JP5573098B2 - Chemically amplified photoresist composition - Google Patents

Description

  The present invention relates to a chemically amplified photoresist composition used for semiconductor microfabrication, and a pattern forming method using the chemically amplified photoresist composition.

  Recently, a resin obtained by polymerizing monomers G, B and D shown below as a resin in a molar ratio of 40:20:40, and p-adamantylphenyldiphenylsulfonium perfluorobutanesulfonate as an acid generator A chemically amplified photoresist composition comprising 2,6-diisopropylaniline as a quencher and a solvent has been proposed (Patent Document 1).

JP 2008-107377 A

  In the conventional chemically amplified photoresist composition, the shape of the pattern obtained and the line edge roughness may not be sufficient.

［式（Ｉ）中、Ｑ^１及びＱ^２は、互いに独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｘ^０は、２価のＣ_１-17飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙ^１は、炭素数３〜３６の飽和環状炭化水素基を表し、該飽和環状炭化水素基に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基又は炭素数６〜１２のアリール基で置換されていてもよく、該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。
Ｚ^＋は、飽和環状炭化水素基を含む有機カチオンを表す。］

［式（ＩＩ）中、Ｒ^１は、水素原子又はメチル基を表す。
Ｘ^２は、単結合又は−［ＣＨ_２］_ｋ−を表し、該−［ＣＨ_２］_ｋ−に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
ｋは、１〜８の整数を表す。
Ｙ^２は、炭素数４〜３６の飽和環状炭化水素基を表し、該飽和環状炭化水素基に含まれる水素原子は、ハロゲン原子、水酸基、炭素数１〜１２の脂肪族炭化水素基、アルコキシ基、炭素数６〜２０の芳香族炭化水素基、炭素数７〜２１のアラルキル基、グリシドキシ基又は炭素数２〜４のアシル基で置換されていてもよく、該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。］ The present invention includes the following inventions.
1. A chemically amplified photoresist composition comprising an acid generator represented by formula (I) and a resin having a structural unit represented by formula (II).

[In Formula (I), Q < ¹ > and Q < ² > represent a fluorine atom or a C1-C6 perfluoroalkyl group mutually independently.
X ⁰ represents a divalent C _1-17 saturated hydrocarbon group, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Y ¹ represents a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Z ⁺ represents an organic cation containing a saturated cyclic hydrocarbon group. ]

[In Formula (II), R ¹ represents a hydrogen atom or a methyl group.
X ² represents a single bond or — [CH ₂ ] _k —, and —CH ₂ — contained in — [CH ₂ ] _k — may be replaced by —O— or —CO—.
k represents an integer of 1 to 8.
Y ² represents a saturated cyclic hydrocarbon group having 4 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a halogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group. , An aromatic hydrocarbon group having 6 to 20 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidoxy group, or an acyl group having 2 to 4 carbon atoms, and is included in the saturated cyclic hydrocarbon group —CH ₂ — may be replaced by —CO— or —O—. ]

［式（Ｉ−１）中、Ｑ^１、Ｑ^２、Ｙ^１及びＺ^＋は、上記と同じ意味を表す。Ｘ^１は、単結合又は−［ＣＨ_２］_ｋ１−を表し、該−［ＣＨ_２］_ｋ１−に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
ｋ１は、１〜８の整数を表す。］ 2. 2. The composition according to 1, wherein the acid generator represented by the formula (I) is an acid generator represented by the formula (I-1).

[In formula (I-1), Q ¹ , Q ² , Y ¹ and Z ⁺ represent the same meaning as described above. X ¹ represents a single bond or — [CH ₂ ] _k1 —, and —CH ₂ — contained in — [CH ₂ ] _k1 — may be replaced by —O— or —CO—.
k1 represents an integer of 1 to 8. ]

