solution was 5.5 hours. When dropping of the monomer solution and the polymerization initiator solution was started, the temperature gradually decreased to 85 ° C. Thereafter, the reaction solution temperature was controlled at 85 ° C. After completion of dropping of the polymerization initiator solution, the mixture was aged at the same temperature for 2 hours. The residual monomer amount at this time was about 3% by weight based on the polymer. After completion of aging, 2,2′-azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide} [radical generator; manufactured by Wako Pure Chemical Industries, Ltd., trade name “VA-085” ] A solution prepared by dissolving 1.4 g (4.1 mmol; equimolar with respect to the amount of residual monomers) in 10 g of tetrahydrofuran was added to the system and stirred at the same temperature for 2 hours. After cooling the obtained reaction solution (polymer dope), 240 g of methyl isobutyl ketone (MIBK) was added thereto and mixed, and further 240 g of water was added, and after stirring well, the mixture was allowed to stand for 30 minutes to separate the liquid. I let you. The obtained organic layer was washed again in the same manner. The amount of residual monomer in the obtained organic layer was 0.2% by weight based on the polymer. The organic layer is subjected to flash distillation to distill off water and methyl isobutyl ketone to obtain a polymer solution for photoresist having a polymer concentration of 25% by weight (residual monomer amount: 0.2% by weight based on the polymer). It was. The weight average molecular weight of the polymer was 8800, and the molecular weight distribution was 2.01.

Comparative Example 1
Preparation of Photoresist Polymer Solution Containing Photoresist Polymer Compound with Same Structure as Example 1 In a separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen inlet tube, propylene glycol monomethyl ether After introducing 130 g of acetate (PGMEA) and raising the temperature to 87 ° C., 7.1 g (30 mmol) of 1-methacryloyloxy-3-hydroxyadamantane (HMA), 5-methacryloyloxy-2,6-norbornylcarbolactone (MNBL) 11.4 g (50 mmol), 2-methacryloyloxy-2-methyladamantane (2MMA) 16.7 g (70 mmol) dissolved in propylene glycol monomethyl ether acetate (PGMEA) 70 g, and dimethyl-2 , 2'-azobis ( -Methylpropionate) (polymerization initiator; manufactured by Wako Pure Chemical Industries, trade name “V-601”) 1.5 g of propylene glycol monomethyl ether acetate (PGMEA) dissolved in 30 g of polymerization initiator solution Each was dropped from the container at a constant rate. The dropping time of the monomer solution was 5 hours, and the dropping time of the polymerization initiator solution was 5 hours. When dropping of the monomer solution and the polymerization initiator solution was started, the temperature gradually decreased to 85 ° C. Thereafter, the reaction solution temperature was controlled at 85 ° C. After completion of dropping of the polymerization initiator solution, the mixture was aged at the same temperature for 2 hours. After cooling the obtained reaction solution (polymer dope) (residual monomer amount: 5% by weight based on the polymer), 240 g of methyl isobutyl ketone (MIBK) was added and mixed, and 240 g of water was further added and stirred well. After being performed, the solution was allowed to stand for 30 minutes for liquid separation. The obtained organic layer was washed again in the same manner. The amount of residual monomer in the obtained organic layer was 5% by weight based on the polymer. Since the transparency to ultraviolet rays is low as it is, it cannot be used as a raw material for a photoresist composition. Therefore, the organic layer was dropped into a mixed solution of heptane and ethyl acetate, stirred and allowed to stand for purification. The supernatant was removed, heptane was added to the residue, and the repulping operation was performed twice, followed by draining by centrifugation to obtain a wet polymer. The wet polymer was rinsed with heptane and then dried to obtain a polymer. The polymer was dissolved in propylene glycol monomethyl ether acetate (PGMEA) to obtain a polymer solution for photoresist having a polymer concentration of 25% by weight (residual monomer amount: 0.2% by weight based on the polymer). The weight average molecular weight of the polymer was 8400, and the molecular weight distribution was 1.95.

Evaluation test 10 parts by weight of triphenylsulfonium hexafluoroantimonate with respect to 100 parts by weight of the polymer was added to each photoresist polymer solution obtained in Examples and Comparative Examples, and propylene glycol monomethyl ether acetate (PGMEA) was further added. In addition, a photoresist composition was prepared by adjusting the polymer concentration to 15% by weight. This photoresist composition was applied to a silicon wafer by spin coating to form a photosensitive layer having a thickness of 0.7 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. Next, the resist film was developed with a 2.38M tetramethylammonium hydroxide aqueous solution for 60 seconds and rinsed with ultrapure water. As a result, when any of the photoresist polymer solutions of Examples and Comparative Examples was used, it was 0.25 μm. A clear line and space pattern was obtained with high accuracy.

