JP5737114B2 - Compound, polymer and photoresist composition - Google Patents

Description

  The present invention relates to compounds, polymers and photoresist compositions.

  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 the resist film is formed through a mask pattern. A fine resist pattern is formed by exposing to short wavelength radiation such as excimer laser and removing the exposed portion with an alkaline developer.

  In recent years, the use of the immersion exposure method is expanding as a method for forming a finer resist pattern having a line width of about 45 nm. The immersion exposure method has an advantage that the depth of focus is hardly lowered even when the numerical aperture (NA) of the lens is increased, and high resolution can be obtained. In the photoresist composition used in the immersion exposure method, it is possible to prevent degradation of the coating film performance and contamination of the lens by suppressing the elution of the acid generator from the resist film to the immersion medium. It is required to prevent the watermark from remaining by improving the water drainage and to enable high-speed scanning exposure.

  As means for achieving these, for example, Japanese Patent Application Laid-Open No. 2005-352384 proposes a technique for forming an upper layer film (protective film) on a resist film, but requires a separate film formation step, which is complicated. . Therefore, methods for increasing the hydrophobicity of the resist film surface have been studied. For example, International Publication No. 2007/116664 proposes a photoresist composition containing a fluorine-containing polymer having high hydrophobicity.

  However, if the hydrophobicity of the resist film is increased, the surface wettability of the developing solution and the rinsing solution decreases, so that the development residue deposited on the unexposed portion of the resist surface during development becomes insufficient, and blob (Blob) etc. Development defects may occur. For the purpose of suppressing such development defects, Japanese Patent Application Laid-Open No. 2010-032994 proposes a fluorine atom-containing polymer that is hydrophobic during immersion exposure but decreases in alkali development. However, even in a resist film using the fluorine atom-containing polymer, the above-described change in hydrophobicity is not sufficient in an actual immersion exposure process.

  In these documents, the change in hydrophobicity of the resist film is confirmed using the static contact angle with water as an index. However, it is considered that the static contact angle is not sufficient as an index regarding the above-mentioned water drainage performance in the actual immersion exposure process.

JP 2005-352384 A International Publication No. 2007/116664 JP 2010-032994 A

  The present invention has been made based on the circumstances as described above, and the purpose of the present invention is to provide an excellent exposure to water on the resist film surface during exposure in an immersion exposure process, and after alkali development. Is to provide a novel compound capable of suppressing the occurrence of development defects with greatly reduced water drainage, a polymer having a structural unit derived from the compound, and a photoresist composition containing the polymer.

（式（１）中、Ｒ^１は、水素原子又はメチル基である。Ｒ^２及びＲ^３は、それぞれ独立して、水素原子、フッ素原子、ヒドロキシ基又は炭素数１〜６のアルキル基である。但し、Ｒ^２及びＲ^３が共にヒドロキシ基である場合はない。Ｒ^４及びＲ^５は、それぞれ独立して、水素原子又は炭素数１〜２０の１価の有機基である。但し、Ｒ^４とＲ^５とが互いに結合して、これらが結合している炭素原子と共に炭素数３〜２０の環構造を形成してもよい。この環構造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。但し、Ｒ^４及びＲ^５のうち少なくとも１つの基は、フッ素原子を有する。ｎは１〜４の整数である。ｎが２以上の場合、複数のＲ^２及びＲ^３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
A compound represented by the following formula (1) (hereinafter also referred to as “compound (1)”).

(In Formula (1), R ¹ is a hydrogen atom or a methyl group. R ² and R ³ are each independently a hydrogen atom, a fluorine atom, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms. However, R ² and R ³ are not both hydroxy groups, and R ⁴ and R ⁵ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. ⁴ and R ⁵ may be bonded to each other to form a ring structure having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and some or all of the hydrogen atoms of the ring structure may be substituted. Provided that at least one group of R ⁴ and R ⁵ has a fluorine atom, n is an integer of 1 to 4. When n is 2 or more, a plurality of R ² and R ³ May be the same or different.)

  Since the compound of the present invention has a structure represented by the above formula (1), a photoresist composition containing a polymer incorporating the compound is an upper layer for the purpose of blocking the resist film from the immersion medium. The resist film surface exhibits great water drainage without separately forming a film or the like. In addition, according to this photoresist composition, the drainability of the resist film is greatly reduced after alkali development. As a result, the wettability of the resist film surface with respect to the developing solution and the rinsing liquid is greatly improved, and thus the occurrence of development defects in the resist film due to the low cleaning efficiency with the rinsing liquid can be suppressed. The reason why the drainage of the resist film is greatly reduced during development is not clear, but it is conceivable that, for example, the lactone ring of the above formula (1) is cleaved by the developer.

In the case where at least one of R ⁴ and R ⁵ in the above formula (1) is a monovalent organic group, and R ⁴ and R ⁵ are not bonded to each other to form a ring structure, this monovalent The organic group preferably has a fluorine atom. Thereby, it is considered that the polymer incorporating the compound can be unevenly distributed on the surface layer side in the resist film. Accordingly, it is possible to further increase the water drainage after alkali development, and as a result, it is possible to further suppress development defects.

At least one of R ⁴ and R ⁵ in the above formula (1) is —R ^C —R ^f , —R ^C —OR ^f or —R ^C —OCOR ^f , R ^C is a single bond or a divalent linking group, R ^f is preferably a fluorinated alkyl group or a hydroxyfluorinated alkyl group. As described above, when at least one of R ⁴ and R ⁵ is the specific group, the resist film obtained from the compound can effectively reduce water drainage after development, resulting in development defects. Can be further suppressed.

（式（１−１）中、Ｒ^１、Ｒ^２、Ｒ^３及びｎは、上記式（１）と同義である。Ｒ^Ａは、ラクトン環を構成している炭素原子と共に炭素数３〜２０の環構造を形成する（ｍ＋２）価の有機基である。Ｒ^Ｂは、フッ素原子、ヒドロキシ基又は炭素数１〜２０の有機基である。ｍは１〜６の整数である。ｍが２以上の場合、複数のＲ^Ｂは、同一でも異なっていてもよく、互いに結合して環構造を形成してもよい。この環構造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。但し、Ｒ^Ｂのうち少なくとも１つは、フッ素原子を有する。） The compound is preferably represented by the following formula (1-1).

(In the formula (1-1), R ¹ , R ² , R ³ and n have the same meanings as in the above formula (1). R ^A together with the carbon atom constituting the lactone ring has 3 to 20 carbon atoms. of a ring structure to form an (m + 2) -valent organic group .R ^B is a fluorine atom, an organic group having a hydroxy group or a C 1 to 20 .m is an integer from 1 to 6 .m 2 If above, the plurality of R ^B, may be the same or different, they may be bonded together to form a ring structure. some or all of the hydrogen atoms and the ring structure has also be substituted However, at least one of R ^B has a fluorine atom.)

  When the compound is represented by the above formula (1-1), the rigidity of the polymer incorporating the compound is increased, and the reduction in water drainage during development of the resulting resist film can be further increased. As a result, development defects can be further suppressed.

The ^{R B} is ^{-R C -R f, -R C -OR} f or ^{-R C} -OCOR ^{f, R} C is a single bond or a divalent linking group and ^{R f} is a fluorinated alkyl group or a hydroxyalkyl fluorinated alkyl, It is preferably a group. By this way it R ^B is the specific group, the resist film obtained from the compounds effectively can reduce the drainage after the development, as a result, can be further suppressed generation of development defects.

  The polymer of the present invention is a polymer having a structural unit (I) derived from the compound (hereinafter also referred to as “polymer (I)”). According to the photoresist composition containing the polymer (I), the resist film exhibits excellent water drainage without separately forming an upper layer film for the purpose of blocking the resist film and the immersion medium. After development, the water drainage of the resist film is greatly reduced. As a result, the wettability of the resist film surface with respect to the developing solution and the rinsing liquid is greatly improved, and thus the occurrence of development defects in the resist film due to the low cleaning efficiency with the rinsing liquid can be suppressed.

（式（３）中、Ｒ^１１は、水素原子、フッ素原子、メチル基又はトリフルオロメチル基である。Ｒ^１２〜Ｒ^１４は、それぞれ独立して、炭素数１〜６のアルキル基又は炭素数４〜２０の脂環式炭化水素基である。但し、Ｒ^８及びＲ^９は、互いに結合して、これらが結合している炭素原子と共に２価の脂環式炭化水素基を形成してもよい。） The polymer preferably further has a structural unit (III) represented by the following formula (3). When the polymer further has the structural unit (III), according to the photoresist composition containing the polymer, the dissolution rate with respect to the developer can be controlled, and a better resist pattern can be formed.

(In Formula (3), R ¹¹ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^{12 to} R ¹⁴ are each independently an alkyl group having 1 to 6 carbon atoms or a carbon number. 4 to 20 alicyclic hydrocarbon groups, provided that R ⁸ and R ⁹ are bonded to each other to form a divalent alicyclic hydrocarbon group together with the carbon atom to which they are bonded. Good.)

The photoresist composition of the present invention comprises:
[A] a polymer having an acid dissociable group (hereinafter, also referred to as “[A] polymer”),
[B] the polymer (hereinafter also referred to as “[B] polymer”),
[C] an acid generator, and [D] a solvent.

