JP5741289B2 - Photoresist composition - Google Patents

Description

  The present invention relates to a photoresist composition.

  A chemically amplified photoresist composition generates an acid in an exposed area by irradiation with far ultraviolet rays typified by KrF excimer laser light or ArF excimer laser light. It is a composition for forming a resist pattern on a substrate by changing the dissolution rate of the exposed portion with respect to the developer (see Japanese Patent Application Laid-Open No. 59-45439).

  The acid generator contained in such a chemically amplified photoresist composition is excellent in transparency to exposure light, as well as the strength of the acid generated, the high boiling point, and the diffusion distance in the resist film (hereinafter referred to as “the acid generator”). , Also referred to as “diffusion length”).

  In the ionic acid generator, the structure of the anion portion is important in order to make the acid strength, the boiling point height, and the diffusion length appropriate. For example, an acid generator having a trifluoromethanesulfonyl structure is characterized in that the generated acid is sufficiently strong and the resolution performance of the resulting photoresist composition is enhanced. Further, an acid generator having a sulfonyl structure bonded to a large organic group such as a 10-camphorsulfonyl structure has a feature that the boiling point of the generated acid is sufficiently high, but the solubility is low depending on the type of organic solvent. There is an inconvenience.

  On the other hand, when more precise line width control is performed, for example, when the device design dimension is sub-half micron or less, the above photoresist composition not only has excellent sensitivity, but also can reduce nano edge roughness. In addition, a wide depth of focus (DOF) is also required.

  Under such circumstances, various adjustments of the acid generator in the photoresist composition as described above have been studied. However, the conventional photoresist composition still cannot satisfy the above requirements, and the pattern formed on the substrate to be processed is transferred because the nano edge shape of the resist pattern is transferred to the substrate by processing such as etching. There is an inconvenience that the dimensional accuracy is reduced.

JP 59-45439 A

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a photoresist composition that can reduce nanoedge roughness and is excellent in depth of focus.

（式（１）中、Ｒ^１は、炭素数１〜２０のアルキル基、炭素数３〜２０の１価の脂環式炭化水素基、炭素数６〜１５のアリール基又は炭素数４〜１５のヘテロアリール基である。但し、上記アルキル基、脂環式炭化水素基、アリール基及びヘテロアリール基が有する水素原子の一部又は全部は置換されていてもよい。Ｒ^２は、２価の連結基である。Ｒ^ｆは、フッ素原子又は炭素数１〜３０のフッ素化アルキル基である。Ｍ^＋は、１価のカチオンである。ｎ１及びｎ２は、それぞれ独立して、０又は１である。）

（式（２−１）中、Ｒは、水素原子又はメチル基である。Ｒ^ａは、１価の有機基である。ｐは、０〜３の整数である。但し、Ｒ^ａが複数の場合、複数のＲ^ａは同一でも異なっていてもよい。ｑは、１〜３の整数である。但し、ｐ＋ｑ≦５の条件を満たす。） The invention made to solve the above problems is
[A] A compound represented by the following formula (1) (hereinafter also referred to as “[A] compound”), and [B] a polymer having a structural unit (I) represented by the following formula (2-1) (Hereinafter also referred to as “[B] polymer”)
Is a photoresist composition containing

(In the formula (1), R ¹ is an alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, or 4 to 15 carbon atoms. Provided that a part or all of the hydrogen atoms of the alkyl group, alicyclic hydrocarbon group, aryl group and heteroaryl group may be substituted, and R ² is a divalent group. R ^f is a fluorine atom or a fluorinated alkyl group having 1 to 30 carbon atoms, M ⁺ is a monovalent cation, and n1 and n2 are each independently 0 or 1 is there.)

(In the formula (2-1), R is a hydrogen atom or a methyl group. R ^a is a monovalent organic group. P is an integer of 0 to 3, provided that R ^a is a plurality of R ^a . In this case, a plurality of R ^a may be the same or different, and q is an integer of 1 to 3, provided that the condition of p + q ≦ 5 is satisfied.

  The photoresist composition of the present invention contains the [A] compound as an acid generator and the [B] polymer having a phenolic hydroxyl group, so that the nano edge roughness can be reduced and the focal depth can be reduced. Excellent. Although it is not necessarily clear why the photoresist composition can reduce nanoedge roughness by having the above-described configuration, for example, in the [A] compound, the number of carbon atoms in the vicinity of the sulfonate group is within a specific range. The acid diffusion length of the acid generated from the compound [A] in the resist film is sufficiently large due to the synergistic effect of the fluorine atom bonding and the [B] polymer having a phenolic hydroxyl group. It may be shortened. In addition, it is considered that the acid diffusion length of the acid is sufficiently shortened to increase the accuracy of pattern formation, and as a result, the depth of focus of the photoresist composition is increased.

R ¹ is preferably a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. It is considered that when R ¹ in the [A] compound is the specific group, the bulk of the acid generated from the [A] compound is increased, and the acid diffusion length in the resist film is further shortened. As a result, according to the photoresist composition, the nano edge roughness is further reduced and the depth of focus is further improved.

（式（ｉ−１）中、ｇ１、ｇ２及びｇ３は、それぞれ独立して、０〜２の整数である。但し、ｇ１、ｇ２及びｇ３のうちの少なくとも１つは１又は２である。Ｒ^Ａ１、Ｒ^Ａ２及びＲ^Ａ３は、それぞれ独立して、１価の有機基、ヒドロキシル基又はハロゲン原子である。ａ、ｂ及びｃは、それぞれ独立して、０〜９の整数である。但し、Ｒ^Ａ１、Ｒ^Ａ２及びＲ^Ａ３がそれぞれ複数の場合、複数のＲ^Ａ１、Ｒ^Ａ２及びＲ^Ａ３はそれぞれ同一でも異なっていてもよい。
式（ｉｉ−１）中、ｈ１及びｈ２は、それぞれ独立して、０〜２の整数である。但し、ｈ１及びｈ２のうちの少なくとも１つは１又は２である。Ｒ^Ｂ１及びＲ^Ｂ２は、それぞれ独立して、１価の有機基、ヒドロキシル基又はハロゲン原子である。ｄ及びｅは、それぞれ独立して、０〜９の整数である。但し、Ｒ^B１及びＲ^B２がそれぞれ複数の場合、複数のＲ^B１及びＲ^B２はそれぞれ同一でも異なっていてもよい。） The M ⁺ is preferably at least one cation selected from the group consisting of a cation represented by the following formula (i-1) and a cation represented by the following formula (ii-1).

(In formula (i-1), g1, g2, and g3 are each independently an integer of 0 to 2, provided that at least one of g1, g2, and g3 is 1 or 2. R ^A1 , R ^A2 and R ^A3 are each independently a monovalent organic group, a hydroxyl group or a halogen atom, and a, b and c are each independently an integer of 0 to 9, provided that R ^{A1, R} when ^A2 and ^{R A3} is plural, respectively, a plurality of ^{R A1, R A2} and ^{R A3} may be the same as or different from each other.
In formula (ii-1), h1 and h2 are each independently an integer of 0 to 2. However, at least one of h1 and h2 is 1 or 2. R ^B1 and R ^B2 are each independently a monovalent organic group, a hydroxyl group, or a halogen atom. d and e are each independently an integer of 0 to 9. However, in the case of multiple R ^B1 and R ^B2 are each, or different in each of the plurality of R ^B1 and R ^B2 same. )

  [A] When the cation in the compound has at least one aromatic ring selected from the group consisting of a naphthalene ring and an anthracene ring, the exposure light is absorbed by the aromatic ring, so that a standing wave generated in the resist film Is reduced. As a result, according to the photoresist composition, the nano edge roughness is further reduced and the depth of focus is further improved.

（式（２−２）中、Ｒ’は、水素原子又はメチル基である。Ｒ^ｂは、酸解離性基を含まない１価の有機基である。ｒは、０〜３の整数である。Ｒ^ｃは、１価の酸解離性基である。ｓは、１〜３の整数である。但し、Ｒ^ｂ及びＲ^ｃがそれぞれ複数の場合、複数のＲ^ｂ及びＲ^ｃはそれぞれ同一でも異なっていてもよい。また、ｒ＋ｓ≦５の条件満たす。） [B] The polymer preferably further has a structural unit (II) represented by the following formula (2-2).

(In Formula (2-2), R ′ is a hydrogen atom or a methyl group. R ^b is a monovalent organic group not containing an acid-dissociable group. R is an integer of 0 to 3. .R ^c is a is .s monovalent acid-dissociable group, an integer of 1 to 3. However, in the case of multiple ^{R b} and ^{R c} are each, in each of the plurality of ^{R b} and ^{R c} identical (It may be different, and the condition of r + s ≦ 5 is satisfied.)

  [B] When the polymer further has the structural unit (II), the photoresist composition can improve the positive resist pattern forming ability.

  As described above, the present invention can provide a photoresist composition that can reduce nanoedge roughness and is excellent in depth of focus.

It is the typical top view which looked at the line pattern from upper direction. It is typical sectional drawing of a line pattern shape.

<Photoresist composition>
The photoresist composition contains a [A] compound and a [B] polymer. In addition, the photoresist composition may contain [C] another radiation-sensitive compound (hereinafter also referred to as “[C] compound”) and [D] an acid diffusion controller as suitable components. Furthermore, the said photoresist composition may contain another arbitrary component in the range which does not impair the effect of this invention.

  The photoresist composition can be used as either a positive photoresist composition or a negative photoresist composition. In the case of a positive photoresist composition, the [B] polymer preferably has a structural unit containing an acid dissociable group. In the photoresist composition, when the polymer [B] has a structural unit containing an acid-dissociable group, the acid-dissociable group in the exposed area is dissociated by the acid generated from the compound [A] and the polar group. It becomes soluble in the developer and can form a positive resist pattern effectively. Here, the “acid-dissociable group” refers to a group that substitutes a hydrogen atom of a polar group such as a hydroxyl group or a carboxyl group and dissociates in the presence of an acid.

  On the other hand, when it is set as a negative photoresist composition, it is preferable that the said photoresist composition further contains the [E] crosslinking agent mentioned later. When the photoresist composition contains the [E] cross-linking agent, the acid generated from the [A] compound or the like causes the cross-linking reaction of the [B] polymer having a phenol structure to proceed in the exposed portion, thereby developing the developer. Therefore, a negative resist pattern can be effectively formed. Hereinafter, each component will be described.

<[A] Compound>
[A] A compound is a compound denoted by the above-mentioned formula (1). The compound [A] generates a compound represented by the following formula (1 ′) by irradiation with exposure light. In the compound represented by the following formula (1 ′), it is considered that the acid diffusion length is shortened when a specific number of fluorine atoms are bonded to carbon atoms in the vicinity of the sulfonate group.

In the above formula (1) and formula (1 ′), R ¹ is an alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an aryl group having 6 to 15 carbon atoms. Or it is a C4-C15 heteroaryl group. Some or all of the hydrogen atoms of the alkyl group, alicyclic hydrocarbon group, aryl group, and heteroaryl group may be substituted. R ² is a divalent linking group. R ^f is a fluorine atom or a fluorinated alkyl group having 1 to 30 carbon atoms. n1 and n2 are each independently 0 or 1.
In the above formula (1), M ⁺ is a monovalent cation.

Examples of the alkyl group having 1 to 20 carbon atoms represented by R ¹ include a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, a 2-butyl group, and 2- (2 -Methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- (3-methylpentyl) group, 1- (4- Methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- (2-methylpentyl) group, 3- (3- Methylpentyl) group and the like.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ¹ include monocyclic hydrocarbon groups such as a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group;
Examples thereof include polycyclic hydrocarbon groups such as a 2-norbornyl group, a 1-adamantyl group, and a 2-adamantyl group.

Examples of the aryl group having 6 to 15 carbon atoms represented by R ¹ include a phenyl group, a methylphenyl group, a dimethylphenyl group, a trimethylphenyl group, a naphthyl group, a methylnaphthyl group, a dimethylnaphthyl group, a trimethylnaphthyl group, Anthranyl group etc. are mentioned.

