JP5117484B2 - NOVEL COMPOUND AND PROCESS FOR PRODUCING THE SAME - Google Patents

Description

The present invention relates to the production side of the novel compounds, and compounds.

In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology. As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, F ₂ excimer laser having a shorter wavelength than these excimer lasers, electron beams, also consider such extreme ultraviolet radiation and X-rays have been made.
In addition, as one of the resist materials that satisfy the high resolution conditions that can reproduce patterns with fine dimensions, it contains a base resin whose alkali solubility changes due to the action of acid and an acid generator that generates acid upon exposure. A chemically amplified resist composition is known. The chemically amplified resist composition includes a negative type containing an alkali-soluble resin, an acid generator and a crosslinking agent, and a positive type containing a resin whose acid solubility is increased by the action of an acid and an acid generator.

 For example, as a resist base resin used in ArF excimer laser lithography or the like, a resin (acrylic resin) having a structural unit derived from (meth) acrylic acid is mainly used because of excellent transparency near 193 nm. (Patent Document 1 etc.).

JP 2003-167347 A

 However, in the conventional resist composition, the resolution required as the pattern is rapidly miniaturized due to the progress of the lithography technique as described above has become insufficient.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the technique in connection with the resist composition which can improve resolution.

As a result of intensive studies, the present inventors have found that the above problems can be solved by a polymer compound having a structural unit having a specific structure and a structural unit having an acid dissociable, dissolution inhibiting group, and completed the present invention. It was.
That is, the first aspect of the present invention is a compound represented by the following general formula (K-1).

［式中、Ｒ^３〜Ｒ^４はそれぞれ独立して水素原子又は炭素数１〜１２のアルキル基を示し、Ｒ^５は炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基をし、ａは１を示し、ｔは０又は１〜３の整数を示す。］

[Wherein, R ^{3 to} R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ⁵ represents an alkyl group having 1 to 5 carbon atoms or an alkyl halide having 1 to 5 carbon atoms. A represents 1 and t represents 0 or an integer of 1 to 3; ]

In a second embodiment of the present invention, tetracyclododecene alcohol is subjected to R ⁵ —SO ₂ —Cl (R ⁵ is an alkyl group having 1 to 5 carbon atoms or an alkyl halide having 1 to 5 carbon atoms) under a base catalyst. And a compound represented by the following general formula (K-1) is obtained.

［式中、Ｒ^３〜Ｒ^４はそれぞれ独立して水素原子又は炭素数１〜１２のアルキル基を示し、Ｒ^５は炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基をし、ａは１を示し、ｔは０又は１〜３の整数を示す。］

[Wherein, R ^{3 to} R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ⁵ represents an alkyl group having 1 to 5 carbon atoms or an alkyl halide having 1 to 5 carbon atoms. A represents 1 and t represents 0 or an integer of 1 to 3; ]

In the present invention, “structural unit” means a monomer unit constituting a polymer.
Further, “(α-lower alkyl) acrylic acid ester” means one or both of α-lower alkyl acrylic acid ester such as methacrylic acid ester and acrylic acid ester. Here, the “α-lower alkyl acrylate ester” means that a hydrogen atom bonded to the α carbon atom of the acrylate ester is substituted with a lower alkyl group. The “structural unit derived from (α-lower alkyl) acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of (α-lower alkyl) acrylate ester.
In addition, “exposure” is a concept including general radiation irradiation.

  According to the present invention, a technique related to a resist composition capable of improving resolution can be provided.

≪Polymer compound≫
The polymer compound of the present invention (hereinafter sometimes referred to as polymer compound (A1)) has the structural unit (a0) represented by the general formula (A0) and an acid dissociable, dissolution inhibiting group (α- And a structural unit (a1) derived from a lower alkyl) acrylate ester.

・ Structural unit (a0)
In formula (A0), R represents a hydrogen atom or a lower alkyl group. The lower alkyl group of R is an alkyl group having 1 to 5 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group. And a lower linear or branched alkyl group such as a group, an isopentyl group and a neopentyl group. R is preferably a hydrogen atom or a methyl group in terms of industrial availability. The hydrogen atom of R or the hydrogen atom of the lower alkyl group may be substituted with a fluorine atom.

R ^{1 to} R ⁴ each independently represent a hydrogen atom or an alkyl group (including a cycloalkyl group and a chain alkyl group). The alkyl group for R ^{1 to} R ⁴ may be linear, branched or cyclic, and is preferably an alkyl group having 1 to 12 carbon atoms.
The linear or branched alkyl group preferably has 1 to 12 carbon atoms, and more preferably 1 to 5 carbon atoms. Examples of the linear or branched alkyl group having 1 to 5 carbon atoms include those similar to the lower alkyl group for R.
The cyclic alkyl group preferably has 4 to 12 carbon atoms, and more preferably 5 to 10 carbon atoms. Examples of the alkyl group include a cyclohexyl group, a cyclopentyl group, an adamantyl group, a norbornyl group, a tricyclodecanyl group, and a tetracyclodecanyl group.
R ^{1 to} R ⁴ are more preferably a linear or branched alkyl group or a hydrogen atom.
The case where R ¹ and R ² are simultaneously an alkyl group, that is, a case where they are dissociated with an acid is not included in the present invention.