  Since the photoresist composition of the present invention contains the polymer, the resist film formed in the immersion exposure process exhibits excellent water drainage at the time of exposure, and the water drainage is greatly reduced after alkali development. As a result, the occurrence of development defects in the resist film is suppressed, and a good resist pattern can be formed.

  According to the compound, polymer and photoresist composition of the present invention, the resist film formed in the immersion exposure process has a reasonably large water drainage property at the time of exposure, while the water drainage property is greatly reduced after alkali development. As a result, development defects are suppressed and a good resist pattern can be formed.

<Compound (1)>
The said compound is a compound represented by the said Formula (1). Since the compound (1) has the above specific structure, a photoresist composition containing a polymer incorporating the compound exhibits a large dynamic contact angle during exposure in an immersion exposure process. Exhibits excellent water drainage, and during development, the water drainage is greatly reduced, so that development defects can be suppressed.

In said formula (1), R < ¹ > is a hydrogen atom or a methyl group. R ² and R ³ are each independently a hydrogen atom, a fluorine atom, a hydroxy group or an alkyl group having 1 to 6 carbon atoms. However, there is no case where R ² and R ³ are both hydroxy groups. R ⁴ and R ⁵ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. However, R ⁴ and R ⁵ may be bonded to each other to form a ring structure having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. Some or all of the hydrogen atoms of the ring structure may be substituted. However, at least one group of R ⁴ and R ⁵ has a fluorine atom. n is an integer of 1-4. When n is 2 or more, the plurality of R ² and R ³ may be the same or different.

The alkyl group having 1 to 6 carbon atoms represented by R ² and R ^3, for example a methyl group, an ethyl group, and a n- propyl group.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ⁴ and R ⁵ include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, —CO—, —COO—, —OCO—, It is composed of at least one group selected from the group consisting of —O—, —NR—, —CS—, —S—, —SO— and —SO ₂ — and a hydrocarbon group having 1 to 20 carbon atoms. A monovalent organic group etc. are mentioned, and what has these further has a substituent. Examples of the substituent include a hydroxy group, a carboxy group, and a cyano group. However, said R is a hydrogen atom or a C1-C10 monovalent organic group.

  Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a linear or branched chain hydrocarbon group, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and an aromatic group having 6 to 20 carbon atoms. A hydrocarbon group etc. are mentioned.

  Examples of the linear or branched chain hydrocarbon group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a dodecyl group. It is done.

  Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, and a cyclododecyl group.

  As said C6-C20 aromatic hydrocarbon group, a phenyl group, a tolyl group, a naphthyl group etc. are mentioned, for example.

Examples of the ring structure having 3 to 20 carbon atoms that may be formed by combining R ⁴ and R ⁵ with each other include, for example, cyclopropane structure, cyclobutane structure, cyclopentane structure, cyclohexane structure, cycloheptane structure, cyclooctane structure Monocyclic saturated hydrocarbon structures such as cyclodecane structure, methylcyclohexane structure, and ethylcyclohexane structure;
Monocyclic unsaturated hydrocarbon structures such as cyclobutene structure, cyclopentene structure, cyclohexene structure, cycloheptene structure, cyclooctene structure, cyclodecene structure, cyclopentadiene structure, cyclohexadiene structure, cyclooctadiene structure, cyclodecadiene structure;
Bicyclo [2.2.1] heptane structure, bicyclo [2.2.2] octane structure, tricyclo [5.2.1.0 ^2,6 ] decane structure, tricyclo [3.3.1.1 ^3,7 ] Decane structure, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] polycyclic saturated hydrocarbon structures such as dodecane structure and adamantane structure;
Bicyclo [2.2.1] heptene structure, bicyclo [2.2.2] octene structure, tricyclo [5.2.1.0 ^2,6 ] decene structure, tricyclo [3.3.1.1 ^3,7 ] Decene structure, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecene structure and the like, and polycyclic unsaturated hydrocarbon structures and the like, and -CO-, -COO-, -OCO-, -O-, -NR-, -CS- , —S—, —SO—, and —SO ₂ —, which contain at least one group selected from the group consisting of, and the like. The ring structure having 3 to 20 carbon atoms which R ⁴ and R ⁵ may be bonded to each other may contain a substituent. Examples of the substituent include a hydroxy group, a carboxy group, and a cyano group. R is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms.

  Examples of the ring structure composed of the -CO- and the hydrocarbon group having 1 to 20 carbon atoms include a cyclic ketone structure having 3 to 8 carbon atoms.

  Examples of the ring structure composed of the -COO- and the hydrocarbon group having 1 to 20 carbon atoms include a lactone structure having 3 to 8 carbon atoms.

  Examples of the ring structure composed of the above -O- and a hydrocarbon group having 1 to 20 carbon atoms include a cyclic ether structure having 3 to 8 carbon atoms.

  Examples of the ring structure composed of -NR- and a hydrocarbon group having 1 to 20 carbon atoms include a cyclic amine structure having 3 to 8 carbon atoms. Examples of the organic group having 1 to 10 carbon atoms represented by R include a chain hydrocarbon group having 1 to 10 carbon atoms, an aliphatic cyclic hydrocarbon group, an aromatic hydrocarbon group, an epoxy group, a cyano group, and a carboxy group. Etc.

  Examples of the ring structure composed of -S- and a hydrocarbon group having 1 to 20 carbon atoms include a cyclic thioether structure having 3 to 8 carbon atoms.

  Examples of the ring structure composed of the -SO- and the hydrocarbon group having 1 to 20 carbon atoms include a cyclic sulfoxide structure having 8 to 8 carbon atoms.

Examples of the ring structure composed of the —SO ₂ — and the hydrocarbon group having 1 to 20 carbon atoms include a cyclic sulfonyl structure having 3 to 8 carbon atoms.

As the ring structure formed together with the carbon atom to which R ⁴ and R ⁵ are bonded, a 5-membered or 6-membered ring structure is preferable from the viewpoint of ease of synthesis.

  n is preferably 1 or 2, and more preferably 1.

Note that at least one of R ⁴ and R ⁵ in the formula (1) is a monovalent organic group containing a fluorine atom. A photoresist composition containing a polymer in which at least one of R ⁴ and R ⁵ in the above formula (1) is a monovalent organic group containing a fluorine atom, and the polymer is incorporated in the immersion exposure process , The resist film surface exhibits excellent water drainage by exhibiting a large dynamic contact angle at the time of exposure, and the occurrence of development defects can be suppressed by significantly reducing the water drainage at the time of development.

Examples of the monovalent organic group having a fluorine atom include a fluorinated hydrocarbon group having 1 to 20 carbon atoms such as a trifluoromethyl group and a trifluoroethyl group, -CO-, -COO-, -OCO-,- Composed of at least one group selected from the group consisting of O—, —NR—, —CS—, —S—, —SO— and —SO ₂ —, and a hydrocarbon group having 1 to 20 carbon atoms; Examples thereof include monovalent organic groups in which a part of hydrogen atoms are substituted with at least fluorine atoms, and further, those having a substituent. Examples of the substituent include a hydroxy group, a carboxy group, and a cyano group (provided that R is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms).

A monovalent organic group containing the fluorine ^{atom, -R C -R f, -R C} -OR f or ^{-R C} -OCOR ^{f, R} C is a single bond or a divalent linking group, and ^{R f} Is preferably a fluorinated alkyl group or a hydroxyfluorinated alkyl group. When the monovalent organic group having a fluorine atom is the specific group, water drainage after development can be effectively reduced, and as a result, development defects can be further suppressed.

Examples of the divalent linking group represented by R ^C include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, or a group thereof and —CO. One of at least one group selected from the group consisting of —, —COO—, —OCO—, —O—, —NR—, —CS—, —S—, —SO— and —SO ₂ —; Examples include groups in which two or more are combined (wherein R is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms).

As the R ^E, a single bond is more preferable.

Examples of the alkyl group of the fluorinated alkyl group represented by R ^f include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, and a 1-methylpropyl group. , T-butyl group and the like.

Examples of the alkyl group of the hydroxyfluorinated alkyl group represented by R ^f include a 2-hydroxy-2-trifluoromethyl-1,1,1-trifluoropropyl group.

Among these, ^Rf is preferably a trifluoromethyl group, a trifluoroethyl group, or a 2-hydroxy-2-trifluoromethyl-1,1,1-trifluoropropyl group.

<Compound (1-0)>
As a preferred embodiment of the compound (1), at least one of R ⁴ and R ⁵ in the above formula (1) is a monovalent organic group, and R ⁴ and R ⁵ are bonded to each other to form a ring structure. In this case, the monovalent organic group includes a fluorine atom (hereinafter also referred to as “compound (1-0)”). The polymer incorporating the compound (1-0) is unevenly distributed on the surface layer side in the resist film. Accordingly, it is possible to further reduce the water drainage after development, and as a result, it is possible to further suppress development defects.

Examples of the monovalent organic group having a fluorine atom include a fluorinated hydrocarbon group having 1 to 20 carbon atoms such as a trifluoromethyl group and a trifluoroethyl group, -CO-, -COO-, -OCO-,- It is composed of at least one group selected from the group consisting of O—, —NR—, —CS—, —S—, —SO— and —SO ₂ — and a hydrocarbon group having 1 to 20 carbon atoms and hydrogen. Examples thereof include monovalent organic groups in which some of the atoms are substituted with at least fluorine atoms, and further, those having a substituent. Examples of the substituent include a hydroxy group, a carboxy group, and a cyano group. R is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. )

The monovalent organic group having the fluorine ^{atom, -R C -R f, -R C} -OR f or ^{-R C} -OCOR ^{f, R} C is a single bond or a divalent linking group, and ^{R f} is A fluorinated alkyl group or a hydroxyfluorinated alkyl group is preferred. When the monovalent organic group having a fluorine atom is the specific group, water drainage after development can be effectively reduced, and as a result, development defects can be further suppressed.