Examples of the heteroaryl group having 4 to 15 carbon atoms represented by R ¹ include oxygen-containing heterocyclic groups such as a furyl group, a pyranyl group, and an isobenzofuranyl group;
Nitrogen-containing heterocyclic groups such as a pyrrolyl group, an imidazolyl group, a pyrazole group, a pyridyl group, an indolyl group, a quinolinyl group, and a carbazolyl group;
Sulfur-containing heterocyclic groups such as thienyl group, thiantenyl group;
Oxygen-nitrogen-containing heterocyclic groups such as isoxazolyl groups and phenoxazinyl groups;
Nitrogen-sulfur-containing heterocyclic groups such as isothiazolyl groups and phenothiazinyl groups;
And oxygen-sulfur-containing heterocyclic groups such as a phenoxathiinyl group.

  Examples of the substituent that the alkyl group, alicyclic hydrocarbon group, aryl group, and heteroaryl group may have include a cyano group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), A phenyl group, a hydroxyl group, an acyloxy group, an alkoxy group, an alkoxycarbonyl group, etc. are mentioned. The substituent may be an oxygen atom (═O) that substitutes two hydrogen atoms bonded to the same carbon atom to form a carbonyl group.

R ¹ is preferably a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, more preferably a cyclohexyl group, a 1-adamantyl group, or a 2-adamantyl group, and even more preferably a cyclohexyl group or a 1-adamantyl group. .

Examples of the divalent linking group represented by R ² include an ether group, an ester group, a carbonyl group, a divalent chain hydrocarbon group having 1 to 30 carbon atoms, and a divalent chain having 3 to 30 carbon atoms. And a group obtained by combining at least one or two or more groups selected from the group consisting of an alicyclic hydrocarbon group and a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms.

  Examples of the divalent chain hydrocarbon group include a methylene group, an ethylene group, a 1,2-propylene group, a 1,3-propylene group, and a 1,4-butylene group.

  Examples of the alicyclic hydrocarbon group include a cyclopentanediyl group, a cyclohexanediyl group, a norbornanediyl group, an adamantanediyl group, and the like.

  Examples of the aromatic hydrocarbon group include a phenylene group, a methylphenylene group, and a naphthylene group.

R ² includes a divalent chain hydrocarbon group having 1 to 30 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, and a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Group is preferred, a divalent chain hydrocarbon group having 1 to 10 carbon atoms is more preferred, and an ethylene group is more preferred.

Examples of the fluorinated alkyl group having 1 to 30 carbon atoms represented by R ^f include, for example, a linear or branched alkyl group having 1 to 6 carbon atoms substituted with at least one fluorine atom, and at least 1 Examples thereof include a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms substituted with the above fluorine atom or a group derived therefrom.

  Examples of the linear or branched alkyl group having 1 to 6 carbon atoms substituted with at least one fluorine atom include a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, and 1-butyl. Group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- (3 -Methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- (2 -Methylpentyl) group, 3- (3-methyl) Such partially fluorinated alkyl group or a perfluoroalkyl group such as pentyl) groups.

  Examples of the C 4-20 monovalent alicyclic hydrocarbon group substituted with at least one fluorine atom or a group derived therefrom include a cyclopentyl group, a cyclopentylmethyl group, and 1- (1-cyclopentyl). Ethyl) group, 1- (2-cyclopentylethyl) group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group, Examples thereof include partially fluorinated alicyclic hydrocarbon groups such as 1- (1-cycloheptylethyl) group, 1- (2-cycloheptylethyl) group, and 2-norbornyl group, and perfluoroalicyclic hydrocarbon groups. .

R ^f is preferably a fluorine atom or a trifluoromethyl group.

  As said n1, 1 is preferable. As said n2, 1 is preferable.

Examples of the monovalent cation represented by M ⁺ include onium cations having atoms such as O, S, Se, N, P, As, Sb, Cl, Br, and I. Among these, an onium cation (sulfonium cation) having an S atom and an onium cation (iodonium cation) having an I atom are preferable.

Examples of the [A] compound when the monovalent cation represented by M ⁺ is a sulfonium cation include a sulfonium salt represented by the following formula (1-1).

In the above formula ^{(1-1), R 1, R} 2, R f, n1 and n2 are as defined in the above formula (1). R ³ , R ⁴ and R ⁵ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group, an oxoalkyl group, an aryl group having 6 to 18 carbon atoms, an aralkyl group or An aryloxoalkyl group; However, some or all of the hydrogen atoms contained in these groups may be substituted with a monovalent organic group, a hydroxyl group or a halogen atom. Further, any two or more of R ³ , R ⁴ and R ⁵ may be bonded to each other to form a ring structure together with the sulfur atom to which they are bonded.

  Examples of the sulfonium cation include a sulfonium cation represented by the above formula (i-1) and a sulfonium cation represented by the following formula (i-2). [A] When the cation in the compound has at least one aromatic ring selected from the group consisting of a naphthalene ring and an anthracene ring, the exposure light is absorbed by the aromatic ring, so that a standing wave generated in the resist film Is reduced. As a result, according to the photoresist composition, the nano edge roughness is further reduced and the depth of focus is further improved.

In the above formula (i-1), g1, g2 and g3 are each independently an integer of 0 to 2. However, at least one of g1, g2, and g3 is 1 or 2. R ^A1 , R ^A2 and R ^A3 are each independently a monovalent organic group, a hydroxyl group or a halogen atom. a, b and c are each independently an integer of 0 to 9; ^However, when R ^{A1, R A2} and ^{R A3} is plural, respectively, a plurality of ^{R A1, R A2} and ^{R A3} may be the same as or different from each other.

In the formula (i-2), R ^A4 and R ^A5 are each independently a monovalent organic group, a hydroxyl group, or a halogen atom. a 'is an integer of 0-9. b 'is an integer of 0-5. ^However, in the case of multiple ^{R A4} and ^{R A5} are each the plurality of ^{R A4} and ^{R A5} may each be the same or different. m is an integer of 0-3.

Examples of the monovalent organic group represented by R ^{A1 to} R ^A5 include an alkyl group, an alicyclic hydrocarbon group, an aryl group, an aralkyl group, an alkoxy group, and the like, or these groups and an ether And a group obtained by combining at least one group selected from the group consisting of a group, an ester group, a carbonyl group, a carbonate group, an amide group, a urea group, and a carbamate group.

As a halogen atom represented by said R < ^A1 > -R < ^A5 >, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example.

Examples of cations represented by the above formulas (i-1) and (i-2) include cations represented by the following formulas (i-1) to (i-84).

  Among these, from the viewpoint of availability, the above formula (i-1), formula (i-2), formula (i-6), formula (i-8), formula (i-13), formula (I-19), formula (i-25), formula (i-27), formula (i-29), formula (i-33), formula (i-51), formula (i-54) and formula ( The sulfonium cation represented by i-65) is preferable, and the sulfonium cation represented by the formula (i-1) is more preferable.

  From the viewpoint of reducing standing waves in the resist film during exposure, sulfonium represented by the above formulas (i-54) to (i-57) and formulas (i-66) to (i-84) A cation is preferable, and it has two or more naphthalene rings or anthracene rings, and the nanoedge roughness in the photoresist composition is further reduced and the depth of focus is further improved. Therefore, the above formula (i-66), ( The sulfonium cations represented by i-68) to (i-73) and (i-75) to (i-77) are more preferable, and are represented by the above formulas (i-66) and (i-68). A sulfonium cation is more preferable, and a sulfonium cation represented by the above formula (i-66) is particularly preferable.

Examples of the [A] compound when the monovalent cation represented by M ⁺ is an iodonium cation include an iodonium salt represented by the following formula (1-2).

In the above formula ^{(1-2), R 1, R} 2, R f, n1 and n2 are as defined in the above formula (1). R ⁶ and R ⁷ have the same meanings as R ³ and R ⁴ in the above formula (1-1), respectively.

  As the iodonium cation, an iodonium cation represented by the above formula (ii-1) is preferable. The iodonium cation represented by the above formula (ii-1) is selected from the group consisting of a naphthalene ring and an anthracene ring, as in the case of the sulfonium cation represented by the above formulas (i-1) and (i-2). Therefore, exposure light is absorbed by this aromatic ring, and standing waves generated in the resist film are reduced. As a result, according to the photoresist composition, the nano edge roughness is further reduced and the depth of focus is further improved.

In the above formula (i-2), h1 and h2 are each independently an integer of 0 to 2. However, at least one of h1 and h2 is 1 or 2. R ^B1 and R ^B2 are each independently a monovalent organic group, a hydroxyl group, or a halogen atom. d and e are each independently an integer of 0 to 9. However, in the case of multiple R ^B1 and R ^B2 are each, or different in each of the plurality of R ^B1 and R ^B2 same.

Examples of the monovalent organic group and halogen atom represented by R ^B1 and R ^B2 include the same groups as the groups exemplified as R ^{A1 to} R ^A5 .

  Examples of the iodonium cation represented by the above formula (i-2) include iodonium cations represented by the following formulas (ii-1) to (ii-45).

  Among these, from the viewpoint of availability, iodonium cations represented by the above formula (ii-1) and formula (ii-2) are preferable.

  Further, from the viewpoint of reducing standing waves in the resist film during exposure, iodonium represented by the above formulas (ii-36), (ii-37), and formulas (ii-40) to (ii-45). (Ii-36), (ii-) because a cation is preferable, and it has two or more naphthalene rings or anthracene rings, and in the photoresist composition, nanoedge roughness is further reduced and depth of focus is further improved. 37), (ii-41) and iiinium cations represented by (ii-43) to (ii-45) are more preferred, and (ii-36), (ii-37), (ii-41) and (ii) The iodonium cation represented by -44) is more preferable.

  [A] As content of a compound, it is 0.1 mass part-20 mass parts normally with respect to 100 mass parts of [B] polymer mentioned later, 0.1 mass part-15 mass parts are preferable, 0 More preferably, 2 parts by mass to 10 parts by mass. If the content of the compound [A] is less than 0.1 parts by mass, the sensitivity of the photoresist composition may be lowered. On the other hand, if it exceeds 20 parts by mass, transparency to exposure light, pattern formability, heat resistance, and the like may decrease. [A] A compound can be used individually or in mixture of 2 or more types.

<[A] Compound Synthesis Method>
The compound [A] can be synthesized using, for example, a compound represented by the following formula (1-0) as a raw material.

In the above formula ^{(1-0), R 2, R} f, n2 and ^{M +} is as defined in the above formula (1). Among the compounds represented by the above formula (1-0), a compound in which n2 is 1 can be synthesized by a method described in Journal of Fluorine Chemistry, 129 (2008), 607, for example. A compound in which n2 is 0 can be synthesized by a method described in Journal of Fluorine Chemistry, 129 (2008), 607 using, for example, a compound represented by the following formula (1-0 ′) as a raw material.

In the above formula (1-0 '), ^{R 2} and ^{R f} is as defined in the above formula (1). R ^α is a monovalent organic group.

  About the compound represented by the said Formula (1-0), the compound represented by Formula (1) can be obtained by making the following reaction, for example.

In the above reaction ^{formula, R 1, R 2, R} f, n2 and ^{M +} is as defined in the above formula (1). X ¹ is a hydroxyl group, a halogen atom or O—CO—R ¹ . X ² is a halogen atom.

<[B] polymer>
[B] The polymer is a polymer having the structural unit (I) represented by the above formula (2-1). The said photoresist composition can form a resist pattern because the solubility with respect to the developing solution of the [B] polymer in an exposure part changes by the effect | action of the acid generate | occur | produced from a [A] compound.

  [B] The polymer may have structural units (II) to (V) in addition to the structural unit (I). In addition, the [B] polymer may have 1 type, or 2 or more types of each of these structural units.

