JP2006169330A - Polymer compound for photoresist for immersion exposure and manufacturing method of semiconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer compound for a photoresist for immersion exposure, which is capable of forming a high-performance resist film excellent in water resistance. <P>SOLUTION: The polymer compound for the photoresist for immersion exposure contains a monomer unit containing a cyclic ether skeleton. The monomer unit containing the cyclic ether skeleton used here is at least one monomer unit chosen from formulas (Ia)-(Ig). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polymer compound for photoresist for immersion exposure, which is used when performing fine processing of a semiconductor using a wet exposure method for exposure, and a resin composition for photoresist for immersion exposure containing the polymer compound. The present invention also relates to a semiconductor manufacturing method using the photoresist resin composition.

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

  In order to make a pattern finer, a lithography exposure light source used for manufacturing a semiconductor has become a shorter wavelength year by year. However, since there is a limit to the types of glass materials that transmit light of short wavelengths, the working distance between a substrate such as a wafer and the lens surface closest to the substrate is filled with a liquid that transmits exposure light, There has been proposed an immersion type exposure apparatus that makes an exposure pattern finer by increasing the numerical aperture (for example, Patent Document 1). Such a method of performing exposure under liquid immersion is called a wet exposure method.

  On the other hand, conventional polymer compounds for photoresist usually contain a monomer unit having a group that is partially eliminated by an acid and becomes alkali-soluble, and a monomer unit for imparting a substrate adhesion function. . Of the two types of monomer units, the former is generally low in polarity and the latter is generally high in polarity. Therefore, when only monomers corresponding to these two types of monomer units are copolymerized, Unevenness occurs and it is difficult to obtain a copolymer having a uniform composition. Therefore, a monomer containing a hydroxyl group having a polarity intermediate between these two types of monomers is often copolymerized. However, in the above immersion exposure, when a composition containing a polymer compound having a monomer unit corresponding to such a monomer containing a hydroxyl group is used, water penetrates into the resist film having the hydroxyl group. In addition, the resist film swells and thickness unevenness occurs, and as a result, there is a problem that it is difficult to obtain a clear and highly accurate pattern.

JP-A-10-303114

Accordingly, an object of the present invention is to provide a polymer compound for photoresist for immersion exposure and a resin composition for photoresist for immersion exposure, which can form a high-performance resist film having excellent water resistance.
Another object of the present invention is to provide a photoresist resin composition for immersion exposure that can form a fine pattern clearly and accurately, and a semiconductor manufacturing method.

  As a result of intensive investigations to achieve the above object, the present inventors have found that when a polymer containing a monomer unit containing a cyclic ether skeleton is used as a photoresist polymer for immersion exposure, the monomer unit containing a hydroxyl group is reduced or not. Even if it is contained, a polymer having a uniform composition is formed, and it is possible to form a resist film having excellent water resistance and high performance, and therefore, it is found that a fine pattern can be formed clearly and accurately using a wet exposure method. completed.

  That is, the present invention provides a photoresist polymer compound for immersion exposure containing a monomer unit containing a cyclic ether skeleton.

［式中、Ｒ^aは水素原子、ハロゲン原子、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を示す。Ａ¹は単結合又は連結基を示す。環Ｚ¹、環Ｚ⁶、環Ｚ⁸、環Ｚ¹³はそれぞれ、単環又は多環の脂環式炭素環を示し、環Ｚ²、環Ｚ³、環Ｚ⁴、環Ｚ⁵、環Ｚ⁷、環Ｚ⁹、環Ｚ¹⁰、環Ｚ¹¹、環Ｚ¹²はそれぞれ、環内にエーテル結合を含む環を示す。但し、式（Ic）、式（Id）において、Ａ¹がエステル結合を含み、該エステル結合を構成する酸素原子が環Ｚ⁵、環Ｚ⁷に結合している場合には、該酸素原子は環Ｚ⁵、環Ｚ⁷の酸素原子の隣接位以外の原子に結合している］
から選択された少なくとも１種のモノマー単位を用いることができる。 Examples of the monomer unit containing the cyclic ether skeleton include, for example, the following formulas (Ia) to (Ig)

[Wherein, R ^a represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms. A ¹ represents a single bond or a linking group. Ring Z ¹ , Ring Z ⁶ , Ring Z ⁸ , and Ring Z ¹³ each represent a monocyclic or polycyclic alicyclic carbocyclic ring. Ring Z ² , Ring Z ³ , Ring Z ⁴ , Ring Z ⁵ , Ring Z ⁷ , Ring Z ⁹ , Ring Z ¹⁰ , Ring Z ¹¹ , and Ring Z ¹² each represent a ring containing an ether bond in the ring. However, in Formula (Ic) and Formula (Id), when A ¹ includes an ester bond and the oxygen atom constituting the ester bond is bonded to ring Z ⁵ or ring Z ⁷ , the oxygen atom is Ring Z ⁵ is bonded to an atom other than the adjacent position of the oxygen atom of ring Z ⁷ ]
At least one monomer unit selected from can be used.

  The proportion of monomer units containing a cyclic ether skeleton is preferably 1 to 70 mol% of all monomer units.

  The polymer compound for photoresist for immersion exposure may further contain a monomer unit having a group that is partially eliminated by an acid and becomes alkali-soluble.

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

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

  The polymer compound for photoresist for immersion exposure may further contain a monomer unit having a lactone skeleton.