Examples of the divalent linking group represented by R ^C include, for example, a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, or these groups and- CO -, - COO -, - OCO -, - O -, - NR -, - CS -, - S -, - SO- and -SO ₂ - one of the at least one group selected from the group consisting of Or the group etc. which combined 2 or more are mentioned. R is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms.

As said ^RC , a single bond is more preferable.

Examples of the alkyl group of the fluorinated alkyl group represented by R ^f include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, and a 1-methylpropyl group. , T-butyl group and the like.

Examples of the alkyl group of the hydroxyfluorinated alkyl group represented by R ^f include a 2-hydroxy-2-trifluoromethyl-1,1,1-trifluoropropyl group.

R ^f is preferably a trifluoromethyl group, trifluoroethyl, or 2-hydroxy-2-trifluoromethyl-1,1,1-trifluoropropyl group.

  Examples of the compound (1-0) include compounds (1-0-1) to (1-0-13) represented by the following formulas.

  As the compound (1-0), among the above compounds, the compounds (1-0-1) and (1-0-2) are preferable.

<Compound (1-1)>
A preferred embodiment of the compound (1) includes the compound (1-1) represented by the above formula (1-1). When the compound has the specific structure, the rigidity of the polymer in which the compound is incorporated is increased, and the decrease in water drainage during development can be further increased. As a result, development defects can be further suppressed.

In the above formula ^{(1-1), R 1, R} 2, R 3 and n have the same meanings as in formula (1). R ^A is an (m + 2) -valent organic group that forms a ring structure having 3 to 20 carbon atoms together with the carbon atoms constituting the lactone ring. R ^B is a fluorine atom, a hydroxy group, or an organic group having 1 to 20 carbon atoms. m is an integer of 1-6. When m is 2 or more, the plurality of R ^B may be the same or different and may be bonded to each other to form a ring structure. Some or all of the hydrogen atoms of the ring structure may be substituted. However, at least one of R ^B has a fluorine atom.

Examples of the ring structure having 3 to 20 carbon atoms formed by the ^RA and the carbon atom constituting the lactone ring include, for example, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cycloheptane structure, and a cyclooctane structure. Monocyclic saturated hydrocarbon structures such as cyclodecane structure, methylcyclohexane structure, and ethylcyclohexane structure;
Monocyclic unsaturated hydrocarbon structures such as cyclobutene structure, cyclopentene structure, cyclohexene structure, cycloheptene structure, cyclooctene structure, cyclodecene structure, cyclopentadiene structure, cyclohexadiene structure, cyclooctadiene structure, cyclodecadiene structure;
Bicyclo [2.2.1] heptane structure, bicyclo [2.2.2] octane structure, tricyclo [5.2.1.0 ^2,6 ] decane structure, tricyclo [3.3.1.1 ^3,7 ] Decane structure, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] polycyclic saturated hydrocarbon structures such as dodecane structure and adamantane structure;
Bicyclo [2.2.1] heptene structure, bicyclo [2.2.2] octene structure, tricyclo [5.2.1.0 ^2,6 ] decene structure, tricyclo [3.3.1.1 ^3,7 ] Decene structure, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecene structure and the like, and polycyclic unsaturated hydrocarbon structures and the like, and -CO-, -COO-, -OCO-, -O-, -NR-, -CS- , —S—, —SO—, and —SO ₂ —, and the like, which include at least one group selected from the group consisting of —SO— and the like. Group).

Examples of the organic group having 1 to 20 carbon atoms represented by R ^B, for example, such as a monovalent organic group and similar groups in the above R ⁴ and R ⁵ carbon atoms exemplified as 20 and the like.

It said ^R as the ^{B -R C -R f, -R C} -OR f or ^-R C -OCOR ^{f, R C} is a single bond or a divalent linking group and ^{R f} is a fluorinated alkyl group or a hydroxy fluorinated, An alkyl group is preferred. R ^B is, that it is the specific group, can be effectively reduce the drainage after the development, as a result, can be further suppressed generation of development defects.

Examples of the divalent linking group represented by R ^C include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, or a group thereof and —CO. The group which combined 1 or 2 or more among-, -CS-, -O-, -NH-, -S- is mentioned.

As said ^RC , a single bond is more preferable.

Examples of the alkyl group of the fluorinated alkyl group represented by R ^f include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, and a 1-methylpropyl group. , T-butyl group and the like.

Examples of the hydroxyfluorinated alkyl group represented by R ^f include a 2-hydroxy-2-trifluoromethyl-1,1,1-trifluoropropyl group.

R ^f is preferably a trifluoromethyl group, a trifluoroethyl group, or a 2-hydroxy-2-trifluoromethyl-1,1,1-trifluoropropyl group.

  Examples of the compound (1-1) include compounds (1-1-1) to (1-1-18) represented by the following formulas.

  Of the above compounds, compounds (1-1-1) to (1-1-4) are preferable.

<Method for Producing Compound (1)>
As a manufacturing method of a compound (1), the following method is mentioned, for example.

  In accordance with the reaction represented by the following formula, a ketone compound is added to a solvent such as tetrahydrofuran (THF) to which zinc is added, and a bromoalkyl-substituted acrylic ester is added dropwise and stirred at room temperature, whereby compound (1) Is synthesized. Note that an activator such as chlorotrimethylsilane may be added to the THF solvent to which zinc has been added before the compound is added.

In said formula, R < ¹ > -R < ⁵ > and n are synonymous with the said Formula (1). R ′ is a monovalent hydrocarbon group.

<Polymer (I)>
The polymer of the present invention has a structural unit (I) derived from the compound (1). The photoresist composition containing the polymer (I) exhibits a large water drainage characteristic on the resist film surface without separately forming an upper film for the purpose of blocking the resist film from the immersion medium. The drainage of the resist film is greatly reduced. As a result, the wettability of the resist film surface with respect to the developing solution and the rinsing liquid is greatly improved, and thus the occurrence of development defects in the resist film due to the low cleaning efficiency with the rinsing liquid can be suppressed. Accordingly, the polymer is suitable as a component of, for example, a photoresist composition used in lithography technology. In addition to the structural unit (I), the polymer (I) may have a structural unit (II) having a fluorine atom. Furthermore, the polymer (I) may have other structural units as long as the effects of the present invention are not impaired, and the polymer (I) may have two or more kinds of each structural unit. Hereinafter, each structural unit will be described in detail.

[Structural unit (I)]
The structural unit (I) is a structural unit derived from the compound (1). The structural unit (I) is represented by the following formula (Ia), for example.

In said formula (Ia), R < ¹ > -R < ⁵ > and n are synonymous with said formula (1).

Examples of the group represented by R ^{1 to} R ⁵ and n include the same groups as those in formula (1) of compound (1).

  Examples of the compound (1) that gives the structural unit (I) include the compounds exemplified as the compound (1).

  The content ratio of the structural unit (I) in the polymer (I) is preferably 1 mol% or more and 100 mol% or less, preferably 5 mol% or more and 90 mol% or less with respect to all the structural units constituting the polymer (I). Is more preferable. By setting the content ratio of the structural unit (I) within the above range, an upper layer film or the like for the purpose of blocking the resist film and the immersion medium is separately formed from the photoresist composition containing the polymer (I). Therefore, the resist film surface shows a great water drainage, and the water drainage of the resist film is greatly reduced during development. As a result, the wettability of the resist film surface with respect to the developing solution and the rinsing solution is greatly improved, so that the effect of the present invention that can suppress the occurrence of development defects in the resist film due to the low cleaning efficiency with the rinsing solution is more exhibited. Can be made.

[Structural unit (II)]
The polymer (I) may further have a structural unit (II) containing a fluorine atom. By further including the structural unit (II), uneven distribution of the polymer (I) on the surface layer side of the resist film can be promoted.

  The structural unit (II) is preferably at least one structural unit selected from the group consisting of structural units represented by the following formulas (2-1) and (2-2). It is considered that even when the structural unit (II) is the specific structural unit described above, the uneven distribution of the polymer (I) on the surface layer side of the resist film can be promoted. Can be bigger.

In the formula (2-1), ^{R 6} is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ⁷ is a linear or branched chain hydrocarbon 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.
In the above formula (2-2), ^{R 8} represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. k is an integer of 1 to 3. R ⁹ is a (k + 1) -valent linking group. X is a divalent linking group having a fluorine atom. R ¹⁰ is a hydrogen atom or a monovalent organic group. However, when k is 2 or 3, a plurality of X and R ¹⁰ may be the same or different.

Among linear or branched chain hydrocarbon group having 1 to 6 carbon atoms and having a fluorine atom represented by R ^7, straight-chain or branched-chain hydrocarbon group having 1 to 6 carbon atoms Examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group.

Among the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms having a fluorine atom represented by R ⁷ , examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include a cyclopentyl group. , Cyclopentylpropyl group, cyclohexyl group, cyclohexylmethyl group, cycloheptyl group, cyclooctyl group, cyclooctylmethyl group and the like.

