JP2007146022A - Method for producing resin solution for photoresist - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a resin solution for a photoresist, having very small contents of low-boiling point impurities becoming the factor for reducing resist characteristics while suppressing the decomposition of the resin for the photoresist as possible. <P>SOLUTION: The method for producing the resin solution for the photoresist obtained by dissolving the resin for the photoresist at least containing a repeating unit A containing a group becoming alkali-soluble by releasing a part thereof by an acid, and a repeating unit B containing an alicyclic skeleton having a polar group in one or more kinds of coated film-forming solvents comprises precipitating the resin for the photoresist obtained by polymerization with a poor solvent, redissolving the separated wet crystal of the resin for the photoresist in a solvent containing at least one kind of the coated film-forming solvents, and distilling off the low-boiling point impurities contained in the wet crystal of the resin for the photoresist by distilling the obtained redissolved liquid by a thin-film evaporator. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a photoresist resin solution useful for preparing a photoresist resin composition used for semiconductor microfabrication and the like, and a photoresist resin composition using the photoresist resin solution obtained by the production method The present invention relates to a method for producing a semiconductor, and a method for producing a semiconductor using a resin composition obtained by the method for producing a resin composition for a photoresist.

  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).

  These polymers are usually prepared by polymerizing the monomer mixture, and then separating and removing the residual monomer that exhibits strong absorption with respect to far ultraviolet rays used for exposure. (For example, Patent Document 3). The obtained wet crystals are redissolved in a solvent for forming a coating film (resist solvent) to form a photoresist resin solution. In this solution, the poor solvent and wet crystals used in the previous precipitation operation are washed. The solvent used in the process is included. These solvents are generally low-boiling components, but if they remain in the resist film, problems such as deterioration of resist characteristics occur, and thus it is necessary to separate them by distillation. In JP-A-2005-173252, a solid material containing a resist polymer has a boiling point at a coating film forming solvent (a) and / or normal pressure that is lower than the boiling point of the coating film forming solvent (a). Impurity removal by re-dissolving in solvent containing solvent (b) and removing low-boiling impurities by distilling off solvent (b) and / or excess amount of solvent (a) under reduced pressure from the resulting redissolved solution A method for producing a resist polymer solution including a process is disclosed. Further, this document describes that it is preferable to carry out the impurity removal step by controlling the liquid temperature to 70 ° C. or lower in order to reduce the thermal load on the resist polymer and the decomposition of the resist polymer caused by the heat load. . However, although this method can remove low-boiling impurities, the decomposition of the resist polymer cannot always be sufficiently suppressed. Moreover, since the liquid residence time in the distillation can is increased in batch distillation, the photoresist resin is easily decomposed by receiving a thermal history.

JP 2000-26446 A JP-A-9-73137 JP 2004-269855 A JP 2005-173252 A

  An object of the present invention is to provide a method for producing a photoresist resin solution capable of efficiently reducing low-boiling-point impurities that cause a reduction in resist characteristics while suppressing decomposition of the photoresist resin as much as possible, and a photo obtained by the production method. It is providing the manufacturing method of the resin composition for photoresists using the resin solution for resists, and the manufacturing method of the semiconductor using this resin composition for photoresists.

  As a result of intensive investigations to achieve the above-mentioned object, the present inventors have applied a resin polymerization solution for photoresist obtained by polymerization to a precipitation operation and formed at least one kind of coating film on wet crystals separated by centrifugation or the like. When the redissolved solution obtained by redissolving in a solvent containing a solvent is distilled with a thin-film evaporator, low-boiling impurities that cause degradation of resist characteristics are efficiently suppressed while suppressing decomposition of the resin for photoresist as much as possible. It has been found that it can be removed, and the present invention has been completed.

  That is, the present invention relates to a photoresist resin comprising at least a repeating unit A containing a group that is partly eliminated by an acid and becomes alkali-soluble, and a repeating unit B containing an alicyclic skeleton having a polar group. A method for producing a photoresist resin solution dissolved in one or more kinds of coating film forming solvents, wherein the photoresist resin obtained by polymerization is precipitated in a poor solvent, and the precipitated photoresist resin Are separated as wet crystals, the wet crystals are redissolved in a solvent containing at least one coating film forming solvent, and the resulting redissolved solution is distilled by a thin film evaporator to obtain a wet solution of the photoresist resin. Provided is a method for producing a photoresist resin solution, which comprises a step of distilling off low-boiling impurities contained in crystals.

  In this method, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, or a mixed solvent thereof may be used as the coating film forming solvent.