［式（ＡＡ）中、Ａ^１及びＡ^２は、互いに独立に、炭素数１〜２０の脂肪族炭化水素基、炭素数６〜２０の芳香族炭化水素基又は炭素数７〜２１のアラルキル基を表すか、Ａ^１とＡ^２とが互いに結合して炭素数１〜２０の環を形成していてもよい。
Ａｒ^１は、（ｍ_４＋１）価の炭素数６〜２０の芳香族炭化水素基又は炭素数５〜２０の芳香族複素環基を表す。
Ｂ^１は、単結合又は炭素数１〜６のアルキレン基を表し、該アルキレン基に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。
Ｂ^２は、炭素数６〜３６の飽和環状炭化水素基を表す。
ｍ_１及びｍ_２は、互いに独立に、０〜２の整数を表す。
ｍ_３は、１〜３の整数を表す。ただし、ｍ_１＋ｍ_２＋ｍ_３＝３である。
ｍ_４は、１〜３の整数を表す。］ 3. Item 3. The composition according to item 1 or 2, wherein Z ⁺ is a cation represented by the formula (AA).

[In Formula (AA), A ¹ and A ² are each independently an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 21 carbon atoms. Or A ¹ and A ² may be bonded to each other to form a ring having 1 to 20 carbon atoms.
Ar ¹ represents an (m ₄ +1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 5 to 20 carbon atoms.
B ¹ represents a single bond or an alkylene group having 1 to 6 carbon atoms, and —CH ₂ — contained in the alkylene group may be replaced by —CO— or —O—.
B ² represents a saturated cyclic hydrocarbon group having 6 to 36 carbon atoms.
m ₁ and m ₂ each independently represent an integer of 0 to 2.
m ₃ represents an integer of 1 to 3. _However, it is _{m 1 + m 2 + m 3} = 3.
m ₄ represents an integer of 1 to 3. ]

4). 4. The composition according to 3, wherein B ² is a saturated polycyclic hydrocarbon group having 10 to 36 carbon atoms.

5. Item 5. The composition according to item 3 or 4, wherein B ² and Y ² are rings having the same skeleton.

6). Furthermore, the composition in any one of Claims 1-5 containing the other acid generator different from the acid generator represented by Formula (I).

7). 7. The composition according to any one of 1 to 6, wherein the resin having a structural unit represented by formula (II) is a resin containing three or more different structural units.

8). A pattern forming method including the following steps.
(1) The process of apply | coating the composition in any one of 1-7 on a board | substrate (2) The process of removing a solvent from the composition after application | coating, and forming a composition layer (3) In a composition layer Step of exposing using exposure machine (4) Step of heating composition layer after exposure (5) Step of developing composition layer after heating using developing device

  According to the chemically amplified photoresist composition of the present invention, a pattern having an excellent shape and line edge roughness can be obtained.

  The chemically amplified photoresist composition of the present invention (hereinafter sometimes referred to as “resist composition”) may be referred to as an acid generator represented by formula (I) (hereinafter referred to as “acid generator (A)”). Contains).

[In Formula (I), Q < ¹ > and Q < ² > represent a fluorine atom or a C1-C6 perfluoroalkyl group mutually independently.
X ⁰ represents a divalent C _1-17 saturated hydrocarbon group, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Y ¹ represents a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Z ⁺ represents an organic cation containing a saturated cyclic hydrocarbon group. ]

［式（Ｉ−１）中、Ｑ^１、Ｑ^２、Ｙ^１及びＺ^＋は、上記と同じ意味を表す。Ｘ^１は、単結合又は−［ＣＨ_２］_ｋ−を表し、該−［ＣＨ_２］_ｋ−に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。］ Especially, as an acid generator, the acid generator represented by a formula (I-1) is preferable.

[In formula (I-1), Q ¹ , Q ² , Y ¹ and Z ⁺ represent the same meaning as described above. X ¹ represents a single bond or — [CH ₂ ] _k —, and —CH ₂ — contained in — [CH ₂ ] _k — may be replaced by —O— or —CO—. ]

Z ⁺ may be a cation having a saturated cyclic hydrocarbon group. For example, an aromatic hydrocarbon group is bonded to a sulfur cation, and the aromatic hydrocarbon group is substituted with a saturated cyclic hydrocarbon group. An arylsulfonium cation etc. are mentioned.

Examples of X ¹ include a methylene group, a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, and a propylidene group.
Examples of the saturated cyclic hydrocarbon group having 3 to 36 carbon atoms in Y ¹ include a cation represented by the formula (AA).