（式中、Ｒは水素原子、ハロゲン原子、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を示す。Ｘ¹、Ｘ²及びＸ³は、同一又は異なって、−ＣＨ₂−又は−ＣＯ−Ｏ−を示す。但し、Ｘ¹、Ｘ²及びＸ³のうち少なくとも１つは−ＣＯ−Ｏ−である。Ｒ²²、Ｒ²³及びＲ²⁴は、同一又は異なって、水素原子又はメチル基を示す。Ｒ²⁵、Ｒ²⁶及びＲ²⁷は、同一又は異なって、水素原子、メチル基又はトリフルオロメチル基を示す。Ｒ²⁸、Ｒ²⁹、Ｒ³⁰、Ｒ³¹及びＲ³²は、同一又は異なって、水素原子又はメチル基を示す。Ｒ³³、Ｒ³⁴、Ｒ³⁵及びＲ³⁶は、同一又は異なって、水素原子又はメチル基を示す。ｏ、ｐ、ｑ及びｔは、それぞれ、０又は１を示す）
から選択された少なくとも１種のモノマー単位が用いられる。 Examples of monomer units having a lactone skeleton include the following formulas (IIIa) to (IIIe):

(In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. X ¹ , X ² and X ³ are the same or different and represent —CH _2. -Or -CO-O-, provided that at least one of X ¹ , X ² and X ³ is -CO-O-, R ²² , R ²³ and R ²⁴ are the same or different and represent hydrogen R ²⁵ , R ²⁶ and R ²⁷ are the same or different and each represents a hydrogen atom, a methyl group or a trifluoromethyl group, and R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ and R ³² represent R ³³ , R ³⁴ , R ³⁵ and R ³⁶ are the same or different and represent a hydrogen atom or a methyl group, and o, p, q and t are respectively the same or different. , 0 or 1)
At least one monomer unit selected from is used.

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

  The present invention includes a step of applying the photoresist resin composition for immersion exposure on a substrate or a substrate to form a resist coating film, and forming a pattern through exposure and development under immersion. A semiconductor manufacturing method is provided.

  According to the present invention, a homogeneous resist film having excellent water resistance can be formed. Therefore, by employing a wet exposure method, a fine pattern can be formed with high accuracy.

  The polymer compound for photoresist of immersion exposure of the present invention contains a monomer unit (repeating unit) containing a cyclic ether skeleton (hereinafter sometimes referred to as “monomer unit 1”).

  The monomer unit 1 is formed by subjecting a polymerizable monomer containing a cyclic ether skeleton to (co) polymerization. Since this polymerizable monomer containing a cyclic ether skeleton has a medium polarity, for example, a monomer having a group that is partially eliminated by an acid and becomes alkali-soluble (generally low polarity), a substrate When a monomer (generally high polarity) used for imparting an adhesion function and a polymerizable monomer containing the cyclic ether skeleton are subjected to copolymerization, the monomer composition in the polymer is uniform. A copolymer (with no bias in monomer units) can be obtained. Therefore, it is not necessary to incorporate a large amount of monomer units containing a hydroxyl group into the polymer molecule as in conventional photoresist resins, so that the water resistance of the resist film can be improved. Therefore, when the exposure is performed by the wet exposure method, the penetration of water into the resist film can be suppressed, and the swelling of the resist film with water can be prevented. The monomer unit 1 also has a substrate adhesion function. The monomer unit 1 may have a group (for example, an ester group bonded to a tertiary carbon atom, a hemiacetal ester group, or the like) that is partly eliminated by an acid and becomes alkali-soluble. It does not have to be. The monomer unit 1 preferably includes a cyclic ether skeleton and an alicyclic carbocycle.

  The ratio of the monomer unit 1 is, for example, 1 to 70 mol%, preferably 10 to 60 mol%, more preferably 20 to 50 mol%, based on all monomer units. When the proportion of the monomer unit 1 is too small, a homogeneous resist film is difficult to be formed. When the proportion is too large, the amount of alkali-soluble units is relatively reduced, and the balance of functions as a resist is likely to be lowered.

As the monomer unit containing a cyclic ether skeleton, at least one monomer unit selected from the monomer units represented by the formulas (Ia) to (Ig) can be used. In the formula, Ra represents ^a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms. A ¹ represents a single bond or a linking group. Ring Z ¹ , Ring Z ⁶ , Ring Z ⁸ , and Ring Z ¹³ each represent a monocyclic or polycyclic alicyclic carbocyclic ring. Ring Z ² , Ring Z ³ , Ring Z ⁴ , Ring Z ⁵ , Ring Z ⁷ , Ring Z ⁹ , Ring Z ¹⁰ , Ring Z ¹¹ , and Ring Z ¹² each represent a ring containing an ether bond in the ring. However, in Formula (Ic) and Formula (Id), when A ¹ includes an ester bond and the oxygen atom constituting the ester bond is bonded to ring Z ⁵ or ring Z ⁷ , the oxygen atom is It is bonded to an atom other than the adjacent position of the oxygen atom of ring Z ⁵ or ring Z ⁷ . The monomer units represented by the formulas (Ia) to (Ic) and (Ie) to (Ig) have a function of improving the uniformity of the monomer composition in the polymer and also have an alicyclic carbocyclic ring so that they are resistant to etching. Also has sexual function.

The halogen atom in R ^a includes a fluorine, chlorine, bromine atom and the like. Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, and hexyl groups. Examples of the haloalkyl group having 1 to 6 carbon atoms include groups in which at least one hydrogen atom of the alkyl group having 1 to 6 carbon atoms is substituted with a fluorine atom, such as monofluoromethyl, difluoromethyl, trifluoromethyl, 2,2 , 2-trifluoroethyl, tetrafluoroethyl, 2,2,3,3,3-tetrafluoropropyl group and the like.

