JPWO2013147267A1 - Composition for forming immersion upper layer film - Google Patents

Abstract

The present invention is a composition for forming an immersion upper layer film comprising a polymer component containing a polymer (a1) having a structural unit represented by the following formula (1), and a solvent. In the following formula (1), R1 is an alkali dissociable group. A is —CO—O— *, —O—, —NRA— or —SO 2 —O— *. X is a C1-C20 bivalent hydrocarbon group or a C1-C20 bivalent fluorinated hydrocarbon group. R1 in the above formula (1) is preferably a fluorinated alkyl group having 1 to 20 carbon atoms or a fluorinated alkylcarbonyl group having 1 to 20 carbon atoms.

Description

  The present invention relates to a composition for forming a liquid immersion upper layer film.

  In the field of microfabrication represented by the manufacture of integrated circuit elements, conventionally, a resist film is formed on a substrate with a photoresist composition containing a polymer having an acid-dissociable group, and an excimer laser beam or the like is passed through a mask pattern. A fine resist pattern is formed by exposing a resist film by irradiation with short-wavelength radiation and removing an exposed portion with an alkaline developer. At this time, a “chemically amplified resist” is used in which an acid generator that generates an acid upon irradiation with radiation is contained in the photoresist composition, and the sensitivity is improved by the action of the acid.

  In such a chemically amplified resist, the use of the immersion exposure method is expanding as a method for forming a finer resist pattern. In this method, exposure is performed by filling the space between the exposure lens and the resist film with an immersion exposure liquid having a higher refractive index than air or an inert gas. According to this immersion exposure method, there is an advantage that even when the numerical aperture of the lens is increased, the depth of focus is hardly lowered and high resolution is obtained.

  As a photoresist composition used in the above immersion exposure method, elution of an acid generator and the like from the resist film to the immersion exposure liquid is prevented, and water drainage of the resist film surface is improved, enabling high-speed scanning. For this purpose, a method for increasing the water repellency of the resist film surface has been studied. For example, a highly water-repellent upper layer film is provided on this surface, or the fluorine-containing weight having a high water repellency is applied to the photoresist composition. It has been proposed to contain coalesces (see WO 2007/116664).

  However, when the water repellency of the resist film surface is increased, the wettability with respect to the developing solution and the rinsing solution is lowered, so that the development residue deposited on the unexposed portion of the resist film surface at the time of development becomes insufficient. Development defects may occur. In order to suppress the occurrence of such development defects, there has been proposed a technique using a fluorine atom-containing polymer that is water-repellent during immersion exposure but decreases in water-repellency during alkali development (JP 2010). No. 032994). According to this technique, it is said that the receding contact angle with respect to the immersion exposure liquid such as water on the resist film surface during the immersion exposure can be increased and development defects can be suppressed.

  However, even if the above conventional technique is used, the occurrence of development defects has not been sufficiently suppressed. On the other hand, it is also required to increase the receding contact angle at the time of immersion exposure to further increase the scanning speed and improve the productivity of the immersion exposure process. In addition, the liquid immersion upper layer film is also required to improve the resist pattern shape.

International Publication No. 2007/116664 JP 2010-032994 A

  The present invention has been made based on the circumstances as described above, and its purpose is to increase the receding contact angle at the time of immersion exposure on the surface of the immersion upper layer in the immersion exposure process. In addition, an object of the present invention is to provide a composition for forming a liquid immersion upper layer film that can suppress development defects and can form a resist pattern having a better shape.

（式（１）中、Ｒ^１は、アルカリ解離性基である。Ａは、−ＣＯ−Ｏ−＊、−Ｏ−、−ＮＲ^Ａ−又は−ＳＯ_２−Ｏ−＊である。Ｒ^Ａは、水素原子又は炭素数１〜１０の１価の炭化水素基である。＊は、Ｒ^１との結合部位を示す。Ｘは、炭素数１〜２０の２価の炭化水素基又は炭素数１〜２０の２価のフッ素化炭化水素基である。Ｒ^２は、炭素数１〜２０の（ｎ＋１）価の炭化水素基、炭素数１〜２０の（ｎ＋１）価のフッ素化炭化水素基、又はこれらの基と−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−Ｏ−、−ＮＲ^Ｂ−、−ＣＳ−、−Ｓ−、−ＳＯ−及び−ＳＯ_２−からなる群より選択される少なくとも１種の基とを組み合わせた基である。但し、ｎが１の場合、Ｒ^２は、単結合であってもよい。Ｒ^Ｂは、水素原子又は炭素数１〜１０の１価の炭化水素基である。Ｒ^３は、炭素数１〜２０の１価の炭化水素基、炭素数１〜２０の１価のフッ素化炭化水素基、又はこれらの基と−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−Ｏ−、−ＮＲ^Ｃ−、−ＣＳ−、−Ｓ−、−ＳＯ−及び−ＳＯ_２−からなる群より選択される少なくとも１種の基とを組み合わせた基である。Ｒ^Ｃは、水素原子又は炭素数１〜１０の１価の炭化水素基である。ｎは、１〜３の整数である。ｎが２以上の場合、複数のＲ^１、Ａ及びＸは、それぞれ同一でも異なっていてもよい。）The invention made to solve the above problems is
Polymer component (hereinafter also referred to as “[A] polymer component”) including a polymer (a1) having a structural unit represented by the following formula (1) (hereinafter also referred to as “structural unit (I)”) And solvent (hereinafter also referred to as “[B] solvent”)
Is a composition for forming a liquid immersion upper layer film.

(In the formula (1), ^{R 1} is an alkali dissociable group .A is, -CO-O - *, - O -, - NR A - , or .R ^A is _-SO 2 -O- * is , A hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, * represents a bonding site with R ¹ , X is a divalent hydrocarbon group having 1 to 20 carbon atoms or 1 carbon atom; A divalent fluorinated hydrocarbon group having ˜20, R ² is an (n + 1) valent hydrocarbon group having 1 to 20 carbon atoms, an (n + 1) valent fluorinated hydrocarbon group having 1 to 20 carbon atoms, Or at least selected from the group consisting of these groups and —CO—, —COO—, —OCO—, —O—, —NR ^B —, —CS—, —S—, —SO— and —SO ₂ —. is a group which combines with one group. However, when n is 1, R ² is a single bond which may be a .R ^B is a hydrogen atom or a carbon number from 1 to 10 The monovalent hydrocarbon is a group .R ^3, and a monovalent hydrocarbon group, a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms, or their group having 1 to 20 carbon atoms -CO-, A group in which at least one group selected from the group consisting of —COO—, —OCO—, —O—, —NR ^C —, —CS—, —S—, —SO— and —SO ₂ — is combined. R ^C is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, n is an integer of 1 to 3. When n is 2 or more, a plurality of R ¹ , A and X may be the same or different.

  The immersion film forming composition (hereinafter also referred to as “immersion exposure film forming composition (TC)”) contains the polymer (a1) as a polymer component [A]. By forming the liquid immersion upper layer film on the resist film using the liquid immersion upper film forming composition, the polymer (a1) contained in the liquid film on the surface of the liquid immersion upper layer film has a high water repellency. The receding contact angle during immersion exposure can be further increased. Further, the polymer (a1) is highly hydrophilic due to dissociation of alkali dissociable groups during alkali development. Accordingly, the affinity or solubility of the surface of the liquid immersion upper layer film to the developer or rinse liquid is increased, and as a result, development defects can be suppressed. This is considered to be due to the fact that the structural unit (I) of the polymer (a1) has an alkali dissociable group at the specific site in the composition for forming a liquid immersion upper layer film.

R ¹ in the above formula (1) is preferably a fluorinated alkyl group having 1 to 20 carbon atoms or a fluorinated alkylcarbonyl group having 1 to 20 carbon atoms. When R ¹ contains a fluorine atom, the composition for forming a liquid immersion upper film can increase the receding contact angle at the time of liquid immersion exposure on the surface of the liquid immersion upper film, and can cause development defects. Can be suppressed.

  X in the above formula (1) is preferably a C1-C20 divalent fluorinated hydrocarbon group. When X contains a fluorine atom, the composition for forming a liquid immersion upper layer film can further increase the receding contact angle at the time of liquid immersion exposure on the surface of the liquid immersion upper layer film and dissociate the alkali-dissociable group. As a result, development defects can be further suppressed.

R ³ in the above formula (1) preferably has acid dissociability. Since the R ³ has acid dissociation properties, the composition for forming a liquid immersion upper layer film can improve the solubility of the polymer (a1) in the exposed portion in an alkaline developer, and as a result, development defects. Can be further suppressed.

  [A] The polymer component is selected from the group consisting of a structural unit containing a fluorinated sulfonamide group and a structural unit containing an α-trifluoromethyl alcohol group in the same or different polymer as the polymer (a1). It is preferable to further have at least one structural unit (hereinafter also referred to as “structural unit (III)”). The composition for forming a liquid immersion upper layer film can improve the water repellency and removability of the liquid immersion upper layer film because the polymer component [A] further has the specific structural unit. Occurrence can be suppressed.

  [A] The polymer component preferably further has a structural unit containing a sulfo group (hereinafter also referred to as “structural unit (IV)”) in the same or different polymer as the polymer (a1). In the composition for forming a liquid immersion upper layer film, the [A] polymer component further includes the above-mentioned specific structural unit, whereby the removability and peeling resistance of the liquid immersion upper film can be further improved, and development defects Can be further suppressed.

（式（２）中、Ｒ^４は、水素原子、ハロゲン原子、ニトロ基、炭素数１〜２０のアルキル基、炭素数３〜２０の１価の脂環式炭化水素基、炭素数１〜２０のアルコキシ基、炭素数１〜２０のアシル基、炭素数７〜２０のアラルキル基又は炭素数６〜２０のアリール基である。上記アルキル基、脂環式炭化水素基、アルコキシ基、アシル基、アラルキル基及びアリール基が有する水素原子の一部又は全部は、置換されていてもよい。Ｒ^５は、−Ｃ（＝Ｏ）−Ｒ^６、−Ｓ（＝Ｏ）_２−Ｒ^７、−Ｒ^８−ＣＮ、又は−Ｒ^９−ＮＯ_２である。上記Ｒ^６及びＲ^７は、それぞれ独立して、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のフッ素化アルキル基、炭素数３〜２０の１価の脂環式炭化水素基、炭素数１〜２０のアルコキシ基、シアノ基、シアノメチル基、炭素数７〜２０のアラルキル基又は炭素数６〜２０のアリール基である。但し、Ｒ^６又はＲ^７と、Ｒ^４とが互いに結合して環構造を形成していてもよい。上記Ｒ^８及びＲ^９は、それぞれ独立して、単結合、メチレン基又は炭素数２〜５のアルキレン基である。）[A] The polymer component is selected from the group consisting of a structural unit containing a carboxy group and a structural unit containing a group represented by the following formula (2) in the same or different polymer as the polymer (a1). It is preferable to further have at least one structural unit (hereinafter also referred to as “structural unit (V)”).

(In Formula (2), R ⁴ is a hydrogen atom, a halogen atom, a nitro group, an alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or 1 to 20 carbon atoms. An alkoxy group, an acyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, the above-described alkyl group, alicyclic hydrocarbon group, alkoxy group, acyl group, Some or all of the hydrogen atoms of the aralkyl group and aryl group may be substituted, and R ⁵ represents —C (═O) —R ⁶ , —S (═O) ₂ —R ⁷ , —R. ⁸ -CN, or -R ⁹ -NO _{2. The} above R ⁶ and R ⁷ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a fluorinated alkyl group having 1 to 20 carbon atoms, C3-C20 monovalent alicyclic hydrocarbon group, C1-C20 alkoxy group Cyano group, a cyanomethyl group, an aralkyl group or an aryl group having 6 to 20 carbon atoms having 7 to 20 carbon atoms. However, the R ⁶ or R ^7, to form a ring structure and R ⁴ together R ⁸ and R ⁹ are each independently a single bond, a methylene group or an alkylene group having 2 to 5 carbon atoms.)

  In the composition for forming a liquid immersion upper layer dew film, the [A] polymer component further includes the specific structural unit described above, whereby the removability and peeling resistance of the liquid immersion upper layer film can be further improved, and development The occurrence of defects can be further suppressed.

  According to the composition for forming a liquid immersion upper film of the present invention, in the liquid immersion exposure process, a large receding contact angle can be given to the surface of the liquid immersion upper film at the time of liquid immersion exposure, and the occurrence of development defects can be suppressed. A resist pattern having a good shape can be formed. Therefore, the liquid immersion upper layer film forming composition can be suitably used for a manufacturing process in a semiconductor device that is further miniaturized, and can improve product quality and productivity in the liquid immersion exposure process. .

<Film forming composition for immersion exposure>
The film forming composition for immersion exposure contains a [A] polymer component and a [B] solvent. Moreover, the said film formation composition for immersion exposure may contain arbitrary components in the range which does not impair the effect of this invention. Hereinafter, each component will be described in detail.

<[A] Polymer component>
[A] The polymer component contains a polymer (a1). Moreover, the [A] polymer component may contain other polymers, such as a polymer (a2) mentioned later and (a3), in the range which does not impair the effect of this invention. In addition, the [A] polymer component may contain 2 or more types of said each polymer. Hereinafter, the polymer (a1) will be described in detail.

<Polymer (a1)>
The polymer (a1) is a polymer having the structural unit (I). Moreover, the polymer (a1) may have other structural units other than the structural unit (I). In addition, the polymer (a1) may have 2 or more types of each structural unit. Hereinafter, each structural unit will be described in detail.

[Structural unit (I)]
The structural unit (I) is a structural unit represented by the above formula (1). When the film forming composition for immersion exposure is used as a photoresist composition or the like, the polymer (a1) has a higher receding contact angle during immersion exposure on the surface of the resist film or the like due to its high water repellency. be able to. Further, the polymer (a1) is highly hydrophilic due to dissociation of alkali dissociable groups during alkali development. Accordingly, the affinity or solubility of the surface of the resist film or the like to the developing solution or rinsing solution is increased, and as a result, development defects can be suppressed. This is considered to be due to the fact that the structural unit (I) of the polymer (a1) has an alkali-dissociable group at the specific site in the film forming composition for immersion exposure.