R ⁵ represents a lower alkyl group or a halogenated lower alkyl group. As the lower alkyl group, the same as the lower alkyl group for R can be used. The halogenated lower alkyl group is one in which one or more hydrogen atoms in the lower alkyl group are substituted with halogen atoms such as fluorine, chlorine, bromine and the like, and those substituted with fluorine are preferable. .
R ⁵ is preferably a lower alkyl group, and particularly preferably a methyl group.

X is a cyclic group, which is a divalent to tetravalent cyclic group. The cyclic group is preferably divalent or trivalent, and more preferably divalent.
X may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and ═O.
Examples of the cyclic group include “aliphatic cyclic group”. Here, “aliphatic” in the present specification and claims is a relative concept with respect to aromatics, and is defined to mean groups, compounds, and the like that do not have aromaticity. The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity. The aliphatic cyclic group may be saturated or unsaturated, but is usually preferably saturated.
The structure of the basic ring (basic ring) excluding the substituent in the aliphatic cyclic group may be a ring consisting of carbon and hydrogen (hydrocarbon ring), and the carbon atoms constituting the hydrocarbon ring It may be a heterocyclic ring partially substituted with a heteroatom such as a sulfur atom. For the effect of the present invention, the basic ring in X is preferably a hydrocarbon ring.
Specific examples of the hydrocarbon ring include monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
X is preferably a group obtained by removing a hydrogen atom from adamantane, norbornane or tetracyclododecane, more preferably a group obtained by removing a hydrogen atom from adamantane or norbornane.

s and t are each independently an integer of 0 or 1-3. s is preferably 0 or 1, and most preferably 0. t is preferably 0 or 1.
u is an integer of 1 to 3, preferably 1 or 2, and most preferably 1. When u is 1, X is divalent, when u is 2, X is trivalent, and when u is 3, X is tetravalent.

  More specifically, examples of the structural unit (a0) include a structural unit (a0-1) represented by the following general formula (a0-1) and a structural unit (k0) represented by the following general formula (k0). Is mentioned.

（式中、Ｒ、Ｒ^３〜Ｒ^５、ｔ、ｕは上記と同様である。）

(In the formula, R, R ^{3 to} R ⁵ , t, and u are the same as described above.)

（式中、Ｒ、Ｒ^３〜Ｒ^５、ｔ、ｕは上記と同様である。ａは０または１である。）

(In the formula, R, R ^{3 to} R ⁵ , t and u are the same as above. A is 0 or 1.)

  As the structural unit (a0-1), structural units represented by general formula (a0-1-1) shown below are preferred.

（式中、Ｒは上記と同様である。）

(In the formula, R is the same as above.)

  As the structural unit (k0), structural units represented by general formula (k0-1) shown below are preferred.

（式中、Ｒ、Ｒ^３〜Ｒ^５、ｔ、ａは上記と同様である。）

(In the formula, R, R ^{3 to} R ⁵ , t, and a are the same as above.)

  As the structural unit (k0), structural units represented by general formula (k0-1-1) shown below are more preferable.

（式中、Ｒ、ａは上記と同様である。）

(In the formula, R and a are the same as above.)

  In the polymer compound (A1), the proportion of the structural unit (a0) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, based on all structural units constituting the polymer compound (A1). More preferred is ˜50 mol%. By setting it to the lower limit value or more, the effect of the present invention is improved, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

As the monomer for deriving the structural unit (a0), for example, in a compound having a cyclic skeleton having a hydroxyl group in the ester part of (meth) acrylic acid ester, a commercially available reagent such as R ⁵ —SO ₂ —Cl is used. , Can be produced by introducing a side chain having a bond having a structure of “—O—SO ₂ —R ⁵ ” (hereinafter referred to as “sulfonic acid group” for convenience) into the cyclic skeleton.
Alternatively, as shown by the following general formula (I), a compound obtained by dissolving a side chain having a sulfonic acid group on a cyclic group having a double bond is dissolved in dry tetrahydrofuran (THF) to give 0 After cooling to ° C., a THF solution of BH ₃ -tetrahydrofuran complex was added dropwise and stirred to add a B—H bond to the double bond, and then 30% by mass hydrogen peroxide and 3 molar hydroxylation. It is obtained by oxidizing with alkaline hydrogen peroxide comprising an aqueous sodium solution to give an alcohol, and then reacting with (α-lower alkyl) acrylic acid chloride to give (α-lower alkyl) acrylic acid ester.

（式中、Ｒ、Ｒ^３〜Ｒ^５、ｔ、ａは上記と同様である。）

(In the formula, R, R ^{3 to} R ⁵ , t, and a are the same as above.)