Examples of the linking group in A ¹ include divalent groups such as linear or branched alkylene groups such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene groups (C _1-6 alkylene group, etc.). Aliphatic hydrocarbon group; 1,2-cyclopentylene, 1,3-cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, cyclopentylidene, cyclohexylidene Divalent alicyclic hydrocarbon group such as a group; carbonyl group; oxygen atom (ether bond; -O-); sulfur atom (thioether bond; -S-); oxycarbonyl group (ester bond; -COO-, ring Z ¹ , ring Z ³ , ring Z ⁵ and ring Z ⁷ may be bonded to the right or left side; aminocarbonyl group (amide bond; —CONH—, ring Z ¹ , Ring Z ³ , ring Z ⁵ , and the side bonded to ring Z ⁷ may be the right side or the left side); and a group in which a plurality of these are bonded. Preferred examples of the linking group include an oxygen atom (ether bond; —O—), an oxycarbonyl group (ester bond; —COO—, ring Z ¹ , ring Z ³ , ring Z ⁵ , ring Z ⁷ , and the side bonded to the right side. A C _1-4 alkylene group, a divalent alicyclic hydrocarbon group, a group in which two or more of these are bonded, and the like.

Examples of the monocyclic alicyclic carbocyclic ring in ring Z ¹ , ring Z ⁶ , ring Z ⁸ , and ring Z ¹³ include, for example, cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cyclooctane ring, cyclododecane ring And the like (for example, a 3- to 15-membered cycloalkane ring, preferably a 5- to 8-membered cycloalkane ring). Examples of the polycyclic alicyclic carbocyclic ring in ring Z ¹ , ring Z ⁶ , ring Z ⁸ , and ring Z ¹³ include, for example, a bicyclo [3.3.0] octane ring and a bicyclo [4.3.0] nonane ring. , Decalin ring, perhydroanthracene ring, norbornane ring, bicyclo [2.2.2] octane ring, tricyclo [5.2.1.0 ^2,6 ] ring, tricyclo [4.4.0.1 ^2,5 ] Ring, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] ring and the like. Examples of the ring containing an ether bond in ring Z ² , ring Z ³ , ring Z ⁴ , ring Z ⁵ , ring Z ⁷ , ring Z ⁹ , ring Z ¹⁰ , ring Z ¹¹ , ring Z ¹² include oxirane ring, oxetane And oxygen-containing monocycles such as a ring, an oxolane ring, an oxane ring and an oxepane ring (for example, a 3- to 15-membered oxygen-containing monocycle, preferably a 5- to 8-membered oxygen-containing monocycle).

A ring composed of ring Z ¹ and ring Z ² in formula (Ia), a ring composed of ring Z ³ and ring Z ⁴ in formula (Ib), and a ring Z ⁵ and ring Z ⁶ in formula (Ic) A ring composed of ring Z ⁸ and ring Z ⁹ in formula (Ie), a ring composed of ring Z ¹⁰ and ring Z ¹¹ in formula (If), in formula (Ig) A typical example of the ring composed of the ring Z ¹² and the ring Z ¹³ is a ring represented by the following formula.

Ring Z ¹ to ring Z ¹³ are each 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, Protected with a halogen atom such as a fluorine atom, a hydroxyl group that may be protected with a protecting group, a hydroxyalkyl group that may be protected with a protecting group, a mercapto group that may be protected with a protecting group, or a protecting group It may have a substituent such as a carboxyl group that may be protected, an amino group that may be protected with a protecting group, or a sulfonic acid group that 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.

  In addition to the monomer unit (monomer unit 1) containing the cyclic ether skeleton, the polymer compound for photoresist of immersion exposure according to the present invention has a monomer having a group that is partly eliminated by acid and becomes alkali-soluble. It preferably contains a unit (hereinafter sometimes referred to as “monomer unit 2”). Since the monomer unit 2 changes to alkali-soluble upon light irradiation, it functions as an alkali-soluble unit that solubilizes the resin during alkali development.

  The monomer unit having a group that is partially eliminated by an acid and becomes alkali-soluble is not particularly limited. For example, it is used as a monomer unit having an acid-eliminable group or an alkali-soluble group in a polymer compound for photoresist. Known monomer units can be employed. The polymer compound of the present invention may have one kind of these monomer units or two or more kinds.

  Monomer units preferable as monomer units having a group that is partially eliminated by an acid and becomes alkali-soluble include monomer units represented by the above formulas (IIa) to (IIh).

R in the formulas (IIa) to (IIh) represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms. As the halogen atom, the alkyl group having 1 to 6 carbon atoms, and the haloalkyl group having 1 to 6 carbon atoms, those similar to the halogen atom in ^Ra can be used.

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

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

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

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

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

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

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

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

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

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

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

  The monomer unit represented by the formula (IIa) is desorbed from the carboxylic acid moiety in which the site containing the adamantane skeleton is bonded to the main chain by an acid to generate a free carboxyl group. In the monomer unit represented by the formula (IIb), a carboxyl group protected by a protecting group bonded to an adamantane skeleton is deprotected by an acid to generate a free carboxyl group. The monomer unit represented by the formula (IIc) generates a free carboxyl group by elimination from the carboxylic acid moiety in which the adamantane skeleton is bonded to the main chain by an acid. Furthermore, in the monomer units represented by the formulas (IId), (IIe), (IIf), (IIg) and (IIh), the carboxylic acid ester moiety is decomposed and eliminated by an acid to generate a free carboxyl group.

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

  The polymer compound for photoresist of the present invention for immersion exposure has a lactone skeleton in addition to the monomer unit (monomer unit 1) containing the cyclic ether skeleton or in addition to the monomer unit 1 and the monomer unit 2. It preferably contains a monomer unit (hereinafter sometimes referred to as “monomer unit 3”). Since the monomer unit 3 has a highly polar and hydrophilic —COO— group, it functions as a substrate adhesion unit.

  The monomer unit having a lactone skeleton is not particularly limited, and for example, a monomer unit having a known lactone skeleton used for a polymer compound for photoresist can be employed. The polymer compound of the present invention may have one kind of these monomer units or two or more kinds.