[Structural unit (I)]
The structural unit (I) is a structural unit represented by the above formula (2-1). [B] Since the polymer has the structural unit (I), in the positive photoresist composition, by adjusting the solubility in the developer, in the negative photoresist composition, in the exposed portion. By allowing the crosslinking reaction to proceed efficiently, the photoresist composition can exhibit excellent resolution, and the adhesion of the resist pattern to the substrate can be improved. The acid generated from the [A] compound is considered to have a sufficiently short acid diffusion length in the resist film due to the presence of the structural unit (I) of the [B] polymer. As a result, the photoresist composition According to the thing, it is guessed that nano edge roughness can be reduced and the depth of focus can be made excellent.

In said formula (2-1), R is a hydrogen atom or a methyl group. R ^a is a monovalent organic group. p is an integer of 0-3. If R ^a is plural, the plurality of R ^a may be the same or different. q is an integer of 1 to 3. However, p and q satisfy the condition of p + q ≦ 5.

  R is preferably a hydrogen atom.

Examples of the monovalent organic group represented by R ^a include a monovalent chain hydrocarbon group having 1 to 12 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and the number of carbon atoms. 6-20 monovalent aromatic hydrocarbon groups, monovalent oxygen atom-containing organic groups, monovalent nitrogen atom-containing organic groups, and the like.

  Examples of the monovalent chain hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, and a t-butyl group. Group, n-pentyl group, n-hexyl group, n-decyl group and the like.

  Examples of the monovalent alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a norbornyl group, an adamantyl group, and the like.

  Examples of the monovalent aromatic hydrocarbon group include a phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,4-xylyl group, 2,6-xylyl group, 3,5- Examples include xylyl group, mesityl group, o-cumenyl group, m-cumenyl group, p-cumenyl group, benzyl group, phenethyl group, 1-naphthyl group, and 2-naphthyl group.

Examples of the monovalent oxygen atom-containing organic group include:
Carboxyl group;
Hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl A linear or branched hydroxyalkyl group having 1 to 8 carbon atoms such as a 4-hydroxybutyl group;
A hydroxycycloalkyl group having 3 to 8 carbon atoms such as a 3-hydroxycyclopentyl group and a 4-hydroxycyclohexyl group;
Linear or branched having 1 to 8 carbon atoms such as methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group In the form of an alkoxy group;
A cycloalkyloxy group such as a cyclopentyloxy group and a cyclohexyloxy group;
A linear alkoxycarbonyloxy group having 2 to 9 carbon atoms such as a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, and an n-butoxycarbonyloxy group;
(1-methoxyethoxy) methyl group, (1-ethoxyethoxy) methyl group, (1-n-propoxyethoxy) methyl group, (1-n-butoxyethoxy) methyl group, (1-methoxypropoxy) methyl group, ( A linear or branched (1-alkoxyalkoxy) alkyl group having 3 to 11 carbon atoms such as 1-ethoxypropoxy) methyl group;
A (1-cycloalkyloxyalkoxy) alkyl group having 5 to 11 carbon atoms such as a (1-cyclopentyloxyethoxy) methyl group and a (1-cyclohexyloxyethoxy) methyl group;
3 to 10 carbon atoms such as methoxycarbonyloxymethyl group, ethoxycarbonyloxymethyl group, n-propoxycarbonyloxymethyl group, i-propoxycarbonyloxymethyl group, n-butoxycarbonyloxymethyl group, t-butoxycarbonyloxymethyl group, etc. A linear or branched alkoxycarbonyloxyalkyl group of
Examples thereof include a cycloalkyloxycarbonyloxyalkyl group having 5 to 10 carbon atoms such as a cyclopentyloxycarbonyloxymethyl group and a cyclohexyloxycarbonyloxymethyl group.

As the monovalent nitrogen atom-containing organic group, for example,
A cyano group;
Cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl group, 1-cyanopropyl group, 2-cyanopropyl group, 3-cyanopropyl group, 1-cyanobutyl group, 2-cyanobutyl group, 3-cyanobutyl group, 4-cyanobutyl group A linear or branched cyanoalkyl group having 2 to 9 carbon atoms, such as
C4-C9 cyanocycloalkyl groups such as 3-cyanocyclopentyl group and 4-cyanocyclohexyl group are exemplified.

Among these, from the viewpoint of improving the rectangularity of the pattern, ^Ra is preferably a monovalent chain hydrocarbon group, and preferably a methyl group, an ethyl group, an n-propyl group, or an i-propyl group.

  As said p, 0-2 are preferable, 0 or 1 is more preferable, and 0 is further more preferable. The q is preferably 1 or 2, and more preferably 1.

  Examples of the monomer that gives the structural unit (I) include 2-hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene, 2-hydroxy-α-methylstyrene, 3-hydroxy-α-methylstyrene, 4 -Hydroxy-α-methylstyrene, 2-methyl-3-hydroxystyrene, 4-methyl-3-hydroxystyrene, 5-methyl-3-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3-methyl-4- Examples thereof include hydroxystyrene, 3,4-dihydroxystyrene, 2,4,6-trihydroxystyrene and the like. Among these, from the viewpoint of the acidity of the phenolic hydroxyl group of the resulting structural unit (I), 4-hydroxystyrene and 4-hydroxy-α-methylstyrene are preferable, and 4-hydroxystyrene is more preferable.

  As a content rate of the said structural unit (I), 50-90 mol% is preferable with respect to all the structural units which comprise a [B] polymer, 60-85 mol% is more preferable, and 65-80 mol% is further. preferable. When the content ratio of the structural unit (I) is less than 50 mol%, the adhesion of the resist pattern to the substrate may be lowered. Moreover, in the case of a negative photoresist composition, there is a possibility that the pattern formability is lowered. On the contrary, if the content ratio exceeds 90 mol%, the contrast after development may be lowered.

[Structural unit (II)]
The structural unit (II) is a structural unit represented by the above formula (2-2). When the photoresist composition is positive, the [B] polymer preferably further has a structural unit (II) as a structural unit containing an acid dissociable group. In the photoresist composition, the [B] polymer has the structural unit (II), so that nano edge roughness can be reduced and a positive resist pattern can be formed while exhibiting excellent depth of focus. can do.

In said formula (2-2), R 'is a hydrogen atom or a methyl group. R ^b is a monovalent organic group not containing an acid dissociable group. r is an integer of 0-3. R ^c is a monovalent acid dissociable group. s is an integer of 1 to 3. When R ^b and R ^c is plural, respectively, it may be different in each of the plurality of R ^b and R ^c identical. However, r and s satisfy the condition r + s ≦ 5.

  R ′ is preferably a hydrogen atom.

Examples of the monovalent organic group not containing the acid dissociable group represented by R ^b include, for example, a chain hydrocarbon in the monovalent organic group represented by R ^a in the above formula (2-1). Group, alicyclic hydrocarbon group, aromatic hydrocarbon group, monovalent oxygen atom-containing organic group, carboxyl group, hydroxyalkyl group, hydroxycycloalkyl group, alkoxy group and cycloalkyloxy group, and monovalent group Examples thereof include the same groups as those exemplified for the nitrogen atom-containing organic group.

Examples of the monovalent acid-dissociable group represented by R ^c include:
Examples thereof include a substituted methyl group, a 1-substituted ethyl group, a 1-branched alkyl group, a triorganosilyl group, a triorganogermyl group, an alkoxycarbonyl group, an acyl group, and a monovalent cyclic acid dissociable group.

  Examples of the substituted methyl group include a methoxymethyl group, a methylthiomethyl group, an ethoxymethyl group, an ethylthiomethyl group, a methoxyethoxymethyl group, a benzyloxymethyl group, a benzylthiomethyl group, a phenacyl group, a bromophenacyl group, and a methoxyphenacyl group. Group, methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxybenzyl group , Ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, i-propoxycarbonylmethyl group, n-butoxycarbonylmethyl group, t-butoxy Rubonirumechiru group, and the like.

  Examples of the 1-substituted ethyl group include 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1-diethoxy. Ethyl group, 1-propoxyethyl group, 1-cyclohexyloxyethyl group, 1-phenoxyethyl group, 1-phenylthioethyl group, 1,1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzylthioethyl Group, 1-cyclopropylethyl group, 1-phenylethyl group, 1,1-diphenylethyl group, 1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group, 1-isopropoxy Carbonylethyl group, 1-n-butoxycarbonylethyl group, 1-t-butoxycarbonylethyl group And the like.

  Examples of the 1-branched alkyl group include i-propyl group, sec-butyl group, t-butyl group, 1,1-dimethylpropyl group, 1-methylbutyl group, 1,1-dimethylbutyl group and the like. .

  Examples of the triorganosilyl group include trimethylsilyl group, ethyldimethylsilyl group, diethylmethylsilyl group, triethylsilyl group, dimethyl i-propylsilyl group, methyldi-i-propylsilyl group, tri-i-propylsilyl group, Examples thereof include a t-butyldimethylsilyl group, a di-t-butylmethylsilyl group, a tri-t-butylsilyl group, a dimethylphenylsilyl group, a methyldiphenylsilyl group, and a triphenylsilyl group.

  Examples of the triorganogermyl group include trimethylgermyl group, ethyldimethylgermyl group, diethylmethylgermyl group, triethylgermyl group, dimethyl i-propylgermyl group, methyldi-i-propylgermyl group, -I-propylgermyl group, t-butyldimethylgermyl group, di-t-butylmethylgermyl group, tri-t-butylgermyl group, dimethylphenylgermyl group, methyldiphenylgermyl group, triphenylgermyl group Etc.

  Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an i-propoxycarbonyl group, and a t-butoxycarbonyl group.

  Examples of the acyl group include acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, lauroyl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group, malonyl group, Succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, canphoroyl group, benzoyl Group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isoni Chinoiru group, and the like.

  Examples of the monovalent cyclic acid dissociable group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexenyl group, a 4-methoxycyclohexyl group, a tetrahydrofuranyl group, a tetrahydropyranyl group, a tetrahydrothiofuranyl group, Examples thereof include a tetrahydrothiopyranyl group, a 3-bromotetrahydropyranyl group, a 4-methoxytetrahydropyranyl group, a 4-methoxytetrahydrothiopyranyl group, and a 3-tetrahydrothiophene-1,1-dioxide group.

  Among these, t-butyl group, benzyl group, 1-methoxyethyl group, 1-ethoxyethyl group, trimethylsilyl group, t-butoxycarbonyl group, t-butoxycarbonylmethyl group, tetrahydrofuranyl group, tetrahydropyranyl group, tetrahydro A thiofuranyl group and a tetrahydrothiopyranyl group are preferable, and a t-butyl group is more preferable.

  Examples of the monomer that gives the structural unit (II) include 4-t-butoxystyrene, 4-t-butoxy-α-methylstyrene, 4- (2-ethyl-2-propoxy) styrene, 4- ( 2-ethyl-2-propoxy) -α-methylstyrene, 4- (1-ethoxyethoxy) styrene, 4- (1-ethoxyethoxy) -α-methylstyrene, acetoxystyrene and the like. Of these, 4-t-butoxystyrene is preferred.

  As a content rate of the said structural unit (II), in the case of a positive type photoresist composition, 1-50 mol% is preferable with respect to all the structural units which comprise a [B] polymer, and 5-40 mol%. Is more preferable, and 10-30 mol% is further more preferable. If the content of the structural unit (II) is less than 1 mol%, the resolution may be lowered. On the other hand, if the content ratio exceeds 50 mol%, the adhesion of the resist pattern to the substrate may be reduced.

[Structural unit (III)]
The structural unit (III) is a structural unit represented by the following formula (2-3). [B] When the polymer has the structural unit (III), the photoresist composition can reduce nanoedge roughness and improve the depth of focus.

In the above formula (2-3), R ″ is a hydrogen atom or a methyl group. R ^d is a monovalent hydrocarbon group or a monovalent oxyhydrocarbon group not containing an acid dissociable group. t is an integer of 0-3. If R ^d is plural, a plurality of R ^d may be the same or different.