Examples of the (k + 1) -valent linking group represented by R ⁹ include a linear or branched chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, C6-C30 aromatic hydrocarbon group, or these groups and -CO-, -COO-, -OCO-, -O-, -NR-, -CS-, -S-, -SO- and- And a group in which at least one group selected from the group consisting of SO ₂ — is combined. The (k + 1) -valent linking group may have a substituent. R is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms.

  Examples of the linear or branched chain hydrocarbon group having 1 to 30 carbon atoms include hydrocarbon groups such as methane, ethane, propane, butane, pentane, hexane, heptane, decane, icosane, and triacontane ( and groups excluding k + 1) hydrogen atoms.

Examples of the alicyclic hydrocarbon group having 3 to 30 carbon atoms include monocyclic saturated hydrocarbons such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, methylcyclohexane, and ethylcyclohexane;
Monocyclic unsaturated hydrocarbons such as cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclopentadiene, cyclohexadiene, cyclooctadiene, cyclodecadiene;
Bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [3.3.1.1 ^3,7 ] decane, Tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] polycyclic saturated hydrocarbons such as dodecane and adamantane;
Bicyclo [2.2.1] heptene, bicyclo [2.2.2] octene, tricyclo [5.2.1.0 ^2,6 ] decene, tricyclo [3.3.1.1 ^3,7 ] decene, Tetracyclo [6.2.1.1 ^3,6 . And a group obtained by removing (k + 1) hydrogen atoms from a polycyclic hydrocarbon group such as 0 ^2,7 ] dodecene.

  Examples of the aromatic hydrocarbon group having 6 to 30 carbon atoms include aromatic hydrocarbon groups such as benzene, naphthalene, phenanthrene, anthracene, tetracene, pentacene, pyrene, picene, toluene, xylene, ethylbenzene, mesitylene, cumene ( and groups excluding k + 1) hydrogen atoms.

R ⁹ is preferably a branched chain hydrocarbon group having 1 to 30 carbon atoms.

  Examples of the divalent linking group having a fluorine atom represented by X include, for example, a C1-C20 divalent chain hydrocarbon group having a fluorine atom and a C1-C1 having a fluorine atom containing a carbonyl group. 20 divalent chain hydrocarbon groups and the like. Examples of the C1-C20 divalent chain hydrocarbon group having a fluorine atom include groups represented by the following formulas (X-1) to (X-7).

  X is preferably a group represented by the formula (X-7).

Examples of the monovalent organic group represented by R ¹⁰ include a linear or branched chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and the number of carbon atoms. 6-30 aromatic hydrocarbon groups, or these groups and —CO—, —COO—, —OCO—, —O—, —NR—, —CS—, —S—, —SO— and —SO ₂ And a group in which at least one group selected from the group consisting of-is combined. R is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms.

R ¹⁰ is preferably a linear or branched chain hydrocarbon group having 1 to 30 carbon atoms.

  As the structural unit (II), a structural unit represented by the above formula (2-2) is more preferable.

  Examples of the monomer that gives the structural unit represented by the formula (2-1) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, and perfluoroethyl (meth). Acrylate, perfluoro n-propyl (meth) acrylate, perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, perfluoro t-butyl (meth) Acrylate, perfluorocyclohexyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,5 , 5-octafluoro) pentyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-o Tafluoro) hexyl (meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2,2,3,3, 4,4,4-heptafluoro) penta (meth) acrylate, 1- (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10, 10-heptadecafluoro) decyl (meth) acrylate, 1- (5-trifluoromethyl-3,3,4,4,5,6,6,6-octafluoro) hexyl (meth) acrylate and the like.

  Examples of the monomer that gives the structural unit represented by the above formula (2-2) include (meth) acrylic acid 2- (1-ethoxycarbonyl-1,1-difluoro) butyl ester, (meth) acrylic acid 2 -(1-t-butoxycarbonyl-1,1-difluoro) butyl ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester, ( (Meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl) -2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) Ter, (meth) acrylic acid 2-{[5- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl] bicyclo [2.2.1] heptyl} Examples include esters. Of these, (meth) acrylic acid 2- (1-t-butoxycarbonyl-1,1-difluoro) butyl ester and (meth) acrylic acid 2- (1-ethoxycarbonyl-1,1-difluoro) butyl ester are preferable.

  The content ratio of the structural unit (II) in the polymer (I) is preferably 0 mol% or more and 90 mol% or less, and 0 mol% or more and 80 mol% or less with respect to all the structural units constituting the [B] polymer. Is more preferable.

[Structural unit (III)]
The polymer (I) preferably further has a structural unit (III) represented by the above formula (3). When the polymer (I) further has the structural unit (III), according to the photoresist composition containing the polymer, the dissolution rate in the developer can be controlled, and a better resist pattern is formed. be able to.

In the formula (3), R ¹¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^{12 to} R ¹⁴ are each independently an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 4 to 20 carbon atoms. However, R ¹² and R ¹³ may be bonded to each other to form a divalent alicyclic hydrocarbon group together with the carbon atom to which they are bonded.

As a C1-C6 alkyl group represented by said R < ¹² > -R < ¹⁴ >, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example.

Examples of the alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ^{12 to} R ¹⁴ include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, an adamantyl group, and the like.

Examples of the divalent alicyclic hydrocarbon group that R ¹² and R ¹³ may be bonded to each other include a cyclopentanediyl group, a norbornanediyl group, an adamantanediyl group, and the like.

Examples of the monomer that gives the structural unit (III) include monomers (3-1) to (3-11) represented by the following formulas.

  Among the above monomers, monomers (3-2), (3-3), (3-8), (3-9) and (3-11) are preferable.

  As a content rate of structural unit (III) in polymer (I), 10 mol% or more and 60 mol% or less are preferable with respect to all the structural units which comprise polymer (I), 15 mol% or more and 55 mol% or less Is more preferable. By setting the content ratio of the structural unit (III) in the above range, according to the photoresist composition containing the polymer (I), the dissolution rate in the developer can be controlled, and a better resist pattern can be obtained. Can be formed.

<Method for producing polymer (I)>
The polymer (I) can be produced by, for example, compound (1) and other monomers as necessary according to a conventional method such as radical polymerization. Examples of the production method include a method in which a solution containing a monomer and a radical initiator is dropped into a reaction solvent or a solution containing the monomer to cause a polymerization reaction; a solution containing the monomer and a radical initiator A solution containing each of the monomers separately added to a reaction solvent or a solution containing a monomer to cause a polymerization reaction; a plurality of types of solutions containing each monomer; and a solution containing a radical initiator And a method of dropping them into a reaction solvent or a monomer-containing solution to cause a polymerization reaction.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane;
Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane;
Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene;
Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene;
Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate and methyl propionate;
Ketones such as acetone, 2-butanone, 4-methyl-2-pentanone, 2-heptanone;
Ethers such as tetrahydrofuran, dimethoxyethanes, diethoxyethanes;
Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. In addition, these solvents may use 2 or more types together.

  As reaction temperature in the said superposition | polymerization, it is 40 to 150 degreeC normally, Preferably it is 50 to 120 degreeC. The reaction time is usually 1 hour to 48 hours, preferably 1 hour to 24 hours.

  Examples of the radical initiator include 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis ( 2-cyclopropylpropionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobisisobutyrate and the like. These radical initiators can be used in combination of two or more.

  The polymer obtained by the polymerization reaction can be recovered by a reprecipitation method. As the reprecipitation solvent, an alcohol solvent or the like can be used.

  In the polymerization reaction for synthesizing the polymer (I), a molecular weight modifier can be used to adjust the molecular weight. Examples of the molecular weight modifier include halogenated hydrocarbons such as chloroform and carbon tetrabromide; mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and thioglycolic acid; Xanthogens such as xanthogen sulfide and diisopropylxanthogen disulfide; terpinolene, α-methylstyrene dimer and the like.

  The Mw of the polymer (I) is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and further preferably 3,000 to 15,000. When Mw of the polymer (I) is less than 1,000, there is a tendency that a sufficient receding contact angle cannot be obtained. On the other hand, when the Mw of the polymer (I) exceeds 5,0000, the developability when used as a resist tends to be lowered.

  The ratio (Mw / Mn) between the Mw of the polymer (I) and the polystyrene-equivalent number average molecular weight (Mn) by the GPC method is preferably 1 to 5, and more preferably 1 to 3.

  In addition, Mw and Mn in the present specification are values measured by gel permeation chromatography (GPC) under the following conditions.

Column: 2 G2000HXL, 1 G3000HXL, and 1 G4000HXL (manufactured by Tosoh)
Mobile phase: Tetrahydrofuran Column temperature: 40 ° C
Flow rate: 1.0 mL / min Sample concentration: 1.0 mass%
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

<Photoresist composition>
The photoresist composition of the present invention contains [A] polymer, [B] polymer, [C] acid generator and [D] solvent. Moreover, the said photoresist composition may contain an [E] acid diffusion control body as a suitable component, and also may contain other arbitrary components, unless the effect of this invention is impaired.