Monomer units preferred as monomer units having a lactone skeleton include monomer units represented by the formulas (IIIa) to (IIIe). R in the formulas (IIIa) to (IIIe) is the same as described above. In the formula (IIIa), the direction of the —CO—O— group in X ^{1 to} X ³ is not limited.

  In addition to the monomer unit 1, the monomer units 1 and 2, or the monomer units 1 to 3, the polymer compound for photoresist of immersion exposure of the present invention has characteristics necessary as a resist resin. The monomer unit (repeating unit) may be included. Examples of such monomer units include monomer units represented by the following formulas (IVa) to (IVd) (hereinafter sometimes referred to as “monomer unit 4”).

（式中、Ｒは水素原子、ハロゲン原子、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を示す。Ｒ³⁷及びＲ³⁸は、同一又は異なって、水素原子、ヒドロキシル基又はカルボキシル基を示し、Ｒ³⁹はヒドロキシル基、オキソ基又はカルボキシル基を示す。Ｒ⁴⁰は、水素原子、又は置換基を有していてもよい炭素数１〜２０の直鎖状、分岐鎖状、環状若しくは有橋環状炭化水素基を示す。Ｒ⁴¹は、水素原子、ヒドロキシル基、ヒドロキシメチル基又はカルボキシル基を示す。ｒは０又は１を示す）

(In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. R ³⁷ and R ³⁸ may be the same or different and each represents a hydrogen atom, a hydroxyl group or R ³⁹ represents a hydroxyl group, an oxo group or a carboxyl group, R ⁴⁰ represents a hydrogen atom or a linear or branched chain having 1 to 20 carbon atoms which may have a substituent, A cyclic or bridged cyclic hydrocarbon group, R ⁴¹ represents a hydrogen atom, a hydroxyl group, a hydroxymethyl group or a carboxyl group, r represents 0 or 1)

R in the formulas (IVa) to (IVd) is the same as described above. In formula (IVb), the linear, branched, cyclic or bridged cyclic hydrocarbon group (bridged cyclic group) having 1 to 20 carbon atoms for R ⁴⁰ is methyl, ethyl, propyl, isopropyl, butyl , Isobutyl, t-butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl, etc. linear or branched aliphatic hydrocarbon group (especially alkyl group) such as cyclopentyl, cyclohexyl C3-C20 cycloalkyl or cycloalkenyl group such as cyclooctyl, cyclododecyl group; perhydroindene ring, perhydrofluorene ring, perhydronaphthalene ring (decalin ring), perhydroanthracene ring, norbornane ring, norbornene Ring, pinane ring, bornane ring, isobornylane ring, tricyclo [5.2.1 0 ^2,6] decane ring, tetracyclo [4.4.0.1 ^{2, 5.} 1 ^{7, 10} ] bridged cyclic hydrocarbon group having 6 to 20 carbon atoms (bridged cyclic hydrocarbon group) corresponding to dodecane ring, etc .; tricyclo [5.2.1.0 ^2,6 ] decylmethyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] Dodecylmethyl group, 2-norbornylmethyl group and the like, and the like groups bonded to each of the hydrocarbon groups. These hydrocarbon groups include an alkyl group, a halogen atom, a hydroxyl group that may be protected with a protecting group, a hydroxymethyl group that may be protected with a protecting group, and a carboxyl group that may be protected with a protecting group ( For example, it has a substituent such as a carboxyl group, a t-butyloxycarbonyl group, a 2-tetrahydrofuranyloxycarbonyl group, a 2-tetrahydropyranyloxycarbonyl group, a 2-oxepanyloxycarbonyl group, and an oxo group. May be. As the protecting group, a protecting group commonly used in the field of organic synthesis can be used.

The monomer unit represented by the formula (IVa) has a function of improving adhesion to a substrate because a highly hydrophilic group (hydroxyl group, carboxyl group, oxo group) is bonded to the adamantane skeleton. In addition, since the monomer units represented by the formulas (IVa), (IVb) (R ⁴⁰ is a cyclic or bridged cyclic hydrocarbon group), and (IVd) have an alicyclic carbon skeleton, transparency, Contributes to improvement in etching resistance and the like. The monomer unit represented by the formula (IVb) (in which R ⁴⁰ is a hydrogen atom), (IVc), (IVd) (in which R ⁴¹ is a hydroxyl group, a hydroxymethyl group or a carboxyl group) has a hydrophilic group It has a function to provide adhesion. Thus, since these monomer units can give various functions based on their structures, incorporation of each of the above monomer units into the polymer makes it possible to finely balance the various properties required as a resist resin depending on the application. Can be adjusted.

  In the polymer compound for photoresists for immersion exposure according to the present invention, in the preferred polymer compound, the monomer unit 2 is, for example, 20 to 99 mol%, preferably 30 to 90 mol, based on the entire monomer unit constituting the polymer. %, More preferably about 35 to 80 mol%. When the ratio of the monomer unit 2 is too small, the alkali solubility after irradiation baking is inferior, and it becomes difficult to obtain a clear pattern. Moreover, content of the monomer unit 3 is about 0-50 mol% with respect to the whole monomer unit which comprises a polymer, Preferably it is 10-45 mol%, More preferably, it is about 15-40 mol%. When the ratio of the monomer unit 3 is too large, hydrophilicity increases, and it becomes difficult to obtain a clear pattern due to swelling of the coating film. Furthermore, the content of the monomer unit 4 is, for example, about 0 to 30 mol%, preferably 2 to 25 mol%, and more preferably about 5 to 20 mol% with respect to the entire monomer unit constituting the polymer. If the proportion of the monomer unit 4 is too large, the content of the monomer unit 1, 2 or 3 is lowered, and the function of the lowered monomer unit is not sufficiently exhibited.