  R ″ is preferably a hydrogen atom.

Examples of the monovalent hydrocarbon group represented by R ^d include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, and t-butyl; cyclopentyl, cyclohexyl, and the like. An aromatic hydrocarbon group such as a phenyl group, a naphthyl group, and a benzyl group.

Examples of the monovalent oxyhydrocarbon group that does not contain an acid dissociable group represented by R ^d include primary groups such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and an n-butoxy group. Or a secondary alkoxy group; a cycloalkyloxy group such as a cyclopentyloxy group and a cyclohexyloxy group; and an oxyaromatic hydrocarbon group such as a phenoxy group and a benzyloxy group.

Among these, R ^d is preferably an alkyl group or an alkoxy group, more preferably a methyl group, an ethyl group, a methoxy group or an ethoxy group, still more preferably a methyl group or a methoxy group, and particularly preferably a methyl group.

  As said t, 0-2 are preferable, 0 or 1 is more preferable, and 0 is further more preferable.

  Examples of the monomer that gives the structural unit (III) include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, 4- And methoxystyrene. Of these, styrene is preferred.

  In the case of a positive photoresist composition, the content of the structural unit (III) is preferably 20 mol% or less, preferably 1 to 10 mol, based on all structural units constituting the [B] polymer. % Is more preferable, and 2 to 8 mol% is more preferable. When the content ratio of the structural unit (II) exceeds 20 mol%, the developability of the resist film may be deteriorated. Moreover, in the case of a negative photoresist composition, 0-50 mol% is preferable with respect to all the structural units which comprise a [B] polymer, 10-40 mol% is more preferable, and 20-35 mol is preferable. % Is more preferable. If the content ratio of the structural unit (III) exceeds 50 mol%, the pattern formability may be lowered.

[Structural unit (IV)]
The structural unit (IV) is a structural unit represented by the following formula (2-4). When the said photoresist composition is positive type, the [B] polymer may have structural unit (IV) as a structural unit containing an acid dissociable group.

In the above formula (2-4), R ^A is a hydrogen atom or a methyl group. R ^e is an acid dissociable group.

As said ^RA , a hydrogen atom is preferable.

The monovalent acid-dissociable group represented by R ^e, for example, t- butyl group, 1-methylcyclopentyl, 1-ethylcyclopentyl, 2-methyl-adamantyl group, and a 2-ethyl adamantyl group It is done.

  Examples of the monomer that gives the structural unit (IV) include t-butyl (meth) acrylate, 1-methylcyclopentyl (meth) acrylate, 1-ethylcyclopentyl (meth) acrylate, and (meth) acrylic acid. Examples include 2-methyladamantyl and 2-ethyladamantyl (meth) acrylate.

  As a content rate of the said structural unit (IV), in the case of a positive photoresist composition, 10-40 mol% is preferable with respect to all the structural units which comprise a [B] polymer, and 10-30 mol%. Is more preferable. If the content of the structural unit (IV) is less than 10 mol%, the resolution may be lowered. On the other hand, if the content ratio exceeds 40 mol%, the dry etching resistance may be insufficient.

  [B] The polymer is a structural unit represented by the following formula (2-4-a) that forms a cross-linked structure via a divalent acid dissociable group between molecular chains among the structural units (IV) ( It is preferred to have IV-a). [B] Since the polymer has the structural unit (IV-a), in the development of the resist film, the molecular weight of the polymer decreases with the generation of the polar group. In this case, the contrast can be improved.

In the above formula (2-4-a), R ^B and R ^{B ′} are each independently a hydrogen atom or a methyl group. R ^C is a divalent acid dissociable group.

Above for ^{R B} and R ^{B 'is} preferably a hydrogen atom.

Examples of the divalent acid dissociable group represented by R ^C include, for example, 1,1,3,3-tetramethylpropanediyl group, 1,1,4,4-tetramethylbutanediyl group, 1,1 , 5,5-tetramethylpentanediyl group and the like. Among these, 1,1,4,4-tetramethylbutanediyl group is preferable.

  Examples of the monomer that gives the structural unit (IV-a) include 2,4-dimethylpentane-2,4-diacrylate, 2,5-dimethylhexane-2,5-diacrylate, 2,6- Examples thereof include dimethyl heptane-2,6-diacrylate. Among these, 2,5-dimethylhexane-2,5-diacrylate is more preferable.

  As a content rate of the said structural unit (IV-a), in the case of a positive type photoresist composition, 10 mol% or less is preferable with respect to all the structural units which comprise a [B] polymer, and 1-5 mol % Is more preferable. When the content rate of a structural unit (IV-a) exceeds 10 mol%, the pattern formation property of the said photoresist composition may fall.

[Structural unit (V)]
The structural unit (V) is a structural unit derived from the following monomer. [B] The polymer may have a structural unit (V) in addition to the structural units (I) to (IV). [B] When the polymer has the structural unit (V), the photoresist composition can further reduce the nano edge roughness and further improve the depth of focus.

As the monomer that gives the structural unit (V), for example,
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate 1-methylpropyl (meth) acrylate, n-pentyl (meth) acrylate, neopentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid 2-hydroxyethyl, 2-hydroxy-n-propyl (meth) acrylate, 3-hydroxy-n-propyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylic acid 1-methyl-2-adamantyl, 1-ethyl-2-adamantyl (meth) acrylate, (meth) acrylic acid 8- Tyl-8-tricyclodecyl, 8-ethyl-8-tricyclodecyl (meth) acrylate, 3-methyl-3-tetracyclododecenyl (meth) acrylate, 3-ethyl (meth) acrylate (Meth) acrylic acid esters such as 3-tetracyclododecenyl and 2,5-dimethylhexane-2,5-di (meth) acrylate;
Unsaturated carboxylic acids (anhydrides) such as (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, cinnamic acid;
Carboxyalkyl esters of unsaturated carboxylic acids such as 2-carboxyethyl (meth) acrylate, 2-carboxy-n-propyl (meth) acrylate, 3-carboxy-n-propyl (meth) acrylate;
Unsaturated nitrile compounds such as (meth) acrylonitrile, α-chloroacrylonitrile, crotonnitrile, maleinnitrile, fumaronitrile;
Unsaturated amide compounds such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleinamide, fumaramide;
Unsaturated imide compounds such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide; N-vinyl-ε-caprolactam, N-vinylpyrrolidone, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2-vinylimidazole And nitrogen-containing vinyl compounds such as 4-vinylimidazole.

  Among these monomers, an unsaturated amide compound is preferable and N, N-dimethyl (meth) acrylamide is more preferable from the viewpoint that the photoresist composition can further reduce nanoedge roughness and further improve the depth of focus. preferable.

  As a content rate of the said structural unit (V), it is 25 mol% or less normally with respect to all the structural units which comprise a [B] polymer, and 15 mol% or less is preferable. When the content ratio of the structural unit (V) exceeds 25 mol%, the resolution may be lowered.

  [B] Examples of the polymer include 4-hydroxystyrene / 4-t-butoxystyrene copolymer, 4-hydroxystyrene / 4-t-butoxystyrene / acrylic acid 1-methylcyclopentyl copolymer, 4-hydroxy Styrene / 4-tert-butoxystyrene / 1-ethylcyclopentyl acrylate copolymer, 4-hydroxystyrene / 4-tert-butoxystyrene / styrene copolymer, 4-hydroxystyrene / tert-butyl acrylate / styrene copolymer 4-hydroxystyrene / 1-methylcyclopentyl acrylate / styrene copolymer, 4-hydroxystyrene / 1-ethylcyclopentyl acrylate / styrene copolymer, 4-hydroxystyrene / 4-tert-butoxystyrene / 2 5-dimethylhexane-2,5-diacrylate copolymer , 4-hydroxystyrene / 2-ethyladamantyl acrylate / styrene copolymer, 4-hydroxystyrene / 2-ethyladamantyl acrylate copolymer, 4-hydroxystyrene / 4- (1-ethoxyethoxy) styrene / 4 -Tert-butoxystyrene copolymer, 4-hydroxystyrene / 4- (1-ethoxyethoxy) styrene copolymer, 4-hydroxystyrene / 4- (1-ethoxyethoxy) styrene / styrene copolymer, 4-hydroxy Examples thereof include styrene / 4-t-butoxystyrene / N, N-dimethylacrylamide copolymer. Among these, 4-hydroxystyrene / 4-t-butoxystyrene / styrene copolymer, 4-hydroxystyrene / 4-t-butoxystyrene / 2,5-dimethylhexane-2,5-diacrylate copolymer 4-hydroxystyrene / 4-t-butoxystyrene / N, N-dimethylacrylamide copolymer is preferred.

<[B] Polymer Synthesis Method>
[B] The method for synthesizing the polymer is not particularly limited, and a conventionally known method can be used. For example, (i) a monomer in which the phenolic hydroxyl group of substituted or unsubstituted hydroxystyrene is protected with a protecting group, such as butoxycarbonyloxystyrene, butoxystyrene, acetoxystyrene, tetrahydropyranyloxystyrene, and the structural unit ( (Ii) A method in which a protective group is hydrolyzed and removed by addition polymerization of a monomer that gives a structural unit other than I) and then reacting with an acid catalyst or a basic catalyst; (ii) substituted or non-substituted Examples thereof include a method of addition polymerization of substituted hydroxystyrene and a monomer that gives a structural unit other than the structural unit (I). Among these, the method (i) is preferable from the viewpoint of efficiently synthesizing the [B] polymer.

  Examples of the addition polymerization include radical polymerization, anionic polymerization, cationic polymerization, and thermal polymerization.

  Examples of the acid catalyst used for the hydrolysis reaction in the method (i) include inorganic acids such as hydrochloric acid and sulfuric acid. Moreover, as a basic catalyst, organic bases, such as a trialkylamine, inorganic bases, such as sodium hydroxide, etc. are mentioned, for example.

  [B] The weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is not particularly limited, but is preferably 1,000 to 150,000, and more preferably 3,000 to 100,000. In addition, the ratio (Mw / Mn) of [B] polymer Mw to polystyrene-reduced number average molecular weight (Mn) by GPC is usually 1 to 5, preferably 1 to 3.

In addition, Mw and Mn of the polymer in this specification are values measured by GPC under the following conditions.
GPC column: 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (manufactured by Tosoh)
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Column temperature: 40 ° C
Standard material: monodisperse polystyrene

  The content of the [B] polymer in the photoresist composition is usually 70% by mass or more and preferably 80% by mass with respect to the total solid content. [B] A polymer can use 1 type (s) or 2 or more types.

<[C] Radiation sensitive compound>
Since the said photoresist composition contains the said [A] compound as an acid generator, it is not necessarily required, You may contain a [C] compound. The compound [C] is a compound other than the compound [A] among compounds that generate an acid upon irradiation with exposure light. As the [C] compound, from the viewpoint of good acid generation efficiency, heat resistance and the like, for example, onium salts, diazomethane compounds, N-sulfonyloxyimide compounds, sulfone compounds, sulfonic acid ester compounds, disulfonylmethane compounds, Examples include oxime sulfonate compounds and hydrazine sulfonate compounds. The photoresist composition may contain one or more [C] compounds.