[In Formula (AA), A ¹ and A ² are each independently an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 21 carbon atoms. Or A ¹ and A ² may be bonded to each other to form a ring having 1 to 20 carbon atoms.
Ar ¹ represents an (m ₄ +1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 5 to 20 carbon atoms.
B ¹ represents a single bond or an alkylene group having 1 to 6 carbon atoms, and —CH ₂ — contained in the alkylene group may be replaced by —CO— or —O—.
B ² represents a saturated cyclic hydrocarbon group having 6 to 36 carbon atoms.
m ₁ and m ₂ each independently represent an integer of 0 to 2.
m ₃ represents an integer of 1 to 3. _However, it is _{m 1 + m 2 + m 3} = 3.
m ₄ represents an integer of 1 to 3. ]

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms in A ¹ and A ² include a phenyl group, a naphthyl group, and an anthranyl group, and a phenyl group and a naphthyl group are preferable.
The aromatic hydrocarbon group may have a hetero atom, and examples of the aromatic hydrocarbon group having a hetero atom include a pyrrole group and an indole group, preferably an indole group. It is done.
Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms in A ¹ and A ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. , N-pentyl group, n-hexyl group, n-octyl group and the like.
Examples of the saturated cyclic hydrocarbon group having 3 to 20 carbon atoms in A ¹ and A ² include a cyclopropyl group, a cyclohexyl group, a norbornane group, and an adamantyl group.
Examples of the aralkyl group having 7 to 21 carbon atoms in A ¹ and A ² include a benzyl group and a phenethyl group.
In A ¹ and A ² , it is preferable that both A ¹ and A ² are phenyl groups, or A ¹ and A ² together form a ring having 4 to 6 carbon atoms.
Ar ¹ is, for example, an aromatic hydrocarbon group having 6 to 20 carbon atoms in A ¹ and A ² in which a hydrogen atom corresponding to the valence is removed and becomes a bond, preferably p-adamantylphenyl Groups.
Examples of the alkylene group having 1 to 6 carbon atoms in B ¹ include a methylene group, a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and a propylidene group. —CH ₂ — contained in the alkylene group may be replaced by —CO— or —O—.
Examples of the saturated cyclic hydrocarbon group having 6 to 36 carbon atoms for B ² include a saturated monocyclic hydrocarbon group and a saturated polycyclic hydrocarbon group.
Examples of the monocyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.
Preferred examples of the polycyclic hydrocarbon group include an adamantyl group, a norbornane group, a bicyclo [2.2.2] octane group, a tetracyclododecanyl group, a tricyclodecanyl group, a diamantyl group, and the like. An adamantyl group is preferable.

  Examples of the cation having a saturated cyclic hydrocarbon group include a cation represented by the formula (AA-a) and a cation represented by the formula (AA-b), and preferably a cation represented by the formula (AA-a). Cations.

[Ar ¹ , B ¹ , B ² , m ₁ , m ₂ , m ₃ and m ₄ in Formula (AA-a) and Formula (AA-b) represent the same meaning as in Formula (AA).
Ar ² and Ar ³ each independently represent an aromatic hydrocarbon group having 6 to 20 carbon atoms. ]

  Specific examples of preferable cations in the acid generator (A) are shown below.

  Examples of the anion moiety of the acid generator (A) include anions represented by the following formula (IA), formula (IB), formula (IC), and formula (ID).

[In formula (IA), formula (IB), formula (IC) and formula (ID), Q ¹ , Q ² and Y ¹ represent the same as those in formula (I).
X ¹¹ represents an alkylene group having 1 to 15 carbon atoms.
X ¹² represents an alkylene group having 1 to 16 carbon atoms. ]

Furthermore, Y ¹ is an anion having an alkyl group having 1 to 12 carbon atoms as a substituent, Y ¹ is an anion having a hydroxyl group as a substituent (excluding those having a lactone structure), and Y ¹ is an anion having a lactone structure. Part, Y ¹ is an anion part having a ketone structure, Y ¹ is an anion part having an aryl group having 6 to 12 carbon atoms as a substituent.

  Examples of the anion moiety represented by the formula (IA) include the followings.

In the formula (IA), specific examples of the anion moiety in which Y ¹ has an alkyl group having 1 to 12 carbon atoms as a substituent include the following.

Specific examples of the anion moiety in which Y ¹ has a hydroxyl group as a substituent in formula (IA) include the following.