  Further, in the above method, the wet crystal of the separated photoresist resin is redissolved in propylene glycol monomethyl ether, and the obtained redissolved solution is heated to 140 ° C. or less in a heating jacket and / or tube of a distillation can. After distilling while circulating steam to distill off low-boiling impurities contained in the wet crystal of the resin for photoresist, propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether are added. You may obtain the resin solution for photoresists which uses this mixed solvent as the solvent for film formation.

  The weight ratio of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether in the mixed solvent is, for example, the former / the latter = 40/60 to 95/5.

（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種の繰り返し単位である。 The repeating unit A includes, for example, the following formulas (Ia) to (Id)

(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 repeating unit selected from the group consisting of:

（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種の繰り返し単位である。 Examples of the repeating unit B include the following formulas (IIa) to (IIe):

(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 repeating unit selected from the group consisting of:

  The present invention also provides a method for producing a photoresist resin composition, wherein a photoacid generator is dissolved in the photoresist resin solution obtained by the method for producing a photoresist resin solution. .

  The present invention further includes a method for producing a semiconductor comprising a step of applying a photoresist resin composition obtained by the above-described method for producing a photoresist resin composition to a substrate or a substrate to form a resist coating film. provide.

  According to the production method of the present invention, the low boiling point impurities contained in the wet crystals of the photoresist resin obtained by polymerization are distilled off using a thin film evaporator, so that the liquid residence time during distillation is batch distillation. Evaporation cans that are significantly shorter than distillation using water and distillation cans and have a large heat transfer area, so that the temperature of the heating medium or steam for heating can be set low, and contact with the re-dissolved solution of photoresist resin. The temperature of the wall surface or tube wall surface can be lowered, and the decomposition of the polymer can be remarkably suppressed on the wall surface. For this reason, it is possible to efficiently reduce low-boiling impurities that cause a decrease in resist characteristics while suppressing decomposition of the resin for photoresist as much as possible. In addition, the photoresist resin composition containing the photoresist resin solution obtained by this manufacturing method has significantly less polymer degradation products and low-boiling impurities, so there are problems and troubles caused by these components in the semiconductor manufacturing process. This can be avoided, and a fine pattern can be formed stably and accurately.

  The resin for photoresist in the present invention contains at least a repeating unit A containing a group that is partly eliminated by acid and becomes alkali-soluble, and a repeating unit B containing an alicyclic skeleton having a polar group. .

  The repeating unit A containing a group that becomes partially soluble by acid and becomes alkali-soluble is one that is partially eliminated by the action of an acid generated from a photoacid generator upon exposure and is soluble in an alkali developer. (Repeating unit having an acid-eliminable group) There is no particular limitation, for example, a group containing an alicyclic hydrocarbon group having 6 to 20 carbon atoms and capable of leaving by the action of an acid. And a repeating unit corresponding to (meth) acrylic acid ester (repeating unit when polymerized at a carbon-carbon double bond site). “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. As a typical example of a unit corresponding to such a (meth) acrylic acid ester, units represented by the formulas (Ia) and (Ib) are exemplified.

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. In addition, 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. As a typical example of a unit corresponding to such a (meth) acrylic acid ester, a unit represented by the formula (Ic) is exemplified.

  In addition, examples of the repeating unit A containing a group that is partly eliminated by acid and becomes alkali-soluble include monomer units corresponding to (meth) acrylic acid hemiacetal esters. Specifically, the unit represented by the formula (Id) is exemplified.

  In addition, as a repeating unit A containing a group that is partly eliminated by acid and becomes alkali-soluble, the oxygen atom constituting the ester bond is bonded to the β-position of the lactone ring and at least one hydrogen is bonded to the α-position of the lactone ring. It is also possible to use a repeating unit corresponding to a (meth) acrylic acid ester having an atom and a lactone ring (a repeating unit when polymerized at a carbon-carbon double bond site). The repeating unit A may be only one type or a combination of two or more types.

The repeating unit A is preferably at least one repeating unit selected from the formulas (Ia) to (Id). In formulas (Ia) to (Id), 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.

R in the formulas (Ia) to (Id), and carbon atoms which may have a substituent in R ^{1 to} R ³ , R ⁵ and R ⁶ in the formulas (Ia), (Ib) and (Id) 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 (Ic), 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 are protected with alkyl groups (C _1-4 alkyl groups, etc.), haloalkyl groups (C _1-4 haloalkyl groups, etc.), halogen atoms, hydroxyl groups that may be protected with protecting groups, and protecting groups. 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 (Id) 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.