  The weight average molecular weight (Mw) of the polymer compound for photoresist for immersion exposure is, for example, about 5000 to 50000, preferably about 7000 to 20000, and the molecular weight distribution (Mw / Mn) is, for example, 1.2-3. About 5. In addition, said Mn shows a number average molecular weight, and both Mn and Mw are values of polystyrene conversion.

  The monomer units represented by the formulas (Ia) to (Ig) can be formed by subjecting the corresponding polymerizable unsaturated compound to polymerization as a (co) monomer. The monomer units represented by the formulas (IIg), (IIId), (IVc) and (IVd) each have a corresponding ethylenically unsaturated compound as a (co) monomer, and the formulas (IIa) to (IIf) , (IIh), (IIIa) to (IIIc), (IIIe), (IVa), (IVb), each monomer unit is a corresponding unsaturated carboxylic acid such as (meth) acrylic acid or an ester thereof Can be formed by polymerization as a (co) monomer.

[Monomer units of the formulas (Ia) to (Ig)]
Monomers corresponding to the monomer units of the formulas (Ia) to (Ig) are represented by the following formulas (1a) to (1g).

［式中、Ｒ^aは水素原子、ハロゲン原子、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を示す。Ａ¹は単結合又は連結基を示す。環Ｚ¹、環Ｚ⁶、環Ｚ⁸、環Ｚ¹³はそれぞれ、単環又は多環の脂環式炭素環を示し、環Ｚ²、環Ｚ³、環Ｚ⁴、環Ｚ⁵、環Ｚ⁷、環Ｚ⁹、環Ｚ¹⁰、環Ｚ¹¹、環Ｚ¹²はそれぞれ、環内にエーテル結合を含む環を示す。但し、式（1c）、式（1d）において、Ａ¹がエステル結合を含み、該エステル結合を構成する酸素原子が環Ｚ⁵、環Ｚ⁷に結合している場合には、該酸素原子は環Ｚ⁵、環Ｚ⁷の酸素原子の隣接位以外の原子に結合している］

[Wherein, R ^a represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms. A ¹ represents a single bond or a linking group. Ring Z ¹ , Ring Z ⁶ , Ring Z ⁸ , and Ring Z ¹³ each represent a monocyclic or polycyclic alicyclic carbocyclic ring. Ring Z ² , Ring Z ³ , Ring Z ⁴ , Ring Z ⁵ , Ring Z ⁷ , Ring Z ⁹ , Ring Z ¹⁰ , Ring Z ¹¹ , and Ring Z ¹² each represent a ring containing an ether bond in the ring. However, in the formulas (1c) and (1d), when A ¹ includes an ester bond and the oxygen atom constituting the ester bond is bonded to the ring Z ⁵ or the ring Z ⁷ , the oxygen atom is Ring Z ⁵ is bonded to an atom other than the adjacent position of the oxygen atom of ring Z ⁷ ]

As typical examples of the monomer represented by the formula (1a), 8- (meth) acryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decane, 4- (meth) acryloyloxy -1,2-epoxycyclohexane, 3- (meth) acryloyloxy-8-oxabicyclo [4.3.0 ^1,6 ] nonane, 4- (meth) acryloyloxy-11-oxapentacyclo [6.5. 1.1 ^3,6 . 0 ^2,7 . ^0,13 ] pentadecane, 8-vinyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decane, and the like.

  Representative examples of the monomer represented by the formula (1b) include 2- (meth) acryloyloxy-7-oxabicyclo [2.2.1] heptane.

  Representative examples of the monomer represented by the formula (1c) include 4- (meth) acryloyloxy-2-oxabicyclo [4.3.0] nonane, 4- (meth) acryloyloxy-2-oxabicyclo [ 4.4.0] decane and the like.

  Representative examples of the monomer represented by the formula (1d) include 3- (meth) acryloyloxytetrahydrofuran and 3- (meth) acryloyloxymethyltetrahydrofuran.

Representative examples of the monomer represented by the formula (1e) include 4-oxatricyclo [5.2.1.0 ^2,6 ] -8-decene, 11-oxapentacyclo [6.5.1. 1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] -4-pentadecene and the like.

  A typical example of the monomer represented by the formula (1f) includes 7-oxabicyclo [2.2.1] -2-heptene.

  The monomers represented by the formulas (1a) to (1g) can be obtained using a known method or a known reaction (for example, esterification reaction, etherification reaction, ester-ether exchange reaction, etc.). Moreover, a commercial item can also be used.

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

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

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

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

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

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

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

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

[Monomer unit of formula (IIIa)]
Typical compounds of the monomer corresponding to the monomer unit of the formula (IIIa) include the following compounds. 1- (meth) acryloyloxy-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-5-one, 1- (meth) acryloyloxy-4,7-dioxatricyclo [4. 4.1.1 ^3,9 ] dodecane-5,8-dione, 1- (meth) acryloyloxy-4,8-dioxatricyclo [4.4.1.1 ^3,9 ] dodecane-5,7 -Dione, 1- (meth) acryloyloxy-5,7-dioxatricyclo [4.4.1.1 ^3,9 ] dodecane-4,8-dione.

[Monomer unit of formula (IIIb)]
Typical compounds of the monomer corresponding to the monomer unit of the formula (IIIb) include the following compounds. 2- (meth) acryloyloxy-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one [= 5- (meth) acryloyloxy-2,6-norbornanecarbolactone], 2 -(Meth) acryloyloxy-2-methyl-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one, 2- (meth) acryloyloxy-9-methyl-4-oxatri Cyclo [4.2.1.0 ^3,7 ] nonan-5-one.