<[A] polymer>
[A] The polymer is a polymer having an acid dissociable group. Moreover, [A] polymer turns into a base polymer in the said photoresist composition. The “base polymer” refers to a polymer that is a main component of a polymer that constitutes a resist film formed from a photoresist composition, and preferably 50% of the total polymer that constitutes the resist film. A polymer occupying at least mass%. [A] The specific structure of the polymer is not particularly limited as long as it is a polymer having an acid dissociable group. Examples of the structural unit containing an acid dissociable group include the structural unit (III) in the polymer (I). [A] The polymer further has at least one structural unit (IV) selected from the group consisting of a lactone structure, a cyclic carbonate structure and a sultone structure, which is a structural unit other than the structural unit (I). Is preferred. [A] The polymer may have, for example, the structural unit (II) in the polymer (I) described above as the structural unit having a fluorine atom. Furthermore, the [A] polymer may have other structural units as long as the effects of the present invention are not impaired, and the [A] polymer may have two or more kinds of each structural unit. Hereinafter, each structural unit will be described in detail.

[Structural unit (III)]
[A] The polymer has, for example, the structural unit (III) in the polymer (I) described above as the structural unit having an acid-dissociable group. [A] When the polymer has a structural unit containing an acid-dissociable group, [C] the acid-dissociable group is dissociated by the action of the acid generated from the acid generator, a carboxy group is generated, and the polarity changes. As a result, the solubility in the developer changes. As a result, a resist pattern can be formed.

  [A] The content ratio of the structural unit containing an acid-dissociable group in the polymer is preferably 5 mol% or more and 90 mol% or less, and preferably 10 mol% or more and 85 mol% with respect to all structural units constituting the [A] polymer. The mol% or less is more preferable. [A] By making the content rate of the structural unit containing an acid dissociable group in a polymer into the said range, the said photoresist composition can improve a sensitivity etc. more.

[Structural unit (II)]
[A] The polymer may have a structural unit (II) containing a fluorine atom. The structural unit (II) is the same as the structural unit (II) in the polymer (I) described above.

  [A] The content of the structural unit (II) in the polymer is preferably 0 mol% or more and 95 mol% or less, and preferably 5 mol% or more and 85 mol% or less with respect to all the structural units constituting the [A] polymer. Is more preferable.

  [A] The monomer that gives the structural unit (II) when the polymer has the structural unit (II) is 2- (1-t-butoxycarbonyl-1,1-difluoro) butyl (meth) acrylate Esters are preferred.

[Structural unit (IV)]
[A] The polymer is preferably a structural unit other than the structural unit (I), and has at least one structural unit (IV) selected from the group consisting of a lactone structure, a cyclic carbonate structure and a sultone structure. . [A] When the polymer has the structural unit (IV), the adhesion of the resist film to the substrate can be enhanced.

  As a monomer which gives structural unit (IV), the monomer represented by a following formula is mentioned, for example.

  Of the above monomers, monomer (4-1) and monomer (4-2) are preferred.

  [A] The content ratio of the structural unit (IV) in the polymer is preferably 10 mol% or more and 65 mol% or less, and 15 mol% or more and 60 mol% or less with respect to all the structural units constituting the [A] polymer. Is more preferable. The adhesiveness of a resist film can be improved by making the content rate of structural unit (IV) into the said range.

[Other structural units]
[A] The polymer may further have, for example, a structural unit containing a polar group as another structural unit. As the polar group, a carboxy group and a hydroxy group are preferable.

  [A] The content of the polymer is usually 70% by mass or more and preferably other than 80% by mass with respect to the total solid content in the photoresist composition.

<[A] Polymer Synthesis Method>
[A] The polymer can be synthesized according to a conventional method such as radical polymerization using a monomer or the like that gives a structural unit containing an acid-dissociable group. Examples of the synthesis method include a method in which a solution containing a monomer and a radical initiator is dropped into a reaction solvent or a solution containing a monomer to cause a polymerization reaction; a solution containing the monomer and a radical initiator A solution containing each of the monomers separately added to a reaction solvent or a solution containing a monomer to cause a polymerization reaction; a plurality of types of solutions containing each monomer; and a solution containing a radical initiator And a method of dropping them into a reaction solvent or a monomer-containing solution to cause a polymerization reaction.

  Conditions such as solvent and temperature can be the same as in the production method of the polymer (I).

  [A] The Mw of the polymer is preferably 1,000 to 20,000, more preferably 2,000 to 10,000. [A] By making Mw of a polymer into the said range, the said photoresist composition will become the thing excellent in lithography performance, such as a sensitivity.

  [A] The Mw ratio (Mw / Mn) of the polymer is usually from 1 to 5, preferably from 1 to 3, more preferably from 1 to 2. By setting Mw / Mn in the above range, the photoresist composition has excellent lithography performance such as sensitivity and etching resistance.

<[B] polymer>
[B] The polymer is the polymer. [B] The polymer functions as a “surface hydrophobized polymer”. The “surface hydrophobized polymer” refers to a subcomponent polymer that tends to be unevenly distributed on the surface layer side of a resist film to be formed by being contained in a photoresist composition. When the photoresist composition contains such [A] polymer and [B] polymer, the [B] polymer is unevenly distributed when the resist film is formed, and the resist film surface is exposed during exposure. Hydrophobizing can enable high-speed scanning in immersion exposure.

In the photoresist composition, in order for the [B] polymer to function well as a surface hydrophobizing polymer, the fluorine atom content of the [B] polymer is preferably higher than that of the [A] polymer. Thereby, the [B] polymer is more unevenly distributed on the surface layer side of the resist film. [B] The fluorine atom content of the polymer is preferably 5% by mass or more, more preferably 7% by mass or more, and further preferably 10% by mass or more. On the other hand, the fluorine atom content of the [A] polymer is preferably less than 5% by mass, more preferably 3% by mass or less, and even more preferably 1% by mass or less. The fluorine atom content can be calculated from this structure by identifying the structure of the polymer using ¹³ C-NMR.

  [B] Examples of the polymer include the polymers exemplified as the polymer (I).

  [B] The content of the polymer is preferably 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 15 parts by mass or less, with respect to 100 parts by mass of the polymer [A]. More preferably, it is 3 parts by mass or more and 10 parts by mass or less.

<[C] acid generator>
The photoresist composition contains a [C] acid generator. The [C] acid generator generates an acid upon exposure, and the acid dissociable group of the [A] polymer is dissociated by the acid to generate a carboxy group. As a result, the polarity of the [A] polymer increases and the [A] polymer in the exposed area becomes soluble in the developer. As the form of inclusion of the [C] acid generator in the photoresist composition, the form of a compound as will be described later (hereinafter also referred to as “[C] acid generator” as appropriate) is incorporated as part of the polymer. Either of these forms may be used.

  [C] Examples of the acid generator include onium salt compounds, sulfonimide compounds, halogen-containing compounds, diazoketone compounds, and the like. Of these, onium salt compounds and sulfonimide compounds are preferred.

  Examples of the onium salt compound include sulfonium salts (including tetrahydrothiophenium salts), iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like. Of these, sulfonium salts and iodonium salts are preferred.

  Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept- 2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2- (1-adamantyl) -1,1-difluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenyl Sulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4- Methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl -1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 1,1,2,2-tetrafluoro-6- (1-adamantylcarbonyloxy) -hexane-1-s Honeto, and the like.

  Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nona. Fluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophene Nitro 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium trifluoromethane Sulfonate, 1- (6-n-butoxynaphthalene-2 Yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalene- 2-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydro Thiophenium perfluoro-n-octance Phonates, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, etc. Can be mentioned.

  Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t -Butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetra Le Oro ethanesulfonate.

  Examples of the sulfonimide compound include N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [ 2.2.1] Hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3- Dicarboximide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene -2,3-dicarboximide and the like.

  Of these [C] acid generators, onium salt compounds are more preferred.

  These [C] acid generators can use 2 or more types together. The content when the [C] acid generator is a [C] acid generator is usually from 0 to 100 parts by mass of the [A] polymer from the viewpoint of ensuring sensitivity and developability as a resist. 1 part by mass or more and 20 parts by mass or less, preferably 0.5 part by mass or more and 15 parts by mass or less. [C] When the content of the acid generator is less than 0.1 parts by mass, the sensitivity and developability of the photoresist composition tend to decrease. On the other hand, when the content of the [C] acid generator exceeds 20 parts by mass, transparency to radiation tends to decrease.

<[D] solvent>
The photoresist composition usually contains a [D] solvent. [D] As the solvent, a solvent in which each component is uniformly dissolved or dispersed and does not react with each component is preferably used. [D] Examples of the solvent include alcohols, ethers, ketones, amides, esters and the like. In addition, these organic solvents can use 2 or more types together.

Examples of alcohols include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec -Pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-he Monoalcohols such as butadecyl alcohol, furfuryl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2 Polyhydric alcohols such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol Monomethyl ether, dipropylene glycol monoethyl ether, polyhydric alcohol partial ether and dipropylene glycol monopropyl ether, and the like.

  Examples of ethers include diethyl ether, dipropyl ether, dibutyl ether, diphenyl ether, methoxybenzene and the like.

  Examples of ketones 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, and methyl-n-hexyl. Examples of the ketone include ketones such as ketone, di-iso-butyl ketone, trimethylnonanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, and acetophenone.

  Examples of amides include N, N′-dimethylimidazolidinone, N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N -Methylpropionamide, N-methylpyrrolidone and the like.