The repeating unit B including an alicyclic skeleton having a polar group includes (1) an alicyclic hydrocarbon group having 6 to 20 carbon atoms containing a lactone ring [lactone ring and monocyclic or polycyclic (bridged ring). Group having a structure in which an alicyclic carbocycle of) is condensed] is a monomer unit B1 (carbon-carbon double bond site) corresponding to (meth) acrylate ester bonded to an oxygen atom constituting an ester bond In the case of polymerization with a). As a typical example of such a repeating unit B1, in the formula (IIa), at least one of V ^{1 to} V ³ is —COO—, and (IIb), (IIc), (IId), ( Illustrated are units represented by IIe).

The repeating unit B including an alicyclic skeleton having a polar group includes (2) an alicyclic hydrocarbon group having 6 to 20 carbon atoms having a polar group such as a hydroxyl group, a carboxyl group, and an oxo group (particularly, The monomer unit B2 corresponding to the (meth) acrylic ester in which the bridged cyclic hydrocarbon group) is bonded to the oxygen atom constituting the ester bond (repeating unit when polymerized at the carbon-carbon double bond site) is also available included. As a typical example of such a repeating unit B2, in the formula (IIa), at least one of V ^{1 to} V ³ is —CO—, or at least one of R ^{8 to} R ¹⁰ is a protecting group. And a unit which is a hydroxyl group which may be protected with, a hydroxyalkyl group which may be protected with a protecting group, or a carboxyl group which may be protected with a protecting group.

  The repeating unit B provides adhesion to a substrate such as a silicon wafer by a polar group and dry etching resistance by an alicyclic skeleton. The repeating unit B may be only one type or a combination of two or more types. The repeating unit B is preferably at least one repeating unit selected from the formulas (IIa) to (IIe). In addition, when the repeating unit B1 and the repeating unit B2 are combined as the repeating unit B, not only a good balance of properties such as substrate adhesion, dry etching resistance and solubility in a resist solvent is provided, but also a homogeneous reactivity during polymerization. And a great advantage that a polymer having high uniformity in molecular weight and molecular structure is produced.

R in the formulas (IIa) to (IIe) is the same as R in the above (Ia) to (Id). In formulas (IIa) to (IIe), 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.

  The resin for photoresist in the present invention is a repeating unit other than the repeating units A and B 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. Units may be included. Such a repeating unit is a unit corresponding to a monomer copolymerizable with the monomer corresponding to the repeating unit A and the monomer corresponding to the repeating unit B, and does not impair the resist characteristics. If it is a thing, it will not specifically limit. For example, units corresponding to (meth) acrylic acid or derivatives thereof, maleic acid or derivatives thereof, fumaric acid or derivatives thereof, cyclic olefins, and the like can be given. 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 content of the repeating unit A in the photoresist resin is, for example, 5 to 90 mol%, preferably 10 to 80 mol%, and more preferably 20 to 70 mol%. When the content of the repeating unit A is less than 5 mol%, the solubility of the resist film at the time of alkali development becomes insufficient, the resolution is lowered, and it becomes difficult to form a fine pattern with high accuracy. Further, when the content of the repeating unit A exceeds 90 mol%, the substrate adhesion and the dry etching resistance are lowered, and the problem that the pattern is not peeled off by development is likely to occur.

  The content of the repeating unit B in the photoresist resin is, for example, 10 to 95 mol%, preferably 20 to 90 mol%, and more preferably 30 to 80 mol%. When the content of the repeating unit B is less than 10 mol%, the substrate adhesion and the dry etching resistance are liable to be reduced, and when it exceeds 95 mol%, the amount of alkali-soluble units introduced is reduced. The solubility of the resist film tends to be insufficient. When the repeating unit B1 and the repeating unit B2 are combined as the repeating unit B, the ratio of both is not particularly limited, but generally the former / the latter (molar ratio) = 5/95 to 95/5, preferably 10/90 to 90 / 10, more preferably about 30/70 to 70/30.

  The weight average molecular weight (Mw) of the photoresist resin is, for example, in the range of 3000 to 15000, preferably 4000 to 14000, and more preferably about 5000 to 13000. The molecular weight distribution (Mw / Mn) of the photoresist resin is, for example, about 1.1 to 3.5, preferably 1.3 to 3.0, and particularly preferably about 1.5 to 2.5. In addition, said Mn shows a number average molecular weight, and both Mn and Mw are values of polystyrene conversion. The weight average molecular weight and molecular weight distribution of the resin can be measured by GPC (gel permeation chromatography).

  The photoresist resin can be synthesized by a commonly used polymerization method, but is preferably synthesized by a dropping polymerization method in which a polymer having a uniform composition and molecular weight can be easily obtained. For example, a monomer a (a monomer corresponding to the repeating unit A) containing a group that is partly eliminated by acid and becomes alkali-soluble and a monomer b (repeating a alicyclic skeleton having a polar group) A monomer solution containing at least a monomer corresponding to unit B) and a polymerization solution containing a polymerization initiator are dropped into a reaction vessel and polymerized at a temperature of 60 to 130 ° C. be able to. Moreover, it is also possible to drop the monomer solution containing the monomer mixture and the polymerization initiator solution containing the polymerization initiator into the reaction vessel in parallel from separate containers. It is preferable to control the polymerization temperature at a constant temperature with the smallest possible swing.