In the above formula (1), R ¹ is an alkali dissociable group. A is —CO—O— *, —O—, —NR ^A — or —SO ₂ —O— *. R ^A is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * Indicates a binding site with ^{R 1.} X is a C1-C20 bivalent hydrocarbon group or a C1-C20 bivalent fluorinated hydrocarbon group. R ² represents an (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, an (n + 1) -valent fluorinated hydrocarbon group having 1 to 20 carbon atoms, or these groups and —CO—, —COO—, — ^{OCO -, - O -, -} NR B -, - CS -, - S -, - SO- and -SO ₂ - is a group formed by combining at least one group selected from the group consisting of. However, when n is 1, R ² may be a single bond. R ^B is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ³ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms, or these groups and —CO—, —COO—, —OCO—, — The group is a combination of at least one group selected from the group consisting of O-, -NR ^C- , -CS-, -S-, -SO- and -SO _2- . R ^C is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. n is an integer of 1 to 3. When n is 2 or more, the plurality of R ¹ , A, and X may be the same or different.

  Here, the alkali dissociable group is, for example, a group that substitutes a hydrogen atom in a polar functional group such as a hydroxy group or a sulfo group, and is in the presence of an alkali (for example, 2.38% by mass of tetravalent at 23 ° C. A group that dissociates in an aqueous solution of methylammonium hydroxide.

Examples of the alkali dissociable group include groups represented by the following formulas. Among these, in the above formula (1), when A is —O— or —NR ^A —, those represented by the following formula (R1-1) are preferable, and A is —CO—O— * or In the case of —SO ₂ —O— *, those represented by any of the following formulas (R1-2) to (R1-4) are preferable.

In the above formula (R1-1), R ^K1 is a monovalent fluorinated alkyl group having 1 to 20 carbon atoms or a fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms.
In the above formulas (R1-2) and (R1-3), R ^K2 is a substituent. If R ^K2 is plural, the plurality of R ^K2 may be the same or different. m1 is an integer of 0-5. m2 is an integer of 0-4.
In the above formula (R1-4), R ^K3 and R ^K4 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a fluorinated alkyl group having 1 to 20 carbon atoms. However, R ^K3 and R ^K4 may be bonded to each other to form a divalent alicyclic hydrocarbon group together with the carbon atom to which they are bonded.

The monovalent fluorinated alkyl group having 1 to 20 carbon atoms represented by ^{R K1,} for example, a methyl group, an ethyl group, 1-propyl, 2-propyl, 1-butyl, 2-butyl 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) ) Group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- (2-methylpentyl) group, 3- (3-methylpentyl) group, octyl group, Examples include a group in which some or all of the hydrogen atoms of an alkyl group having 1 to 20 carbon atoms such as a nyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, and an icosanyl group are substituted with fluorine atoms.

Examples of the fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^K1 include a cyclopentyl group, a cyclopentylmethyl group, a 1- (1-cyclopentylethyl) group, and 1- (2-cyclopentylethyl). ) Group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group, 1- (1-cycloheptylethyl) group, Examples include a group in which part or all of the hydrogen atoms of the 1- (2-cycloheptylethyl) group, 2-norbornyl group, 1-adamantyl group, 2-adamantyl group and the like are substituted with fluorine atoms.

Substituents represented by ^{R K2 is, -R P1, -R P2 -O-} R P1, -R P2 -CO-R P1, -R P2 -CO-OR P1, -R P2 -O-CO- R ^P1, a ^-R P2 ^{-OH, -R} P2 ^-CN, or ^-R P2 -COOH. R ^P1 represents a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. It is a group. A part or all of the hydrogen atoms possessed by R ^P1 may be substituted with fluorine atoms. R ^P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a divalent aroma having 6 to 30 carbon atoms. Group hydrocarbon group. Some or all of the hydrogen atoms which the R ^P2 has may be substituted by a fluorine atom.

Examples of the divalent alicyclic hydrocarbon group which may be formed together with the carbon atom to which R ^K3 and R ^K4 are bonded to each other include a 1,1-cyclopentanediyl group, 1 , 1-cyclohexanediyl group and the like.

  Examples of the group represented by the formula (R1-4) include a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, a 1-pentyl group, and 2- Pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3- Hexyl group, 1- (2-methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) ) Group, 3- (2-methylpentyl) group, and a group in which some or all of hydrogen atoms of these groups are substituted with fluorine atoms.

The alkali dissociable group represented by R ¹ is preferably a fluorinated alkyl group having 1 to 20 carbon atoms or a fluorinated alkylcarbonyl group having 1 to 20 carbon atoms. That is, R ^K1 in the above formula (R1-1) is a fluorinated alkyl group having 1 to 20 carbon atoms, or R ^K3 and R ^K4 in the above formula (R1-4) are hydrogen atoms and 1 to 20 carbon atoms. Or an alkyl group having 1 to 20 carbon atoms (provided that at least one of R ^K3 and R ^K4 contains a fluorine atom). When R ¹ contains a fluorine atom, the film-forming composition for immersion exposure can further increase the receding contact angle during immersion exposure on the surface of a resist film or the like, and suppress the occurrence of development defects. can do.

Examples of the fluorinated alkyl group having 1 to 20 carbon atoms represented by R ¹ include the same groups as those exemplified as the group represented by the formula (R1-4).

Examples of the fluorinated alkylcarbonyl group having 1 to 20 carbon atoms represented by R ¹ include alkylcarbonyl groups having 1 to 20 carbon atoms such as a methylcarbonyl group, an ethylcarbonyl group, a propylcarbonyl group, and a butylcarbonyl group. Examples include a group in which part or all of the hydrogen atoms are substituted with fluorine atoms. Among these, a fluorinated alkylcarbonyl group having 1 to 5 carbon atoms is preferable, a fluorinated methylcarbonyl group is more preferable, and a trifluoromethylcarbonyl group is more preferable.

Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ^A , R ^B and ^RC include, for example, an alkyl group having 1 to 10 carbon atoms and a monovalent alicyclic ring having 3 to 10 carbon atoms. A formula hydrocarbon group and the like.

  Examples of the alkyl group having 1 to 10 carbon atoms include linear alkyl groups such as methyl group, ethyl group, n-propyl group, and n-butyl group; i-propyl group, i-butyl group, sec- Examples thereof include branched alkyl groups such as a butyl group and a t-butyl group.

  Examples of the monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, a norbornyl group, an adamantyl group, and cyclobutyl. A methyl group, a cyclohexylethyl group, etc. are mentioned.

  Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms represented by X include, for example, an alkanediyl group having 1 to 20 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and carbon. The bivalent aromatic hydrocarbon group of several 6-20, or the bivalent group which combined 2 or more types of these groups etc. are mentioned.

  As said C1-C20 alkanediyl group, a methanediyl group, an ethanediyl group, a propanediyl group, a butanediyl group, a pentanediyl group etc. are mentioned, for example.

  Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include a cyclopropanediyl group, a cyclobutanediyl group, a cyclopentanediyl group, a cyclobutenediyl group, a cyclopentenediyl group, a norbornylene group, and an adamantylene group. Etc.

  Examples of the divalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenylene group, a biphenylene group, a terphenylene group, a benzylene group, a phenyleneethylene group, a phenylenecyclohexylene group, and a naphthylene group.

  In the divalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by X, a part or all of the hydrogen atoms of the divalent hydrocarbon group having 1 to 20 carbon atoms is substituted with a fluorine atom. It is a group. As said C1-C20 bivalent hydrocarbon group, the group similar to the group illustrated as a C1-C20 bivalent hydrocarbon group represented by said X, etc. are mentioned, for example.

  X is preferably a divalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. When the X contains a fluorine atom, the film forming composition for immersion exposure can further increase the receding contact angle at the time of immersion exposure on the surface of a resist film or the like, and the dissociation property of the alkali dissociable group. As a result, development defects can be further suppressed.

Examples of the (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms represented by R ² include a group in which (n + 1) hydrogen atoms are removed from a hydrocarbon having 1 to 20 carbon atoms. . Examples of the hydrocarbon having 1 to 20 carbon atoms include methane, ethane, propane, butane, propene, 1-butene, and 2-methylpropene.

In the (n + 1) -valent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ² , some or all of the hydrogen atoms of the (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms are It is a group substituted with a fluorine atom. Examples of the (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms include the same groups as those exemplified as the (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms represented by R ² above. Is mentioned.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ³ include the carbon number exemplified as the monovalent organic group having 1 to 20 carbon atoms represented by R ^{K1 to} R ^K4. Examples thereof include the same groups as 1 to 20 monovalent hydrocarbon groups.

In the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ³ , a part or all of the hydrogen atoms of the monovalent hydrocarbon group having 1 to 20 carbon atoms is substituted with a fluorine atom. It is a group that has been. Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include the same groups as those exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ³ .

R ³ preferably has acid dissociation properties. Since the R ³ has acid dissociation properties, the immersion exposure film-forming composition can enhance the solubility of the polymer (a1) in the alkaline developer in the exposed portion, and as a result, development defects. Can be further suppressed. In addition, acid dissociation refers to the property of dissociating in the presence of an acid.

Examples of the group having acid dissociability represented by R ³ include the same groups as the acid dissociable groups exemplified as Y in the formula (4) described later.

  Examples of the structural unit (I) include structural units represented by the following formulas (1-1) to (1-7).

  Among these, from the viewpoint of further increasing the receding contact angle at the time of immersion exposure on the surface of the resist film or the like, the structural units represented by the formulas (1-2) to (1-6) are preferable. The structural units represented by 3) and (1-4) are more preferred. Moreover, from the viewpoint of solubility in an alkali developer, the structural unit represented by the formulas (1-2), (1-4), (1-6) and (1-7) having an acid dissociable group Are preferred, and structural units represented by formulas (1-2), (1-4) and (1-6) are more preferred.

  As the compound that gives the structural unit (I) having an acid dissociable group, a compound represented by the following formula (3) is preferable.

In the formula ^{(3), R 1, A} , X, R 2 and n have the same meanings as in formula (1). R ^{3 ′} is an acid dissociable group.

Examples of the acid dissociable group represented by R ^{3 ′} include the same groups as the acid dissociable groups exemplified as Y in the formula (4) described later.

  Examples of the compound (monomer) that gives the structural unit (I) include compounds represented by the following formulas (i-1) to (i-7).

<Method of compound synthesis>
As a method for synthesizing the compound giving the structural unit (I), when R ² in the above formula (1) has —O—, for example, in a solvent such as tetrahydrofuran, an alcohol having an alkali dissociable group, and 2- Examples thereof include a method of reacting with a haloalkyl acrylate such as (bromomethyl) ethyl acrylate. When R ² in the above formula (1) is a hydrocarbon group, for example, in a solvent such as tetrahydrofuran, in the presence of zinc, a halocarboxylic acid ester such as ethyl 2-bromo-2,2-difluoroacetate and 2 Examples thereof include a method of reacting with a haloalkyl acrylate ester such as-(bromomethyl) ethyl acrylate.

  As a content rate of structural unit (I) in a polymer (a1), 10 mol%-100 mol% are preferable with respect to all the structural units which comprise a polymer (a1), 30 mol%-100 mol% are preferable. More preferably, it is more preferably 50 mol% to 100 mol%. By making the content ratio of the structural unit (I) in the polymer (a1) within the above range, a large receding contact angle at the time of immersion exposure on the surface of the resist film and the like, and development defects can be effectively expressed. Can do.

[Other structural units]
The polymer (a1) may have other structural units such as structural units (II) to (VI) described later as long as the effects of the present invention are not impaired. The content ratio of the other structural units can be appropriately determined according to the purpose.

  As a content rate of a polymer (a1), 0.1 mass%-30 mass% are preferable with respect to the total polymer which comprises a [A] polymer component, and 0.5 mass%-20 mass% are more. Preferably, 1% by mass to 10% by mass is more preferable. By making the content rate of a polymer (a1) into the said range, the big receding contact angle at the time of the immersion exposure of surfaces, such as a resist film, and suppression of a development defect can be expressed more effectively.

<[A] Method for synthesizing each polymer in polymer component>
[A] Each polymer constituting the polymer component is synthesized, for example, by subjecting a predetermined monomer to polymerization such as radical polymerization in a polymerization solvent in the presence of a suitably selected polymerization initiator. Can do.

As the polymerization initiator, for example,
As azo radical initiators, azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropio) Nitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate), dimethyl 2,2′-azobisisobutyrate and the like;
Examples of the peroxide radical initiator include benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, and the like.

  Of these, azo radical initiators are preferred, and AIBN is more preferred. In addition, you may use a polymerization initiator individually or in combination of 2 or more types.

As the polymerization solvent, for example,
Examples of alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethylene glycol, diethylene glycol, and propylene glycol;
As cyclic ethers, tetrahydrofuran, dioxane and the like;
As alkyl ethers of polyhydric alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, Propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc .;
Examples of polyhydric alcohol alkyl ether acetates include ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol monomethyl ether acetate;
As aromatic hydrocarbons, toluene, xylene, etc .;
Examples of ketones include acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol, and the like;
Esters include ethyl acetate, butyl acetate, methyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy Examples include methyl-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, and the like.

  Among these, cyclic ethers, alkyl ethers of polyhydric alcohols, alkyl ether acetates of polyhydric alcohols, ketones or esters are preferable, ketones are more preferable, and 2-butanone is further preferable. In addition, the said polymerization solvent can use 1 type (s) or 2 or more types.

  As a polystyrene conversion weight average molecular weight (Mw) by gel permeation chromatography (GPC) of each polymer, 1,000-50,000 are preferable, 1,000-30,000 are more preferable, 1,000-20 1,000 is more preferable, and 2,000 to 10,000 is particularly preferable. By setting the Mw of each polymer to 1,000 or more, water resistance and mechanical properties of the formed resist film can be improved, and by setting the Mw to 50,000 or less, the polymer dissolves in the solvent. Can increase the sex.

  The ratio (Mw / Mn) of Mw of each polymer to the number average molecular weight (Mn) in terms of polystyrene by GPC is preferably 1 to 5, more preferably 1 to 3, and still more preferably 1 to 2.

  The film forming composition for immersion exposure is more preferable as it contains less impurities such as halogen ions and metals. By reducing the impurities, it is possible to improve coatability and uniform solubility in an alkali developer. Examples of methods for purifying each polymer in order to reduce impurities include chemical purification methods such as water washing, liquid-liquid extraction, and demetalization filter passage, these chemical purification methods and ultrafiltration, centrifugation, etc. And a combination with a physical purification method.

  [A] The content of the polymer component is preferably 70% by mass to 100% by mass and more preferably 80% by mass to 100% by mass with respect to the total solid content in the film forming composition for immersion exposure. 90 mass% to 100 mass% is more preferable.

<[B] Solvent>
[B] The solvent is a solvent that dissolves or uniformly disperses each component such as the polymer component [A].

  [B] Examples of the solvent include alcohol solvents, ether solvents, hydrocarbon solvents, ketone solvents, ester solvents, water, and the like.

  Examples of the alcohol solvent include monohydric alcohols such as butanol, pentanol and 4-methyl-2-pentanol; polyhydric alcohols such as ethylene glycol and propylene glycol.