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

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

[Monomer unit of formula (IIIe)]
Typical examples of the monomer forming the monomer unit of the formula (IIIe) include the following compounds. 8- (meth) acryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-5-one [= 9- (meth) acryloyloxy-4-oxatricyclo [5.2. 1.0 ^2,6 ] decan-3-one], 9- (meth) acryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-5-one [= 8- (meta ) Acryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-3-one], 8- (meth) acryloyloxy-9-hydroxy-4-oxatricyclo [5.2. 1.0 ^2,6 ] decan-5-one [= 9- (meth) acryloyloxy-8-hydroxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-3-one], 9- (Meth) acryloyloxy-8-hydroxy-4-oxatricyclo [5. .1.0 ^2,6] decan-5-one [= 8- (meth) acryloyloxy-9-hydroxy-4-oxa-tricyclo [5.2.1.0 ^2,6] decan-3-one] , 8- (meth) acryloyloxy-3-oxatricyclo [5.2.1.0 ^2,6 ] decan-4-one, 9- (meth) acryloyloxy-3-oxatricyclo [5.2. 1.0 ^2,6 ] decan-4-one, 9- (meth) acryloyloxy-4-oxatricyclo [6.2.1.0 ^2,7 ] undecan-3-one, 10- (meth) acryloyl Oxy-4-oxatricyclo [6.2.1.0 ^2,7 ] undecan-3-one, 9- (meth) acryloyloxy-4-oxatricyclo [6.2.1.0 ^2,7 ] Undecan-5-one, 10- (meth) acryloyloxy-4-oxatricycl B [6.2.1.0 ^2,7 ] Undecan-5-one.

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

[Monomer unit of formula (IVb)]
Typical examples of the monomer forming the monomer unit of the formula (IVb) include the following compounds. (Meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, decahydro (meth) acrylate Naphthyl, norbornyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dimethyladamantyl (meth) acrylate, tricyclo [5.2.1.0 ^2,6 ] decyl (meth) acrylate , Tetracyclo (meth) acrylate [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecyl. A compound in which a substituent such as a hydroxy group, a hydroxymethyl group, a carboxyl group, or an oxo group is bonded to a group corresponding to R ³⁹ of these compounds is also preferable.

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

[Monomer unit of formula (IVd)]
As typical examples of the monomer forming the monomer unit of the formula (IVd), there may be mentioned the following compounds. Norbornene, 5-hydroxy-2-norbornene.

  In obtaining the polymer compound for a photoresist for immersion exposure of the present invention, the polymerization of the monomer mixture produces an acrylic polymer, such as solution polymerization, bulk polymerization, suspension polymerization, bulk-suspension polymerization, and emulsion polymerization. Although it can be carried out by a conventional method used at the time, solution polymerization is particularly preferred. Furthermore, drop polymerization is preferable among solution polymerization. Specifically, for example, (i) a monomer solution previously dissolved in an organic solvent and a polymerization initiator solution dissolved in an organic solvent are prepared in an organic solvent kept at a constant temperature. A method in which the monomer solution and the polymerization initiator solution are respectively dropped, and (ii) a method in which a mixed solution in which the monomer and the polymerization initiator are dissolved in an organic solvent is dropped into an organic solvent maintained at a constant temperature. (Iii) A monomer solution previously dissolved in an organic solvent and a polymerization initiator solution dissolved in the organic solvent are respectively prepared, and the polymerization initiator solution is dropped into the monomer solution maintained at a constant temperature. It is performed by a method or the like.

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

  The polymer obtained by polymerization can be purified by precipitation or 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) is preferable. In such a solvent containing at least hydrocarbon, the ratio of hydrocarbon (for example, aliphatic hydrocarbon such as hexane) and other solvent is, for example, the former / the latter (volume ratio; 25 ° C.) = 10/90 to 99 / 1, preferably the former / the latter (volume ratio; 25 ° C.) = 30/70 to 98/2, more preferably the former / the latter (volume ratio; 25 ° C.) = 50/50 to 97/3.

  The resin composition for a photoresist for immersion exposure according to the present invention contains the polymer compound for a photoresist for immersion exposure according to the present invention and a photoacid generator.

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

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

  Resin compositions for photoresists for immersion exposure include alkali-soluble components such as alkali-soluble resins (for example, novolak resins, phenol resins, imide resins, carboxyl group-containing resins), colorants (for example, dyes), organic Including solvents (for example, hydrocarbons, halogenated hydrocarbons, alcohols, esters, amides, ketones, ethers, cellosolves, carbitols, glycol ether esters, mixed solvents thereof, etc.) You may go out.

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

  Examples of the base material or the substrate include a silicon wafer, metal, plastic, glass, and ceramic. The application of the photoresist resin composition can be performed using a conventional application means such as a spin coater, a dip coater, or a roller coater. The thickness of the coating film is, for example, about 0.01 to 20 μm, preferably about 0.05 to 2 μm.

For exposure, various wavelengths of light such as ultraviolet rays and X-rays can be used. For semiconductor resists, g-line, i-line, and excimer lasers (eg, XeCl, KrF, KrCl, ArF, ArCl, F) are generally used. ₂ , Kr ₂ , KrAr, Ar ₂ etc.). The exposure energy is, for example, about 0.1 to 1000 mJ / cm ² . In the present invention, since the resist film has high water resistance, exposure can be performed under immersion using an immersion type exposure apparatus. Therefore, it is possible to further advance the pattern miniaturization.

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

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

Production Example 1
Synthesis of 9-hydroxy-2-oxatetrahydro-exo-dicyclopentadiene (= 8-hydroxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decane) Raw material of cyclopentadiene and maleic anhydride Was synthesized by the method described in J. Am. Chem. Soc., 82, 2541-2547 (1960). That is, cyclopentadiene and maleic anhydride are subjected to a Diels-Alder reaction (Step 1) and subjected to ring-opening reduction (Step 2) to form norbornene dimethanol. Next, the diol is dehydrated to form a cyclic ether (Step 3), the olefin is acetoxylated (Step 4), the acetyl group is removed by hydrolysis to form an alcohol (Step 5), and the target compound represented by the following formula: Got.