・ Structural unit (a1)
The structural unit (a1) is a structural unit derived from an (α-lower alkyl) acrylate ester having an acid dissociable, dissolution inhibiting group.
Examples of the lower alkyl group as a substituent at the α-position of the (α-lower alkyl) acrylate ester include the same as the lower alkyl group for R in the structural unit (a0).

  The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire polymer compound (A1) insoluble in alkali before dissociation, and the entire polymer compound (A1) is alkalinized after dissociation. As long as it is changed to be soluble, those that have been proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used. Generally, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group of (meth) acrylic acid, or a group that forms a cyclic or chain alkoxyalkyl ester is widely known. . “(Meth) acrylic acid ester” means one or both of acrylic acid ester and methacrylic acid ester.

Here, the tertiary alkyl ester is an ester formed by substituting a hydrogen atom of a carboxy group with an alkyl group or a cycloalkyl group, and a carbonyloxy group (—C (O) —O—). ), The tertiary carbon atom of the alkyl group or cycloalkyl group is bonded to the terminal oxygen atom. In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The alkyl group or cycloalkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.
The cyclic or chain alkoxyalkyl ester forms an ester by replacing the hydrogen atom of the carboxy group with an alkoxyalkyl group, and the carbonyloxy group (—C (O) —O—) A structure in which the alkoxyalkyl group is bonded to a terminal oxygen atom is shown. In this alkoxyalkyl ester, when an acid acts, a bond is cut between an oxygen atom and an alkoxyalkyl group.

  As the structural unit (a1), one type selected from the group consisting of structural units represented by general formula (a1-0-1) shown below and structural units represented by general formula (a1-0-2) shown below. It is preferable to use the above.

（式中、Ｒは水素原子または低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。）

(In the formula, R represents a hydrogen atom or a lower alkyl group; X ¹ represents an acid dissociable, dissolution inhibiting group.)

（式中、Ｒは水素原子または低級アルキル基を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２は脂肪族環式基を示す。）

(In the formula, R represents a hydrogen atom or a lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an aliphatic cyclic group.)

In general formula (a1-0-1), R is the same as described above. X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include an alkoxyalkyl group, a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, and the like. Acid dissociable, dissolution inhibiting groups are preferred. Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. A polycyclic group is preferred.
Specific examples of such aliphatic cyclic groups include, for example, monocycloalkanes, bicycloalkanes, tricycloalkanes, tetraalkyls which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. Examples thereof include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as cycloalkane. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
Specific examples of the aliphatic branched acid dissociable, dissolution inhibiting group include a tert-butyl group and a tert-amyl group.
Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cycloalkyl group. Specifically, 2-methyl- Examples thereof include an adamantyl group and a 2-ethyladamantyl group. Alternatively, as a structural unit represented by the following general formula, a group having an aliphatic cyclic group such as an adamantyl group and a branched alkylene group having a tertiary carbon atom bonded thereto can be given.

［式中、Ｒは上記と同じであり、Ｒ^１５、Ｒ^１６はアルキル基（直鎖、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R is the same as described above, and R ¹⁵ and R ¹⁶ represent an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms). ]

  Further, the alkoxyalkyl group is preferably a group represented by the following general formula.

（式中、Ｒ^２１、Ｒ^２２はそれぞれ独立してアルキル基または水素原子であり、Ｒ^２３はアルキル基又はシクロアルキル基である。または、Ｒ^２１とＲ^２３の末端が結合して環を形成していてもよい。）

(In the formula, R ²¹ and R ²² are each independently an alkyl group or a hydrogen atom, and R ²³ is an alkyl group or a cycloalkyl group. Alternatively, the ends of R ²¹ and R ²³ are combined to form a ring. You may do it.)

In R ²¹ and R ²² , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. In particular, it is preferable that one of R ²¹ and R ²² is a hydrogen atom and the other is a methyl group.
R ²³ is an alkyl group or a cycloalkyl group, preferably having 1 to 15 carbon atoms, and may be linear, branched or cyclic. When R ²³ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ²³ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include a group excluding a hydrogen atom. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ²¹ and R ²³ are each independently an alkylene group having 1 to 5 carbon atoms, and the end of R ^{23 and} the end of R ²¹ may be bonded.
In this case, a cyclic group is formed by R ²¹ , R ²³ , the oxygen atom to which R ²³ is bonded, and the carbon atom to which the oxygen atom and R ²¹ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

In general formula (a1-0-2), R is the same as defined above. X ² is the same as X ¹ in formula (a1-0-1).
Y ² is a divalent aliphatic cyclic group.
Since Y ² is a divalent aliphatic cyclic group, it is the same as the description of the “aliphatic cyclic group” in the structural unit (a1) except that a group in which two or more hydrogen atoms are removed is used. Can be used.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［上記式中、Ｘ’は、第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０または１〜３の整数を表し；ｍは０または１を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[In the above formula, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; M represents 0 or 1; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. ]

In the R ¹ ′ and R ² ′, at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. n is preferably 0 or 1.