As the ether solvent, for example,
Examples of polyhydric alcohol alkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene glycol diethyl ether, and diethylene glycol dimethyl ether;
Examples of polyhydric alcohol alkyl ether acetates include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate;
Examples of aliphatic ethers include diethyl ether, dipropyl ether, dibutyl ether, butyl methyl ether, butyl ethyl ether, diisoamyl ether, hexyl methyl ether, octyl methyl ether, cyclopentyl methyl ether, dicyclopentyl ether and the like;
Aliphatic-aromatic ethers such as anisole and phenylethyl ether;
Examples of cyclic ethers include tetrahydrofuran, tetrahydropyran, dioxane and the like.

  Examples of the hydrocarbon solvent include higher hydrocarbons such as decane, dodecene, and untecan.

  Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl- n-hexyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, etc. Can be mentioned.

  Examples of the ester solvent include methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether, acetic acid Ethylene glycol monoethyl ether, acetic acid diethylene glycol monomethyl ether, acetic acid diethylene glycol monoethyl ether, acetic acid diethylene glycol mono-n-butyl ether, acetic acid propylene glycol monomethyl ether, vinegar Propylene glycol monoethyl ether, Propylene glycol monopropyl ether, Propylene glycol monobutyl ether, Dipropylene glycol monomethyl ether acetate, Dipropylene glycol monoethyl ether acetate, Diacetic acid glycol, Methoxytriglycol acetate, Ethyl propionate, Propionic acid n -Butyl, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate, etc. Can be mentioned.

  Of these, ketone solvents and ester solvents are preferred, the ketone solvent is more preferably cyclohexanone, and the ester solvent is more preferably propylene glycol monomethyl ether acetate.

<Optional component>
The film forming composition for immersion exposure may contain an optional component. Each optional component may be used alone or in combination of two or more. Moreover, content of each arbitrary component can be suitably determined according to the objective.

<Method for Preparing Film Formation Composition for Immersion Exposure>
The film forming composition for immersion exposure can be prepared by mixing the [A] polymer component, the [B] solvent, and, if necessary, optional components at a predetermined ratio.

  As solid content concentration of the said film formation composition for immersion exposure, 0.1 mass%-50 mass% are preferable, 0.5 mass%-30 mass% are more preferable, 1 mass%-10 mass% are further preferable.

<Film-forming composition for immersion exposure used as a photoresist composition>
The film forming composition for immersion exposure can be suitably used, for example, as a photoresist composition (hereinafter, the film forming composition for immersion exposure used as a photoresist composition is referred to as “film for immersion exposure”). Forming composition (PR) "). By using the film-forming composition for immersion exposure as a photoresist composition, the film-forming composition for immersion exposure (PR) becomes a resist film because the polymer (a1) is unevenly distributed on the resist film surface layer. It is possible to increase the receding contact angle during immersion exposure on the surface, and to further reduce the receding contact angle due to dissociation of alkali dissociable groups during alkali development, thereby further suppressing development defects. can do.

  In addition to the above [A] polymer component and [B] solvent, the film forming composition for immersion exposure (PR) includes [C] acid generator, [D] acid diffusion controller, and other optional components as suitable components. It may contain components. Hereinafter, each component will be described in detail. The [B] solvent has been described above in the section <Film forming composition for immersion exposure>, and will not be described in detail.

  The [A] polymer component (hereinafter, also referred to as “[A1] polymer component”) in the film forming composition for immersion exposure (PR) is preferably the following polymer component.

<[A1] Polymer component>
[A1] The polymer component is not particularly limited as long as it contains the polymer (a1). [A1] The polymer (a1) in the polymer component (hereinafter also referred to as “polymer (a1-1)”). ) Is preferably the following polymer. [A1] The polymer component preferably contains a polymer (a2) having a fluorine atom content lower than that of the polymer (a1) and having an acid dissociable group.

<Polymer (a1-1)>
The polymer (a1-1) preferably has a structural unit (II) in addition to the above structural unit (I).

[Structural unit (II)]
The structural unit (II) is a structural unit containing an acid dissociable group. Since the polymer (a1-1) has the structural unit (II), the film-forming composition for immersion exposure (PR) is soluble in the alkaline developer of the polymer (a1-1) in the exposed area. As a result, the occurrence of development defects can be further suppressed.

  Examples of the structural unit (II) include a structural unit represented by the following formula (4).

  In said formula (4), R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y is an acid dissociable group.

  The acid dissociable group represented by Y is preferably a group represented by the following formula (Y-1).

In the above formula (Y-1), R ^a1 , R ^a2 and R ^a3 are each independently an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. . R ^a2 and R ^a3 may be bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.

Examples of the alkyl group having 1 to 4 carbon atoms represented by R ^a1 , R ^a2 and R ^a3 include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and 2-methyl. A propyl group, a 1-methylpropyl group, a t-butyl group, etc. are mentioned.

Along with the C 3-20 monovalent alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 , and the carbon atom to which R ^a2 and R ^a3 are bonded to each other and bonded to each other Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms formed include a bridged skeleton such as an adamantane skeleton and a norbornane skeleton, and a monocyclic cycloalkane skeleton such as cyclopentane and cyclohexane. Group; these groups are, for example, one or more of linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms such as methyl group, ethyl group, n-propyl group and i-propyl group. And groups having an alicyclic hydrocarbon skeleton such as a group substituted with.

  Among these, a group having a monocyclic cycloalkane skeleton is preferable in that the shape of the resist pattern after development can be improved.

  Examples of the structural unit represented by the formula (4) include structural units represented by the formulas (4-1) to (4-7).

In said formula (4-1)-(4-7), R is synonymous with Formula (4). R ^a1 , R ^a2 and R ^a3 have the same ^meaning as in formula (Y-1). Each r is independently an integer of 1 to 3. Among these, the structural unit represented by the formula (4-3) is preferable, r in the formula (4-3) is more preferably 1, and R in the formula (4-3) is preferable. More preferably, ^a1 is an ethyl group.

  As a content rate of structural unit (II), 0 mol%-90 mol% are preferable with respect to all the structural units which comprise a polymer (a1-1), 0 mol%-70 mol% are more preferable, 10 More preferably, mol% to 50 mol%. By making the content rate of the said structural unit into the said range, the undissolved residue of an exposure part can be suppressed effectively.

<Polymer (a2)>
The polymer (a2) is a polymer having a fluorine atom content smaller than that of the polymer (a1-1) and a polymer having an acid dissociable group. [A] Since the polymer component contains the polymer (a2) as a base polymer, the film-forming composition for immersion exposure (PR) is effective for the polymer (a1-1) as a resist film surface layer. As a result, the receding contact angle at the time of immersion exposure on the resist film surface can be further increased. The base polymer refers to a polymer that is the main component of the polymer that constitutes the resist film formed from the photoresist composition, and preferably 50% by mass with respect to the total polymer that constitutes the resist film. The polymer which occupies the above is said.

  Although it does not specifically limit as long as it has the said structure as a polymer (a2), It is preferable to have the structural unit (II) about the above-mentioned polymer (a1-1). Moreover, the polymer (a2) may have another structural unit in the range which does not impair the effect of this invention. The content ratio of other structural units can be appropriately determined according to the purpose. In addition, the polymer (a2) may contain 2 or more types of each structural unit.

  As a content rate of structural unit (II) in a polymer (a2), 10 mol%-100 mol% are preferable with respect to all the structural units which comprise a polymer (a2), 20 mol%-90 mol% are preferable. More preferably, it is more preferably 30 mol% to 80 mol%. By making the content rate of the said structural unit into the said range, the shape of the resist pattern after image development can be improved effectively.

[Other structural units]
Examples of the structural unit other than the structural unit (II) that the polymer (a2) may have include at least one structure selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure. Examples include structural units. As the structural unit, for example, structural units represented by the following formulas (L-1) and (L-4) to (L-14) as structural units including a lactone structure include structural units including a cyclic carbonate structure: As a structural unit represented by the following formula (L-2), and a structural unit represented by the following formula (L-3) as a structural unit containing a sultone structure. When the polymer (a2) has a structural unit including at least one structure selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure, the adhesion of the resist film can be improved.

In the above formula, R ^L1 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  As a content rate of another structural unit, 10 mol%-90 mol% are preferable with respect to all the structural units which comprise a polymer (a2), and 20 mol%-80 mol% are more preferable.

  As content of a polymer (a2), 300 mass parts-5,000 mass parts are preferable with respect to 100 mass parts of polymers (a1-1), and 1,000 mass parts-3,000 mass parts are more. preferable. By making content of a polymer (a2) into the said range, the said polymer (a1-1) can be unevenly distributed efficiently in a resist film surface layer.

<[C] acid generator>
[C] The acid generator is a radiation-sensitive component that generates an acid upon exposure to radiation. Since the film forming composition for immersion exposure (PR) contains a [C] acid generator, the acid-dissociable group in the polymer is dissociated by the action of the acid generated by exposure, and the generated carboxy group or the like Due to the polarity, the polymer in the exposed area becomes easily soluble in the developer. As a result, a resist pattern with high contrast can be formed. The inclusion form of the [C] acid generator constituting the film forming composition for immersion exposure (PR) may be a compound form as described later (hereinafter also referred to as “[C] acid generator”). It may be a form incorporated as part of the coalescence or both forms. In addition, you may use a [C] acid generator individually or in combination of 2 or more types.

  [C] Examples of the acid generator include onium salt compounds such as sulfonium salts, tetrahydrothiophenium salts and iodonium salts, and sulfonic acid compounds.

  Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium perfluoro-n-butanesulfonate, triphenylsulfonium 6-adamantylcarbonyloxy-1,1,2,2-tetrafluorohexanesulfonate, and triphenyl. Sulfonium perfluoro-n-octane sulfonate, cyclohexyl, 2-oxocyclohexyl, methylsulfonium trifluoromethanesulfonate, dicyclohexyl, 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate, 4-hydroxy-1-naphthyl Dimethylsulfonium trifluoromethanesulfonate, tri E sulfonyl sulfonium 2- (bicyclo [2.2.1] hept-2-yl) 1,1,2,2-tetrafluoroethane sulfonate, and the like.

  Examples of the tetrahydrothiophenium salt include 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-hydroxy-1-naphthyltetrahydrothiophenium nonafluoro-n-butanesulfonate, 4-hydroxy-1 -Naphtyltetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium nonafluoro-n-butane Sulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydro Ofenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium Examples include perfluoro-n-octane sulfonate.

  Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis ( 4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, and the like.

  Examples of the sulfonic acid compound include trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5. -Ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N-hydroxysuccinimide trifluoromethanesulfonate, N- Examples thereof include hydroxysuccinimide nonafluoro-n-butanesulfonate, N-hydroxysuccinimide perfluoro-n-octanesulfonate, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate, and the like.

  [C] The acid generator is preferably an onium salt compound, more preferably a sulfonium salt, and further preferably triphenylsulfonium perfluoro-n-butanesulfonate.

  [C] The content of the acid generator is from the viewpoint of ensuring the sensitivity and developability as a resist with respect to 100 parts by mass of the polymer component [A] contained in the film forming composition for immersion exposure (PR). 0.1 to 30 parts by mass is preferable, and 0.1 to 20 parts by mass is more preferable. When the content of the [C] acid generator is less than 0.1 parts by mass, the sensitivity and developability of the film forming composition for immersion exposure (PR) tend to be lowered. On the other hand, if it exceeds 30 parts by mass, the transparency to radiation tends to decrease, and it becomes difficult to obtain a rectangular resist pattern.

<[D] Acid diffusion controller>
[D] The acid diffusion controller is a component that controls the diffusion of the acid generated in the resist film during exposure and suppresses an undesirable chemical reaction in the unexposed area. When the film forming composition for immersion exposure (PR) contains the [D] acid diffusion controller, the contrast between the exposed portion and the unexposed portion can be increased, and a good resist pattern can be formed. [D] The content of the acid diffusion controller in the immersion exposure film-forming composition (PR) may be a free compound (hereinafter also referred to as “[D] acid diffusion controller”). It may be a form incorporated as part or both of these forms. In addition, you may use [D] acid spreading | diffusion controlling agent individually or in combination of 2 or more types.

  [D] Examples of the acid diffusion controller include amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

  Examples of the amine compound include mono (cyclo) alkylamines; di (cyclo) alkylamines; tri (cyclo) alkylamines; substituted alkylanilines or derivatives thereof; ethylenediamine, N, N, N ′, N ′. -Tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4 -Aminophenyl) -2- (4-hydroxyphenyl) propane 1,4-bis (1- (4-aminophenyl) -1-methylethyl) benzene, 1,3-bis (1- (4-aminophenyl) -1-methylethyl) benzene, bis (2-dimethylamino) Ethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ) Ethylenediamine, N, N, N ′, N ″ N ″ -pentamethyldiethylenetriamine and the like.

  Examples of the amide group-containing compound include Nt-butoxycarbonyl group-containing amide compounds such as Nt-butoxycarbonyl-4-hydroxypiperidine; N-t-amyloxycarbonyl-4-hydroxypiperidine and the like N- t-amyloxycarbonyl group-containing amide compound; formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric acid tris (2-hydroxyethyl) and the like can be mentioned.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tri-n-butyl. Examples include thiourea.

  Examples of the nitrogen-containing heterocyclic compound include imidazoles such as 2-phenylimidazole; pyridines; piperazines; pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidineethanol, 3-piperidino-1,2 -Propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4 -Diazabicyclo [2.2.2] octane etc. are mentioned.

  Of these, amide group-containing compounds are preferred, Nt-amyloxycarbonyl group-containing amide compounds are more preferred, and Nt-amyloxycarbonyl-4-hydroxypiperidine is more preferred.

  [D] A photodegradable base can also be used as the acid diffusion controller. This photodegradable base functions as a quencher due to the high acid capturing function by the anion in the unexposed area, and as a result of capturing the acid diffusing from the exposed area, the contrast of the deprotection reaction is improved and the resolution is further improved. Can do. As an example of the photodegradable base, an onium salt compound that is decomposed by exposure and loses acid diffusion controllability can be mentioned. Examples of the onium salt compound include a sulfonium salt compound represented by the following formula (5-1), an iodonium salt compound represented by the following formula (5-2), and the like.