  Examples of the esters include diethyl carbonate, propylene carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-acetate. Butyl, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl 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 acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol acetate Mono-n-butyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate Methoxytriglycol acetate, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, Examples include diethyl malonate, dimethyl phthalate, diethyl phthalate, and γ-butyrolactone.

Examples of the hydrocarbons include n-pentane, iso-pentane, n-hexane, iso-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, cyclohexane, Aliphatic hydrocarbons such as methylcyclohexane;
Fragrances such as benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene and n-amylnaphthalene Group hydrocarbons and the like.

  Of these, propylene glycol monomethyl ether acetate, cyclohexanone, and γ-butyrolactone are preferred.

<[E] Acid diffusion controller>
The photoresist composition preferably contains an [E] acid diffusion controller. [E] The acid diffusion controller controls the diffusion phenomenon of the acid generated from the [C] acid generator upon exposure in the resist film, and has the effect of suppressing undesirable chemical reactions in the non-exposed areas. As the form of inclusion of the [E] acid diffusion controller in the photoresist composition, a compound form as will be described later (hereinafter also referred to as “[E] acid diffusion controller” as appropriate) is incorporated as part of the polymer. Or both of these forms.

  [E] Examples of the acid diffusion controller include Nt-butoxycarbonyldi-n-octylamine, Nt-amyloxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-amyloxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt-amyloxycarbonyldi-n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt -Amyloxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-amyloxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-amyloxy Carbonyl-2-adamantylamine, Nt-butoxycal Nyl-N-methyl-1-adamantylamine, Nt-amyloxycarbonyl-N-methyl-1-adamantylamine, (S)-(−)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (S)-(−)-1- (t-amyloxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-( +)-1- (t-amyloxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonylpyrrolidine N-N-amyloxycarbonylpyrrolidine, N, N′-di-t-butoxycarbonylpiperazine, N, N′-di-t-a Roxycarbonylpiperazine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-amyloxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′-diamino Diphenylmethane, Nt-amyloxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N′-di-t-amyloxycarbonylhexamethylenediamine, N , N, N ′, N′-tetra-t-butoxycarbonylhexamethylenediamine, N, N, N ′, N′-tetra-t-amyloxycarbonylhexamethylenediamine, N, N′-di-t-butoxy Carbonyl-1,7-diaminoheptane, N, N′-di-t-amyloxycarbonyl-1,7-di Aminoheptane, N, N'-di-t-butoxycarbonyl-1,8-diaminooctane, N, N'-di-t-amyloxycarbonyl-1,8-diaminooctane, N, N'-di-t -Butoxycarbonyl-1,9-diaminononane, N, N'-di-t-amyloxycarbonyl-1,9-diaminononane, N, N'-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-amyloxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N′-di-t-amyloxycarbonyl- 1,12-diaminododecane, N, N′-di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-amyloxycarbonyl-4,4′-diamy Diphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonylbenzimidazole, Nt-amyloxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, Nt -Nt-butoxycarbonyl group-containing amino compounds such as -amyloxycarbonyl-2-phenylbenzimidazole.

  [E] In addition to the Nt-butoxycarbonyl group-containing amino compound, examples of the acid diffusion controller include tertiary amine compounds and quaternary ammonium hydroxide compounds.

Examples of the tertiary amine compound include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octyl. Tri (cyclo) alkylamines such as amine, cyclohexyldimethylamine, dicyclohexylmethylamine, and tricyclohexylamine;
Fragrances such as aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, 2,6-dimethylaniline, 2,6-diisopropylaniline Group amines;
Alkanolamines such as triethanolamine and N, N-di (hydroxyethyl) aniline;
N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1- Methylethyl] benzenetetramethylenediamine, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether and the like.

  Examples of the quaternary ammonium hydroxide compound include tetra-n-propylammonium hydroxide and tetra-n-butylammonium hydroxide.

  Furthermore, as the [E] acid diffusion control agent, an onium salt compound that decomposes upon exposure and loses basicity as acid diffusion controllability can be used. Examples of such an onium salt compound include a sulfonium salt compound represented by the following formula (5-1), an iodonium salt compound represented by the formula (5-2), and the like.

In the above formulas (5-1) and (5-2), R ^{15 to} R ¹⁹ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxy group, or a halogen atom. Anb ⁻ is OH ⁻ , R ²⁰ —COO ⁻ , R ²⁰ —SO ₃ ⁻ , or an anion represented by the following formula (6). R ²⁰ each independently represents an alkyl group, an aryl group or an alkanol group.

  Examples of the sulfonium salt compound and iodonium salt compound include triphenylsulfonium hydroxide, triphenylsulfonium acetate, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium hydroxide, diphenyl-4-hydroxyphenylsulfonium acetate, and diphenyl. -4-hydroxyphenylsulfonium salicylate, bis (4-t-butylphenyl) iodonium hydroxide, bis (4-t-butylphenyl) iodonium acetate, bis (4-t-butylphenyl) iodonium hydroxide, bis ( 4-t-butylphenyl) iodonium acetate, bis (4-t-butylphenyl) iodonium salicylate, 4-t-butyl Phenyl-4-hydroxyphenyliodonium hydroxide, 4-t-butylphenyl-4-hydroxyphenyliodonium acetate, 4-t-butylphenyl-4-hydroxyphenyliodonium salicylate, bis (4-t-butylphenyl) iodonium Examples thereof include 10-camphor sulfonate, diphenyliodonium 10-camphor sulfonate, triphenylsulfonium 10-camphor sulfonate, 4-t-butoxyphenyl diphenylsulfonium 10-camphor sulfonate, and the like.

  [E] Two or more acid diffusion control agents may be used in combination. [E] The content of the acid diffusion controller is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass with respect to 100 parts by mass of the polymer [A]. It is below mass parts. [E] By making the content of the acid diffusion control agent in the specific range, pattern developability and the like are further improved.

<Other optional components>
The said photoresist composition may contain other arbitrary components, such as surfactant and a sensitizer, in the range which does not impair the effect of this invention. In addition, the said photoresist composition may contain 2 or more types of said other arbitrary components.

[Surfactant]
Surfactants have the effect of improving coatability, striation, developability, and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate are listed. Examples of commercially available products include KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), MegaFac F171, F173 (above, manufactured by Dainippon Ink & Chemicals), Fluorad FC430, FC431 ( As above, manufactured by Sumitomo 3M, Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, Asahi Glass Industry) Manufactured) and the like.

[Sensitizer]
The sensitizer exhibits an action of increasing the amount of [C] acid generator to be produced, and has an effect of improving the “apparent sensitivity” of the photoresist composition. Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines and the like.

<Method for preparing photoresist composition>
The photoresist composition is prepared, for example, by mixing [A] polymer, [B] polymer, [C] acid generator and optional components in a predetermined ratio in [D] solvent. The Moreover, it is preferable to filter the obtained liquid mixture with a filter with a pore diameter of about 0.20 μm.

<Resist pattern formation method>
A resist pattern forming method using the photoresist composition includes (1) a step of applying the photoresist composition on a substrate and forming a resist film (hereinafter also referred to as “step (1)”), (2 ) A step of immersion exposure of the resist film by irradiation with radiation through a photomask (hereinafter also referred to as “step (2)”), and (3) a step of heating the resist film subjected to immersion exposure (hereinafter referred to as “step (2)”). And (4) a step of developing the heated resist film (hereinafter also referred to as “step (4)”). Hereinafter, each process is explained in full detail.

[Step (1)]
In this step, the photoresist composition is applied onto a substrate to form a resist film. As the substrate, for example, a conventionally known substrate such as a silicon wafer or a wafer coated with aluminum can be used. Further, for example, an organic or inorganic lower-layer antireflection film disclosed in Japanese Patent Publication No. 6-12452, Japanese Patent Application Laid-Open No. 59-93448, or the like may be formed on the substrate.

  Examples of the coating method include spin coating (spin coating), cast coating, and roll coating. In addition, as a film thickness of the resist film formed, it is 10 nm-150 nm normally, and 10 nm-120 nm are preferable.

  After applying the photoresist composition, the solvent in the coating film may be volatilized by soft baking (SB) as necessary. The heating conditions for SB are appropriately selected depending on the composition of the photoresist composition, but are usually about 30 ° C to 200 ° C, preferably 50 ° C to 150 ° C.

[Step (2)]
In this step, the desired region of the resist film formed in step (1) is exposed through a mask and an immersion liquid. Examples of the immersion liquid used for exposure include water and a fluorine-based inert liquid. The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient that is as small as possible so as to minimize distortion of the optical image projected onto the film. When the exposure light source is ArF excimer laser light (wavelength 193 nm), water is preferable from the viewpoints of availability and ease of handling in addition to the above-described viewpoints. When water is used, an additive that decreases the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist layer on the wafer and can ignore the influence on the optical coating on the lower surface of the lens. The water used is preferably distilled water.

  The radiation used for the exposure is appropriately selected according to the type of the [C] acid generator, and examples thereof include ultraviolet rays, far ultraviolet rays, X-rays, and charged particle beams. Among these, far ultraviolet rays represented by ArF excimer laser light and KrF excimer laser light (wavelength 248 nm) are preferable, and ArF excimer laser light is more preferable. The exposure conditions such as the exposure amount are appropriately selected according to the composition of the photoresist composition and the type of additive. In the resist pattern forming method of the present invention, the exposure process may be performed a plurality of times, and the plurality of exposures may be performed using the same light source or different light sources, but ArF excimer laser is used for the first exposure. It is preferable to use light.