Claims (10)

  A polymerization step of polymerizing a monomer mixture containing at least a monomer having an alkali-soluble group with an acid and a monomer having a group containing a polar group-containing alicyclic skeleton by a dropping polymerization method; And a post-process for reducing the residual monomer by adding a radical generator after completion of the polymerization process.   The method for producing a photoresist polymer compound according to claim 1, further comprising a water washing step of subjecting the solution containing the polymer produced by polymerization to water washing after the post step.   The photoresist according to claim 1 or 2, wherein in the polymerization step, the monomer solution containing the monomer mixture and the polymerization initiator solution containing the polymerization initiator are independently dropped into a solvent heated to the polymerization temperature. For producing a polymer compound for use.   4. The method for producing a polymer compound for photoresists according to claim 3, wherein the dropping of the polymerization initiator solution is continued even after completion of dropping of the monomer solution.   The production of the polymer compound for photoresist according to any one of claims 1 to 4, wherein the radical generator used in the subsequent step is a polymerization initiator having an oxygen atom-containing group or a substituted or unsubstituted amino group in the molecule. Method.   The method for producing a photoresist polymer compound according to any one of claims 1 to 5, wherein the radical generator used in the subsequent step is a polymerization initiator having a hydroxyl group or a carboxyl group. Monomers having groups that become alkali-soluble by acid are represented by the following formulas (1a) to (1d):

(In the formula, ring Z represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms which may have a substituent. R represents a hydrogen atom or an optionally substituted substituent having 1 to 6 carbon atoms. R ^{1 to} R ³ are the same or different and each represents an optionally substituted alkyl group having 1 to 6 carbon atoms, and R ⁴ is a substituent bonded to ring Z. And may be the same or different and may be protected with an oxo group, an alkyl group, a hydroxyl group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, or a protecting group. Represents a carboxyl group, provided that at least one of n R ⁴ groups represents ^a —COOR ^a group, wherein R ^a represents ^a tertiary hydrocarbon group which may have ^a substituent, a tetrahydrofuranyl group, A tetrahydropyranyl group or an oxepanyl group, where n is an integer of 1 to 3. R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms, R ⁷ represents a hydrogen atom or an organic group. ⁵ , R ⁶ , or R ⁷ may be bonded to each other to form a ring with adjacent atoms.
The method for producing a polymer compound for a photoresist according to any one of claims 1 to 6, wherein the compound is at least one compound selected from the group consisting of: Monomers having a group containing a polar group-containing alicyclic skeleton are represented by the following formulas (2a) to (2e)

(In the formula, R represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms. R ^{8 to} R ¹⁰ are the same or different and each represents a hydrogen atom, an alkyl group, or a protecting group. A hydroxyl group which may be protected, a hydroxyalkyl group which may be protected with a protecting group, or a carboxyl group which may be protected with a protecting group, V ^{1 to} V ³ are the same or different, and CH _2- , -CO- or -COO-, provided that (i) at least one of V ^{1 to} V ³ is -CO- or -COO-, or (ii) R ^{8 to} R ¹⁰ at least one of the, optionally protected hydroxyl group, a protected or unprotected hydroxyalkyl group with a protecting group, or be protected by a protecting group is also a carboxyl group which .R ¹¹ ~ R ¹⁵ is the same or different and is a hydrogen atom , An alkyl group, a hydroxyl group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, and a carboxyl group that may be protected with a protecting group, R ^{16 to} R ²⁴ represent It is the same or different and represents a hydrogen atom, an alkyl group, a hydroxyl group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, or a carboxyl group that may be protected with a protecting group. R ^{25 to} R ³³ are the same or different and are protected by a hydrogen atom, an alkyl group, a hydroxyl group which may be protected with a protecting group, a hydroxyalkyl group which may be protected with a protecting group, or a protecting group. (P represents 0 or 1, q represents 1 or 2)
The method for producing a polymer compound for photoresist according to any one of claims 1 to 7, wherein the compound is at least one compound selected from the group consisting of:   The photoresist composition containing the high molecular compound for photoresists manufactured by the method of any one of Claims 1-8, and a photo-acid generator.   The manufacturing method of the semiconductor including the process of apply | coating the photoresist composition of Claim 9 to a board | substrate or a base material, and forming a resist coating film.