Production Example 2
Synthesis of 9-methacryloyloxy-2-oxatetrahydro-exo-dicyclopentadiene (= 8-methacryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decane) 9-hydroxy-2-oxa Tetrahydro-exo-dicyclopentadiene (= 8-hydroxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decane) 10 g (0.0649 mol), N, N-dimethylaniline 9.49 g, phenothiazine 20 mg was dissolved in 60 ml of dry tetrahydrofuran (THF) and ice-cooled. A solution prepared by dissolving 6.5 g of methacryloyl chloride in 10 ml of dry THF was added dropwise thereto. The mixture was stirred for 2 hours under ice-cooling and for 3 hours at room temperature, then filtered, and the filtrate was concentrated under reduced pressure. To the residue, 250 ml of ether was added and washed successively with 200 ml of 0.5N hydrochloric acid, saturated brine, 200 ml of 3 wt% aqueous sodium hydrogen carbonate solution, saturated brine and water. After the ether layer was dried over magnesium sulfate, the ether was distilled off under reduced pressure. The residue was purified by silica gel column chromatography to obtain 6.2 g of the target compound represented by the following formula.
¹ H-NMR (CDCl ₃ ) δ: 1.5-1.7 (6H, m), 1.9 (3H, s), 2.0 (1H, m), 3.7 (4H, m), 4.2 (1H, m), 5.6 (1H , d), 6.2 (1H, d)

還流管、撹拌子、３方コックを備えた１００ｍｌ丸底フラスコに、窒素雰囲気下、テトラヒドロフラン（ＴＨＦ）１０ｇを入れ、温度を６０℃に保ち、撹拌しながら、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン１．４０ｇ（６．３０ｍｍｏｌ）、９−メタクリロイルオキシ−２−オキサテトラヒドロ−ｅｘｏ−ジシクロペンタジエン１．４０ｇ（６．３０ｍｍｏｌ）、１−（１−メタクリロイルオキシ−１−メチルエチル）アダマンタン２．２０ｇ（８．４０ｍｍｏｌ）、ラジカル重合開始剤（和光純薬工業製、商品名「Ｖ−６５」）０．５０ｇ及びＴＨＦ１６ｇを混合したモノマー溶液を２時間かけて一定速度で滴下した。滴下終了後、さらに６時間撹拌を続けた。重合反応終了後、得られた反応液をヘキサンと酢酸エチルの９：１（体積比；２５℃）混合液５００ｍｌ中に撹拌しながら滴下した。生じた沈殿物を濾別し、減圧乾燥（２５℃）することにより、所望の樹脂４．３ｇを得た。回収したポリマーをＧＰＣ（ゲルパーミエーションクロマトグラフィー）分析したところ、重量平均分子量（Ｍｗ）が８５００、分子量分布（Ｍｗ／Ｍｎ）が１．９３であった。 Example 1
Synthesis of resin with the following structure

In a 100 ml round bottom flask equipped with a reflux tube, a stirring bar and a three-way cock, 10 g of tetrahydrofuran (THF) was placed under a nitrogen atmosphere, and the temperature was kept at 60 ° C., while stirring, 5-methacryloyloxy-2,6- 1.40 g (6.30 mmol) of norbornanecarbolactone, 1.40 g (6.30 mmol) of 9-methacryloyloxy-2-oxatetrahydro-exo-dicyclopentadiene, 1- (1-methacryloyloxy-1-methylethyl) adamantane A monomer solution obtained by mixing 2.20 g (8.40 mmol), 0.50 g of a radical polymerization initiator (trade name “V-65” manufactured by Wako Pure Chemical Industries, Ltd.) and 16 g of THF was added dropwise at a constant rate over 2 hours. After completion of the dropwise addition, stirring was continued for 6 hours. After completion of the polymerization reaction, the obtained reaction solution was added dropwise to 500 ml of a 9: 1 (volume ratio; 25 ° C.) mixture of hexane and ethyl acetate while stirring. The resulting precipitate was filtered off and dried under reduced pressure (25 ° C.) to obtain 4.3 g of the desired resin. When the recovered polymer was analyzed by GPC (gel permeation chromatography), the weight average molecular weight (Mw) was 8500, and the molecular weight distribution (Mw / Mn) was 1.93.

実施例１において、モノマー成分として、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン１．４７ｇ（６．６１ｍｍｏｌ）、９−メタクリロイルオキシ−２−オキサテトラヒドロ−ｅｘｏ−ジシクロペンタジエン１．４７ｇ（６．６１ｍｍｏｌ）、２−メタクリロイルオキシ−２−メチルアダマンタン２．０６ｇ（８．８２ｍｍｏｌ）を用いた以外は、実施例１と同様の操作を行ったところ、所望の樹脂３．９ｇを得た。回収したポリマーをＧＰＣ分析したところ、重量平均分子量（Ｍｗ）が８１００、分子量分布（Ｍｗ／Ｍｎ）が１．９５であった。 Example 2
Synthesis of resin with the following structure

In Example 1, as monomer components, 1.47 g (6.61 mmol) of 5-methacryloyloxy-2,6-norbornanecarbolactone, 1.47 g of 9-methacryloyloxy-2-oxatetrahydro-exo-dicyclopentadiene (6 .61 mmol) and 2-methacryloyloxy-2-methyladamantane (2.06 g, 8.82 mmol) were used in the same manner as in Example 1 to obtain 3.9 g of the desired resin. When the recovered polymer was analyzed by GPC, the weight average molecular weight (Mw) was 8100, and the molecular weight distribution (Mw / Mn) was 1.95.