[Step (3)]
In this step, post-exposure baking (PEB) is performed after exposure. By performing PEB, the dissociation reaction of the acid dissociable group in the photoresist composition can proceed smoothly. As PEB temperature, it is 30 degreeC or more and less than 200 degreeC normally, and 50 degreeC or more and less than 150 degreeC are preferable. At a temperature lower than 30 ° C., the dissociation reaction may not proceed smoothly. On the other hand, at a temperature of 200 ° C. or higher, the acid generated from the [C] acid generator diffuses widely to the unexposed area and is good. There is a possibility that a pattern cannot be obtained.

[Step (4)]
In this step, the resist film heated after exposure is developed with a developer. After development, it is common to wash with water and dry. As the developer, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyl Dimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3 0.0] -5-Nonene, an alkaline aqueous solution in which at least one alkaline compound is dissolved is preferable.

  As a developing method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle method) ), A method of spraying the developer on the substrate surface (spray method), a method of continuously applying the developer while scanning the developer coating nozzle on the substrate rotating at a constant speed (dynamic dispensing method) Etc.

  EXAMPLES Hereinafter, although this invention is explained in full detail based on an Example, this invention is not limited to an Example. The measuring method of various physical property values is shown below.

[ ¹ H-NMR analysis and ¹³ C-NMR analysis]
For ¹ H-NMR analysis of the compound and ¹³ C-NMR analysis of the polymer, a nuclear magnetic resonance apparatus (JNM-EX400, manufactured by JEOL Ltd.) was used, and deuterated chloroform was used as a measurement solvent.

<Synthesis of monomer>
[Example 1]
To a dry 1 L three-neck reactor equipped with a dropping funnel and a condenser, 13.1 g (200 mmol) of zinc powder (manufactured by Aldrich, particle diameter of 150 μm or less) was added, and after making the nitrogen atmosphere, 240 mL of tetrahydrofuran (THF) was added. While stirring with a magnetic stirrer, 1.9 mL (15 mmol) of chlorotrimethylsilane was added, and the mixture was stirred at 20 ° C. to 25 ° C. for 30 minutes. A solution prepared by dissolving 33.2 g (200 mmol) of hexafluoroacetone in 40 mL of THF was added thereto. Next, a solution of 34.8 g (180 mmol) of ethyl (2-bromomethyl) acrylate in 50 mL of THF was added dropwise. After dropping, the mixture was stirred at room temperature for 2 hours. After confirming the completion of the reaction by gas chromatography, an aqueous ammonium chloride solution and ethyl acetate were added to separate the layers. The obtained organic layer was washed successively with water and saturated brine. Thereafter, the organic layer was dried and concentrated under reduced pressure. Thereafter, purification by column chromatography was performed to synthesize 14.9 g of a compound represented by the following formula (Fs-1) (64 mmol, yield 32%).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 2.21-2.43 (m, 2H), 5.51-5.61 (m, 1H), 6.00-6.18 (m, 1H)

[Example 2]
The same procedure as in Example 1 was performed except that 33.2 g of 4-trifluoromethylcyclohexanone was used instead of 33.2 g of hexafluoroacetone in Synthesis Example 1, and represented by the following formula (Fs-2). 31.9 g of the above compound was synthesized (136 mmol, yield 68%).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.53-2.11 (m, 8H), 2.16-2.31 (m, 1H), 2.70 (t, J = 2.8 Hz, 1H) 2.75 (t, J = 2.8 Hz, 1H), 5.60-5.65 (m, 1H), 6.20-6.27 (m, 1H)

[Example 3]
First, 1,004 g (8.64 mol) of 1,4-cyclohexanediol was added to a 20 L reactor, and 4,320 mL of THF was added thereto, followed by stirring with a mechanical stirrer. To the reactor was added 21.71 g (86.39 mmol) of pyridinium p-toluenesulfonate, followed by 726.73 g (8.64 mol) of 3,4-dihydro-2H-pyran and allowed to react at room temperature for 12 hours. Thereafter, 17.28 g (170.77 mmol) of triethylamine was added to stop the reaction, and the mixture was concentrated. The concentrated solution was partitioned between hexane and water, and NaCl was added to the obtained aqueous layer until saturation, followed by extraction with methylene chloride. The obtained organic layer was dried over magnesium sulfate and concentrated under reduced pressure to synthesize 737 g of a compound represented by the following formula (Fs-A) (3.68 mol, yield 43%).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.24-1.91 (m, 13H), 1.94-2.05 (m, 2H), 3.45-3.53 (m, 1H), 3 .59-3.70 (m, 1H), 3.71-3.78 (m, 1H), 3.87-3.95 (m, 1H), 4.67-4.71 (m, 1H)

  Next, 300 g (1.5 mol) of the synthesized (Fs-A) was added to a 5 L three-necked reactor, and 1,200 mL of methylene chloride and 0.228 g of 2-azaadamantane-N-oxyl (1. 5 mmol), 17.85 g (150 mmol) of potassium bromide, and 450 mL of a saturated aqueous sodium hydrogen carbonate solution were sequentially added, and the mixture was stirred with a mechanical stirrer. The reactor was cooled to 0 ° C., and a solution prepared by mixing 1,913 g of a 7 mass% sodium hypochlorite aqueous solution and 450 mL of a saturated sodium hydrogen carbonate aqueous solution was added dropwise over 3 hours. After completion of dropping, the mixture was stirred at 0 ° C. for 30 minutes, and then 100 mL of a saturated aqueous sodium thiosulfate solution was added to stop the reaction and liquid separation was performed. The obtained organic layer was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure to synthesize 214 g of a compound represented by the following formula (Fs-B) (1.08 mol, yield 72%). .

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.51-2.16 (m, 10H), 2.22-2.35 (m, 2H), 2.50-2.69 (m, 2H), 3 .49-3.56 (m, 1H), 3.88-3.95 (m, 1H), 4.05-4.11 (m, 1H), 4.74-4.78 (m, 1H)

  Subsequently, the crude product obtained in the same manner as in Example 1 except that 39.7 g of the synthesized (Fs-B) was used instead of 33.2 g of hexafluoroacetone in Example 1. Was dissolved in 500 mL of ethanol, and then 9.51 g (50 mmol) of paratoluenesulfonic acid monohydrate was added and reacted at room temperature for 3 hours. This was extracted with methylene chloride, washed with water and saturated brine, and then purified by column chromatography to synthesize 25.1 g of a compound represented by the following formula (Fs-C) (138 mmol, yield 69). %).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.55-2.09 (m, 8H), 2.72 (t, J = 2.8 Hz, 1H), 2.76 (t, J = 2.8 Hz, 1H), 3.67-3.77 (m, 0.5H), 3.96-4.04 (m, 0.5H), 5.62-5.68 (m, 1H), 6.22- 6.28 (m, 1H)

  Thereafter, 18.2 g (100 mmol) of the above synthesized (Fs-C) was added to a 500 mL three-necked reactor under a nitrogen atmosphere, and 100 mL of methylene chloride was added thereto. After the reactor was cooled to 0 ° C., 23.1 g (110 mmol) of trifluoroacetic anhydride was added dropwise over 15 minutes. After completion of dropping, the mixture was stirred at 0 ° C. for 2 hours, and 300 mL of saturated aqueous sodium hydrogen carbonate solution was added to stop the reaction and liquid separation was performed. The obtained organic layer was washed with saturated brine, dried over magnesium sulfate, concentrated under reduced pressure, and purified by column chromatography to synthesize 19.7 g of a compound represented by the following formula (Fs-3). (70.8 mmol, 71% yield).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.62-2.01 (m, 8H), 2.22 (s, 3H), 2.75-2.89 (m, 2H), 4.81-4 .95 (m, 0.5H), 5.02-5.16 (m, 0.5H), 5.64-5.72 (m, 1H), 6.27-6.33 (m, 1H)

[Example 4]
In Example 3, except that 23.8 g of 3,3,3-trifluoropropionic anhydride was used instead of 23.1 g of trifluoroacetic anhydride, the same procedure as in Synthesis Example 4 was performed, and the following formula: 14.9 g of a compound represented by (Fs-4) was synthesized (51.0 mmol, yield 51%).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.61-2.00 (m, 8H), 2.61-2.91 (m, 4H), 4.86-4.99 (m, 0.5H) , 5.06-5.19 (m, 0.5H), 5.63-5.70 (m, 1H), 6.21-6.30 (m, 1H)

[Example 5]
First, in Example 3, except that 16.6 g of 5-hydroxyadamantan-2-one was used instead of 18.2 g of (Fs-C), the same operation as in Example 3 was performed. 22.0 g of the compound represented by -D) was synthesized (83.9 mmol, 84% yield).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.13-2.69 (m, 13H)

  Next, in Example 1, instead of 33.2 g of hexafluoroacetone, the same procedure as in Example 1 was used except that 52.4 g of the synthesized (Fs-D) was used, and the following formula (Fs- 21.8 g of the compound represented by 5) was synthesized (66.0 mmol, yield 33%).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.10-2.68 (m, 13H), 2.77-2.91 (m, 2H), 5.63-5.70 (m, 1H), 6 .21-6.30 (m, 1H)

[Example 6]
In Example 1, 4,4,4-trifluoro-3-hydroxy-3-trifluoromethylbutanal synthesized according to the literature (Chemische Berichte 1986, 119, 3502-3506) instead of 33.2 g of hexafluoroacetone Except for using 42.0 g, the same operation as in Example 1 was performed to synthesize 11.8 g of a compound represented by the following formula (Fs-6) (42.4 mmol, yield 21%).