The formula (5-1) and formula ^(5-2), independently R b1 ^{to R b5} are each a hydrogen atom, an alkyl group, an alkoxy group, hydroxy group, is a halogen atom or _-SO 2 -R ^X . R ^X is an alkyl group, a cycloalkyl group, an alkoxy group or an aryl group. Z ⁻ is OH ⁻ , R ^b6 —COO ⁻ , R ^Y —SO ₂ —N ^— Rb ⁶ , R ^b6 —SO ₃ ⁻ , or an anion represented by the following formula (5 ′). R ^b6 is a linear or branched alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms. However, one part or all part of the hydrogen atom which the said alkyl group, cycloalkyl group, aryl group, and aralkyl group have may be substituted. R ^Y is a linear or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms. However, some or all of the hydrogen atoms of the alkyl group and cycloalkyl group may be substituted with fluorine atoms. When Z ⁻ is R ^b6 —SO ₃ ^— , a fluorine atom is not bonded to a carbon atom to which SO ₃ ^— is bonded.

In the above formula (5 ′), R ^b7 is a linear or branched alkyl group having 1 to 12 carbon atoms or a linear or branched alkoxy group having 1 to 12 carbon atoms. However, some or all of the hydrogen atoms of the alkyl group and alkoxy group may be substituted with fluorine atoms. u is an integer of 0-2.

Examples of the alkyl group represented by R ^{b1 to} R ^b5 include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, an i-butyl group, and a t-butyl group.

Examples of the alkoxy group represented by R ^{b1 to} R ^b5 include a methoxy group, an ethoxy group, and a butoxy group.

The halogen atoms represented by R ^b1 to R ^b5, for example, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

As the alkyl group and alkoxy group represented by R ^X , for example, the same groups as the groups exemplified for R ^{b1 to} R ^b5 can be applied.

Examples of the cycloalkyl group represented by R ^X include a cyclopentyl group, a cyclohexyl group, a norbornyl group, a tricyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, and the like.

Examples of the aryl group represented by R ^X include a phenyl group, a naphthyl group, and an anthryl group.

As the ^R b1 ^{to R b5,} hydrogen atom and _-SO 2 -R ^X are preferred. Moreover, as said R ^<X >, a cycloalkyl group is preferable and a cyclohexyl group is more preferable.

Examples of the alkyl group represented by R ^b6 include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, an i-butyl group, and a t-butyl group.

Examples of the cycloalkyl group represented by R ^b6 include a cyclopentyl group, a cyclohexyl group, a norbornyl group, a tricyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, and the like.

Examples of the aryl group represented by R ^b6 include a phenyl group, a naphthyl group, and an anthryl group.

Examples of the aralkyl group represented by R ^b6 include a benzyl group, a phenethyl group, and a phenylpropyl group.

  Examples of the substituent that the alkyl group, cycloalkyl group, aryl group, and aralkyl group may have include a hydroxy group, a halogen atom, an alkoxy group, a lactone group, and an alkylcarbonyl group.

As the alkyl group and cycloalkyl group represented by R ^Y , for example, the same groups as the groups exemplified for R ^b6 can be applied.

  Examples of the sulfonium salt compound represented by the formula (5-1) include triphenylsulfonium hydroxide, triphenylsulfonium salicylate, triphenylsulfonium 4-trifluoromethyl salicylate, and diphenyl-4-hydroxyphenyl. Examples include sulfonium salicylate, triphenylsulfonium 10-camphor sulfonate, 4-t-butoxyphenyl diphenylsulfonium 10-camphor sulfonate, and the like. Among these, triphenylsulfonium salicylate and triphenylsulfonium 10-camphorsulfonate are more preferable. In addition, you may use these sulfonium salt compounds individually or in combination of 2 or more types.

  Examples of the iodonium salt compound represented by the above formula (5-2) include bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium salicylate, and bis (4- t-butylphenyl) iodonium 4-trifluoromethyl salicylate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, and the like. In addition, you may use these iodonium salt compounds individually or in combination of 2 or more types.

  As the photodegradable base, a sulfonium salt compound is preferable, and triphenylsulfonium salicylate and triphenylsulfonium 10-camphorsulfonate are more preferable.

  [D] The content of the acid diffusion controller is preferably 30 parts by mass or less, and 20 parts by mass with respect to 100 parts by mass of the polymer component [A] contained in the film forming composition for immersion exposure (PR). The following is more preferable, and 10 parts by mass or less is more preferable. [D] If the acid diffusion controller is excessively contained, the sensitivity of the formed resist film may be significantly lowered.

<Other optional components>
The film forming composition for immersion exposure (PR) may contain other optional components such as an [E] uneven distribution accelerator as long as the effects of the present invention are not impaired. Each optional component may be used alone or in combination of two or more. Further, the content of other optional components can be appropriately determined according to the purpose.

<[E] Uneven distribution promoter>
[E] The uneven distribution promoter is a component that causes the polymer (a1-1) to segregate on the resist film surface more efficiently. When the film forming composition for immersion exposure (PR) contains the [E] uneven distribution accelerator, the blending amount of the polymer (a1-1) can be reduced. [E] Examples of the uneven distribution promoter include lactone compounds, carbonate compounds, nitrile compounds, and polyhydric alcohols. In addition, you may use [E] uneven distribution promoter individually or in combination of 2 or more types.

Examples of the lactone compound include γ-butyrolactone, valerolactone, mevalonic lactone, norbornane lactone, and the like.
Examples of the carbonate compound include propylene carbonate, ethylene carbonate, butylene carbonate, vinylene carbonate, and the like.
Examples of the nitrile compound include succinonitrile.
Examples of the polyhydric alcohol include glycerin.

  Of these, lactone compounds are preferred, and γ-butyrolactone is more preferred.

  [E] The content of the uneven distribution accelerator is preferably 5 parts by mass to 300 parts by mass with respect to 100 parts by mass of the total amount of the polymer.

<Film-forming composition for immersion exposure used as a composition for forming an upper-layer film for immersion>
The film forming composition for immersion exposure can be suitably used, for example, as a composition for forming an upper liquid immersion film (hereinafter referred to as a film forming composition for immersion exposure used as a composition for forming an upper film for immersion). (The composition for forming a liquid immersion upper layer film of the present invention) is also referred to as “film forming composition for liquid immersion exposure (TC)”). By forming the liquid immersion upper film on the resist film using the film formation composition for liquid immersion exposure (TC), the receding contact angle at the time of liquid immersion exposure on the liquid immersion upper film can be further increased. During alkali development, the receding contact angle can be further reduced by dissociation of the alkali-dissociable group, and as a result, development defects can be further suppressed.

  The film forming composition (TC) for immersion exposure may contain other components in addition to the above [A] polymer component and [B] solvent. Hereinafter, each component will be described in detail. The [B] solvent has been described above in the section <Film forming composition for immersion exposure>, and will not be described in detail.

  The [A] polymer component (hereinafter also referred to as “[A2] polymer component”) in the film forming composition (TC) for immersion exposure is preferably the following polymer component.

<[A2] Polymer component>
[A2] The polymer component is particularly limited as long as it contains the polymer (a1) (the polymer in the [A2] polymer component (a1 is hereinafter also referred to as “polymer (a1-2)”)). However, a polymer different from the polymer (a1) (hereinafter also referred to as “polymer (a3)”) may be included as long as the effects of the present invention are not impaired. [A2] The polymer component preferably has structural units (III) to (V) in the same or different polymer (a3) as the polymer (a1-2). [A2] The polymer component may have other structural units such as the structural unit (VI) in the same or different polymer (a3) as the polymer (a1-2). In addition, each polymer may have 2 or more types of each structural unit, respectively. Hereinafter, each structural unit will be described in detail.

[Structural unit (III)]
The structural unit (III) includes a structural unit containing a fluorinated sulfonamide group (hereinafter also referred to as “structural unit (III-1)”) and a structural unit containing an α-trifluoromethyl alcohol group (hereinafter referred to as “structural unit ( III-2) ”) is at least one structural unit selected from the group consisting of. The film forming composition for liquid immersion exposure (TC) can improve the water repellency and removability of the liquid immersion upper layer film by the [A2] polymer component further having the structural unit (III), Occurrence of development defects can be suppressed.

  The structural unit (III-1) is preferably a structural unit represented by the following formula (5).

In said formula (5), ^RD is a hydrogen atom, a methyl group, a fluorine atom, or a trifluoromethyl group. R ⁿ¹ is a divalent linking group. R ⁿ² is a fluorinated alkyl group having 1 to 20 carbon atoms.

The ^RD is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of the copolymerizability of the monomer that gives the structural unit represented by the formula (5).

Examples of the divalent linking group represented by R ⁿ¹ include a divalent chain hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms. It is done.

Examples of the divalent chain hydrocarbon group having 1 to 6 carbon atoms include:
As saturated chain hydrocarbon groups, methanediyl group, 1,2-ethanediyl group, 1,1-ethanediyl group, 1,3-propanediyl group, 1,2-propanediyl group, 1,1-propanediyl group, 2 , 2-propanediyl group, 1,4-propanediyl group, 1,5-pentanediyl group, 1,6-hexanediyl group, 1-methyl-1,3-propanediyl group, 2-methyl-1,3- Propanediyl group, 2-methyl-1,2-propanediyl group, 1-methyl-1,4-butanediyl group, 2-methyl-1,4-butanediyl group and the like;
Examples of the unsaturated chain hydrocarbon group include a 1,2-ethenediyl group, a 1,3-propenediyl group, and a 1,2-propenediyl group.

Examples of the divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms include:
As monocyclic hydrocarbon group, cyclobutanediyl group such as 1,3-cyclobutanediyl group; cyclopentanediyl group such as 1,3-cyclopentanediyl group; 1,4-cyclohexanediyl group, 1,2-cyclohexanediyl Cyclohexanediyl groups such as groups; cyclooctanediyl groups such as 1,5-cyclooctanediyl groups;
As polycyclic hydrocarbon groups, 1,4-norbornanediyl groups, norbornanediyl groups such as 2,5-norbornanediyl groups, 1,3-adamantanediyl groups, adamantanediyl groups such as 2,4-adamantanediyl groups, etc. Is mentioned.
Among these, a monocyclic hydrocarbon group is preferable, a cyclohexanediyl group is more preferable, and a 1,2-cyclohexanediyl group is more preferable.

R ⁿ¹ is preferably a divalent chain hydrocarbon group having 1 to 6 carbon atoms, more preferably a divalent chain hydrocarbon group having 1 to 3 carbon atoms, and further preferably a 1,2-ethanediyl group. .

Examples of the fluorinated alkyl group having 1 to 20 carbon atoms represented by R ⁿ² include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a trifluoroethyl group, a pentafluoromethyl group, a heptafluoropropyl group, Nonafluorobutyl group etc. are mentioned. Of these, a trifluoromethyl group is preferred.

As the structural unit (III-2), any structural unit including an α-trifluoromethyl alcohol group (—C (R) (OH) (CF ₃ ) group, R is a monovalent organic group) may be used. Although it does not specifically limit, For example, the structural unit etc. which are represented by following formula (6) are mentioned.

In said formula (6), ^RE is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^t1 is a divalent linking group.

The above-mentioned R ^E, from the viewpoint of copolymerizability of the monomer giving the structural unit represented by the above formula (6), a hydrogen atom, preferably a methyl group, more preferably a methyl group.

Examples of the divalent linking group represented by R ^t1 include the same groups as those exemplified as R ⁿ¹ in the above formula (5). Moreover, the methylene group (—CH ₂ —) in these chain hydrocarbon groups and alicyclic hydrocarbon groups may be substituted with an oxygen atom, a carbonyl group or an ester group. R ^t1 is preferably a divalent chain hydrocarbon group having 1 to 3 carbon atoms or a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, and a divalent group containing a propanediyl group or a cyclohexane skeleton. Further, a divalent group containing a norbornene skeleton and a divalent group containing an adamantane skeleton are more preferred, and a 1,2-propanediyl group and a 1-cyclohexyl-1,2-ethanediyl group are more preferred.

  Examples of the structural unit represented by the above formula (6) include structural units represented by the following formulas (6-1) to (6-8).

In the above formulas (6-1) to (6-8), R ^E has the same meaning as the above formula (6).

  Among these, the structural units represented by the above formulas (6-4) and (6-8) are preferable.

  [A2] The content ratio of the structural unit (III) in the polymer component is preferably 0 mol% to 90 mol%, preferably 1 mol% to 80 mol, based on all structural units constituting the [A2] polymer component. % Is more preferable, 4 mol% to 75 mol% is further preferable, and 20 mol% to 70 mol% is particularly preferable. [A2] By making the content ratio of the structural unit (III) in the polymer component within the above range, the water repellency and removability of the liquid immersion upper layer film formed from the film formation composition for liquid immersion exposure (TC) are effective. And development defects can be effectively suppressed.

  As a content rate of structural unit (III) in a polymer (a1-2), 0 mol%-90 mol% are preferable with respect to all the structural units which comprise a polymer (a1-2)-5 mol%- 85 mol% is more preferable and 15 mol%-65 mol% is still more preferable. By making the content rate of structural unit (III) in a polymer (a1-2) into the said range, the characteristics, such as said water repellency, can be improved effectively.

  As a content rate of structural unit (III) in a polymer (a3), 0 mol%-90 mol% are preferable with respect to all the structural units which comprise a polymer (a3), and 5 mol%-85 mol% are preferable. More preferably, 15 mol% to 65 mol% is more preferable. By making the content rate of structural unit (III) in a polymer (a3) into the said range, the characteristics, such as the said water repellency, can be improved effectively.

[Structural unit (IV)]
The structural unit (IV) is a structural unit containing a sulfo group. The film forming composition for liquid immersion exposure (TC) can further improve the removability and peeling resistance of the liquid immersion upper layer film by the [A2] polymer component further having the structural unit (IV). The occurrence of development defects can be further suppressed.

  Examples of the structural unit (IV) include a structural unit represented by the following formula (7).

In said formula (7), R ^<F> is a hydrogen atom, a methyl group, a fluorine atom, or a trifluoromethyl group. R ^s1 is a single bond, oxygen atom, sulfur atom, divalent chain hydrocarbon group having 1 to 6 carbon atoms, divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, or 6 to 12 carbon atoms. A divalent aromatic hydrocarbon group or a —C (═O) —X′—R′— group. X ′ is an oxygen atom, a sulfur atom or an NH group. R ′ is a single bond, a divalent chain hydrocarbon group having 1 to 6 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, or a divalent aromatic carbon group having 6 to 12 carbon atoms. It is a hydrogen group.

As R ^F , a hydrogen atom or a methyl group is preferable from the viewpoint of the copolymerizability of the monomer giving the structural unit (IV).

Examples of the divalent chain hydrocarbon group having 1 to 6 carbon atoms and the divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms represented by R ^s1 and R ′ include, for example, the above formula (5 ), The same groups as those exemplified as R ^{n1 in the} above.

As a C6-C12 bivalent aromatic hydrocarbon group represented by said ^Rs1 , arylene groups, such as a phenylene group and a tolylene group, etc. are mentioned, for example.