  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 propylene glycol monomethyl ether acetate single solvent, 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.

  A known polymerization initiator can be used as the polymerization initiator.

  In the drop polymerization, the ratio of the amount of the solvent charged in advance and the total amount of the solution to be dropped (monomer solution, polymerization initiator solution) is a resin that takes into consideration productivity, economy, workability, operability, etc. In general, the former / the latter (weight ratio) = 5/95 to 90/10, preferably 10/90 to 70/30, and more preferably 20/80 to 60 /. A range of 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 and the polymerization initiator solution varies depending on the polymerization temperature and the kind of the monomer, but is generally 1 to 10 hours, preferably about 3 to 8 hours. In addition, after completion | finish of dripping, you may age | cure | ripen for appropriate time (for example, about 0.1 to 10 hours, Preferably about 1 to 6 hours) and appropriate temperature (for example, 60-130 degreeC), and you may complete superposition | polymerization.

  The resin containing each repeating unit represented by the above formulas (Ia) to (Id) and (IIa) to (IIe) can be produced by subjecting the corresponding (meth) acrylic acid ester to a polymerization as a comonomer.

[Repeating units represented by formulas (Ia) to (Id)]
Monomers corresponding to the repeating units represented by the formulas (Ia) to (Id) are represented by the following formulas (1a) to (1d), respectively. 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.

（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）

(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.

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 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 Adamantane ring)

  The compound represented by the above formula (1a) is obtained by, for example, reacting a corresponding cyclic alcohol with (meth) acrylic acid or a reactive derivative thereof according to a conventional esterification method using an acid catalyst or a transesterification catalyst. Can be obtained.

Although the following compound is mentioned as a typical example of a compound represented by Formula (1b), It is not limited to these.
[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) is, for example, a methanol derivative having an alicyclic group at the corresponding 1-position and (meth) acrylic acid or a reactive derivative thereof, using an acid catalyst or a transesterification catalyst. It can be obtained by reacting according to a conventional esterification method.

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 obtained by, for example, reacting a corresponding cyclic alcohol with (meth) acrylic acid or a reactive derivative thereof according to a conventional esterification method using an acid catalyst or a transesterification catalyst. Can be obtained.

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.

[Repeating units represented by formulas (IIa) to (IIe)]
Monomers corresponding to the repeating units represented by the formulas (IIa) to (IIe) are represented by the following formulas (2a) to (2e), respectively. 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.

（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）

(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)

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]} nonane-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-oxa-tricyclo [4.2.1.0 ^{4, 8]} nonan-2-(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.

  The polymer produced by polymerization can be isolated by precipitation (including reprecipitation). For example, the polymerization solution (polymer dope) is added to a solvent (precipitation solvent) to precipitate the polymer, or the polymer is dissolved again in a suitable solvent, and this solution is added to the solvent (reprecipitation solvent). The desired polymer can be obtained by reprecipitation. The precipitation or reprecipitation solvent may be either an organic solvent or water, or a mixed solvent. Examples of the organic solvent used as the precipitation or reprecipitation solvent include hydrocarbons (aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatics such as benzene, toluene, and xylene. Aromatic hydrocarbons), 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.) , Nitrile (acetonitrile, benzonitrile, etc.), ether (chain ether such as diethyl ether, diisopropyl ether, dimethoxyethane; cyclic ether such as tetrahydrofuran, dioxane), ketone (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.) Etc.), and mixed solvents containing these solvents.

  Among these, as the organic solvent used as the precipitation or reprecipitation solvent, a solvent containing at least a hydrocarbon (particularly, an aliphatic hydrocarbon such as hexane or heptane) is preferable. In such a solvent containing at least hydrocarbon, the ratio of hydrocarbon (for example, aliphatic hydrocarbon such as hexane and heptane) and other solvent (for example, esters such as ethyl acetate) 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.) = About 50/50 to 97/3.

  The polymer obtained by precipitation (including reprecipitation) is subjected to repulping or rinsing as necessary. A rinse treatment may be applied after the repulping treatment. By repulping the polymer produced by polymerization with a solvent or rinsing, residual monomers and low molecular weight oligomers adhering to the polymer can be efficiently removed.