X ′ is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group exemplified in X ¹ above.
Examples of the aliphatic cyclic group for Y include the same groups as those exemplified in the description of the “aliphatic cyclic group” in the structural unit (a1).

   Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination. Among these, the structural unit represented by General Formula (a1-1) is preferable, and specifically, (a1-1-1) to (a1-1-6) or (a1-1-35) to (a1- It is more preferable to use at least one selected from structural units represented by 1-41).
Furthermore, as the structural unit (a1), in particular, those represented by the following general formula (a1-1-01) including the structural units of the formulas (a1-1-1) to (a1-1-4) And the following general formula (a1-1-02) including the structural units of the formulas (a1-1-36), (a1-1-38), (a1-1-39) and (a1-1-41) preferable.

（式中、Ｒは水素原子または低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。）

(In the formula, R represents a hydrogen atom or a lower alkyl group, and R ¹¹ represents a lower alkyl group.)

（式中、Ｒは水素原子または低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜３の整数を表す）

(Wherein R represents a hydrogen atom or a lower alkyl group, R ¹² represents a lower alkyl group, h represents an integer of 1 to 3)

In general formula (a1-1-01), R is the same as defined above. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.

In general formula (a1-1-02), R is the same as defined above. The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

  In the polymer compound (A1), the proportion of the structural unit (a1) is preferably from 10 to 80 mol%, more preferably from 20 to 70 mol%, based on all structural units constituting the polymer compound (A1), 25 More preferred is ˜50 mol%. By setting it to the lower limit value or more, a pattern can be obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a2)
The polymer compound (A1) is a structural unit derived from an (α-lower alkyl) acrylate ester having a lactone-containing monocyclic or polycyclic group in addition to the structural unit (a0) and the structural unit (a1). It is preferable to have (a2).
The lactone-containing monocyclic or polycyclic group of the structural unit (a2) can be used to increase the adhesion of the resist film to the substrate when the polymer compound (A1) is used for forming a resist film, It is effective in increasing hydrophilicity.
Here, the lactone-containing monocyclic or polycyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group. When it has another ring structure, it is called a polycyclic group regardless of the structure.

As the structural unit (a2), any structural unit can be used without particular limitation as long as it has both such a lactone structure (—O—C (O) —) and a cyclic group.
Specifically, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-butyrolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. In particular, a group obtained by removing one hydrogen atom from a lactone-containing tricycloalkane having the following structural formula is advantageous in that it is easily available industrially.

  More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子または低級アルキル基であり、Ｒ’は水素原子、低級アルキル基、または炭素数１〜５のアルコキシ基であり、ｍは０または１の整数である。］

[Wherein, R is a hydrogen atom or a lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is an integer of 0 or 1. ]

In general formulas (a2-1) to (a2-5), the lower alkyl group for R and R ′ is the same as the lower alkyl group for R in the structural unit (a1).
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.

  Specific structural units of the general formulas (a2-1) to (a2-5) are exemplified.

In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Among these, it is preferable to use at least one selected from general formulas (a2-1) to (a2-5), and at least one selected from general formulas (a2-1) to (a2-3). It is preferable to use more than one species. Specifically, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-3-1), (a2-3) -2), at least one selected from (a2-3-9) and (a2-3-10) is preferably used.

In the polymer compound (A1), as the structural unit (a2), one type of structural unit may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a2) in the polymer compound (A1) is preferably from 5 to 60 mol%, more preferably from 10 to 50 mol%, based on the total of all the structural units constituting the polymer compound (A1). Preferably, 20-50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

  In the present invention, the polymer compound (A1) is preferably a copolymer having all of these structural units (a0) to (a2) from the viewpoint of excellent effects of the present invention, particularly the structural unit (a0). It is preferable that it is a copolymer consisting of (a2).

・ Structural unit (a3)
In addition to the structural units (a0) and (a1), or in addition to the structural units (a0), (a1) and (a2), the polymer compound (A1) may further contain a polar group-containing aliphatic hydrocarbon group The structural unit (a3) derived from an (α-lower alkyl) acrylate ester containing By having the structural unit (a3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. However, in the present invention, it is assumed that the structural unit (a0) plays the role of the structural unit (a3), and the resolution can be improved even if the structural unit (a3) is not included.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). . As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones.
Among them, an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom, and (α-lower alkyl) acrylic A structural unit derived from an acid ester is more preferred. Examples of the polycyclic group include groups in which one or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane, or the like. Specific examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Such a polycyclic group can be appropriately selected and used from among many proposed polymers (resin components) for resist compositions for ArF excimer lasers. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, (α-lower alkyl) acrylic acid A structural unit derived from hydroxyethyl ester is preferred, and when the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by (a3-2) The structural unit represented by (a3-3) is preferable.

（式中、Ｒは前記に同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。）

(Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5) And s is an integer of 1 to 3.)

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3rd position of the adamantyl group is particularly preferred.