As R ^s1 , a single bond, a divalent chain hydrocarbon group having 1 to 6 carbon atoms, a divalent aromatic hydrocarbon having 6 to 12 carbon atoms, or R ′ is divalent having 1 to 6 carbon atoms. —C (═O) —NH—R′—, which is a chain hydrocarbon group, is preferably a single bond, a methanediyl group, a phenylene group, —C (═O) —NH—CH (CH ₃ ) —CH ₂ —. Are more preferable, and a single bond, —C (═O) —NH—CH (CH ₃ ) —CH ₂ — is more preferable.

  Examples of the structural unit (IV) include structural units represented by the following formulas (7-1) to (7-4).

In formulas (7-1) to (7-4), R ^F has the same meaning as formula (7). Among these, the structural unit represented by the above formula (7-1) and the structural unit represented by the above formula (7-4) are preferable.

  [A2] The content ratio of the structural unit (IV) in the polymer component is preferably 0 mol% to 10 mol%, preferably 0.1 mol% to the total structural unit constituting the [A2] polymer component. 5 mol% is more preferable, and 0.2 mol% to 2 mol% is more preferable. [A2] By making the content ratio of the structural unit (IV) in the polymer component within the above range, the removability and peeling resistance of the liquid immersion upper layer film can be effectively improved, and the occurrence of development defects is effective. Can be suppressed.

  As a content rate of structural unit (IV) in a polymer (a3), it is 0 mol%-20 mol% normally with respect to all the structural units which comprise a polymer (a3), 0.2 mol%- 10 mol% is more preferable and 0.5 mol%-7 mol% are further more preferable. By setting the content ratio of the structural unit (IV) in the polymer (a3) within the above range, characteristics such as removability of the liquid immersion upper layer film can be effectively enhanced.

[Structural unit (V)]
The structural unit (V) includes a structural unit containing a carboxy group (hereinafter also referred to as “structural unit (V-1)”) and a structural unit containing the group represented by the above formula (2) (hereinafter referred to as “structural unit ( V-2) is also at least one structural unit selected from the group consisting of. In the film forming composition for liquid immersion exposure (TC), the [A2] polymer component further includes the structural unit (V), so that the removability and peeling resistance of the liquid immersion upper layer film can be further improved. The occurrence of development defects can be further suppressed.

  Examples of the structural unit (V-1) include structural units represented by the following formulas (8-1) to (8-3).

In the above formulas (8-1) to (8-3), R ^G is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^c1 and R ^c2 are each independently a divalent chain hydrocarbon group having 1 to 6 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, or 2 having 6 to 12 carbon atoms. Valent aromatic hydrocarbon group.

As said ^RG , a hydrogen atom and a methyl group are preferable and a methyl group is more preferable.

Examples of the divalent chain hydrocarbon group having 1 to 6 carbon atoms represented by R ^c1 and R ^c2 include the same groups as those exemplified as R ⁿ¹ in the above formula (5). Of these, saturated chain hydrocarbon groups are preferred, and 1,2-ethanediyl groups are more preferred.

Examples of the divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms represented by R ^c1 and R ^c2 include the same groups as those exemplified as R ⁿ¹ in the above formula (5). . Among these, a monocyclic hydrocarbon group is preferable, a cyclohexanediyl group is more preferable, and a 1,2-cyclohexanediyl group is more preferable.

Examples of the divalent aromatic hydrocarbon group having 6 to 12 carbon atoms represented by R ^c1 and R ^c2 include the same groups as those exemplified as R ^s1 in the above formula (7).

  As the structural unit (V-1), for example, structural units represented by the following formulas (8-1-1) to (8-1-3), and the following formulas (8-2-1) and (8- And the structural unit represented by 2-2).

In the above formulas (8-1-1) to (8-2-2), R ^G has the same meaning as the above formulas (8-1) to (8-3).

  Among these, the structural units represented by the above formulas (8-1) and (8-3) are preferable. Moreover, in the structural unit represented by the said Formula (8-1), the structural unit represented by Formula (8-1-1) is more preferable.

  The structural unit (V-2) is a structural unit containing a group represented by the above formula (2).

In the above formula (2), ^{R 4} is a hydrogen atom, a halogen atom, a nitro group, an alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, 1 to 20 carbon atoms An alkoxy group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. Some or all of the hydrogen atoms of the alkyl group, alicyclic hydrocarbon group, alkoxy group, acyl group, aralkyl group and aryl group may be substituted. R ⁵ is —C (═O) —R ⁶ , —S (═O) ₂ —R ⁷ , —R ⁸ —CN, or —R ⁹ —NO ₂ . R ⁶ and R ⁷ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a fluorinated alkyl group having 1 to 20 carbon atoms, or a monovalent alicyclic hydrocarbon having 3 to 20 carbon atoms. Group, an alkoxy group having 1 to 20 carbon atoms, a cyano group, a cyanomethyl group, an aralkyl group having 7 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. However, R ⁶ or R ⁷ and R ⁴ may be bonded to each other to form a ring structure. R ⁸ and R ⁹ are each independently a single bond, a methylene group or an alkylene group having 2 to 5 carbon atoms.

Examples of the halogen atom represented by R ⁴ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom and a chlorine atom are preferable.

Examples of the alkyl group having 1 to 20 carbon atoms and the monovalent alicyclic hydrocarbon group having 1 to 20 carbon atoms represented by R ⁴ include 1 to 1 carbon atoms represented by R ^3. Examples thereof include the same groups as those exemplified for each group shown as a valent hydrocarbon group.

As a C1-C20 alkoxy group represented by said R < ⁴ >, a methoxy group, an ethoxy group, etc. are mentioned, for example.

As a C1-C20 acyl group represented by said R < ⁴ >, an acetyl group, a propionyl group, etc. are mentioned, for example.

Examples of the aralkyl group having 7 to 20 carbon atoms represented by R ⁴ include a benzyl group, a phenethyl group, and a naphthylmethyl group.

Examples of the aryl group having 6 to 20 carbon atoms represented by R ⁴ include a phenyl group, a tolyl group, a dimethylphenyl group, a 2,4,6-trimethylphenyl group, and a naphthyl group.

Examples of the substituent that the alkyl group, monovalent alicyclic hydrocarbon group, alkoxy group, acyl group, aralkyl group and aryl group represented by R ⁴ may have include a fluorine atom and a chlorine atom. And halogen atoms such as hydroxyl group, nitro group, cyano group and the like.

As R ⁴ , among these, from the viewpoint of balancing the solubility of the developer in the liquid immersion upper layer film formed from the film forming composition for liquid immersion exposure (TC) and the peeling resistance, among these, a hydrogen atom, a carbon number A 1-5 alkyl group, a C1-C5 alkoxy group, and a C2-C5 acyl group are preferable, and a hydrogen atom, a methyl group, an ethyl group, and an acetyl group are more preferable.

When R ⁵ is —C (═O) —R ⁶ or —S (═O) ₂ —R ⁷ , the alkyl group represented by R ⁶ and R ⁷ , a monovalent alicyclic hydrocarbon group, alkoxy Examples of the group, the aralkyl group, and the aryl group include the same groups as those exemplified as the respective groups for R ⁴ . Examples of the fluorinated alkyl group represented by R ⁶ and R ⁷ include a group in which at least one hydrogen atom of the group exemplified as the alkyl group for R ⁴ is substituted with a fluorine atom. Among these, as R ⁶ and R ⁷ , a hydrogen atom and an alkyl group are preferable, and a hydrogen atom, a methyl group, and an ethyl group are more preferable.

The group containing a ring structure formed by bonding R ⁶ or R ⁷ and R ⁴ to each other includes an atom to which R ⁶ or R ⁷ and R ⁴ are bonded, and has 5 carbon atoms having an oxo group. ~ 12 divalent alicyclic hydrocarbon groups are preferred.

When R ⁵ is —R ⁸ —CN and —R ⁹ —NO ₂ , R ⁸ and R ⁹ are preferably a single bond, a methanediyl group or an ethanediyl group.

  As group represented by said Formula (2), group represented by following formula (2-1)-(2-8) is preferable.

  In the above formulas (2-1) to (2-8), * represents a binding site.

  The structural unit (V-2) is derived from, for example, a (meth) acrylic acid ester derivative having a group represented by the above formula (2), a (meth) acrylamide derivative, a vinyl ether derivative, an olefin derivative, a styrene derivative, or the like. Examples include structural units. Of these, structural units derived from (meth) acrylic acid ester derivatives are preferred. That is, as the structural unit (V-2), a structural unit represented by the following formula (9) is preferable.

In the above formula (9), ^{R 4} and ^{R 5} is as defined in the above formula (2). m is an integer of 1-3. When R ⁴ and R ⁵ is plural, respectively, it may be different in each of a plurality of R ⁴ and R ⁵ are the same. L ¹ is a (m + 1) -valent linking group. R ^H is a hydrogen atom, a methyl group, a fluorine atom or a trifluoromethyl group.

The ^RH is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of copolymerizability of the monomer that gives the structural unit represented by the formula (9).

Examples of the (m + 1) -valent linking group represented by L ¹ include an alkanediyl group, a divalent alicyclic hydrocarbon group, an alkenediyl group, as a divalent linking group (when n is 1), And arenediyl groups. Note that some or all of the hydrogen atoms contained in these groups may be substituted with a halogen atom such as a fluorine atom or a chlorine atom, a cyano group, or the like.

  Examples of the alkanediyl group include methanediyl group, ethanediyl group, propanediyl group, butanediyl group, hexanediyl group, and octanediyl group. As said alkanediyl group, a C1-C8 alkanediyl group is preferable.

  Examples of the divalent alicyclic hydrocarbon group include monocyclic alicyclic hydrocarbon groups such as cyclopentanediyl group and cyclohexanediyl group; and polycyclic alicyclic groups such as norbornanediyl group and adamantanediyl group. A hydrocarbon etc. are mentioned. As said bivalent alicyclic hydrocarbon group, a C5-C12 bivalent alicyclic hydrocarbon group is preferable.

  Examples of the alkenediyl group include an ethenediyl group, a propenediyl group, and a butenediyl group. As said alkenediyl group, a C2-C6 alkenediyl group is preferable.

  Examples of the arenediyl group include a phenylene group, a tolylene group, and a naphthylene group. As the above arenediyl group, an arenediyl group having 6 to 15 carbon atoms is preferable.

Among these, as L ¹ , an alkanediyl group, a divalent alicyclic hydrocarbon group is preferable, an alkanediyl group having 1 to 4 carbon atoms, and a divalent alicyclic hydrocarbon having 6 to 11 carbon atoms. Groups are more preferred.

  As the structural unit represented by the following formula (9), structural units represented by the following formulas (9-1) to (9-10) are preferable.

In said formula (9-1)-(9-10), ^RH is synonymous with said formula (9).

  [A2] The content of the structural unit (V) in the polymer component is preferably 0 mol% to 30 mol%, preferably 1 mol% to 20 mol, based on all structural units constituting the [A2] polymer component. % Is more preferable, and 4 mol% to 15 mol% is more preferable. [A2] By making the content ratio of the structural unit (V) in the polymer component within the above range, the removability and peeling resistance of the liquid immersion upper layer film formed from the film forming composition for liquid immersion exposure (TC) are effective. And development defects can be effectively suppressed.

  As a content rate of the structural unit (V) in a polymer (a3), 0 mol%-60 mol% are preferable with respect to all the structural units which comprise a polymer (a3), and 10 mol%-55 mol% are preferable. More preferably, it is more preferably 25 mol% to 50 mol%. By making the content rate of the structural unit (V) in a polymer (a3) into the said range, characteristics, such as the removability of the said liquid immersion upper layer film | membrane, can be improved effectively.

[Other structural units]
[A2] As the polymer component, in addition to the structural unit (I) and the structural units (III) to (V), in the polymer (a3) that is the same as or different from the polymer (a1), a structural unit described later You may have other structural units, such as (VI). The content ratio of other structural units can be appropriately determined according to the purpose.

[Structural unit (VI)]
[A2] The polymer component preferably further has a structural unit (VI) represented by the following formula (Z). [A2] When the polymer component further has the structural unit (VI), the water repellency of the formed liquid immersion upper layer film can be increased.

In formula (Z), R ^M1 represents a hydrogen atom, a methyl group, a fluorine atom or a trifluoromethyl group. R ^M2 is a linear or branched alkyl group having 1 to 6 carbon atoms having a fluorine atom or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms having a fluorine atom. However, one part or all part of the hydrogen atom which the said alkyl group and alicyclic hydrocarbon group have may be substituted by the substituent.

Examples of the linear or branched alkyl group having 1 to 6 carbon atoms and having a fluorine atom represented by R ^M2, for example, a methyl group, an ethyl group, a propyl group, having 1 to 6 carbon atoms such as butyl group Examples include a group in which part or all of the hydrogen atoms of the linear or branched alkyl group are substituted with fluorine atoms.

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms having a fluorine atom represented by R ^M2, for example, cyclopentyl, cyclopentyl propyl, cyclohexyl, cyclohexylmethyl group, a cycloheptyl group, a cycloalkyl Examples include a group in which part or all of the hydrogen atoms of a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms such as an octyl group and a cyclooctylmethyl group are substituted with fluorine atoms.

  As said substituent, a fluorine atom, a hydroxy group, a carboxy group, an amino group etc. are mentioned, for example.

Examples of the structural unit (VI) include structural units represented by the following formulas (Z-1) to (Z-6).

In the above formulas (Z-1) to (Z-6), R ^M1 has the same ^meaning as the above formula (Z).

  Among these, the structural units represented by the above formulas (Z-1) and (Z-3) are preferable.

  [A2] The content ratio of the structural unit (VI) in the polymer component is preferably 0 mol% to 50 mol%, preferably 1 mol% to 40 mol, with respect to all structural units constituting the [A2] polymer component. % Is more preferable, and 2 mol% to 30 mol% is more preferable. [A2] By making the content ratio of the structural unit (VI) in the polymer component within the above range, the water repellency and removability of the liquid immersion upper film formed from the liquid immersion upper film formation composition (TC) are further improved. As a result, development defects can be further suppressed.

  As a content rate of structural unit (VI) in a polymer (a1-2), 0 mol%-70 mol% are preferable with respect to all the structural units which comprise a polymer (a1-2), 5 mol%- 65 mol% is more preferable, and 10 mol% to 60 mol% is more preferable. By setting the content ratio of the structural unit (VI) in the polymer (a1-2) within the above range, the water repellency and other characteristics of the liquid immersion upper layer film can be effectively enhanced.

<Other ingredients>
The film forming composition (TC) for immersion exposure may contain other components other than the above-mentioned [A2] polymer component and [B] solvent as long as the effects of the present invention are not impaired. Other components may be used alone or in combination of two or more.