  Examples of the onium salts include sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium benzenesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium 10-camphorsulfonate, and triphenyl. Sulfonium n-octanesulfonate, triphenylsulfonium 4-trifluoromethylbenzenesulfonate, triphenylsulfonium naphthalenesulfonate, triphenylsulfonium perfluorobenzenesulfonate, trinaphthylsulfonium trifluoromethanesulfonate, trinaphthylsulfonium [2.2.1] heptane- 2-yl-1,1,2,2-tetraf Oro ethanesulfonate, trinaphthyl sulfonium adamantyl-1,1,2,2-tetrafluoroethane sulfonate;
(4-t-butoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, (4-t-butoxyphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, (4-t-butoxyphenyl) diphenylsulfonium perfluoro-n-octanesulfonate, (4-t-butoxyphenyl) diphenylsulfonium 10-camphorsulfonate, (4-hydroxyphenyl) diphenylsulfonium trifluoromethanesulfonate, (4-hydroxyphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, (4-hydroxyphenyl) diphenyl Sulfonium perfluoro-n-octanesulfonate, (4-hydroxyphenyl) diphenylsulfonium 10-camphorsulfonate DOO, (4-hydroxyphenyl) diphenyl sulfonium n- octane sulfonate;
Tris (4-methoxyphenyl) sulfonium trifluoromethanesulfonate, tris (4-methoxyphenyl) sulfonium nonafluoro-n-butanesulfonate, tris (4-methoxyphenyl) sulfonium perfluoro-n-octanesulfonate, tris (4-methoxyphenyl) ) Sulfonium 10-camphorsulfonate;
(4-fluorophenyl) diphenylsulfonium trifluoromethanesulfonate, (4-fluorophenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, (4-fluorophenyl) diphenylsulfonium 10-camphorsulfonate;
Tris (4-fluorophenyl) sulfonium trifluoromethanesulfonate, tris (4-fluorophenyl) sulfonium nonafluoro-n-butanesulfonate, tris (4-fluorophenyl) sulfonium 10-camphor sulfonate, tris (4-fluorophenyl) sulfonium p -Toluenesulfonate, tris (4-trifluoromethylphenyl) sulfonium trifluoromethanesulfonate;
2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium 2,4-difluorobenzenesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium 4-trifluoromethylbenzenesulfonate, etc. Is mentioned.

  Among these, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium 10-camphorsulfonate, trinaphthylsulfonium trifluoromethanesulfonate, (4-hydroxyphenyl) diphenylsulfonium trifluoromethanesulfonate, ( 4-hydroxyphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate, tris (4-methoxyphenyl) sulfonium trifluoromethanesulfonate, tris (4-methoxyphenyl) sulfonium nonafluoro-n-butanesulfonate, (4-fluorophenyl) diphenyl Sulfonium trifluoromethanesulfonate, (4-fluorophenyl) Phenylsulfonium nonafluoro-n-butanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium 2,4-difluorobenzenesulfonate, 2,4,6-trimethylphenyl Diphenylsulfonium 4-trifluoromethylbenzenesulfonate, trinaphthylsulfonium [2.2.1] heptan-2-yl-1,1,2,2-tetrafluoroethanesulfonate, trinaphthylsulfonium adamantyl-1,1,2, 2-tetrafluoroethanesulfonate is preferred, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenyl Sulfonium 10-camphorsulfonate, trinaphthylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium 2,4-difluorobenzenesulfonate, trinaphthylsulfonium [2.2.1] heptan-2-yl-1,1 , 2,2-tetrafluoroethanesulfonate, trinaphthylsulfonium adamantyl-1,1,2,2-tetrafluoroethanesulfonate are more preferable.

Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 10-camphorsulfonate, diphenyliodonium n-octanesulfonate;
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 10-camphorsulfonate, bis (4-t-butylphenyl) iodonium n-octanesulfonate, (4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate, (4-methoxyphenyl) phenyliodonium Nonafluoro-n-butanesulfonate, (4-methoxyphenyl) phenyliodonium perfluoro-n-octanesulfonate;
(4-fluorophenyl) phenyliodonium trifluoromethanesulfonate, (4-fluorophenyl) phenyliodonium nonafluoro-n-butanesulfonate, (4-fluorophenyl) phenyliodonium 10-camphorsulfonate;
Bis (4-fluorophenyl) iodonium trifluoromethanesulfonate, bis (4-fluorophenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-fluorophenyl) iodonium 10-camphorsulfonate;
Bis (4-chlorophenyl) iodonium trifluoromethanesulfonate, bis (4-chlorophenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-chlorophenyl) iodonium perfluoro-n-octanesulfonate, bis (4-chlorophenyl) iodonium n- Dodecylbenzenesulfonate, bis (4-chlorophenyl) iodonium 10-camphorsulfonate, bis (4-chlorophenyl) iodonium n-octanesulfonate, bis (4-chlorophenyl) iodonium 4-trifluoromethylbenzenesulfonate, bis (4-chlorophenyl) iodonium Perfluorobenzenesulfonate;
Bis (4-trifluoromethylphenyl) iodonium trifluoromethanesulfonate, bis (4-trifluoromethylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-trifluoromethylphenyl) iodonium perfluoro-n-octanesulfonate, Bis (4-trifluoromethylphenyl) iodonium n-dodecylbenzenesulfonate, bis (4-trifluoromethylphenyl) iodonium p-toluenesulfonate, bis (4-trifluoromethylphenyl) iodoniumbenzenesulfonate, bis (4-trifluoro Methylphenyl) iodonium 10-camphorsulfonate, bis (4-trifluoromethylphenyl) iodonium n-octanesulfonate, bis (4-trifluoro) B methylphenyl) iodonium 4-trifluoromethyl benzenesulfonate, bis (4-trifluoromethylphenyl) iodonium perfluoro benzene sulfonate, and the like.

  Among these, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium 10-camphorsulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) Iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, (4-fluorophenyl) phenyliodonium trifluoromethanesulfonate, (4-fluorophenyl) phenyliodonium nonafluoro-n-butane Sulfonate, (4-fluorophenyl) phenyliodonium 10-camphorsulfonate, bis (4-fluorophenyl) Iodonium trifluoromethanesulfonate, bis (4-fluorophenyl) iodonium nonafluoro -n- butane sulfonate, bis (4-fluorophenyl) iodonium 10-camphorsulfonate, tris (4-trifluoromethylphenyl) sulfonium trifluoromethanesulfonate are preferable.

  Examples of the diazomethane compound include bis (trifluoromethanesulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (3,3-dimethyl-1,5-dioxaspiro [5.5] dodecane-8-sulfonyl) diazomethane, and bis. (1,4-dioxaspiro [4.5] decane-7-sulfonyl) diazomethane, bis (t-butylsulfonyl) diazomethane and the like.

  Among these, bis (cyclohexylsulfonyl) diazomethane, bis (3,3-dimethyl-1,5-dioxaspiro [5.5] dodecane-8-sulfonyl) diazomethane, bis (1,4-dioxaspiro [4.5] decane -7-sulfonyl) diazomethane is preferred.

Examples of the N-sulfonyloxyimide compound include N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyl). Oxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5,6 -Oxy-2,3-dicarboximide;
N- (10-camphorsulfonyloxy) succinimide, N- (10-camphorsulfonyloxy) phthalimide, N- (10-camphorsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2 , 3-dicarboximide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (10-camphorsulfonyloxy) naphthyl Imido, N-[(5-methyl-5-carboxymethylbicyclo [2.2.1] heptan-2-yl) sulfonyloxy] succinimide;
N- (n-octylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (n-octylsulfonyloxy) bicyclo [2.2.1] heptane- 5,6-oxy-2,3-dicarboximide, N- (perfluorophenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro Phenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluorophenylsulfonyloxy) bicyclo [2.2.1] heptane-5 , 6-oxy-2,3-dicarboximide, N- (nonafluoro-n-butylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3 Dicarboximide, N- (nonafluoro-n-butylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butylsulfonyl) Oxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide;
N- (perfluoro-n-octylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octylsulfonyloxy) -7-oxa Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy- 2,3-dicarboximide etc. are mentioned.

  Among these, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) succinimide, N-[( 5-methyl-5-carboxymethylbicyclo [2.2.1] heptan-2-yl) sulfonyloxy] succinimide is preferred, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5 En-2,3-dicarboximide is more preferred.

  Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds thereof. More specifically, phenacylphenylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, 4-trisphenacylsulfone and the like can be mentioned.

  Examples of the sulfonic acid ester compound include alkyl sulfonic acid esters, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates. More specifically, benzoin tosylate, pyrogallol tris (trifluoromethanesulfonate), pyrogallol tris (nonafluorobutanesulfonate), pyrogallol tris (methanesulfonate), nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, α -Methylol benzoin tosylate, α-methylol benzoin trifluoromethanesulfonate, α-methylol benzoin n-octane sulfonate, α-methylol benzoin n-dodecane sulfonate and the like.

  Examples of the disulfonylmethane compound include compounds represented by the following formula (3-1).

In the above formula (3-1), R ^8a and R ^8b each independently represent a linear or branched alkyl group, cycloalkyl group, aryl group, aralkyl group or monovalent organic group having a hetero atom. It is. V ¹ and V ² are each independently a hydrogen atom, an aryl group, a linear or branched monovalent chain hydrocarbon group, or a monovalent organic group having a hetero atom. However, at least one of V ¹ and V ² is an aryl group. V ¹ and V ² are bonded to each other to form a group having a carbon monocyclic structure or carbon polycyclic structure having at least one unsaturated bond, or a group represented by the following formula (3-1a). May be.

In the above formula (3-1a), W ¹ and W ² are each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. However, the alkyl group, cycloalkyl group, aryl group and aralkyl group may be bonded to each other to form a carbon monocyclic structure together with the carbon atom to which they are bonded. u is an integer of 2 to 10.

When W ¹ and W ² are bonded to each other to form a carbon monocyclic structure, the carbon monocyclic structure may be formed by W ¹ and W ² bonded to the same carbon atom or bonded to different carbon atoms. A carbon monocyclic structure may be formed by W ¹ and W ² .

  Examples of the oxime sulfonate compound include compounds represented by the following formula (3-2-A) and formula (3-2-B), respectively.

In the above formulas (3-2-A) and (3-2-B), R ^9a , R ^9b and R ^9c are each independently a monovalent organic group. R ^10a , R ^10b and R ^10c are each independently a monovalent organic group.

Examples of the monovalent organic group represented by R ^9a , R ^9b and R ^9c include a methyl group, an ethyl group, an n-propyl group, a phenyl group, a tosyl group, a trifluoromethyl group, a pentafluoroethyl group, and the like. Is mentioned.

Examples of the monovalent organic group represented by R ^10a , R ^10b, and R ^10c include a phenyl group, a tosyl group, and a 1-naphthyl group.

  Examples of the hydrazine sulfonate compound include bis (benzenesulfonyl) hydrazine, bis (p-toluenesulfonyl) hydrazine, bis (trifluoromethanesulfonyl) hydrazine, bis (pentafluoroethanesulfonyl) hydrazine, and bis (n-propanesulfonyl) hydrazine. Benzenesulfonylhydrazine, p-toluenesulfonylhydrazine, trifluoromethanesulfonylhydrazine, pentafluoroethanesulfonylhydrazine, n-propanesulfonylhydrazine, trifluoromethanesulfonyl, p-toluenesulfonylhydrazine and the like.

  [C] The content of the compound is preferably 20 parts by mass or less, more preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the [B] polymer. When the content of the [C] compound exceeds 20 parts by mass, the transparency to exposure light is lowered, and the pattern shape, heat resistance and the like may be lowered.

<[D] Acid diffusion controller>
The photoresist composition preferably contains a [D] acid diffusion controller. [D] The acid diffusion controlling agent controls the diffusion phenomenon in the resist film of the acid generated from the [A] compound or the like by exposure, and has an action of suppressing an undesirable chemical reaction in the non-exposed region.

  [D] Examples of the acid diffusion controller include nitrogen-containing organic compounds and photosensitive basic compounds. Examples of the nitrogen-containing organic compound include a compound represented by the following formula (4-1) (hereinafter also referred to as “nitrogen-containing compound (i)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound (i)”). , Also referred to as “nitrogen-containing compound (ii)”), a polymer of a polyamino compound having three or more nitrogen atoms or a nitrogen-containing polymerizable compound (hereinafter collectively referred to as “nitrogen-containing compound (iii)”). ), Amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like. [D] One or two or more acid diffusion control agents can be used.

In said formula (4-1), R ^<11a> , R ^<11b> and R ^<11c> are respectively independently a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. Some or all of the hydrogen atoms of the alkyl group, cycloalkyl group, aryl group and aralkyl group may be substituted.