  As the solvent used for the repulping treatment (solvent for repulping) and the solvent used for the rinsing treatment (rinsing solvent), a poor polymer solvent used for precipitation (including reprecipitation) is preferable. Of these, hydrocarbon solvents are particularly preferred. Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, and octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, and aromatic hydrocarbons such as benzene, toluene, and xylene. You may use these in mixture of 2 or more types. Among these, aliphatic hydrocarbons, particularly hexane or heptane, or a mixed solvent containing hexane or heptane is preferable.

  The amount of the repulping solvent used is, for example, about 1 to 200 times by weight, preferably about 5 to 100 times by weight with respect to the polymer. On the other hand, the usage-amount of a rinse solvent is 1-100 weight times with respect to a polymer, Preferably it is about 2-20 weight times. Although the temperature at the time of performing a repulping process and a rinse process changes with kinds etc. of the solvent to be used, generally it is 0-100 degreeC, Preferably it is about 10-60 degreeC. The repulping process and the rinsing process are performed in a suitable container. You may perform a repulping process and a rinse process in multiple times, respectively. The treated liquid (repulp liquid, rinse liquid) is removed by decantation, filtration or the like.

  After completion of the polymerization step, the polymerization solution is dropped into a poor solvent as described above to precipitate the resin, and after performing operations such as repulping as necessary, the precipitated resin is solid-liquid separated with a centrifuge or the like. The The separated resin (wet crystal) contains low-boiling impurities such as a solvent used in the precipitation operation. If such low-boiling impurities are present in the resist film, the resist performance deteriorates and must be removed. Conventionally, it has been dried under reduced pressure to remove such low-boiling impurities, but once the resin is dried, the adhesion between the particles becomes stronger due to drying, or it dissolves in the solvent for coating film formation (resist solvent). It becomes very difficult to dissolve. Further, there is a problem that a part of the acid leaving group in the photoresist resin is decomposed by heat applied during drying.

  In the present invention, wet crystals of photoresist resin are redissolved in a solvent containing at least one solvent for forming a coating film (resist solvent), and the resulting redissolved solution is distilled by a thin film evaporator, Low boiling point impurities contained in the wet crystal of the photoresist resin are distilled off. In this way, the liquid residence time during distillation can be significantly shortened, and since the heat transfer area is large, the heating medium for heating or the vapor temperature can be lowered, so that the decomposition of the resin for photoresist is suppressed as much as possible. However, low boiling point impurities can be efficiently removed. In addition, the operability is excellent and productivity is improved.

  As a solvent for forming a coating film, a solvent that dissolves a resin and has high transparency to light used for exposure is preferable. For example, glycol solvents (propylene glycol solvents, ethylene glycol solvents) exemplified as the polymerization solvent. Etc.), ester solvents (such as lactic acid ester solvents), ketone solvents (such as methyl isobutyl ketone and methyl amyl ketone), and mixed solvents thereof. Further, as preferred coating film forming solvents, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether pro Propylene glycol monoalkyl ether carboxylates such as pionate, propylene glycol monopropyl ether propionate, propylene glycol monobutyl ether propionate; propylene glycol mono such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether A Kill ether; and mixtures thereof.

  Among the above-mentioned solvents, propylene glycol monomethyl ether acetate (PGMEA) has an advantage that it has an excellent function as a solvent in terms of evaporation rate at the time of forming a coating film, and has low toxicity. However, PGMEA tends to be inferior in solubility characteristics, and there remains a problem in dissolving a highly polar resin (in order to improve substrate adhesion, it is essential to introduce a polar group into the resin). About this, a solvent power can be improved significantly by adding propylene glycol monomethyl ether (PGME) to PGMEA. Therefore, it can be said that a mixed solvent of PGMEA and PGME is a particularly preferable solvent for forming a coating film (resist solvent).

  When a mixed solvent of PGMEA and PGME is used as a solvent for forming a coating film, the total proportion of PGMEA and PGME in the total solvent is usually 70% by weight or more, preferably 90% by weight or more, more preferably 95% by weight or more. In particular, a mixed solvent consisting essentially of PGMEA and PGME is preferred. Moreover, the range of 40 / 60-95 / 5 is normally used for the mixing ratio of PGMEA / PGME when using the mixed solvent of PGMEA and PGME as a solvent for film formation. Preferably, it is 50/50 to 90/10, and particularly preferably about 60/40 to 85/15. If the ratio of PGMEA is less than 40% by weight, it is difficult to form a uniform coating film because there is a problem with the evaporation rate at the time of coating film formation. Moreover, when the ratio of PGME is less than 5% by weight, the solubility of the resin tends to deteriorate.