<Polymer>
The polymer of the present invention is a polymer having the structural unit (I) represented by the above formula (1). Since the polymer has the structural unit (I), for example, it is suitably used as a component of a film forming composition for immersion exposure that exhibits a large receding contact angle during immersion exposure and can suppress development defects. be able to.

<Compound>
The compound of the present invention is a compound represented by the above formula (3). Since the compound has the above structure, it is suitable as a monomer that gives the structural unit (I), for example.

  In addition, since the said polymer and compound are mentioned above in the term of the polymer (a1) in <film forming composition for immersion exposure>, description here is abbreviate | omitted.

  The resist pattern formation method (I) using the immersion exposure film-forming composition (PR) and the resist pattern formation method (II) using the immersion exposure film-forming composition (TC) are respectively divided. It is shown below.

<Method for Forming Resist Pattern (I)>
The method of forming a resist pattern using the film forming composition for immersion exposure (PR) is as follows:
(A1) A step of forming a resist film on a substrate using the film formation composition for immersion exposure (PR) (hereinafter also referred to as “step (A1)”),
(A2) immersion exposure of the resist film by irradiation with radiation through an immersion exposure liquid (hereinafter also referred to as “process (A2)”), and (A3) development of the immersion exposed resist film. And a step of developing with a liquid to form a resist pattern (hereinafter also referred to as “step (A3)”). Hereinafter, each process is explained in full detail.

[Step (A1)]
In this step, a resist film is formed on the substrate using the film forming composition for immersion exposure (PR). Examples of the substrate include a silicon wafer and a wafer coated with aluminum. A resist film is formed by applying a film forming composition (PR) for immersion exposure on this substrate. The method for applying the film forming composition for immersion exposure (PR) is not particularly limited, and for example, it can be applied by a known method such as a spin coating method. When applying the film forming composition (PR) for immersion exposure, the amount of the film forming composition (PR) to be applied is adjusted so that the resist film to be formed has a desired thickness. To do. In addition, after apply | coating this composition on a board | substrate, in order to volatilize a solvent, you may perform a soft baking (henceforth "SB"). As heating temperature of SB, it is 30 to 200 degreeC normally, and 50 to 150 degreeC is preferable.

[Step (A2)]
In this step, the resist film formed in the step (A1) is subjected to immersion exposure by irradiation with radiation through the immersion exposure solution. As the immersion exposure liquid, a liquid having a higher refractive index than air is usually used. Specific examples include pure water, long chain or cyclic aliphatic compounds, and the like. In this state through the immersion exposure liquid, that is, in a state where the immersion exposure liquid is filled between the lens and the resist film, the exposure apparatus irradiates radiation, and the resist film is formed through a mask having a predetermined pattern. Exposure.

  The radiation is appropriately selected from visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams, etc., depending on the type of [C] acid generator used. Among these, Far ultraviolet rays represented by ArF excimer laser light (wavelength 193 nm) and KrF excimer laser light (wavelength 248 nm) are preferable, and ArF excimer laser light (wavelength 193 nm) is more preferable. In addition, exposure conditions, such as exposure amount, can be suitably selected according to the compounding composition of the resist composition for immersion exposure, the kind of additive, etc.

  It is preferable to perform heat treatment (PEB) after exposure. By this PEB, the dissociation reaction of the acid dissociable group in the resin component can be smoothly advanced. The heating condition of PEB is appropriately adjusted depending on the composition of the film forming composition for immersion exposure (PR), but is usually 30 ° C to 200 ° C, preferably 50 ° C to 170 ° C.

  Further, in order to maximize the potential of the film forming composition (PR) for immersion exposure, for example, as disclosed in Japanese Patent Publication No. 6-12452 (Japanese Patent Laid-Open No. 59-93448) and the like. An organic or inorganic antireflection film may be formed on the substrate to be used.

[Step (A3)]
In this step, the resist film subjected to the immersion exposure in the above step (A2) is developed with a developer to form a resist pattern. Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl Diethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [ 4.3.0] An alkaline aqueous solution in which at least one alkaline compound such as 5-nonene is dissolved is preferable. For example, a suitable amount of a water-soluble organic solvent such as alcohols such as methanol and ethanol, and a surfactant can be added to the developer.

<Method for Forming Resist Pattern (II)>
The method of forming a resist pattern using the film forming composition for immersion exposure (TC) is as follows:
(B1) A step of forming a resist film on a substrate using a photoresist composition (hereinafter also referred to as “step (B1)”),
(B2) a step of forming an immersion upper layer film on the resist film using the film formation composition for immersion exposure (TC) (hereinafter also referred to as “step (B2)”),
(B3) immersion exposure of the resist film and immersion upper layer film by irradiation with radiation through the immersion exposure liquid (hereinafter also referred to as “process (B3)”), and (B4) the immersion exposure. The resist film and the immersion upper layer film are developed with a developer to form a resist pattern (hereinafter also referred to as “process (B4)”). Hereinafter, each process is explained in full detail.

[Step (B1)]
In this step, a photoresist film is used to form a resist film on the substrate. Examples of the photoresist composition include a positive or negative chemically amplified resist composition containing an acid generator, a positive resist composition comprising an alkali-soluble resin and a quinonediazide-based photosensitizer, and an alkali-soluble resin. Examples thereof include a negative resist composition composed of a crosslinking agent. A commercially available photoresist composition can also be used as this photoresist composition. Although it does not specifically limit as a coating method of the said photoresist composition, The method similar to the method used at the said process (A1) is employable. In addition, after apply | coating a photoresist composition on a board | substrate, you may perform SB by the method similar to the method used at the said process (A1).

[Step (B2)]
In this step, an immersion upper film is formed on the resist film using a film forming composition (TC) for immersion exposure. In this step, it is preferable to bake after applying the film forming composition (TC) for immersion exposure. Since the immersion exposure liquid and the resist film are not in direct contact with each other by this baking, the lithography performance of the resist film due to the immersion exposure liquid penetrating into the resist film is reduced, or the resist film is changed into the immersion exposure liquid. It is possible to effectively prevent the lens of the projection exposure apparatus from being contaminated by the eluted components. The method for forming the liquid immersion upper film is the same as the method for forming the resist film except that the film forming composition for liquid immersion exposure (TC) is used in place of the photoresist composition. Can do.

[Step (B3) and Step (B4)]
In the step (B3), the resist film and the immersion upper layer film are subjected to immersion exposure by irradiation of radiation through the immersion exposure liquid. In the step (B4), the resist film and the liquid immersion upper layer film that have been subjected to the liquid immersion exposure are developed with a developing solution to form a resist pattern. For the step (B3) and the step (B4), the same method as that used in the step (A2) and the step (A3) can be employed.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. The measuring method of various physical property values is shown below.

[ ¹ H-NMR analysis and ¹³ C-NMR analysis]
¹ H-NMR analysis and ¹³ C-NMR analysis were performed using a nuclear magnetic resonance apparatus (JNM-ECX400, manufactured by JEOL Ltd.), using CDCl ₃ as a measurement solvent, and tetramethylsilane (TMS) as an internal standard. .

[Weight average molecular weight (Mw) and number average molecular weight (Mn) measurement]
Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) under the following conditions. The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.
GPC column: 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (manufactured by Tosoh)
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Column temperature: 40 ° C
Standard material: Monodisperse polystyrene Detector: Differential refractometer

<Synthesis of compounds>
[Synthesis Example 1] (Synthesis of Compound (Q ′))
Into a 3 L reactor, 62.1 g (1 mol) of ethylene glycol was added, 1,000 mL of tetrahydrofuran (THF) was added thereto, and the mixture was stirred with a mechanical stirrer. Next, 231.0 g (1.1 mol) of trifluoroacetic anhydride was added to the reactor, and the mixture was stirred at room temperature for 2 hours. Subsequently, 1,000 g of saturated aqueous sodium hydrogen carbonate solution and 2,000 mL of ethyl acetate were added, and the organic layer was separated to obtain an extract. The extract was washed 5 times with water and then dried over anhydrous sodium sulfate (desiccant). Thereafter, the desiccant was filtered off with a Buchner funnel, the organic solvent was distilled off, the residue was purified by silica gel column chromatography, and the compound (Q ′) (2-hydroxyethyl 2) represented by the following formula was obtained. , 2,2-trifluoroacetate) (49.1 g) was obtained (yield 31%).

( ¹ H-NMR analysis of compound (Q ′))
¹ H-NMR (CDCl ₃ ) δ: 3.79 (t, 2H), 4.45 (t, 2H)

[Synthesis Example 2] (Synthesis of Compound (Q-1))
After drying a 1 L three-necked reactor equipped with a dropping funnel and a condenser, 15.81 g (0.1 mol) of the synthesized compound (Q ′), 10.12 g (0.1 mol) of triethylamine and 100 mL of dichloromethane were added. Charged and cooled to 0 ° C. in an ice bath. Thereafter, 19.30 g (0.1 mol) of ethyl 2- (bromomethyl) acrylate was added dropwise over 30 minutes. After dropping, the mixture was stirred at room temperature for 3 hours. Thereafter, the precipitate was removed by filtration, and 200 mL of 1N hydrochloric acid was added to the obtained filtrate to stop the reaction. The obtained organic layer was washed successively with water and saturated brine. Thereafter, the organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. Thereafter, purification was performed by column chromatography to obtain 16.74 g of a compound (Q-1) represented by the following formula (yield 62%).

⁽¹ H-NMR analysis of the compound (Q-1))
¹ H-NMR (CDCl ₃ ) δ: 1.30 (t, 3H), 2.25-2.31 (m, 2H), 3.80-4.22 (m, 4H), 4.44 (t 2H), 5.80 (s, 1H), 6.36 (s, 1H)

[Example 1] (Synthesis of Compound (Q-2))
The same procedure as in Synthesis Example 2 was performed except that 26.12 g of 2- (bromomethyl) acrylic acid-1-ethylcyclopentyl was used instead of 19.30 g of ethyl 2- (bromomethyl) acrylate. Compound (Q-2) 15.22g was obtained (45% yield).

⁽¹ H-NMR analysis of the compound (Q-2))
¹ H-NMR (CDCl ₃ ) δ: 0.82-0.86 (m, 3H), 1.57-1.86 (m, 6H), 1.87-2.08 (m, 2H), 2 12-2.31 (m, 2H), 3.79-4.13 (m, 4H), 4.39 (t, 2H), 5.79 (s, 1H), 6.35 (s, 1H) )

[Synthesis Example 3] (Synthesis of Compound (Q-3))
The same operation as in Synthesis Example 2 was performed except that 16.81 g of methyl 2,2-difluoro-3-hydroxypentanoate was used instead of 15.81 g of compound (Q ′), and represented by the following formula: 9.56 g of compound (Q-3) was obtained (yield 34%).

⁽¹ H-NMR analysis of the compound (Q-3))
¹ H-NMR (CDCl ₃ ) δ: 0.95 (t, 3H), 1.30 (t, 3H), 1.75-1.89 (m, 2H), 3.81-3.92 (m 5H), 4.15-4.25 (m, 2H), 5.34-5.39 (m, 1H), 5.78 (s, 1H), 6.35 (s, 1H)

[Example 2] (Synthesis of Compound (Q-4))
Instead of 19.30 g of ethyl 2- (bromomethyl) acrylate, 26.12 g of 2- (bromomethyl) acrylic acid-1-ethylcyclopentyl was used instead of 15.81 g of compound (Q ′) methyl 2,2-difluoro. 10.80 g of compound (Q-4) represented by the following formula was obtained (yield 31%) except that 16.81 g of -3-hydroxypentanoate was used. .

⁽¹ H-NMR analysis of the compound (Q-4))
¹ H-NMR (CDCl ₃ ) δ: 0.80-0.87 (m, 3H), 0.94 (t, 3H), 1.59-2.11 (m, 10H), 2.10-2 .29 (m, 2H), 3.80-3.94 (m, 5H), 5.32-5.41 (m, 1H), 5.77 (s, 1H), 6.36 (s, 1H) )

[Synthesis Example 4] (Synthesis of Compound (Q-5))
After drying a 1 L three-necked reactor equipped with a dropping funnel and a condenser, 6.54 g (0.1 mol) of zinc powder, 0.5 mL (40 mmol) of trimethylsilyl chloride and 100 mL of tetrahydrofuran (THF) were added thereto. Stir at room temperature for 10 minutes. Thereafter, 24.36 g (0.12 mol) of ethyl 2-bromo-2,2-difluoroacetate dissolved in 20 mL of THF was added dropwise over 30 minutes. After stirring at room temperature for 2 hours, 19.30 g (0.1 mol) of ethyl 2- (bromomethyl) acrylate was added, and the mixture was stirred at room temperature for 3 hours. The reaction was stopped by adding 100 mL of water, and 500 mL of ethyl acetate was added. The obtained organic layer was washed with saturated brine. Thereafter, the organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. Then, it refine | purified by column chromatography and obtained 5.33 g of compounds (Q-5) represented by a following formula (yield 24%).

⁽¹ H-NMR analysis of the compound (Q-5))
¹ H-NMR (CDCl ₃ ) δ: 1.28-1.41 (m, 6H), 3.16 (t, 2H), 4.19-4.36 (m, 4H), 5.85 (s) 1H), 6.44 (s, 1H)

[Example 3] (Synthesis of Compound (Q-6))
The same procedure as in Synthesis Example 4 was performed, except that 26.12 g of 2- (bromomethyl) acrylic acid-1-ethylcyclopentyl was used instead of 19.30 g of ethyl 2- (bromomethyl) acrylate. 5.52 g of the compound (Q-6) obtained was obtained (yield 19%).

⁽¹ H-NMR analysis of the compound (Q-6))
¹ H-NMR (CDCl ₃ ) δ: 0.81-0.88 (m, 3H), 1.33-1.41 (m, 3H), 1.55-1.84 (m, 6H), 1 .85-2.04 (m, 2H), 2.10-2.30 (m, 2H), 3.15 (t, 2H), 4.20-4.24 (m, 2H), 5.82 (S, 1H), 6.42 (s, 1H)

<Synthesis of each polymer>
Compounds (monomers) other than the compounds (Q-1) to (Q-6) used in the synthesis of the polymers of the examples and comparative examples are shown below.

<Synthesis of polymer (a1-1)>
[Example 4] (Synthesis of polymer (a1-1-1))
8.65 g (80 mol%) of the above (Q-1) and 1.35 g (20 mol%) of the compound (M-2) are dissolved in 10 g of 2-butanone, and 0.41 g of AIBN is added to obtain a monomer solution. Prepared. Next, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. This polymerization solution was put into 200 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 40 g of methanol, filtered, and dried at 50 ° C. for 17 hours to obtain a white powdery polymer (a1-1-1) (6.3 g, yield). 63%). Mw of the polymer (a1-1-1) was 4,000, and Mw / Mn was 1.39. As a result of ¹³ C-NMR analysis, the content ratios of structural units derived from (Q-1) and (M-2) were 81.3 mol% and 18.7 mol%, respectively. As a result of the ¹³ C-NMR analysis, the fluorine atom content of the polymer (a1-1-1) was 18.3% by mass.