  In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

  In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of (α-lower alkyl) acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
When the polymer compound (A1) has the structural unit (a3), the proportion of the structural unit (a3) in the polymer compound (A1) is 5 with respect to all the structural units constituting the polymer compound (A1). It is preferably ˜50 mol%, more preferably 15 to 45 mol%, and most preferably 15 to 35 mol%.

・ Structural unit (a4)
The polymer compound (A1) may contain other structural units (a4) other than the structural units (a0) to (a3) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a0) to (a3) described above. For ArF excimer laser, for KrF positive excimer laser (preferably ArF excimer) A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, a structural unit containing an acid non-dissociable aliphatic polycyclic group and derived from an (α-lower alkyl) acrylate ester is preferable. Examples of the polycyclic group include those similar to those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF positive excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used for the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may be substituted with a linear or branched alkyl group having 1 to 5 carbon atoms.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

（式中、Ｒは前記と同じである。）

(In the formula, R is as defined above.)

  The structural unit (a4) is not an essential component of the polymer compound (A1), but when it is contained in the polymer compound (A1), the total of all the structural units constituting the polymer compound (A1). The structural unit (a4) is preferably contained in an amount of 1 to 30 mol%, preferably 10 to 20 mol%.

The polymer compound (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN). it can.
Further, in the polymer compound (A1), a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination in the above polymerization. it may be introduced -C _{(CF 3)} 2 -OH group at the terminal. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

Although the mass mean molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of a high molecular compound (A1) is not specifically limited, 2000-50000 are preferable, 3000-30000 are more preferable, 5000-20000 are preferable. Is most preferred. When it is smaller than the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and the dry etching resistance and resist pattern cross-sectional shape that are larger than the lower limit of this range are good.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

≪Positive resist composition≫
The positive resist composition of the present invention comprises a resin component (A) whose alkali solubility is increased by the action of an acid (hereinafter referred to as “component (A)”) and an acid generator component (B) (hereinafter referred to as “acid generator” which generates acid upon exposure) , (B) component) and a positive resist composition.
In such a positive resist composition, when an acid is generated from the component (B) by exposure, the acid dissociates the acid dissociable, dissolution inhibiting group of the component (A) and increases alkali solubility. Therefore, in the formation of the resist pattern, when the resist composition applied on the substrate is selectively exposed, the alkali solubility of the exposed portion increases and alkali development can be performed.

<(A) component>
The component (A) needs to contain the polymer compound (A1) of the present invention.
The polymer compound (A1) may be used alone or in combination of two or more.
In the component (A), the ratio of the polymer compound (A1) is preferably 50% by mass or more, more preferably 80 to 100% by mass, and most preferably 100% by mass for the effect of the present invention. is there.

In the present invention, as the component (A), in addition to the polymer compound (A1), a resin generally used as a chemically amplified positive resist resin may be contained. As such a resin, for example, it does not have the structural unit (a0) in the polymer compound (A1), has the structural unit (a1), and is arbitrarily selected from the structural units (a2) to (a4). And a polymer compound having at least one kind (hereinafter referred to as polymer compound (A2)).
As such a polymer compound (A2), conventionally, one or two or more kinds of known resin components for chemically amplified positive resists can be appropriately selected and used.

More specifically, examples of the polymer compound (A2) include polymer compounds having the structural units (a1), (a2), and / or (a3) (hereinafter referred to as polymer compound (A2-1)). It is done.
In the polymer compound (A2-1), the proportion of the structural unit (a1) is preferably from 5 to 80 mol%, more preferably from 10 to 70 mol%, based on the total of all the structural units of the polymer compound (A2-1). Is more preferable. Moreover, 5-50 mol% is preferable with respect to the sum total of all the structural units of a high molecular compound (A2-1), and, as for the ratio of a structural unit (a2), 10-40 mol% is more preferable. Moreover, 5-80 mol% is preferable with respect to the sum total of all the structural units of a high molecular compound (A2-1), and, as for the ratio of a structural unit (a3), 10-60 mol% is more preferable.
The polymer compound (A2-1) may further have the structural unit (a4).
The mass average molecular weight of the polymer compound (A2-1) is preferably 5,000 to 30,000, and more preferably 6,000 to 20,000. The dispersity (Mw / Mn) is preferably 1.0 to 5.0, and more preferably 1.0 to 3.0.

  The ratio of the polymer compound (A2) in the positive resist composition is not particularly limited, but in order to obtain the effect by blending the polymer compound (A2), the polymer compound (A1): polymer compound (A2) = A mixture of 9: 1 to 1: 9 (mass ratio) is preferably used, more preferably 8: 2 to 2: 8, and most preferably 5: 5 to 2-8. .

  The proportion of the component (A) in the positive resist composition can be appropriately adjusted depending on the intended resist film thickness.