¹ H-NMR data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.51-1.70 (m, 2H), 2.19-2.45 (m, 2H), 3.88-4.21 (m, 1H), 5 .51-5.61 (m, 1H), 6.00-6.18 (m, 1H)

<Synthesis of polymer>
Each monomer used for the synthesis of the polymer (I) and the [A] polymer is shown below.

  The monomers (Fs-1) to (Fs-6) are structural units (I), the monomers (M-8) and (M-9) are structural units (II), M-1) to (M-5) give structural unit (III), and monomers (M-6) and (M-7) give structural unit (IV).

<Synthesis of Polymer (I) ([B] Polymer)>
[Example 7]
1.00 g (10 mol%) of the above compound (Fs-1), 7.45 g (70 mol%) of the above compound (M-9), 1.55 g (20 mol%) of the above compound (M-2) and 10 g of 2-butanone A monomer solution was prepared by adding 0.42 g of AIBN. Subsequently, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, then heated to 80 ° C. with stirring, and the prepared 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. The cooled 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 synthesize a white powdery polymer (B-1) (4.2 g, yield 42). %). Mw of the polymer (B-1) was 4,000, and Mw / Mn was 1.52. The content rates of the structural unit (I), the structural unit (II), and the structural unit (III) were 9.7 mol%, 72.2 mol%, and 18.1 mol%, respectively.

[Examples 8 to 12 and Synthesis Example 6]
Each polymer was synthesized in the same manner as in Example 7 except that the types and amounts of monomers shown in Table 1 were used. Table 1 shows the Mw and Mw / Mn of each synthesized polymer. "-"
Indicates that the corresponding monomer was not used.

<[A] Synthesis of polymer>
[Synthesis Example 1]
43.1 g (50 mol%) of the compound (M-1) and 56.9 g (50 mol%) of the compound (M-6) are dissolved in 100 g of 2-butanone, and 4.21 g of AIBN is added to the monomer solution. Was prepared. Subsequently, a 1,000 mL three-necked flask containing 200 g of 2-butanone was purged with nitrogen for 30 minutes, then heated to 80 ° C. with stirring, and the prepared 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. The cooled polymerization solution was put into 2,000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 400 g of methanol, filtered, and dried at 50 ° C. for 17 hours to synthesize a white powdery polymer (A-1) (62.3 g, yield 62). %). Mw of the polymer (A-1) was 5,500, and Mw / Mn was 1.41. The content ratio of each structural unit was measured by ¹³ C-NMR analysis. The content rate of structural unit (III) and the content rate of structural unit (IV) were 48.2 mol% and 51.8 mol%, respectively.

[Synthesis Examples 2 to 5]
Each polymer was synthesized in the same manner as in Synthesis Example 1 except that the types and amounts of monomers shown in Table 2 were used. Table 2 shows the Mw and Mw / Mn of each synthesized polymer. "-"
Indicates that the corresponding monomer was not used.

<Preparation of photoresist composition>
Each component used for preparation of each photoresist composition is shown below.

<[C] acid generator>
C-1: Compound represented by the following formula (C-1)

<[D] solvent>
D-1: Propylene glycol monomethyl ether acetate D-2: Cyclohexanone

<[E] acid diffusion controller>
E-1: Compound represented by the following formula (E-1)

[Example 13]
[A] 100 parts by mass of (A-1) as a polymer, 5 parts by mass of (B-1) as a [B] polymer, [C] 9.9 parts by mass of (C-1) as an acid generator [D] (D-1) as a solvent
2,590 parts by mass, (D-2) 1,110 parts by mass, and (E-1) 7.9 parts by mass as an acid diffusion control agent were mixed, and the resulting mixture was mixed with a pore size of 0. A photoresist composition was prepared by filtration through a 20 μm filter.

[Examples 14 to 22 and Comparative Examples 1 and 2]
Each photoresist composition was prepared in the same manner as in Example 13 except that the components of the types and contents shown in Table 3 were mixed.

<Evaluation>
The following evaluation was performed using each prepared photoresist composition. The evaluation results are shown in Table 3.

<Backward contact angle (°)>
With respect to the formed resist film, the receding contact angle was measured in the following procedure using DSA-10 manufactured by KRUS under an environment of room temperature 23 ° C., humidity 45%, and normal pressure. The DSA-10 needle is cleaned with acetone and isopropyl alcohol before measurement, then water is injected into the needle, and the wafer is set on the wafer stage. The height of the stage is adjusted so that the distance between the wafer surface and the tip of the needle is 1 mm or less, and then water is discharged from the needle to form a 25 μL water droplet on the wafer. And a contact angle was measured every second. The average value was calculated for the contact angles of a total of 20 points from the time when the contact angle was stabilized, and was taken as the receding contact angle.

[Backward contact angle after SB]
Each photoresist composition was applied onto an 8-inch silicon wafer to form a coating film having a thickness of 110 nm, and after performing soft baking (SB) at 100 ° C. for 60 seconds, the receding contact angle was measured. This value is shown in “After SB” in Table 3.

[Backward contact angle after development]
Each photoresist composition was applied onto an 8-inch silicon wafer to form a coating film having a thickness of 110 nm, and soft baking (SB) was performed at 100 ° C. for 60 seconds. Thereafter, development was performed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 30 seconds using a GP nozzle of a developing device (manufactured by Tokyo Electron, Clean Track ACT8), rinsed with pure water for 15 seconds, and liquid-washed and dried at 2,000 rpm. Thereafter, the receding contact angle was measured. The receding contact angle was defined as “after development” in Table 3.

[Development defects]
Each photoresist composition was applied onto a 12-inch silicon wafer on which a lower antireflection film (ARC66, manufactured by Nissan Chemical Industries) was formed, thereby forming a coating film having a thickness of 110 nm. Next, this coating film was exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (NSR S610C, manufactured by NIKON) under the conditions of NA = 1.3, ratio = 0.812, and Crosspore. After the exposure, post-baking was performed at 120 ° C. for 60 seconds. Thereafter, the resist film was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, washed with water and dried to form a positive resist pattern. At this time, the exposure amount for forming a line and space having a width of 55 nm was determined as the optimum exposure amount. With this optimum exposure amount, a line and space having a line width of 55 nm was formed on the entire surface of the wafer to obtain a development defect inspection wafer. Note that a scanning electron microscope (S-9380, manufactured by Hitachi High-Technologies) was used for length measurement. Thereafter, the number of defects on the development defect inspection wafer was measured using a defect inspection apparatus (KLA2810, manufactured by KLA-Tencor). The measured defects were classified into those judged to be derived from the resist and foreign matters derived from the outside. After classification, the number of defects (number of defects) determined to be derived from the resist was summed to obtain “development defect number”. The number of development defects is also shown in Table 3. When the number of development defects was 50 / wafer or less, it was judged as good, and when it was 50 / wafer or more, it was judged as bad. Each photoresist composition had a better number of development defects than the comparative example.

  As is clear from the results in Table 3, when the photoresist composition is used, it can be confirmed that the receding contact angle after SB is greatly reduced after development as compared with the comparative example, and the receding contact angle changes. It was found to be excellent. Further, it was found that the photoresist composition can suppress development defects.

  According to the compound, polymer and photoresist composition of the present invention, the resist film formed in the immersion exposure process has a reasonably large water drainage property at the time of exposure, while the water drainage property is greatly reduced after alkali development. As a result, development defects are suppressed and a good resist pattern can be formed.

Claims (4)

A compound represented by the following formula (1-1) .

(In Formula (1-1) , R ¹ is a hydrogen atom or a methyl group. R ² and R ³ are each independently a hydrogen atom, a fluorine atom, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms. However, R ² and R ³ are not both hydroxy groups, n is an integer of 1 to 4. When n is 2 or more, a plurality of R ² and R ³ may be the same or different. R ^A is an (m + 2) -valent organic group that forms a ring structure having 3 to 20 carbon atoms together with the carbon atoms constituting the lactone ring, and R ^B is a fluorine atom or —R ^{C -R f,} -R ^C -OR ^f or ^-R C -OCOR ^f is an organic group having 1 to 20 carbon atoms represented by .R ^C is a single bond or a divalent linking group .R ^f Is a fluorinated alkyl group or a hydroxyfluorinated alkyl group, and m is 1-6. (When m is 2 or more, the plurality of R ^B may be the same or different. ) The polymer which has structural unit (I) derived from the compound of Claim 1 . The polymer according to claim 2 , further comprising a structural unit (III) represented by the following formula (3).

(In Formula (3), R ¹¹ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^{12 to} R ¹⁴ are each independently an alkyl group having 1 to 6 carbon atoms or a carbon number. 4 to 20 alicyclic hydrocarbon groups, provided that R ¹² and R ¹³ are bonded to each other to form a divalent alicyclic hydrocarbon group together with the carbon atom to which they are bonded. Good.) [A] a polymer having an acid dissociable group,
[B] The polymer according to claim 2 or claim 3 ,
[C] A photoresist composition containing an acid generator, and [D] a solvent.