Specific examples of the anion moiety in which Y ¹ has a lactone structure in formula (IA) include the following.

Specific examples of the anion moiety in which Y ¹ has a ketone structure in formula (IA) include the following.

  In the formula (IA), specific examples of the anion moiety having an aryl group having 6 to 12 carbon atoms as a substituent include the following.

  Examples of the anion moiety represented by the formula (IB) include the following.

In the formula (IB), specific examples of the anion moiety in which Y ¹ has an alkyl group having 1 to 12 carbon atoms as a substituent include the following.

Specific examples of the anion moiety in which Y ¹ has a hydroxyl group as a substituent in formula (IB) include the following.

Specific examples of the anion moiety in which Y ¹ has a lactone structure in formula (IB) include the following.

Specific examples of the anion moiety in which Y ¹ has a ketone structure in formula (IB) include the following.

In the formula (IB), specific examples of the anion moiety in which Y ¹ has an aryl group having 6 to 12 carbon atoms as a substituent include the following.

  Specific examples of the anion moiety represented by the formula (IC) include the following.

In the formula (IC), specific examples of the anion moiety in which Y ¹ has an alkyl group having 1 to 12 carbon atoms as a substituent include the following.

Specific examples of the anion moiety in which Y ¹ has a hydroxyl group as a substituent in formula (IC) include the following.

Specific examples of the anion moiety in which Y ¹ has a lactone structure in formula (IC) include the following.

Specific examples of the anion moiety in which Y ¹ has a ketone structure in formula (IC) include the following.

In the formula (IC), specific examples of the anion moiety in which Y ¹ has an aryl group having 6 to 12 carbon atoms as a substituent include the following.

  As an anion part represented by a formula (ID), the following are mentioned, for example.

In the formula (ID), specific examples of the anion moiety in which Y ¹ has an alkyl group having 1 to 12 carbon atoms as a substituent include the following.

In the formula (ID), specific examples of the anion moiety in which Y ¹ has a hydroxyl group as a substituent include the following.

Specific examples of the anion moiety in which Y ¹ has a lactone structure in formula (ID) include the following.

In the formula (ID), specific examples of the anion moiety in which Y ¹ has an aryl group having 6 to 12 carbon atoms as a substituent include the following.

  The cation part and the anion part are combined to form the acid generator (A).

Examples of the method for producing the acid generator (A) represented by the formula (I) include a salt represented by the formula (1) and an onium salt represented by the formula (3), for example, acetonitrile, In an inert solvent such as water or methanol, the acid generator (A) is obtained as a salt by stirring and reacting in a temperature range of about 0 to 150 ° C., preferably in a temperature range of about 0 to 100 ° C. The method etc. are mentioned.
The usage-amount of the onium salt of Formula (3) is about 0.5-2 mol normally with respect to 1 mol of salts represented by Formula (1). The salt may be taken out by recrystallization or may be purified by washing with water.

[In formula (1), Q ¹ , Q ² , X ¹ and Y ¹ represent the same meaning as in formula (I).
M represents Li, Na, K, or Ag.
In formula (3), Z ⁺ represents the same meaning as in formula (I).
Z ¹⁻ represents F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ or ClO ₄ ⁻ . ]

  As a manufacturing method of the salt represented by Formula (1) used for the said manufacture, first, esterifying alcohol represented by Formula (4) and carboxylic acid represented by Formula (6), for example. The method of making it react and obtaining the salt represented by Formula (1) is mentioned.

[In formula (4), Q ¹ , Q ² , X ¹ and Y ¹ represent the same meaning as in formula (I).
In formula (6), M represents the same meaning as in formula (1). ]

  As another method, for example, an esterification reaction of an alcohol represented by the formula (4) and a carboxylic acid represented by the formula (7), followed by hydrolysis with MOH and a salt represented by the formula (1) The method of obtaining is also mentioned.

[In formula (4), X ¹ and Y ¹ represent the same meaning as in formula (I).
In formula (7), Q ¹ and Q ² represent the same meaning as in formula (I). ]

  The esterification reaction is usually stirred in an aprotic solvent such as dichloroethane, toluene, ethylbenzene, monochlorobenzene, acetonitrile, etc. in a temperature range of about 20 to 200 ° C., preferably in a temperature range of about 50 to 150 ° C. You can do it. In the esterification reaction, an organic acid such as p-toluenesulfonic acid and / or an inorganic acid such as sulfuric acid may be added as an acid catalyst.