<(B) component>
The component (B) is not particularly limited, and any component that has been proposed as an acid generator for a chemically amplified positive resist can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and poly (bissulfonyl) diazomethanes. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  Specific examples of the onium salt-based acid generator include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, and triphenylsulfonium trifluoromethane. Sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethane Sulfonate, its heptafluoropropane sulphonate or its Nafluorobutane sulfonate, trifluoromethane sulfonate of monophenyldimethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, trifluoromethane sulfonate of diphenylmonomethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4- Trifluoromethanesulfonate of methylphenyl) diphenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of (4-methoxyphenyl) diphenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, tri (4 -Tert-bu Le) trifluoromethanesulfonate triphenylsulfonium, its like heptafluoropropane sulfonate or nonafluorobutane sulfonates.

  Specific examples of oxime sulfonate acid generators include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzylcyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzylcyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzylcyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope Nthenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile. Of these, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile is preferred.

  An oxime sulfonate acid generator represented by the following chemical formula can also be used.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane (Compound A, decomposition point 135 ° C.), 1,4-bis (phenyl) having the following structure. Sulfonyldiazomethylsulfonyl) butane (compound B, decomposition point 147 ° C.), 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane (compound C, melting point 132 ° C., decomposition point 145 ° C.), 1,10-bis (phenyl) Sulfonyldiazomethylsulfonyl) decane (compound D, decomposition point 147 ° C.), 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane (compound E, decomposition point 149 ° C.), 1,3-bis (cyclohexylsulfonyldiazomethylsulfonyl) ) Propane (Compound F, decomposition point 153 ° C.), , 6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane (Compound G, melting point 109 ° C., decomposition point 122 ° C.), 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane (Compound H, decomposition point 116 ° C.), etc. Can be mentioned.

In the present invention, it is particularly preferable to use an onium salt having a fluorinated alkyl sulfonate ion as an anion as the component (B).
As the component (B), one type of acid generator may be used alone, or two or more types may be used in combination.
(B) Content of a component is 0.5-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is 1-10 mass parts. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

The positive resist composition of the present invention is produced by dissolving the above components (A) and (B) and various optional components described below in an organic solvent (hereinafter sometimes referred to as component (C)). Can do.
As the component (C), any organic solvent may be used as long as it can dissolve each component to be used to form a uniform solution, and any conventionally known solvent for chemical amplification resists can be used. One or two or more can be appropriately selected and used.
For example, lactones such as γ-butyrolactone, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate Polyhydric alcohols such as dipropylene glycol or dipropylene glycol monoacetate monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof, cyclic ethers such as dioxane, Methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, pyruvate Le, methyl methoxypropionate, esters such as ethyl ethoxypropionate can be exemplified.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
A mixed solvent obtained by mixing propylene glycol monomethyl ether acetate (PGMEA) and a polar solvent is preferable. The mixing ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, but is preferably 1: 9 to 9: 9: 1, more preferably 2: 8 to 8: A range of 2 is preferable.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2.
In addition, as the organic solvent, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
(C) Although the usage-amount of a component is not specifically limited, Although it is a density | concentration which can be apply | coated to a board | substrate etc. and is suitably set according to a coating film thickness, generally the solid content concentration 2-2 of a resist composition. It is used so that it may become in the range of 20 mass%, Preferably 5-15 mass%.

In order to improve the resist pattern shape, the stability over time, etc., the positive resist composition is further mixed with a nitrogen-containing organic compound (D) (hereinafter referred to as (D) component) as an optional component. Can do.
Since a wide variety of components (D) have already been proposed, any known one may be used. For example, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, monoalkylamines such as n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, Tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n- Trialkylamines such as dodecylamine; diethanolamine, trieta Ruamin, diisopropanolamine, triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, secondary aliphatic amines and tertiary aliphatic amines are preferable, and tertiary alkanolamines such as triethanolamine or triisopropanolamine are particularly preferable.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

In addition, the positive resist composition of the present invention includes an organic carboxylic acid as an optional component for the purpose of preventing sensitivity deterioration due to the blending of the component (D), and improving the resist pattern shape, retention stability, and the like. Acid or phosphorus oxo acid or its derivative (E) (hereinafter referred to as component (E)) can be contained. In addition, (D) component and (E) component can also be used together, and any 1 type can also be used.
As the organic carboxylic acid, for example, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Phosphorus oxoacids or derivatives thereof include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester and other phosphoric acid or derivatives thereof such as phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid- Like phosphonic acids such as di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester and their esters, phosphinic acids such as phosphinic acid, phenylphosphinic acid and their esters Among these, phosphonic acid is particularly preferable.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  The positive resist composition of the present invention further contains miscible additives as desired, for example, additional resins for improving the performance of the resist film, surfactants for improving coating properties, dissolution inhibitors, Plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be added and contained as appropriate.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the positive resist composition is applied onto a substrate such as a silicon wafer with a spinner and prebaked for 40 to 120 seconds, preferably 60 to 90 seconds under a temperature condition of 80 to 150 ° C. After selectively exposing ArF excimer laser light through a desired mask pattern using, for example, an ArF exposure apparatus or the like, PEB (post-exposure heating) is performed for 40 to 120 seconds at a temperature of 80 to 150 ° C., preferably Apply for 60-90 seconds. Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide. In this way, a resist pattern faithful to the mask pattern can be obtained.
An organic or inorganic antireflection film can be provided between the substrate and the coating layer of the resist composition.
The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The photoresist composition according to the present invention is particularly effective for an ArF excimer laser.