  In the present invention, the solvent used to redissolve the wet crystal of the photoresist resin only needs to contain at least one type of coating film forming solvent. That is, for example, when a mixed solvent of two kinds of solvents is used as a solvent for forming a coating film, the wet crystals may be redissolved using one kind of solvent, and the wet crystals may be formed using a mixed solvent of two kinds of solvents. It may be redissolved. Alternatively, the wet crystals may be redissolved using a coating film forming solvent and other solvent (a solvent having a boiling point lower than that of the coating film forming solvent). When a solvent other than the solvent for forming the coating film is used as the solvent for re-dissolution, the amount of the solvent other than the solvent for forming the coating film can be appropriately selected according to the solubility of the resin, etc. The amount is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably 5% by weight or less of the total solvent for re-dissolution. In addition, when using 2 or more types of mixed solvents as a solvent for film formation, the solvent which was not used for the re-dissolution of the said wet crystal can be added after distillation.

  The redissolved solution thus obtained is continuously charged in a thin film evaporator and distilled to distill off low-boiling impurities. The thin film evaporator may be any of a falling film thin film evaporator, a centrifugal thin film evaporator, a stirring thin film evaporator, and the like. The temperature of the heat medium or vapor used for heating is preferably 140 ° C. or lower, more preferably 130 ° C. or lower, and further preferably 120 from the viewpoint of suppressing decomposition of the photoresist resin (decomposition at the acid-eliminable group). C. or lower, particularly preferably 110 C or lower. The lower limit of the temperature is, for example, about 40 ° C, preferably about 50 ° C. When a heat medium or steam having a temperature exceeding 140 ° C. is used for heating, the resin is easily decomposed on the wall surface of the flow path of the heat medium or steam. If the temperature of the heating medium or steam used for heating is lower than 40 ° C., it is necessary to make the degree of vacuum considerably low, and the temperature of the cooling water for cooling and condensing the solvent to be distilled becomes too low, which is disadvantageous in terms of cost. Prone.

  The pressure during the distillation is preferably a reduced pressure, and varies depending on the type of re-dissolving solvent, but is generally 500 to 1 torr (66.5 to 0.133 kPa), preferably 400 to 2 torr (53.2 to 0.2.0). 266 kPa). If the pressure is high, the distillation temperature becomes high and there is a concern about the thermal decomposition of the resin. If the pressure is too low, the temperature of the refrigerant required for condensing the evaporated solvent needs to be lowered, which is not economical. The liquid temperature in the thin film evaporator is preferably 100 ° C. or lower, more preferably 80 ° C. or lower.

  In distillation, in order to completely remove low-boiling impurities, a part of the solvent for forming a coating film together with the low-boiling impurities (in the case of using a solvent other than the solvent for forming a coating film, the solvent and the solvent for forming a coating film). A part of the solvent. The distillation rate in distillation [(distillation amount / charge amount) × 100 (% by weight)] depends on the content of low-boiling impurities in the wet crystal of the photoresist resin, the type and composition of the solvent for re-dissolution, and the like. Generally, it is about 30 to 90% by weight, preferably about 50 to 87% by weight.

  The resin concentration of the resin solution finally concentrated in the distillation is, for example, about 10 to 70% by weight, preferably about 20 to 60% by weight, and particularly preferably about 30 to 50% by weight.

  After removing low boiling point impurities by distillation, a solvent for forming a coating film is added to the bottoms as necessary to prepare a photoresist resin solution having a desired concentration. The resin concentration in the final photoresist resin solution is, for example, 5 to 50% by weight, preferably 10 to 30% by weight.

  In a preferred embodiment of the present invention, the wet crystal of the separated photoresist resin is redissolved in propylene glycol monomethyl ether (PGME), and the obtained redissolved solution is distilled by a thin film evaporator to obtain the photoresist resin. After distilling off low-boiling impurities contained in the wet crystals, propylene glycol monomethyl ether acetate (PGMEA) is added, and a mixed solvent of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether is used as a film-forming solvent. A resin solution for photoresist is obtained. In this aspect, since PGME having excellent resin solubility and a relatively low boiling point is used as the solvent for re-dissolving the resin, the wet crystals can be reliably dissolved in a short time and the distillation temperature can be lowered. For this reason, decomposition | disassembly, a quality change, etc. of resin can be suppressed further, and a highly transparent solution without an insoluble content is obtained. Therefore, a complicated filtering operation can be omitted or simplified, and contamination of foreign matters can be prevented. In addition, when the PGME single solvent is used, it becomes extremely easy to accurately achieve the mixing ratio of PGMEA and PGME in the final resist solvent. From these points, the PGME used for dissolving the wet crystal is preferably substantially 100% by weight. However, a PGME containing a small amount of other solvent is used as long as the effect of suppressing the decomposition of the resin is not impaired. Also good. The content of such other solvents is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably 5% by weight or less. In addition, when the wet crystal is dissolved in PGMEA alone or in a mixed solvent with PGMEA containing a large amount of PGMEA and then subjected to a distillation operation, it takes time to dissolve the wet crystal and the distillation temperature increases. It is easy to produce a solvent insoluble component. In the said preferable aspect, after removing a low boiling-point impurity by distillation, PGMEA and PGME as needed are added to a residual liquid, and the resin solution for photoresists of desired density | concentration is prepared.