  Further, the esterification reaction may be carried out while dehydrating, such as by using a Dean Stark apparatus.

  The amount of the carboxylic acid represented by the formula (6) in the esterification reaction is usually about 0.2 to 3 mol, preferably 0.5 to 1 mol with respect to 1 mol of the alcohol represented by the formula (4). About 2 moles. The amount of the acid catalyst used in the esterification reaction may be a catalytic amount or an amount corresponding to a solvent, and is usually about 0.001 to 5 mol.

  The acid generator (A) may be used alone or in combination of two or more. Moreover, you may use together the other acid generator different from an acid generator (A). Other acid generators include known acid generators. For example, in addition to the acid generator (A), an acid generator containing a cation that does not contain a saturated cyclic hydrocarbon group in the cation part is used in combination. May be.

  In the acid generator containing a cation that does not contain a group having a saturated cyclic hydrocarbon group, a cation represented by any one of formula (IXz), formula (IXb), formula (IXc), or formula (IXd) and organic It becomes a counter ion.

(In formula (IXz), P ^{a to} P ^c each independently represent a hydroxyl group and an aliphatic hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a hydroxyl group or an alkoxy group having 1 to 12 carbon atoms.
In formula (IXb), P ⁴ and P ⁵ each independently represent a hydrogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
In formula (IXc), P ⁶ and P ⁷ each independently represent an aliphatic hydrocarbon group having 1 to 12 carbon atoms. Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2 -An ethylhexyl group etc. are mentioned. P ⁶ and P ⁷ may be combined to form a heterocycle having 3 to 12 carbon atoms including S ⁺ .
P ⁸ represents a hydrogen atom, and P ⁹ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, or P ^{9 8} and P ⁹ may be combined to form a ring having 3 to 12 carbon atoms. Specific examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group etc. are mentioned.
Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms that may have a substituent include a phenyl group, a benzyl group, and a phenethyl group.
In formula (IXd), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. The aliphatic hydrocarbon group and the alkoxy group have the same meanings as the aliphatic hydrocarbon group and the alkoxy group in formula (IXa). B represents -S- or -O-. m represents 0 or 1. )

  It describes about a formula (IXz).

(In formula (IXz), P ^{a to} P ^c each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, and the aliphatic hydrocarbon group is a hydroxyl group or an alkoxy group having 1 to 12 carbon atoms. May be substituted.)

  Among the cations represented by the formula (IXz), the cation represented by the formula (IXa) is preferable.

(In Formula (IXa), P ^{1 to} P ³ each independently represent a hydrogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.)

  Specific examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, A 2-ethylhexyl group etc. are mentioned, As an example of an alkoxy group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, an octyloxy group, 2-ethylhexyloxy group etc. are mentioned.

Examples of the cation A ⁺ represented by the formula (IXa) include the following cations.

  Among the cations represented by the formula (IXa), the cation represented by the formula (IXe) is preferable because of easy production.

[In Formula (IXe), P ^{22 to} P ²⁴ each independently represent a hydrogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ]

  Next, Formula (IXb) will be described. Formula (IXb) is the following formula containing an iodine cation.

[In Formula (IXb), P ⁴ and P ⁵ each independently represent a hydrogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ]

Examples of the cation A ⁺ represented by the formula (IXb) include the following cations.

  Subsequently, Formula (IXc) will be described.

[In Formula (IXc), P ⁶ and P ⁷ each independently represent an aliphatic hydrocarbon group having 1 to 12 carbon atoms. Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2 -An ethylhexyl group etc. are mentioned. P ⁶ and P ⁷ may be combined to form a ring having 3 to 12 carbon atoms.
P ⁸ represents a hydrogen atom, and P ⁹ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, or P 8 ⁸ and P ⁹ may be combined to form a ring having 3 to 12 carbon atoms. ]

  Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2 -An ethylhexyl group etc. are mentioned.

Examples of the cation A ⁺ represented by the formula (IXc) include the following cations.