[Examples 5 to 9 and Synthesis Example 5] (Synthesis of Polymers (a1-1-2) to (a1-1-6) and (ca-1))
Except having used the compound of the kind and usage-amount shown in following Table 1, it operate | moves similarly to Example 4 and the polymer (a1-1-2)-(a1-1-6) used as (a1-1) component. ) And (ca-1) were synthesized. Table 1 shows the Mw, (Mw / Mn), and fluorine atom content of each polymer obtained. In addition, "-" in Table 1 indicates that the corresponding component was not blended.

<Synthesis of polymer (a2)>
[Synthesis Example 6] (Synthesis of polymer (a2-1))
(M-1) 43.1 g (50 mol%) and (M-6) 56.9 g (50 mol%) were dissolved in 100 g of 2-butanone, and 4.21 g of AIBN was added to prepare a monomer solution. . Then, a 1,000 mL three-necked flask containing 200 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. This polymerization solution was put into 2,000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 400 g of methanol, filtered, and dried at 50 ° C. for 17 hours to obtain a white powdery polymer (a2-1) (62.3 g, yield 62). %). Mw of the polymer (a2-1) was 5,500, and Mw / Mn was 1.41. As a result of ¹³ C-NMR analysis, the content ratios of structural units derived from (M-1) and (M-6) were 48.2 mol% and 51.8 mol%, respectively. In addition, as a result of ¹³ C-NMR analysis, the fluorine atom content of the polymer (a2-1) was 0% by mass.

[Synthesis Examples 7 and 8] (Synthesis of polymers (a2-2) and (a2-3))
Each polymer was synthesized in the same manner as in Synthesis Example 6 except that the types and amounts of compounds shown in Table 2 below were used. Table 2 shows the Mw, (Mw / Mn), and fluorine atom content of each polymer obtained.

<Synthesis of polymer (a1-2)>
[Example 10] (Synthesis of polymer (a1-2-1))
Compound (Q-1) giving structural unit (I) 0.73 g (5 mol%), compound (M-7) giving structural unit (III) 6.83 g (35 mol%), and structural unit (VI) Amount obtained by dissolving 5.44 g (60 mol%) of the compound (M-8) that gives azobenzene, and 1.00 g of the polymerization initiator 2,2′-azobis- (methyl methyl 2-methylpropionate) in 40.00 g of methyl ethyl ketone A body solution was prepared and purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the flask was heated to 80 ° C. while stirring with a magnetic stirrer, and a monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. After completion of dropping, the reaction was continued for another 3 hours. The polymerization liquid was obtained by cooling until it became 30 degrees C or less.
Subsequently, after concentrating the obtained copolymer liquid to 44 g, it moved to the separatory funnel. To this separatory funnel, 44 g of methanol and 220 g of n-hexane were added for separation and purification. After separation, the lower layer solution was recovered. The recovered lower layer solution and 220 g of n-hexane were added to carry out separation and purification. After separation, the lower layer solution was recovered. The recovered lower layer solution was replaced with 4-methyl-2-pentanol to obtain a solution containing the polymer component (a1-2-1). The solid content concentration of the solution containing the polymer component (a1-2-1) is calculated from the mass of the residue after 0.5 g of the polymer solution is placed on an aluminum dish and heated on a hot plate heated to 155 ° C. for 30 minutes. The solid content concentration value was used for the subsequent preparation of the protective film-forming composition solution and the yield calculation. Mw of the obtained polymer (a1-2-1) was 10,000, Mw / Mn was 1.51, and the yield was 75%. As a result of ¹³ C-NMR analysis, the content of each structural unit derived from the compound (Q-1), the compound (M-7), and the compound (M-8) was 4.9 mol% and 34. They were 9 mol% and 60.2 mol%.

[Example 11 and Synthesis Example 9] (Synthesis of polymers (a1-2-2) and (ca-2))
Polymers (a1-2-2) and (ca-2) were obtained in the same manner as in Example 10 except that a predetermined amount of the compounds shown in Table 3 was blended. Moreover, the content rate of each structural unit of each obtained polymer, Mw, and Mw / Mn ratio are shown according to Table 3.

<Synthesis of polymer (a3)>
[Synthesis Example 10] (Synthesis of polymer (a3-1))
40.57 g (85 mol%) of the compound (M-7) giving the structural unit (III) and 4.53 g of the polymerization initiator 2,2′-azobis- (methyl methyl 2-methylpropionate) in 40.00 g of isopropanol A dissolved monomer solution was prepared.
Meanwhile, 50 g of isopropanol was charged into a 200 mL three-necked flask equipped with a thermometer and a dropping funnel, and purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the flask was heated to 80 ° C. while stirring with a magnetic stirrer, and a monomer solution prepared in advance was added dropwise over 2 hours using a dropping funnel. After completion of the dropping, the reaction was further continued for 1 hour, and 10 g of an isopropanol solution of 3.19 g (15 mol%) of the compound (M-9) giving the structural unit (IV) was dropped over 30 minutes. Then, after reacting further for 1 hour, the polymerization liquid was obtained by cooling until it became 30 degrees C or less.
The obtained polymerization solution was concentrated to 150 g and transferred to a separatory funnel. The separatory funnel was charged with 50 g of methanol and 600 g of n-hexane to carry out separation and purification. After separation, the lower layer solution was recovered. This lower layer solution was diluted with isopropanol to 100 g, and again transferred to a separatory funnel. Thereafter, 50 g of methanol and 600 g of n-hexane were put into the above separatory funnel, separation and purification were performed, and the lower layer liquid was recovered after separation. The recovered lower layer solution was replaced with 4-methyl-2-pentanol, and the total amount was adjusted to 250 g. After the adjustment, 250 g of water was added for separation and purification. After separation, the upper layer liquid was recovered. The recovered upper layer liquid was substituted with 4-methyl-2-pentanol to obtain a solution containing the polymer (a3-1). Mw of the obtained polymer (a3-1) was 8,000, Mw / Mn was 1.51, and the yield was 80%. Moreover, the content rate of each structural unit derived from (M-7) and (M-9) was 98 mol% and 2 mol%, respectively.

<Preparation of film forming composition (PR) for immersion exposure>
The [B] solvent, [C] acid generator and [D] acid diffusion controller used for the preparation of the film forming composition for immersion exposure (PR) are shown below.

[[B] solvent]
B-1: Propylene glycol monomethyl ether acetate B-2: Cyclohexanone

[C] Acid generator Triphenylsulfonium nonafluorobutanesulfonate represented by the following formula (C-1)

[D] Acid diffusion controller Nt-amyloxycarbonyl-4-hydroxypiperidine represented by the following formula (D-1)

[Example 12]
[A] (a1-1-1) 5 parts by mass as polymer component and (a2-1) 100 parts by mass, [B] (B-1) 2,590 parts by mass as solvent (B-2) 1,110 parts by mass, (C-1) 9.9 parts by mass as [C] acid generator, and (D-1) 7.9 parts by mass as [D] acid diffusion controller were mixed to obtain The obtained mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a film forming composition (PR) for immersion exposure.

[Examples 13 to 19 and Comparative Examples 1 and 2]
Except having used each component of the kind and compounding quantity shown in following Table 4, it operated similarly to Example 12 and prepared each film | membrane formation composition for immersion exposure.

<Preparation of film forming composition (TC) for immersion exposure>
The [B] solvent used for the preparation of the film forming composition for immersion exposure (TC) is shown below.
[[B] solvent]
(B-3): 4-methyl-2-pentanol (B-4): diisoamyl ether

[Example 20]
20 parts by mass of the polymer (a1-2-1) as the polymer (a1-2), 80 parts by mass of the polymer (a3-1) as the polymer (a3), and (B- 3) 1,000 parts by mass and (B-4) 4,000 parts by mass were mixed, stirred for 2 hours, and then filtered through a filter having a pore diameter of 0.2 μm to form a film for immersion exposure in Example 20. A composition (TC) was obtained.

[Example 21 and Comparative Example 3]
Except having mixed each component of the kind and compounding quantity shown in Table 5, it carried out similarly to Example 20, and obtained each film formation composition (TC) for immersion exposure.

<Preparation of photoresist composition (α) used for evaluation of film forming composition (TC) for each immersion exposure>
A photoresist composition (α) used for evaluating each film forming composition for immersion exposure (TC) was prepared by the following method.

<Synthesis of polymer for photoresist composition>
[Synthesis Example 11]
Compound (M-6) 53.93 g (50 mol%), compound (M-3) 35.38 g (40 mol%), compound (M-10) 10.69 g (10 mol%) into 2-butanone 200 g Dissolve and prepare a monomer solution containing 5.58 g of dimethyl 2,2′-azobis (2-methylpropionate), and purge a 500 mL three-necked flask containing 100 g of 2-butanone with a nitrogen purge for 30 minutes. did. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 2,000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice by slurry with 400 g of methanol, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (P-1). (74 g, 74% yield). This polymer (P-1) had Mw of 6,900 and Mw / Mn = 1.70. In addition, as a result of ¹³ C-NMR analysis, this polymer (P-1) has a content ratio of each structural unit derived from the compound (M-6), the compound (M-3) and the compound (M-10). The copolymer was 53.0: 37.2: 9.8 (molar ratio). In addition, content of the low molecular weight component derived from each monomer in this polymer was 0.03 mass% with respect to 100 mass% of this polymer.

<Preparation of photoresist composition (α)>
100 parts by weight of polymer (P-1), 1.5 parts by weight of triphenylsulfonium nonafluoro-n-butanesulfonate as acid generator and 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 6 parts by mass of nonafluoro-n-butanesulfonate and 0.65 parts by mass of R-(+)-(tert-butoxycarbonyl) -2-piperidinemethanol as an acid diffusion controller were mixed, and this mixture was used as a solvent. By adding 2,900 parts by mass of propylene glycol monomethyl ether acetate, 1,250 parts by mass of cyclohexanone and 100 parts by mass of γ-butyrolactone, adjusting the total solid content concentration to 5% by mass, and filtering through a filter with a pore size of 30 nm A photoresist composition (α) was prepared.

<Evaluation of film forming composition (PR) for immersion exposure>
About each prepared film forming composition for immersion exposure (PR), the resist film and the resist pattern were formed as follows, and the following evaluation was performed. The results are also shown in Table 4.

[Backward contact angle]
The receding contact angle (°) was measured using a receding contact angle measuring device (DSA-10, manufactured by KRUSS) under the conditions of a temperature of 23 ° C., a relative humidity of 45%, and 1 atm. In this measurement, first, the needle was washed with acetone and isopropyl alcohol, then water was injected into the needle, and a silicon wafer as a measurement target was set on the wafer stage of the receding contact angle measuring device. Thereafter, the height of the stage is adjusted so that the distance between the resist film surface and the tip of the needle is 1 mm or less, and water is discharged from the needle to form a 20 μL water droplet on the wafer. While suctioning at a rate of 10 μL / min for 180 seconds, the contact angle was measured every second. A total of 20 contact angles were measured from the time when the contact angle was stabilized, and the average value was defined as the receding contact angle (°).
Table 4 shows the receding contact angle of a resist film having a thickness of 110 nm formed by spin-coating each immersion exposure film-forming composition (PR) on an 8-inch silicon wafer and performing SB at 110 ° C. for 60 seconds. “After SB”. When the receding contact angle after SB is 75 ° or more, the water repellency can be evaluated as good, and when it is less than 75 °, it can be evaluated as defective.
Each immersion exposure film-forming composition (PR) was spin-coated on an 8-inch silicon wafer, and SB was performed at 110 ° C. for 60 seconds to form a resist film having a thickness of 110 nm. Then, using a developing device (Clean Track ACT8, manufactured by Tokyo Electron), developed with a 2.38 mass% TMAH aqueous solution for 30 seconds, rinsed with pure water for 15 seconds, shaken and dried at 2,000 rpm, and then the resist pattern receded. The contact angle was defined as “after development” in Table 4. The receding contact angle after development can be evaluated as good when it is less than 10 °, and as poor when it is 10 ° or more.

[Development defect suppression]
A lower antireflection film is formed on a 12-inch silicon wafer using an antireflection film forming composition (ARC66, manufactured by Nissan Chemical Industries), and each immersion exposure film forming composition (PR ) And spin-coated at 110 ° C. for 60 seconds to form a resist film having a thickness of 110 nm. Next, using a ArF excimer laser immersion exposure apparatus (NSR S610C, manufactured by NIKON), the resist film was exposed through the mask pattern under the conditions of NA = 1.3, ratio = 0.812, and Crosssole. After the exposure, PEB was performed at 120 ° C. for 60 seconds. Thereafter, development was performed with a 2.38 mass% TMAH aqueous solution for 30 seconds, rinsed with pure water for 15 seconds, and shaken and dried at 2,000 rpm to form a positive resist pattern. At this time, the exposure amount for forming a line and space pattern (1L / 1S) having a line width of 55 nm was determined as the optimum exposure amount. A line-and-space pattern (1L / 1S) having a line width of 55 nm was formed on the entire surface of the wafer with this optimum exposure amount, and a wafer for development defect inspection was obtained. Note that a scanning electron microscope (S-9380, manufactured by Hitachi High-Technologies) was used for length measurement. Thereafter, the development defects on the development defect inspection wafer were measured using a development defect inspection apparatus (KLA2810, manufactured by KLA-Tencor). After classifying the measured development defects into those derived from resist and foreign matter derived from the outside, the total number of those determined to be derived from resist is totaled. When this value is 50 / wafer or less, the development defect suppression is good. In the case of more than 50 / wafer, it can be evaluated as defective.

  As is clear from the results in Table 4, in Example, the receding contact angle was good both after SB and after development, whereas in Comparative Example, at least one after SB and after development was poor. In addition, the development defect suppression property was good in the examples, whereas all of the comparative examples were bad.

<Evaluation of film forming composition (TC) for immersion exposure>
Each of the film-forming compositions (TC) for immersion exposure obtained in the above Examples and Comparative Examples was stirred for 30 minutes, and then the following various types were observed with no turbidity observed visually. Evaluation was performed. The evaluation results are shown in Table 5. In addition, Blob defects and bridge defects were evaluated as confirmation of suppression of development defects.