  Examples of the nitrogen-containing compound (i) include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n- Butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. Di (cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine , Tri-n-nonylamine, tri-n-decylamine, cyclohexyl Tri (cyclo) alkylamines such as dimethylamine, methyldicyclohexylamine, tricyclohexylamine; substituted alkylamines such as triethanolamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3- Methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-tert-butyl-N-methylaniline, N-phenyldiethanolamine, 2,6-diisopropylaniline, etc. Of the aromatic amines.

  Examples of the nitrogen-containing compound (ii) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenylether. 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2, -(4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) ) -1-Methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methyl ester L] benzene, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′ , N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and the like.

  Examples of the nitrogen-containing compound (iii) include polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer, and the like.

As the amide group-containing compound, for example,
Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt- Butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)-(−)-1- (t-butoxy Carbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbonylpiperazine, N, N-di-t-butoxy Rubonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t -Butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra-t-butoxycarbonylhexamethylenediamine, N, N'-di-t-butoxycarbonyl-1,7-diaminoheptane, N, N'- Di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di-t-butoxycarbonyl-1,10-diaminodecane N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N′-di-t-butoxycarbonyl-4,4′-diaminodi Nt-butoxycarbonyl group-containing amino compounds such as phenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole;
Formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric Examples include acid tris (2-hydroxyethyl).

  Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea. Etc.

As the nitrogen-containing heterocyclic compound, for example,
Imidazoles such as imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-methyl-1H-imidazole;
Pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, Pyridines such as quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, 2,2 ′: 6 ′, 2 ″ -terpyridine;
Piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine;
Pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3 -(N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like.
Among these, imidazoles are preferable, and 2-phenylbenzimidazole is more preferable.

  The photosensitive basic compound is a component having a property of efficiently decomposing into a corresponding neutral substance in an exposed region and remaining as it is without decomposing in an unexposed portion. Such a photosensitive basic compound can improve the sensitivity because it can effectively use the acid generated in the exposed area as compared with the non-photosensitive basic compound.

  Although it does not specifically limit as said photosensitive basic compound as long as it has the said property, The compound represented by the following formula (4-2-A) and formula (4-2-2-B) is preferable.

In the above formulas (4-2A) and (4-2B), R ^{12a to} R ^12e are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or 3 to 3 carbon atoms. It is a 10 alicyclic hydrocarbon group or a C1-C10 alkoxy group. Some or all of the hydrogen atoms of the alkyl group, alicyclic hydrocarbon group, and alkoxy group may be substituted. E ^- and G ^- each ^{independently,} OH ^-, R D -O - or ^R D -COO ^- a. However, ^RD is a monovalent organic group.

As a halogen atom represented by said R ^<12a > -R <^12e> , a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example.

As a C1-C10 alkyl group represented by said R ^<12a > -R <^12e> , a methyl group, an ethyl group, n-butyl group, t-butyl group etc. are mentioned, for example.

Examples of the alicyclic hydrocarbon group having 3 to 10 carbon atoms represented by R ^{12a to} R ^12e include a cyclopentyl group, a cyclopentenyl group, a cyclohexyl group, a cyclohexenyl group, a norbornyl group, a norbornenyl group, and an adamantyl group. Is mentioned.

As a C1-C10 alkoxy group represented by said R ^<12a > -R <^12e> , a methoxy group, t-butoxy group, etc. are mentioned, for example.

  Examples of the substituent that the alkyl group, alicyclic hydrocarbon group, and alkoxy group may have include, for example, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, an alkoxy group, an alkoxycarbonyl group, and the like. Is mentioned.

  Examples of the substituted alkyl group, alicyclic hydrocarbon group, and alkoxy group include a trifluoromethyl group, a trichloromethyl group, a perfluorocyclopentyl group, and a t-butoxycarbonylmethyloxy group.

As said R ^<12a > -R <^12e> , a hydrogen atom and a t-butyl group are preferable and a hydrogen atom is more preferable.

Examples of the monovalent organic group represented by ^RD include an alkyl group which may have a substituent and an aryl group which may have a substituent.

Examples of the anion represented by E ⁻ and G ⁻ include OH ⁻ , CH ₃ COO ⁻ , the following formula (4-2-2), formula (4-2-2), and formula (4-2-c). At least one anion selected from the anions represented by each is preferred.

The photosensitive basic compound is a triphenylsulfonium compound (a compound represented by the above formula (4-2-2-A)), and its anion (E ⁻ or G ⁻ ) is OH ⁻ , CH ₃ COO. ^-, the formula (4-2-b) and compound is at least one anion selected from anions represented respectively by formula (4-2-c) are preferred.

  [D] The content of the acid diffusion controller is preferably 15 parts by mass or less, more preferably 0.001 to 10 parts by mass, and 0.005 to 5 parts by mass with respect to 100 parts by mass of the polymer [B]. Is particularly preferred. [D] When the content of the acid diffusion controller exceeds 15 parts by mass, the sensitivity of the photoresist composition and the developability of the exposed part may be deteriorated. Conversely, if the content is less than 0.001 part by mass, the shape and dimensional fidelity of the resulting resist pattern may be lowered depending on the process conditions.

<[E] cross-linking agent>
When the said photoresist composition is a negative photoresist composition, it is preferable to further contain an [E] crosslinking agent. The photoresist composition contains the [E] cross-linking agent, so that when exposed to exposure light, the cross-linking reaction of the [E] cross-linking agent proceeds by the catalytic action of an acid generated from the [A] compound or the like. [B] Crosslinks between the molecules of the polymer and within the same molecule form a crosslinked polymer having low solubility in an alkaline developer, so that a negative resist pattern can be formed after development.

  The [E] crosslinking agent is not particularly limited as long as the [B] polymer can be crosslinked and the crosslinked polymer becomes insoluble or hardly soluble in an alkali developer. [E] Examples of the crosslinking agent include compounds having a crosslinkable functional group represented by the following formulas (5-1) to (5-5).

In the above formula (5-1), f is 1 or 2. Q ¹ is a single bond, an oxygen atom, a sulfur atom, a carbonyloxy group or an amino group when f is 1, and a nitrogen atom when f is 2. Q ² is an oxygen atom or a sulfur atom. f is 1 or 2. k1 is an integer of 0-3. k2 is an integer of 1 to 3. However, k1 and k2 satisfy the condition of 1 ≦ k1 + k2 ≦ 4.

  Examples of the crosslinkable functional group represented by the above formula (5-1) include a glycidyl ether group, a glycidyl ester group, a glycidyl amino group, and the like.

In the above formula (5-2), ^{Q 3} is an oxygen atom, a carbonyl group or a carbonyl group. R ^13a and R ^13b are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ^13c is an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 14 carbon atoms. g is an integer of 1 or more.

  Examples of the crosslinkable functional group represented by the above formula (5-2) include a methoxymethyl group, an ethoxymethyl group, a benzyloxymethyl group, an acetoxymethyl group, a benzoyloxymethyl group, a formyl group, and an acetyl group. It is done. Among these, a methoxymethyl group is preferable.

In said formula (5-3), R ^<14a> , R ^<14b> and R ^<14c> are respectively independently a hydrogen atom or a C1-C4 alkyl group.

  Examples of the crosslinkable functional group represented by the above formula (5-3) include a vinyl group and an isopropenyl group.

In said formula (5-4), R ^<15a> and R ^<15b> are respectively independently a hydrogen atom or a C1-C4 alkyl group. R ^16a and R ^16b are each independently an alkyl group having 1 to 5 carbon atoms or a hydroxyalkyl group having 1 to 5 carbon atoms. h is an integer of 1 or more.

  Examples of the crosslinkable functional group represented by the above formula (5-4) include a dimethylaminomethyl group, a diethylaminomethyl group, a dimethylolaminomethyl group, and a diethylolaminomethyl group.

In said formula (5-5), R ^<17a> and R ^<17b> are respectively independently a hydrogen atom or a C1-C4 alkyl group. R ¹⁸ is a divalent group containing any one of an oxygen atom, a sulfur atom and a nitrogen atom, and forms a 3- to 8-membered monovalent heterocyclic group together with the nitrogen atom to which R ¹⁸ is bonded. i is an integer of 1 or more.

  Examples of the crosslinkable functional group represented by the above formula (5-5) include a monophorylmethyl group.

  Examples of the compound having a crosslinkable functional group include a bisphenol A epoxy compound, a bisphenol F epoxy compound, a bisphenol S epoxy compound, a novolac resin epoxy compound, a resole resin epoxy compound, and a poly (hydroxystyrene) system. Epoxy compound, methylol group-containing melamine compound, methylol group-containing benzoguanamine compound, methylol group-containing urea compound, methylol group-containing phenol compound, methoxymethyl group-containing melamine compound, methoxymethyl group-containing phenol compound, methoxymethyl group-containing glycoluril compound, alkoxy Alkyl group-containing melamine compound, alkoxyalkyl group-containing benzoguanamine compound, alkoxyalkyl group-containing urea compound, alkoxyalkyl group-containing phenol Compound, Carboxymethyl group-containing melamine resin, Carboxymethyl group-containing benzoguanamine resin, Carboxymethyl group-containing urea resin, Carboxymethyl group-containing phenol resin, Carboxymethyl group-containing melamine compound, Carboxymethyl group-containing benzoguanamine compound, Carboxymethyl group-containing urea compound And carboxylmethyl group-containing phenol compounds.

  Among these compounds having a crosslinkable functional group, a methylol group-containing phenol compound, a methoxymethyl group-containing melamine compound, a methoxymethyl group-containing phenol compound, a methoxymethyl group-containing glycoluril compound, a methoxymethyl group-containing urea compound, an acetoxymethyl group A contained phenol compound is preferred, a methoxymethyl-containing glycoluril compound is more preferred, and 1,3,4,6-tetrakis (methoxymethyl) glycoluril is further preferred.

  As said methoxymethyl group containing melamine compound, CYMEL300, CYMEL301, CYMEL303, CYMEL305 (above, the product made from CYTEC Industries) etc. are mentioned, for example. Examples of the methoxymethyl group-containing glycoluril compound include CYMEL1174 (manufactured by CYTEC Industries) and MX-270 (manufactured by Sanwa Chemical). Examples of the methoxymethyl group-containing urea compound include MX290 (manufactured by Sanwa Chemical). [E] 1 type (s) or 2 or more types can be used for a crosslinking agent.

  [E] As the crosslinking agent, the above-mentioned polymer having a crosslinkable functional group can also be used. Examples of such a polymer include a polymer obtained by substituting a hydrogen atom of an acidic group such as a phenolic hydroxyl group in the structural unit (I) of the [B] polymer with a crosslinkable functional group. In this polymer, the rate of introduction of the crosslinkable functional group cannot be unconditionally defined depending on the type of the crosslinkable functional group, the type of the polymer, etc., but is 5 to 60 with respect to the total acidic groups. Mol% is preferable, 10 to 50 mol% is more preferable, and 15 to 40 mol% is more preferable. If the introduction ratio of the crosslinkable functional group is less than 5 mol%, the crosslinking reaction by [E] crosslinking agent does not proceed sufficiently, so the degree of crosslinking decreases, the height of the resulting resist pattern decreases, and the meandering and swelling Etc. may occur easily. On the other hand, if the introduction ratio of the crosslinkable functional group exceeds 60 mol%, the developability of the unexposed area may be lowered.

  [E] As content of a crosslinking agent, in the case of a negative photoresist composition, 0.1-30 mass parts is preferable with respect to 100 mass parts of [B] polymers, and 1-25 mass parts is more. Preferably, 3-20 mass parts is more preferable. [E] When the content of the cross-linking agent is less than 0.1 parts by mass, the degree of cross-linking in the resist pattern becomes small, and the pattern formability may be lowered. On the other hand, when the content of the [E] crosslinking agent exceeds 30 parts by mass, the developability in the unexposed area may be deteriorated.