  A photoresist resin composition is obtained by dissolving a photoacid generator in the above-described photoresist resin solution. 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.

  The resin composition for a photoresist 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), or the like. Good.

  The photoresist resin 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. Perform) By forming a 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 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 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 the acid causes, for example, a carboxyl group of a repeating unit (a repeating unit having an acid-eliminable group) that becomes alkali-soluble by the action of an acid of a photoresist resin. The protecting group (leaving group) is rapidly removed to generate a carboxyl group that contributes 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. The resin (polymer) concentration was obtained from 1 g of a resin solution collected in an evaporating dish, dried under reduced pressure at 100 ° C., and the weight loss.

撹拌機、温度計、還流冷却器、滴下用溶液タンク及び定量供給ポンプ、及び窒素導入管を備えた実容量２００Ｌのジャケット付き反応器に、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３３ｋｇ導入し、７５℃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）５ｋｇ（２１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）５ｋｇ（２２モル）、２−メタクリロイルオキシ−２−メチルアダマンタン（２ＭＭＡ）５ｋｇ（２１モル）と、ジメチル−２，２´−アゾビス（２−メチルプロピオネート）（開始剤；和光純薬工業製、商品名「Ｖ−６０１」）０．９３ｋｇと、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）４１ｋｇの混合溶液を、滴下用溶液タンクから、定量ポンプを用いて、反応器内に４時間かけて滴下した。滴下後、同温度で２時間熟成した。得られた反応溶液（ポリマードープ）を冷却後、９００ｋｇのへプタン／酢酸エチル混合液（重量比７５／２５）に撹拌しながら滴下し、滴下終了後、さらに３０分撹拌した。析出した沈殿を遠心分離機により遠心分離した。得られた湿結晶をプロピレングリコールモノメチルエーテル（ＰＧＭＥ）に添加し、撹拌して溶解し、ポリマー濃度約１０重量％の溶液を得た。得られた溶液を、薄膜蒸発器に連続的に仕込み、１００℃のオイルで加熱しながら、圧力１０ｋＰａで減圧蒸留し、ポリマー濃度約４０重量％の缶出液を得た（留出率約７５重量％）。この缶出液に、ＰＧＭＥＡ及びＰＧＭＥを添加して、ポリマー濃度２０重量％のＰＧＭＥＡ／ＰＧＭＥ（重量比６／４）溶液を調製した。この溶液はフォトレジスト用樹脂溶液として使用されるが、完全に透明な溶液であった。また、この溶液の酸価を測定したところ、０．１ｍｍｏｌ−ＫＯＨ／ｇ（溶液）であった。 Example 1
Manufacture of resin solution for photoresist containing resin of the following structure

33 kg of propylene glycol monomethyl ether acetate (PGMEA) was introduced into a jacketed reactor having a real capacity of 200 L equipped with a stirrer, a thermometer, a reflux condenser, a dropping solution tank and a constant supply pump, and a nitrogen introduction tube, After raising the temperature to 1 ° C., 5 kg (21 mol) of 1-methacryloyloxy-3-hydroxyadamantane (HMA), 5 kg (22 mol) of 5-methacryloyloxy-2,6-norbornylcarbolactone (MNBL), 2-methacryloyl Oxy-2-methyladamantane (2MMA) 5 kg (21 mol) and dimethyl-2,2′-azobis (2-methylpropionate) (initiator: Wako Pure Chemical Industries, trade name “V-601”) 0.93kg and propylene glycol monomethyl ether acetate (PGMEA) 41k Mixed solution of, from dropping the solution tank by using a metering pump, was added dropwise over 4 hours into the reactor. After dropping, the mixture was aged at the same temperature for 2 hours. The obtained reaction solution (polymer dope) was cooled and then added dropwise to 900 kg of a heptane / ethyl acetate mixture (weight ratio 75/25) with stirring. After completion of the addition, the mixture was further stirred for 30 minutes. The deposited precipitate was centrifuged with a centrifuge. The obtained wet crystals were added to propylene glycol monomethyl ether (PGME) and dissolved by stirring to obtain a solution having a polymer concentration of about 10% by weight. The obtained solution was continuously charged into a thin film evaporator and distilled under reduced pressure at a pressure of 10 kPa while heating with oil at 100 ° C. to obtain a bottoms having a polymer concentration of about 40% by weight (distillation rate of about 75). weight%). PGMEA and PGME were added to the bottoms to prepare a PGMEA / PGME (weight ratio 6/4) solution having a polymer concentration of 20% by weight. This solution was used as a photoresist resin solution, but was a completely transparent solution. Moreover, when the acid value of this solution was measured, it was 0.1 mmol-KOH / g (solution).