≪New compound≫
In the present invention, a preferable novel compound is represented by the general formula (k-1).
R ^{3 to} R ⁴ , R ⁵ , a, and t in the formula are the same as described above.

Among these, compounds represented by the following general formula (k-2) or (k-3) are preferable.

More specifically, a compound represented by the following chemical formula is preferable.

These compounds can be synthesized by reacting an aliphatic polycyclic alcohol such as norbornene alcohol or tetracyclododecene alcohol with a commercially available reagent such as R ⁵ —SO ₂ —Cl under a base catalyst. These compounds are useful as materials for the polymer compound (A1).
That is, these compounds are converted into a monomer for deriving the structural unit (a0) by substituting the hydrogen atom of (α-lower alkyl) acrylic acid through the process represented by the general formula (I). it can.
Alternatively, since these compounds have an ethylenic double bond in their ring skeleton, they can be polymerized by cleavage to form a high molecular compound. A polymer compound containing such a structural unit is also useful as a resist base resin.
And by using the compound of this invention, a resist composition with favorable resolution can be provided.

Thus, in the present invention, a technique related to a resist composition that can improve resolution can be provided. The reason for this is not clear, but it is presumed that the introduction of a sulfonic acid group can provide good affinity for an alkaline developer.
In addition, by improving the affinity for an alkaline developer, it is also possible to reduce line edge roughness (pattern sidewall irregularities) and development defects.
Moreover, since the high molecular compound of this invention, the resist composition using this, and a compound make a ring structure essential, it can be anticipated that etching resistance is favorable.
Furthermore, by introducing a sulfonic acid group, an effect of excellent heat resistance can be expected. Furthermore, improvement in transparency and adhesion can be expected. The improvement in these functions may be a further factor in improving the resolution.

Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples.
The structures of the monomer components (compounds (1) to (4) represented by the following formulas (1) to (4)) used in the following resin synthesis example 1 and comparative resin synthesis example 1 are shown below.
Compound (4) was synthesized as follows.
That is, it was synthesized by dissolving 3-hydroxy-1-adamantyl methacrylate in THF, adding sodium hydride as a base catalyst, and reacting CH ₃ —SO ₂ —Cl.

[Resin synthesis example 1 (reference example)]
5.0 g of (1), 3.6 g of (2), and 3.3 g of (4) were dissolved in 100 mL of tetrahydrofuran, and 0.44 g of azobisisobutyronitrile was added. After refluxing for 6 hours, the reaction solution was added dropwise to 1 L of n-heptane. The precipitated resin was separated by filtration and dried under reduced pressure to obtain a white powder resin. This resin is referred to as Resin 1 and the structural formula is shown below. Resin 1 had a molecular weight (Mw) of 16,900 and a dispersity (Mw / Mn) of 2.89. As a result of measuring a carbon 13 nuclear magnetic resonance spectrum ( ¹³ C-NMR), the composition ratio was m ¹ : n ¹ : l ¹ = 45.1: 35.1: 19.8.

[Comparative Resin Synthesis Example 1 (Reference Example)]
5.0 g of (1), 3.6 g of (2), and 2.4 g of (3) were dissolved in 100 ml of tetrahydrofuran, and 0.44 g of azobisisobutyronitrile was added. After refluxing for 6 hours, the reaction solution was added dropwise to 1 L of n-heptane. The precipitated resin was separated by filtration and dried under reduced pressure to obtain a white powder resin. This resin is referred to as Comparative Resin 1 and the structural formula is shown below. Comparative resin 1 had a mass average molecular weight (Mw) of 16,800 and a dispersity (Mw / Mn) of 2.47. As a result of measuring carbon-13 nuclear magnetic resonance spectrum ( ¹³ C-NMR), the composition ratio (molar ratio) of each structural unit represented by the following structural formula was m: n: l = 38.5: 39.1: 22. .4.

[Example 1 (reference example)]
100 parts by mass of resin 1, 3 parts by mass of triphenylsulfonium nonafluorobutane sulfonate (TPS-PFBS), and 0.35 parts by mass of triethanolamine were mixed with 1230 parts by mass of propylene glycol monomethyl ether acetate (PGMEA). To obtain a positive resist composition.