<[F] solvent>
The photoresist composition usually contains a [F] solvent. [F] The solvent is not particularly limited as long as it can dissolve at least the [A] compound, the [B] polymer, and optional components added as necessary.

[F] As the solvent, for example,
Ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, ethylene glycol mono-n-butyl ether acetate;
Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether;
Propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether, propylene glycol di-n-butyl ether;
Propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-n-butyl ether acetate;

Lactate esters such as methyl lactate, ethyl lactate, n-propyl lactate, i-propyl lactate;
N-amyl formate, i-amyl formate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, i-propyl propionate Aliphatic carboxylic acid esters such as n-butyl propionate and i-butyl propionate;
Ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxy Methyl propionate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutyl butyrate, Esters of carboxylic acids having oxygen atom-containing groups such as methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate;
Aromatic hydrocarbons such as toluene and xylene;
Ketones such as methyl ethyl ketone, 2-pentanone, 2-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone;
Amides such as N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone;
Examples include lactones such as γ-butyrolacun.

  Among these, propylene glycol monoalkyl ether acetates and lactic acid esters are preferable, and propylene glycol monomethyl ether acetate and ethyl lactate are more preferable. [F] A solvent can use 1 type (s) or 2 or more types.

<Other optional components>
If necessary, the photoresist composition may include surfactants, sensitizers, dyes, pigments, adhesion aids, antihalation agents such as 4-hydroxy-4′-methylchalcone, and shape improvement as other optional components. Agents, storage stabilizers, antifoaming agents, and the like. The photoresist composition may contain one or more other optional components.

[Surfactant]
The surfactant has an effect of improving applicability and striation of the photoresist composition, developability as a resist, and the like.

  Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenol ether, polyoxyethylene n-nonylphenol ether, polyethylene glycol dilaurate, polyethylene glycol distearate. Rate and the like. Commercially available products include, for example, F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), MegaFuck F171, F173 (above, manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (above, Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (above, manufactured by Asahi Glass), KP341 (manufactured by Shin-Etsu Chemical), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.).

  As content of surfactant, it is 2 mass parts or less normally with respect to 100 mass parts of [B] polymers.

[Sensitizer]
The sensitizer exhibits an action of increasing the amount of acid generated from the [A] compound and the [C] compound, and has an effect of improving the “apparent sensitivity” of the photoresist composition. Examples of the sensitizer include rose bengal. As content of a sensitizer, it is 50 mass parts or less normally with respect to 100 mass parts of [B] polymers.

<Method for preparing photoresist composition>
The photoresist composition can be prepared, for example, by mixing the [A] compound, the [B] polymer, and optional components added as necessary at a predetermined ratio. The photoresist composition, for example, after uniformly dissolving or dispersing each component in the [F] solvent so that the total solid content concentration is 0.1 to 50% by mass, preferably 1 to 40% by mass, For example, it is prepared by filtering with a filter having a pore size of about 0.2 μm.

<Method for forming resist pattern>
A resist pattern forming method using the photoresist composition includes (1) a resist film forming step of applying the photoresist composition on a substrate to form a resist film, and (2) an exposure step of exposing the resist film. And (3) a developing step of developing the exposed resist film. Hereinafter, the resist pattern forming method will be described separately for each of a positive type and a negative type.

[Positive resist pattern]
Hereinafter, a method for forming a positive resist pattern will be described.

[(1) Resist film forming step]
In this step, the positive photoresist composition is applied onto a substrate to form a resist film. Examples of the substrate include a silicon wafer, a wafer covered with aluminum, and the like. Examples of the coating method include spin coating, cast coating, roll coating, and the like.

  After applying the photoresist composition, pre-baking (PB) may be performed as necessary. As temperature of PB, it is 70 to 160 degreeC normally, and 80 to 140 degreeC is preferable. The PB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds.

In order to prevent the influence of basic impurities contained in the environmental atmosphere, for example, a protective film described in JP-A-5-188598 can be provided on the resist film.
[(2) Exposure process]
In this step, the resist film formed in the step (1) is exposed through a predetermined mask pattern.

  As exposure light used for exposure, electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, and X-rays; charged particle beams such as electron beams and α rays can be appropriately selected. ArF excimer laser light (wavelength 193 nm) and far ultraviolet rays such as KrF excimer laser light (wavelength 248 nm) are preferable, and KrF excimer laser light is particularly 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 order to stably form a fine resist pattern with high accuracy, it is preferable to perform post-exposure baking (PEB) after exposure. As temperature of PEB, it is 70 to 160 degreeC normally, and 80 to 140 degreeC is preferable. If the temperature of the PEB is less than 70 ° C., there may be an increase in variation in sensitivity depending on the type of substrate. The PEB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 600 seconds.

[(3) Development process]
In this step, after the exposure in the step (2), development is performed using an alkaline developer to form a positive resist pattern.

  Alkali developers include alkali metal hydroxides, ammonia, mono-, di- or tri-alkylamines, mono-, di- or tri-alkanolamines, heterocyclic amines, tetraalkylammonium hydroxides , Choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3.0] -5-nonene, etc. %, Preferably 1 to 5% by mass, particularly preferably an alkaline aqueous solution dissolved so as to have a concentration of 1 to 3% by mass. In addition, for example, a water-soluble organic solvent such as methanol or ethanol or a surfactant can be appropriately added to the alkaline developer.

  The processing conditions in the development step are usually 10 ° C. to 50 ° C. for 10 seconds to 200 seconds, preferably 15 ° C. to 30 ° C. for 15 seconds to 100 seconds, and particularly preferably 20 ° C. to 25 ° C. for 15 seconds to 90 seconds. It is. In addition, after developing with a developing solution, it is preferable to wash and dry with water.

[Negative resist pattern]
Hereinafter, a method for forming a negative resist pattern will be described.

[(1) Resist film forming step]
In this step, the negative photoresist composition is applied onto a substrate to form a resist film. The substrate to be used and the coating method are the same as in the positive type. Also, the formation of the protective film on the PB and the resist film is the same as in the positive type.

[(2) Exposure process]
In this step, the resist film formed in the step (1) is exposed through a predetermined mask pattern. Under the present circumstances, acidic groups, such as a phenolic hydroxyl group in a [B] polymer, react with an [E] crosslinking agent by the effect | action of the acid etc. which generate | occur | produced from the [A] compound by exposure, and are bridge | crosslinked. In this manner, the exposed portion of the resist film having the crosslinked [B] polymer has low solubility in an alkaline developer. The exposure light used in the exposure process is the same as in the positive type.

  It is preferable to perform PEB after exposure. By this PEB, the crosslinking reaction of the [E] crosslinking agent in the resist film proceeds smoothly. The temperature of PEB varies depending on the composition of the photoresist composition, but is preferably 30 to 200 ° C, more preferably 50 to 170 ° C. The PEB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds.

[(3) Development process]
In this step, after the exposure in the step (2), development is performed using an alkali developer to form a negative resist pattern.

  Examples of the alkaline developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl Diethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, and 1,5-diazabicyclo- [4. 3.0] -5] An alkaline aqueous solution in which at least one selected from the group consisting of alkaline compounds such as 5-nonene is dissolved. The concentration of the alkaline aqueous solution is preferably 10% by mass or less. When the concentration of the alkaline aqueous solution exceeds 10% by mass, the unexposed area may be dissolved in the developer.

For example, an organic solvent can be added to the developer. As such an organic solvent, for example,
Ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, 2,6-dimethylcyclohexanone;
Alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol Kind;
Ethers such as tetrahydrofuran and dioxane;
Esters such as ethyl acetate, n-butyl acetate, i-amyl acetate;
Aromatic hydrocarbons such as toluene and xylene;
Phenol, acetonyl acetone, dimethylformamide, etc. are mentioned. In addition, 1 type, or 2 or more types can be used for these organic solvents.

  The content ratio of the organic solvent in the developer is preferably 100 parts by volume or less with respect to 100 parts by volume of the alkaline aqueous solution. When the content ratio of the organic solvent exceeds 100 parts by volume, the developability is lowered, and there is a concern that the development residue in the exposed part increases. An appropriate amount of a surfactant or the like can be added to the developer. Note that the processing conditions of the development process and washing and drying with water are the same as in the positive type.

  By the above-described forming method, the unexposed portion of the resist film is dissolved and removed by the developer, whereby a negative resist pattern can be formed.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measuring method of various physical property values is shown below.

[ ¹³ C-NMR analysis]
The ¹³ C-NMR analysis of the polymer was measured using a nuclear magnetic resonance apparatus (JNM-ECX400, manufactured by JEOL Ltd.).

<[B] Synthesis of polymer>
[B] Monomers (compounds represented by the following formulas (L-1) to (L-5)) used for polymer synthesis are shown below.

[Synthesis Example 1] (Synthesis of polymer (B-1))
117 g (72 mol%) of the compound (L-1), 41 g (23 mol%) of the compound (L-2), 5 g (5 mol%) of the compound (L-3), azobisisobutyro as a polymerization initiator 6 g of nitrile (AIBN) and 1 g of t-dodecyl mercaptan as a chain transfer agent were dissolved in 160 g of propylene glycol monomethyl ether, and then the polymerization reaction was carried out for 16 hours while maintaining the reaction temperature at 70 ° C. in a nitrogen atmosphere. After the polymerization, the reaction solution was dropped into a large amount of n-hexane, and the resulting polymer was coagulated and purified.

  Next, 150 g of propylene glycol monomethyl ether was added to the polymer obtained by this purification, and then 300 g of methanol, 80 g of triethylamine and 15 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. . After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting polymer was dissolved in acetone, then dripped into a large amount of water to solidify, and the resulting white powder was filtered and filtered under reduced pressure at 50 ° C. overnight. It dried and obtained the polymer (B-1) (94g, 71% of yield).

The obtained polymer (B-1) had Mw of 16,000 and Mw / Mn of 1.7. As a result of ¹³ C-NMR analysis, the structural unit represented by the following formula (B1): the structural unit represented by the following formula (B2): the content ratio of the structural unit represented by the following formula (B3) (mol) %) Was 72: 23: 5.

[Synthesis Example 2] (Synthesis of polymer (B-2))
182 g (73 mol%) of the above compound (L-1), 66 g (24 mol%) of the compound (L-2), 11 g of compound (L-4) (3 mol% based on the polymerizable group), 14 g of AIBN and t-dodecyl After 11 g of mercaptan was dissolved in 240 g of propylene glycol monomethyl ether, the polymerization reaction was carried out for 16 hours while maintaining the reaction temperature at 70 ° C. in a nitrogen atmosphere. After the polymerization, the reaction solution was dropped into a large amount of n-hexane to solidify and purify the produced polymer, and dried at 50 ° C. under reduced pressure for 3 hours.

  Next, after adding 150 g of propylene glycol monomethyl ether to 190 g of the polymer obtained by this purification, 300 g of methanol, 100 g of triethylamine and 15 g of water are further added, and a hydrolysis reaction is performed for 8 hours while refluxing at the boiling point. It was. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting polymer was dissolved in acetone, then dripped into a large amount of water to solidify, and the resulting white powder was filtered and filtered under reduced pressure at 50 ° C. overnight. It dried and the polymer (B-2) was obtained (157 g, yield 74%).

The obtained polymer (B-2) had Mw of 27,000 and Mw / Mn of 2.6. As a result of ¹³ C-NMR analysis, the structural unit represented by the following formula (B1): the structural unit represented by the following formula (B3): the content ratio of the structural unit represented by the following formula (B4a) (mol) %) Was 75: 22: 3.

[Synthesis Example 3] (Synthesis of Polymer (B-3))
114 g (69 mol%) of the above compound (L-1), 35 g (20 mol%) of the compound (L-2) and 11 g (11 mol%) of the compound (L-5), 6 g of AIBN and 1 g of t-dodecyl mercaptan are mixed with propylene. After dissolving in 160 g of glycol monomethyl ether, the polymerization reaction was carried out for 16 hours while maintaining the reaction temperature at 70 ° C. in a nitrogen atmosphere. After the polymerization, the reaction solution was dropped into a large amount of n-hexane, and the resulting polymer was coagulated and purified.