Comparative Example 1
The wet crystal obtained in the same manner as in Example 1 was added to 300 kg of propylene glycol monomethyl ether (PGME), and dissolved by stirring. The obtained solution was charged into a distillation can of a single distillation apparatus with a heating medium jacket, and concentrated under reduced pressure while oil at 150 ° C. (jacket inlet temperature) was passed through the heating medium jacket. The liquid temperature in the distillation can was controlled at about 75 ° C. Distillation was stopped when the liquid volume reached approximately 30 L. The polymer concentration of the concentrated liquid was measured and found to be 40% by weight. PGMEA and PGME were added thereto to prepare a PGMEA / PGME (weight ratio 6/4) solution having a polymer concentration of 20% by weight. When the acid value of this solution was measured, it was 1.0 mmol-KOH / g (solution).

  As described above, when continuously distilling using a thin film evaporator, a polymer solution having an extremely low acid value is obtained compared to the batch distillation method, so that decomposition of the polymer is remarkably suppressed. I understand.

Evaluation Test In each photoresist resin solution obtained in Examples and Comparative Examples, 3 parts by weight of triphenylsulfonium hexafluoroantimonate and 2 parts by weight of 1,5-diazabicyclo [4. 3.0] -5-Nonene was added, and further propylene glycol monomethyl ether acetate (PGMEA) was added to adjust the polymer concentration to 15% by weight to prepare a photoresist resin composition. The obtained composition was filtered through a 0.1 μm microfilter and applied onto a silicon wafer by a spin coating method to form a photosensitive layer having a thickness of about 0.4 μm. Then, it was exposed with an ArF excimer laser having a wavelength of 193 nm through a mask, then subjected to a heat treatment at a temperature of 120 ° C. for 90 seconds, developed with a 0.3M tetramethylammonium hydroxide aqueous solution, and rinsed with pure water. As a result, when the photoresist resin solution of the example was used, a 0.15 μm line and space pattern was clearly and accurately obtained, but when the photoresist resin solution of the comparative example was used, The pattern had poor accuracy and lacked clarity.

Claims (8)

  One or more types of photoresist resins containing at least a repeating unit A containing a group that is partly eliminated by an acid and rendered alkali-soluble and a repeating unit B containing an alicyclic skeleton having a polar group A method for producing a photoresist resin solution dissolved in a coating film forming solvent, wherein the photoresist resin obtained by polymerization is precipitated in a poor solvent, and the precipitated photoresist resin is separated as wet crystals. The wet crystals are redissolved in a solvent containing at least one coating film forming solvent, and the obtained redissolved solution is distilled by a thin film evaporator to obtain a low content contained in the wet crystals of the photoresist resin. A method for producing a photoresist resin solution, comprising a step of distilling off boiling impurities.   The method for producing a photoresist resin solution according to claim 1, wherein a photoresist resin solution is obtained using propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, or a mixed solvent thereof as a solvent for forming a coating film.   The separated wet crystal of the photoresist resin is re-dissolved in propylene glycol monomethyl ether, and the obtained redissolved solution is distilled by a thin film evaporator to remove low boiling point impurities contained in the wet crystal of the photoresist resin. 3. The photoresist according to claim 2, wherein after removing the solvent, propylene glycol monomethyl ether acetate is added to obtain a photoresist resin solution using a mixed solvent of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether as a solvent for forming a coating film. For producing a resin solution for use.   The method for producing a resin solution for a photoresist according to claim 2 or 3, wherein the weight ratio of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether in the mixed solvent is the former / the latter = 40/60 to 95/5. The repeating unit A is represented by the following formulas (Ia) to (Id)

(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 photoresist resin solution according to claim 1, wherein the resin unit is at least one repeating unit selected from the group consisting of: The repeating unit B is represented by the following formulas (IIa) to (IIe)

(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 photoresist resin solution according to claim 1, wherein the resin unit is at least one repeating unit selected from the group consisting of:   A photoacid generator is dissolved in a photoresist resin solution obtained by the method for producing a photoresist resin solution according to any one of claims 1 to 6. Production method.   A method for producing a semiconductor comprising a step of applying a photoresist resin composition obtained by the method for producing a photoresist resin composition according to claim 7 to a substrate or a base material to form a resist coating film.