[Solubility]
Each film forming composition (TC) for immersion exposure is spin-coated on an 8-inch silicon wafer with CLEAN TRACK ACT8 (manufactured by Tokyo Electron), SB is performed at 90 ° C. for 60 seconds, and an immersion upper layer having a film thickness of 90 nm A film was formed. The film thickness was measured using Lambda Ace VM90 (Dainippon Screen). The liquid immersion upper layer film was subjected to paddle development for 60 seconds using a 2.38 mass% TMAH aqueous solution, spin-dried by shaking, and the wafer surface was observed. At this time, if there was no residue and development was performed, the solubility in the developer was “A (good)”, and if the residue was observed, it was evaluated as “B [poor]”.

[Backward contact angle]
Each immersion exposure film-forming composition (TC) was spin-coated on an 8-inch silicon wafer, and subjected to SB at 90 ° C. for 60 seconds on a hot plate to form an immersion upper film having a thickness of 30 nm. Then, using DSA-10 (manufactured by KRUS), the receding contact angle (°) was measured immediately under an environment of 23 ° C., humidity 45%, and normal pressure. That is, the wafer stage position of DSA-10 was adjusted, and the wafer was set on the adjusted stage. Next, water was injected into the needle, and the position of the needle was finely adjusted to an initial position where water droplets could be formed on the set wafer. Thereafter, water was discharged from the needle to form a 25 μL water droplet on the wafer. The needle was once withdrawn from the water droplet, and again pulled down to the initial position and placed in the water droplet. Subsequently, a water droplet was sucked with a needle at a speed of 10 μL / min for 90 seconds, and at the same time, the contact angle was measured once every second, for a total of 90 times. Of these, the average value for the contact angle for 20 seconds from the time when the measured value of the contact angle was stabilized was calculated as the receding contact angle (°). The closer the receding contact angle is to 90 °, the higher the water repellency of the liquid immersion upper layer film. When the receding contact angle is 75 ° or more, the water repellency can be evaluated as good, and when it is less than 75 °, it can be evaluated as defective.

[Elution amount]
Silicon rubber with a central portion cut into a circular shape with a diameter of 11.3 cm at the center on an 8-inch silicon wafer that was subjected to HMDS (hexamethyldisilazane) treatment at 100 ° C. for 60 seconds using CLEAN TRACK ACT8 A sheet (made of Kureha elastomer, thickness: 1.0 mm, shape: square with a side of 30 cm) was placed. Next, 10 mL of ultrapure water was filled in the hollowed out portion at the center of the silicon rubber using a 10 mL hole pipette.
On the other hand, a composition for a lower antireflection film (ARC29A, manufactured by Brewer Science) was applied in advance so as to form a lower antireflection film having a film thickness of 77 nm using CLEAN TRACK ACT8. Next, the prepared photoresist composition (α) was spin-coated on the lower antireflection film, and SB was performed at 115 ° C. for 60 seconds to form a resist film having a thickness of 205 nm. Then, each film | membrane formation composition (TC) for immersion exposure was apply | coated on the resist film, and the immersion upper layer film | membrane was formed. The liquid immersion upper layer side was stacked so as to come into contact with the ultrapure water in the silicon rubber sheet of the prepared wafer, and kept in that state for 10 seconds. Thereafter, ultrapure water was collected with a glass syringe and used as a sample for analysis. The recovery rate of ultrapure water after the evaluation was 95% or more.
The peak intensity of the anion part of the acid generator in ultrapure water was measured using LC-MS (liquid chromatograph mass spectrometer, LC part: SERIES1100 manufactured by AGILENT, MS part: Mariner manufactured by Perseptive Biosystems, Inc.) as follows. Measured under measurement conditions. At that time, the peak intensity of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the acid generator was measured under the following measurement conditions to prepare a calibration curve, and the elution amount was calculated from the peak intensity using the calibration curve. Similarly, each peak intensity of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the acid diffusion control agent is measured under the following measurement conditions to create a calibration curve, and the calibration curve is used to calculate the acid diffusion control agent from the peak intensity. The amount of elution was calculated. When both of the elution amounts were 5.0 × 10 ⁻¹² mol / cm ² or less, the elution suppression performance of the photoresist composition was “A (good)”, at least one of which was 5.0 × 10 ^{− When} it was larger than ¹² mol / cm ² , it was evaluated as defective “B (defective)”.

(Measurement condition)
Column used: “CAPCELL PAK MG”, manufactured by Shiseido, 1 flow rate: 0.2 mL / min Eluent: water / methanol (3/7) with 0.1% by weight of formic acid Measurement temperature: 35 ° C.

[Blob defect]
An 8-inch silicon wafer subjected to HMDS (hexamethyldisilazane) treatment at 100 ° C. for 60 seconds was prepared using CLEAN TRACK ACT12. The photoresist composition (α) prepared above was applied onto this 8-inch silicon wafer, and SB was performed on a hot plate at 90 ° C. for 60 seconds to form a resist film having a thickness of 120 nm. On this resist film, each film-forming composition (TC) for immersion exposure was spin-coated, and SB was performed at 90 ° C. for 60 seconds to form an immersion upper film having a thickness of 30 nm. Then, it exposed through the frosted glass in which the pattern is not formed. Ultrapure water was discharged from a rinse nozzle of CLEAN TRACK ACT8 on the immersion upper layer film for 60 seconds, and spin drying was performed by shaking off at 4,000 rpm for 15 seconds. Next, paddle development was performed with an LD nozzle for 30 seconds to remove the liquid immersion upper layer film. In this paddle development, a 2.38 mass% TMAH aqueous solution was used as a developer. After development, the number of locations where the undissolved portion of the liquid immersion upper layer film was observed was measured with KLA2351 (manufactured by KLA Tencor) to determine the Blob defect. The case where the number of detected blob defects was 200 or less was evaluated as “A (good)”, and the case where the number exceeded 200 was evaluated as “B (defective)”.

[Bridge defect]
A 12-inch silicon wafer surface was spin-coated with a lower antireflection film (ARC66, manufactured by Nissan Chemical Co., Ltd.) using a coating apparatus (Lithius Pro-i, manufactured by Tokyo Electron), and then SB (205 ° C., 60 seconds). As a result, a lower antireflection film having a film thickness of 105 nm was formed. Next, the photoresist composition (α) prepared above is spin-coated using CLEAN TRACK ACT12, SB is performed at 100 ° C. for 60 seconds, and cooled at 23 ° C. for 30 seconds to form a resist film having a thickness of 100 nm. did. Then, each film | membrane formation composition (TC) for immersion exposure was apply | coated on the resist film, and the immersion upper layer film | membrane was formed.
Next, using an ArF immersion exposure apparatus (S610C, manufactured by NIKON), exposure was performed through a mask for projecting a pattern of 45 nm line / 90 nm pitch under the optical conditions of NA: 1.30 and Crosspore ( Hereinafter, the dimension of the pattern projected by the mask is referred to as the “pattern dimension.” For example, a mask having a pattern dimension of 40 nm line / 84 nm pitch is a mask for projecting a pattern of 40 nm line / 84 nm pitch. ). PEB is performed on the hot plate of the coating apparatus at 100 ° C. for 60 seconds, cooled at 23 ° C. for 30 seconds, and then paddle developed with a 2.38 mass% TMAH aqueous solution as a developer at the GP nozzle of the developing cup. For 10 seconds and rinsed with ultrapure water. An evaluation substrate on which a resist pattern was formed was obtained by spin-drying at 2,000 rpm for 15 seconds. At this time, the exposure amount at which a resist pattern having a 45 nm line / 90 nm pitch was formed in a mask having a pattern dimension of 45 nm line / 90 nm pitch was determined as the optimum exposure amount. When a resist pattern having a 45 nm / 90 nm pitch was formed, the case where no bridge defect was found was evaluated as “A (good)”, and the case where it was seen was evaluated as “B (bad)”.

[Peeling resistance]
As the substrate, an 8-inch silicon wafer not subjected to HMDS treatment was used. On the substrate, each film forming composition (TC) for immersion exposure is spin-coated with the CLEAN TRACK ACT8, and then SB is performed at 90 ° C. for 60 seconds to form an immersion upper layer film having a thickness of 30 nm. Formed. Thereafter, rinsing with pure water was performed for 60 seconds in CLEAN TRACK ACT8, and drying by shaking was performed. “C (defect)” when peeling is observed at the center after rinsing by visual inspection, “B (somewhat good)” when peeling is observed only at the edge, and “A” when no peeling is observed. (Good) ”.

[Pattern shape]
This evaluation was performed to evaluate whether or not a high-resolution resist pattern was formed. First, on the 12-inch silicon wafer, using the above-mentioned coating apparatus, the lower antireflection film composition (ARC66, manufactured by Nissan Chemical Industries) is spin-coated, and SB (205 ° C., 60 seconds) is performed to obtain a film thickness. A 105 nm lower antireflection film was formed. On the formed lower antireflection film, the prepared photoresist composition (α) was spin-coated, and SB (100 ° C., 60 seconds) was performed to form a resist film having a thickness of 100 nm.
On the formed resist film, each immersion exposure film-forming composition (TC) was spin-coated, and SB (90 ° C., 60 seconds) was performed to form an immersion upper layer film having a thickness of 30 nm. Using an ArF immersion exposure apparatus (S610C, manufactured by NIKON), exposure was performed through a mask for projecting a pattern of 45 nm line / 90 nm pitch. PEB is performed on the hot plate of the coating apparatus at 100 ° C. for 60 seconds, cooled at 23 ° C. for 30 seconds, and then paddle developed with a 2.38 mass% TMAH aqueous solution as a developer at the GP nozzle of the developing cup. For 10 seconds and rinsed with ultrapure water. An evaluation substrate on which a resist pattern was formed was obtained by spin-drying at 2,000 rpm for 15 seconds.
With respect to the formed resist pattern, the exposure amount for forming a line-and-space pattern (1L1S) having a line width of 90 nm in a one-to-one line width was determined as the optimum exposure amount. Note that a scanning electron microscope (CG-4000, manufactured by Hitachi Instruments) was used for the measurement. In addition, the cross-sectional shape of the line-and-space pattern with a line width of 90 nm was observed with a scanning electron microscope (S-4800, manufactured by Hitachi Keiki Co., Ltd.). The line width Lb in the middle of the resist pattern film formed on the substrate and the line width La in the upper part of the film were measured, and when 0.9 ≦ La / Lb ≦ 1.1, the case of “A ( “Good” ”and La / Lb <0.9 or La / Lb> 1.1 were evaluated as“ B (defect) ”.

  As is clear from the results in Table 5, all the evaluation items were good in the examples, whereas in the comparative example, some of the evaluation items were defective.

  The present invention can be used as a photoresist composition or the like to provide a large receding contact angle on the surface of the resist film or the liquid immersion upper layer film at the time of liquid immersion exposure in the liquid immersion exposure process, and to suppress development defects. When used as a composition for forming a liquid immersion upper layer film, a resist pattern having a better shape can be formed. Therefore, the film-forming composition, polymer and compound for immersion exposure can be suitably used for a manufacturing process in a semiconductor device that is further miniaturized, and the product quality and productivity in the immersion exposure process can be improved. Can be improved.

Claims (7)

The composition for liquid immersion upper film | membrane formation containing the polymer component containing the polymer (a1) which has a structural unit represented by following formula (1), and a solvent.

(In the formula (1), ^{R 1} is an alkali dissociable group .A is, -CO-O - *, - O -, - NR A - , or .R ^A is _-SO 2 -O- * is , A hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, * represents a bonding site with R ¹ , X is a divalent hydrocarbon group having 1 to 20 carbon atoms or 1 carbon atom; A divalent fluorinated hydrocarbon group having ˜20, R ² is an (n + 1) valent hydrocarbon group having 1 to 20 carbon atoms, an (n + 1) valent fluorinated hydrocarbon group having 1 to 20 carbon atoms, Or at least selected from the group consisting of these groups and —CO—, —COO—, —OCO—, —O—, —NR ^B —, —CS—, —S—, —SO— and —SO ₂ —. is a group which combines with one group. However, when n is 1, R ² is a single bond which may be a .R ^B is a hydrogen atom or a carbon number from 1 to 10 The monovalent hydrocarbon is a group .R ^3, and a monovalent hydrocarbon group, a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms, or their group having 1 to 20 carbon atoms -CO-, A group in which at least one group selected from the group consisting of —COO—, —OCO—, —O—, —NR ^C —, —CS—, —S—, —SO— and —SO ₂ — is combined. R ^C is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, n is an integer of 1 to 3. When n is 2 or more, a plurality of R ¹ , A and X may be the same or different. 2. The composition for forming a liquid immersion upper layer film according to claim 1, wherein R ¹ in the formula (1) is a fluorinated alkyl group having 1 to 20 carbon atoms or a fluorinated alkylcarbonyl group having 1 to 20 carbon atoms.   The composition for forming a liquid immersion upper layer film according to claim 1, wherein X in the formula (1) is a divalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. The composition for forming a liquid immersion upper layer film according to claim 1, wherein R ³ in the formula (1) has acid dissociation properties.   The polymer component is at least one selected from the group consisting of a structural unit containing a fluorinated sulfonamide group and a structural unit containing an α-trifluoromethyl alcohol group in the same or different polymer as the polymer (a1). The composition for forming a liquid immersion upper film according to claim 1, further comprising a seed structural unit.   The composition for forming a liquid immersion upper layer film according to claim 1, wherein the polymer component further has a structural unit containing a sulfo group in the same or different polymer as the polymer (a1). The polymer component is at least 1 selected from the group consisting of a structural unit containing a carboxy group and a structural unit containing a group represented by the following formula (2) in the same or different polymer as the polymer (a1). The composition for forming a liquid immersion upper film according to claim 1, further comprising a seed structural unit.

(In Formula (2), R ⁴ is a hydrogen atom, a halogen atom, a nitro group, an alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or 1 to 20 carbon atoms. An alkoxy group, an acyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, the above-described alkyl group, alicyclic hydrocarbon group, alkoxy group, acyl group, Some or all of the hydrogen atoms of the aralkyl group and aryl group may be substituted, and R ⁵ represents —C (═O) —R ⁶ , —S (═O) ₂ —R ⁷ , —R. ⁸ -CN, or -R ⁹ -NO _{2. The} above R ⁶ and R ⁷ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a fluorinated alkyl group having 1 to 20 carbon atoms, C3-C20 monovalent alicyclic hydrocarbon group, C1-C20 alkoxy group Cyano group, a cyanomethyl group, an aralkyl group or an aryl group having 6 to 20 carbon atoms having 7 to 20 carbon atoms. However, the R ⁶ or R ^7, to form a ring structure and R ⁴ together R ⁸ and R ⁹ are each independently a single bond, a methylene group or an alkylene group having 2 to 5 carbon atoms.)