実施例１において、モノマー成分として、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン１．３７ｇ（６．１９ｍｍｏｌ）、１−メタクリロイルオキシ−３−ヒドロキシアダマンタン１．４６ｇ（６．１９ｍｍｏｌ）、１−（１−メタクリロイルオキシ−１−メチルエチル）アダマンタン２．１６ｇ（８．２６ｍｍｏｌ）を用いた以外は、実施例１と同様の操作を行ったところ、所望の樹脂３．４ｇを得た。回収したポリマーをＧＰＣ分析したところ、重量平均分子量（Ｍｗ）が８０００、分子量分布（Ｍｗ／Ｍｎ）が２．１０であった。 Comparative Example 1
Synthesis of resin with the following structure

In Example 1, as monomer components, 1.37 g (6.19 mmol) of 5-methacryloyloxy-2,6-norbornanecarbolactone, 1.46 g (6.19 mmol) of 1-methacryloyloxy-3-hydroxyadamantane, 1- The same operation as in Example 1 was performed except that 2.16 g (8.26 mmol) of (1-methacryloyloxy-1-methylethyl) adamantane was used, and 3.4 g of a desired resin was obtained. When the recovered polymer was analyzed by GPC, the weight average molecular weight (Mw) was 8000, and the molecular weight distribution (Mw / Mn) was 2.10.

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

  As is apparent from the table, when the polymer of the example is used, it can be seen that even when immersed in water, there is almost no variation in the thickness of the coating film and the water resistance is excellent. Therefore, the polymer of the example is useful as a resist for immersion exposure. On the other hand, when the polymer of the comparative example is used, it swells when immersed in water, and the thickness of the coating film increases greatly.

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

Claims (9)

  A polymer compound for a photoresist for immersion exposure, comprising a monomer unit containing a cyclic ether skeleton. Monomer units containing a cyclic ether skeleton are represented by the following formulas (Ia) to (Ig)

[Wherein, R ^a represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms. A ¹ represents a single bond or a linking group. Ring Z ¹ , Ring Z ⁶ , Ring Z ⁸ , and Ring Z ¹³ each represent a monocyclic or polycyclic alicyclic carbocyclic ring. Ring Z ² , Ring Z ³ , Ring Z ⁴ , Ring Z ⁵ , Ring Z ⁷ , Ring Z ⁹ , Ring Z ¹⁰ , Ring Z ¹¹ , and Ring Z ¹² each represent a ring containing an ether bond in the ring. However, in the formulas (Ic) and (Id), when A ¹ contains an ester bond and the oxygen atom constituting the ester bond is bonded to the ring Z ⁵ or the ring Z ⁷ , the oxygen atom is Ring Z ⁵ is bonded to an atom other than the adjacent position of the oxygen atom of ring Z ⁷ ]
The high molecular compound for photoresist for immersion exposure according to claim 1, which is at least one monomer unit selected from the group consisting of:   The high molecular compound for photoresists for immersion exposure according to claim 1, wherein the monomer unit containing a cyclic ether skeleton contains 1 to 70 mol% of all monomer units.   Furthermore, the high molecular compound for photoresists for immersion exposure of any one of Claims 1-3 containing the monomer unit which has a group which the one part remove | eliminates with an acid and becomes alkali-soluble. A monomer unit having a group that is partially eliminated by an acid and becomes alkali-soluble is represented by the following formulas (IIa) to (IIh):

(In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms. R ¹ and R ² are the same or different and have 1 to 8 carbon atoms. R ³ , R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom, a hydroxyl group or a methyl group, and R ⁶ and R ⁷ are the same or different and represent a hydrogen atom, a hydroxyl group or shows the -COOR ⁸ group, R ⁸ is t- butyl, 2-tetrahydrofuranyl group, .R ⁹ showing a 2-tetrahydropyranyl group or a 2-oxepanyl group represents a methyl group or an ethyl group, R ¹⁰ and R ¹¹ is the same or different and represents a hydrogen atom, a hydroxyl group or an oxo group, and R ¹² has a substituent having a tertiary carbon atom at the bonding site with the oxygen atom shown in the formula. shows also be a hydrocarbon group .R ^13, R ¹⁴ R ^15, R ¹⁶ and R ¹⁷ are the same or different and are each a hydrogen atom or a methyl group .R ¹⁸ is t- butyl, 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group or a 2-oxepanyl group R ¹⁹ and R ²⁰ are the same or different and each represents a hydrogen atom, an alkyl group or a fluoroalkyl group, R ²¹ represents a hydrogen atom or an organic group, m represents an integer of 1 to 3, and n represents 0 or 1)
The photoresist polymer composition for immersion exposure according to claim 4, wherein the polymer compound is at least one monomer unit selected from the group consisting of:   Furthermore, the high molecular compound for photoresists for immersion exposure as described in any one of Claims 1-5 containing the monomer unit which has lactone skeleton. Monomer units having a lactone skeleton are represented by the following formulas (IIIa) to (IIIe)

(In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. X ¹ , X ² and X ³ are the same or different and represent —CH _2. -Or -CO-O-, provided that at least one of X ¹ , X ² and X ³ is -CO-O-, R ²² , R ²³ and R ²⁴ are the same or different and represent hydrogen R ²⁵ , R ²⁶ and R ²⁷ are the same or different and each represents a hydrogen atom, a methyl group or a trifluoromethyl group, and R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ and R ³² represent R ³³ , R ³⁴ , R ³⁵ and R ³⁶ are the same or different and represent a hydrogen atom or a methyl group, and o, p, q and t are respectively the same or different. , 0 or 1)
The high molecular compound for photoresist for immersion exposure according to claim 6, which is at least one monomer unit selected from the group consisting of:   A resin composition for photoresist for immersion exposure, comprising at least the polymer compound for photoresist for immersion exposure according to any one of claims 1 to 7 and a photoacid generator.   A semiconductor comprising a step of applying a photoresist resin composition for immersion exposure according to claim 8 on a substrate or a substrate to form a resist coating film, and forming a pattern through exposure and development under immersion. Manufacturing method.