  Next, 150 g of propylene glycol monomethyl ether was added to the polymer obtained by this purification, and then 300 g of methanol, 80 g of triethylamine and 15 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. . After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting polymer was dissolved in acetone, then dripped into a large amount of water to solidify, and the resulting white powder was filtered and filtered under reduced pressure at 50 ° C. overnight. It dried and the polymer (B-3) was obtained (94g, yield 72%).

The obtained polymer (B-3) had Mw of 14,000 and Mw / Mn of 1.7. As a result of ¹³ C-NMR analysis, the structural unit represented by the following formula (B1): the structural unit represented by the following formula (B3): the content ratio of the structural unit represented by the following formula (B5) (mol) %) Was 70:20:10.

  Table 1 shows the content ratios of the respective structural units of the polymers (B-1) to (B-3) synthesized in Synthesis Examples 1 to 3. The structural unit (B1) is the structural unit (I), the structural unit (B2) is the structural unit (II), the structural unit (B3) is the structural unit (III), and the structural unit (B4a). ) Corresponds to the structural unit (IV), and the structural unit (B5) corresponds to the structural unit (V).

<Preparation of photoresist composition>
Each component constituting the photoresist composition other than the polymers (B-1) to (B-3) synthesized in the above synthesis example ([A] compound, [B] polymer, [C] compound, [D] The acid diffusion inhibitor, [E] crosslinking agent and [F] solvent) are shown below.

[[B] polymer]
(B-4): Hydroxystyrene / styrene copolymer (obtained by copolymerizing the above compound (L-1) and compound (L-3) (polymerization charge molar ratio = 8: 2), followed by hydrolysis). Mw is 4,000, Mw / Mn is 1.5, the structural unit represented by the above formula (B1): the content ratio (mol%) of the structural unit represented by the above formula (B3) Was 79:21.)
(B-5): Hydroxystyrene / styrene copolymer (obtained by copolymerizing the above compound (L-1) and compound (L-3) (polymerization charge molar ratio = 7: 3), followed by hydrolysis). Mw is 4,000, Mw / Mn is 1.5, the structural unit represented by the above formula (B1): the content ratio (mol%) of the structural unit represented by the above formula (B3) Was 68:32.)

[[A] Compound]
The structural formula of each compound is shown below.
A-1 :: Triphenylsulfonium 4- (1-adamantanecarbonyloxy) -1,1,2-trifluorobutanesulfonate A-2: Trinaphthylsulfonium 4- (1-adamantanecarbonyloxy) -1,1,2 -Trifluorobutanesulfonate A-3: Trinaphthylsulfonium 1,1,2-trifluoro-4- (2- (2-propyloxycarbonyl) cyclohexanecarbonyloxy) butanesulfonate A-4: Trianthrylsulfonium 4- (1 -Adamantanecarbonyloxy) -1,1,2-trifluorobutanesulfonate

[[C] Compound]
The structural formula of each compound is shown below.
C-1: Triphenylsulfonium trifluoromethanesulfonate C-2: Triphenylsulfonium nonafluoro-n-butanesulfonate C-3: Triphenylsulfonium 10-camphorsulfonate C-4: Trinaphthylsulfonium trifluoromethanesulfonate C-5: 2, 4,6-trimethylphenyldiphenylsulfonium 2,4-difluorobenzenesulfonate C-6: N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide

[[D] acid diffusion controller]
D-1: 2-Phenylbenzimidazole

[[E] cross-linking agent]
E-1: 1,3,4,6-tetrakis (methoxymethyl) glycoluril

[[F] solvent]
F-1: Ethyl lactate F-2: Propylene glycol monomethyl ether acetate

[Example 1]
[A] 4 parts by mass of (A-1) compound, (B-1) 100 parts by mass of polymer, (C-5) 0.5 parts by mass of [C] compound, [D It was obtained by mixing 1.2 parts by mass of (D-1) as the acid diffusion controller and 400 parts by mass of (F-1) and 1,000 parts by mass of (F-2) as the solvent. A positive photoresist composition (J-1) according to Example 1 was prepared by filtering the mixed solution with a Teflon (registered trademark) membrane filter having a pore diameter of 0.2 μm.

[Examples 2 to 10 and Comparative Examples 1 to 6]
Except having used each component of the kind and compounding quantity which are shown in Table 2, it is the same as Example 1, and the photoresist composition (J-2)-(J-10) of Examples 2-10 and Comparative Examples 1- 1 are the same. 6 photoresist compositions (CJ-1) to (CJ-6) were prepared. “-” In Table 2 indicates that the corresponding component was not used. Note that the photoresist compositions (J-2) to (J-6), (J-9), (J-10), (CJ-1) to (CJ-3), (CJ-5) and (CJ -6) is a positive photoresist composition, and photoresist compositions (J-7), (J-8) and (CJ-4) are negative photoresist compositions.

<Evaluation>
Using the photoresist compositions of the above examples and comparative examples, resist patterns were formed by the following methods, and the sensitivity, nanoedge roughness, and depth of focus were evaluated. The obtained evaluation results are shown in Table 3 below.

[Formation of resist pattern]
After the photoresist composition was spin-coated on a silicon wafer, PB was performed at 110 ° C. for 90 seconds to form a resist film having a thickness of 0.25 μm. Thereafter, this resist film was exposed to KrF excimer laser light (wavelength 248 nm) using a KrF excimer laser irradiation apparatus (NSR-S203B, manufactured by Nikon) through a mask pattern at a temperature of 110 ° C. PEB was performed for 2 seconds. Thereafter, a 2.38 mass% tetramethylammonium hydroxide aqueous solution was used as a developing solution, developed at 23 ° C. for 60 seconds, washed with water for 30 seconds and dried to form a resist pattern.

[sensitivity]
Optimum exposure for the exposure amount for forming a pattern (line-and-space pattern (1L1S)) composed of a line portion having a line width of 160 nm and a space portion having an interval of 160 nm formed by adjacent line portions with a line width of 1: 1. The optimum exposure dose was taken as sensitivity (mJ / cm ² ).

[Nano edge roughness]
A line pattern of a line-and-space pattern (1L1S) having a design line width of 160 nm was observed using a semiconductor scanning electron microscope (high resolution field emission scanning electron microscope S-4800, manufactured by Hitachi, Ltd.). With respect to the observed shape, as shown in FIGS. 1 and 2, the maximum line width at the most marked portion of the unevenness generated along the lateral side surface 2a of the line portion 2 of the resist film formed on the silicon wafer 1, The difference “ΔCD” from the design line width of 160 nm was defined as the value of nano edge roughness (nm).

[Depth of focus]
A pattern consisting of a line portion having a line width of 1600 nm and a space portion having an interval of 160 nm formed by adjacent line portions (10 line 1 space pattern (10L1S)) is defined as an isolated space pattern (IS pattern). The depth of focus (unit: μm) was measured with the exposure amount at which the part was formed at 160 nm. Depth of focus is measured in 0.05μm steps by observing the exposed IS pattern with the above-mentioned scanning electron microscope for semiconductors, determining that the space has reached the substrate, and measuring the resolution. The range formed was defined as the depth of focus.

  From the results of Table 3, the photoresist composition of the example containing the [A] compound reduces the nano edge roughness while maintaining the sensitivity as compared with the photoresist composition of the comparative example not containing the [A] compound. It has been shown that it is possible to achieve a wide depth of focus. It was also shown that nanoedge roughness can be further reduced and the depth of focus can be further improved by using the [A] compound containing a sulfonium cation having a naphthalene ring or an anthracene ring.

  According to the present invention, it is possible to provide a photoresist composition that can reduce nanoedge roughness and is excellent in depth of focus. Therefore, the present invention is suitable for fine processing by lithography.

1 Substrate 2 Resist pattern 2a Side surface of resist pattern

Claims (3)

[A] a compound represented by the following formula (1), and [B] a polymer having a structural unit (I) represented by the following formula (2-1) ,
[B] The polymer is
Structural unit (III) represented by the following formula (2-3),
Structural unit (IV) represented by the following formula (2-4), or
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate 1-methylpropyl (meth) acrylate, n-pentyl (meth) acrylate, neopentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid 2-hydroxyethyl, 2-hydroxy-n-propyl (meth) acrylate, 3-hydroxy-n-propyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylic acid 1-methyl-2-adamantyl, 1-ethyl-2-adamantyl (meth) acrylate, (meth) acrylic acid 8- Tyl-8-tricyclodecyl, 8-ethyl-8-tricyclodecyl (meth) acrylate, 3-methyl-3-tetracyclododecenyl (meth) acrylate, 3-ethyl (meth) acrylate 3-tetracyclododecenyl, 2,5-dimethylhexane-2,5-di (meth) acrylate, unsaturated carboxylic acid (anhydride), carboxyalkyl ester of unsaturated carboxylic acid, unsaturated nitrile compound, unsaturated Structural units derived from saturated amide compounds, unsaturated imide compounds or nitrogen-containing vinyl compounds (V)
The photoresist composition which further have a.

(In the formula (1), R ¹ is a monovalent alicyclic hydrocarbon group having a carbon number of 3-20. However, some or all of the hydrogen atom of the above Kiabura cyclic hydrocarbon radical substituted R ² is a divalent linking group, R ^f is a fluorine atom or a fluorinated alkyl group having 1 to 30 carbon atoms, M ⁺ is a monovalent cation, n 1 And n2 are each independently 0 or 1.)

(In the formula (2-1), R is a hydrogen atom or a methyl group. R ^a is a monovalent organic group. P is an integer of 0 to 3, provided that R ^a is a plurality of R ^a . In this case, a plurality of R ^a may be the same or different, and q is an integer of 1 to 3, provided that the condition of p + q ≦ 5 is satisfied.

(In formula (2-3), R ″ is a hydrogen atom or a methyl group. R ^d is a monovalent oxyhydrocarbon group not containing a monovalent hydrocarbon group or acid dissociable group. t is an integer of 0 to 3. When R ^d is plural, the plural R ^d may be the same or different.

(In Formula (2-4), R ^A is a hydrogen atom or a methyl group. R ^e is an acid-dissociable group.) The photo according to claim 1, wherein the M ⁺ is at least one cation selected from the group consisting of a cation represented by the following formula (i-1) and a cation represented by the following formula (ii-1). Resist composition.

(In formula (i-1), g1, g2, and g3 are each independently an integer of 0 to 2, provided that at least one of g1, g2, and g3 is 1 or 2. R ^A1 , R ^A2 and R ^A3 are each independently a monovalent organic group, a hydroxyl group or a halogen atom, and a, b and c are each independently an integer of 0 to 9, provided that R ^{A1, R} when ^A2 and ^{R A3} is plural, respectively, a plurality of ^{R A1, R A2} and ^{R A3} may be the same as or different from each other.
In formula (ii-1), h1 and h2 are each independently an integer of 0 to 2. However, at least one of h1 and h2 is 1 or 2. R ^B1 and R ^B2 are each independently a monovalent organic group, a hydroxyl group, or a halogen atom. d and e are each independently an integer of 0 to 9. ^However, in the case of multiple ^{R B1} and ^{R B2} are each, or different in each of the plurality of ^{R B1} and ^{R B2} same. ) [B] The photoresist composition according to claim 1 or 2 , wherein the polymer further has a structural unit (II) represented by the following formula (2-2).

(In Formula (2-2), R ′ is a hydrogen atom or a methyl group. R ^b is a monovalent organic group not containing an acid-dissociable group. R is an integer of 0 to 3. .R ^c is a is .s monovalent acid-dissociable group, an integer of 1 to 3. However, in the case of multiple ^{R b} and ^{R c} are each, in each of the plurality of ^{R b} and ^{R c} identical It may be different, and the condition of r + s ≦ 5 is satisfied.)

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