Subsequently, the following evaluation was performed.
<Sensitivity and resolution>
An organic antireflection film material (trade name ARC-29, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer and baked at 225 ° C. for 60 seconds to form an antireflection film having a thickness of 77 nm. did.
On the substrate, the positive resist composition obtained above is uniformly applied using a spinner, pre-baked on a hot plate at 110 ° C. for 90 seconds, and dried to form a resist layer having a thickness of 250 nm. Formed. Next, using an ArF exposure apparatus (wavelength 193 nm) NSR-S302 (Nikon, NA (numerical aperture) = 0.60, 2/3 annular illumination), selective exposure was performed through a 6% halftone mask. .
Then, PEB treatment is performed at 110 ° C. for 90 seconds, and further paddle development is performed at 23 ° C. with a developer (2.38 mass% tetramethylammonium hydroxide aqueous solution) for 60 seconds, and then pure water is used for 30 seconds. Rinse with water and shake off to dry.
At this time, the sensitivity (Eop) when a 130 nm line and space (1: 1) resist pattern (hereinafter referred to as an L / S pattern) was formed faithfully to the pattern was measured.
When the limit resolution using the sensitivity (Eop) was determined, a 110 nm L / S pattern could be formed.
The results are summarized in Table 1.

[Comparative Example 1 (Reference Example)]
A positive resist composition was prepared in the same manner as in Example 1 except that the resin 1 in Example 1 was changed to the comparative resin 1 and the temperature conditions for pre-baking and PEB treatment were changed to 130 ° C., and the same evaluation was performed. .
The results are shown in Table 1.

  As is clear from the above results, in Example 1 according to the present invention, the resolution was good.

[Example 2 (reference example)]
A compound represented by the following chemical formula (5) was produced as follows.
That is, 10 g of norbornenemethanol was dissolved in 300 g of tetrahydrofuran, 3.6 g of sodium hydride was added at 0 ° C. and stirred for 10 minutes, 11.4 g of methanesulfonyl chloride was added, and the mixture was stirred at room temperature for 5 hours. After completion of the reaction, the mixture was extracted with water / ethyl acetate. The ethyl acetate solution was dried over sodium sulfate and concentrated under reduced pressure to obtain 18.1 g of a compound represented by the following chemical formula (5). Infrared absorption spectrum (IR), showing the results of measurement of the proton nuclear magnetic resonance spectra ⁽¹ H-NMR).
IR (cm ⁻¹ ): 2972, 1356, 1177
¹ H-NMR (CDCl ₃ , internal standard: tetramethylsilane) ppm: 1.94 to 0.55 (m, 4H), 2.58 to 1.78 (m, 1H), 3.01 to 2.27 (M, 2H), 3.00 (s, 3H), 4.33 to 3.78 (m, 2H), 6.25 to 5.95 (m, 2H)

[Example 3]
A compound represented by the following chemical formula (6) was produced as follows.
That is, 10 g of tetracyclododecenemethanol was dissolved in 200 g of tetrahydrofuran, 2.4 g of sodium hydride was added at 0 ° C. and stirred for 10 minutes, 6.9 g of methanesulfonyl chloride was added and stirred at room temperature for 5 hours. It was. After completion of the reaction, the mixture was extracted with water / ethyl acetate. The ethyl acetate solution was dried over sodium sulfate and concentrated under reduced pressure to obtain 15.0 g of a compound represented by the following chemical formula (6). Infrared absorption spectrum (IR), showing the results of measurement of the proton nuclear magnetic resonance spectra ⁽¹ H-NMR).
IR (cm ⁻¹ ): 2958, 1356, 1176
¹ H-NMR (CDCl ₃ , internal standard: tetramethylsilane) ppm: 0.99 to 0.52 (m, 2H), 1.79 to 1.16 (m, 3H), 2.30 to 1.88 (M, 4H), 3.00 (s, 3H), 3.97 to 3.88 (m, 1H), 4.28 to 4.20 (m, 1H), 6.03 to 5.91 (m 2H)

  In Examples 2 and 3, it was confirmed that the compound of the present invention useful for the resist composition of the present invention was obtained. Moreover, the compound represented by the following general formula corresponding to a structural unit (a0) is obtained by acrylate-izing using the compound of Example 2, 3 through the synthetic pathway shown to the said general formula (I). be able to.

［Ｒ、aは前記と同じである。］

[R and a are the same as described above. ]

Claims (3)

A compound represented by the following general formula (K-1):

[Wherein, R ^{3 to} R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ⁵ represents an alkyl group having 1 to 5 carbon atoms or an alkyl halide having 1 to 5 carbon atoms. A represents 1 and t represents 0 or an integer of 1 to 3; ] The compound of Claim 1 represented by the following general formula (K-2).

Tetracyclododecene alcohol is reacted with R ⁵ —SO ₂ —Cl (R ⁵ is an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms) under a base catalyst, The manufacturing method of the compound characterized by obtaining the compound shown by the following general formula (K-1).

[Wherein, R ^{3 to} R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ⁵ represents an alkyl group having 1 to 5 carbon atoms or an alkyl halide having 1 to 5 carbon atoms. A represents 1 and t represents 0 or an integer of 1 to 3; ]