Finally, Formula (IXd) will be described.

[In Formula (IXd), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. The aliphatic hydrocarbon group and the alkoxy group have the same meanings as the aliphatic hydrocarbon group and the alkoxy group in formula (IXa).
B represents -S- or -O-. m represents 0 or 1. ]

Examples of the cation A ⁺ represented by the formula (IXd) include the following cations.

  Other acid generators are represented by formula (Xa), formula (Xb), formula (Xc) or formula (Xd), formula (Xe), formula (Xf), formula (Xg) or formula (Xh). An acid generator is preferred.

[In Formula (Xa) to Formula (Xi), P ^{25 to} P ²⁷ each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. P ²⁸ and P ²⁹ each independently represent an aliphatic hydrocarbon group having 1 to 12 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 12 carbon atoms, or P ²⁸ and P ²⁹ are bonded to each other to form carbon. You may form the ring of several 3-12.
P ³⁰ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent. Or P ³⁰ and P ³¹ may be bonded to each other to form a ring having 3 to 12 carbon atoms. Here, —CH ₂ — contained in the ring may be replaced with —O— or —CO—. Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
X ¹¹ represents a single bond or a methylene group. ]

  The resist composition of the present invention contains a resin having a structural unit represented by the formula (II) (hereinafter sometimes referred to as “resin (B)”).

[In Formula (II), X ² represents a single bond or — [CH ₂ ] _k —, and —CH ₂ — contained in — [CH ₂ ] _k — is replaced with —O— or —CO—. It may be.
k represents an integer of 1 to 8.
Y ² represents a saturated cyclic hydrocarbon group having 4 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a halogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group. , An aromatic hydrocarbon group having 6 to 20 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidoxy group, or an acyl group having 2 to 4 carbon atoms, and is included in the saturated cyclic hydrocarbon group —CH ₂ — may be replaced by —CO— or —O—. ]

  Specific examples of the structural unit represented by the formula (II) include saturation such as isobornyl ester, 2-alkyl-2-adamantyl ester, and 1- (1-adamantyl) -1-alkyl ester. Examples include structural units derived from cyclic esters and the like.

  Among these, the structural unit represented by the formula (IIa) or the formula (IIb) is preferable.

[In Formula (IIa) and Formula (IIb), R ¹ represents a hydrogen atom or a methyl group.
R ² represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 10 carbon atoms.
R ³ represents a methyl group.
n represents an integer of 0 to 14.
R ⁴ and R ⁵ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms which may contain a hetero atom, or R ⁴ and R ⁵ together represent 3 to 12 carbon atoms. The ring may contain a hetero atom. A double bond may be formed between the carbon atom to which R ⁴ is bonded and the carbon atom to which R ⁵ is bonded.
m represents an integer of 1 to 3.
Z ″ represents a single bond, — [CH ₂ ] _k —, and —CH ₂ — contained in — [CH ₂ ] _k — may be replaced by —CO— or —O—.
k represents an integer of 1 to 8. ]

  Specific examples of the monomer for deriving the structural unit represented by the formula (IIa) include the following.

  Specific examples of the monomer for deriving the structural unit represented by the formula (IIb) include the following.

  Among these, for example, (meth) acrylic acid 2-ethyl-2-adamantyl, (meth) acrylic acid 2-isopropyl-2-adamantyl, or methacrylic acid 1- (2-methyl-2-adamantyloxycarbonyl) methyl, etc. Preferable examples can be given.

  (II) may include a plurality of structural units having —OH groups (excluding —OH groups of carboxyl groups) in the side chain.

  Examples of the structural unit having a —OH group (excluding the —OH group of a carboxyl group) in the side chain include, for example, various esters of carboxylic acid, specifically, for example, cyclic typified by cyclopentyl ester and cyclohexyl ester. Alkyl esters; structural units in which a part of a polycyclic ester such as norbornyl ester, 1-adamantyl ester, and 2-adamantyl ester is substituted with a hydroxyl group.

  Among these, the structural unit represented by the formula (III) can be exemplified.

[In the formula (III), R ³¹ represents a hydrogen atom or a methyl group.
R ⁶ and R ⁷ each independently represent a hydrogen atom, a methyl group or a hydroxyl group.
R ⁸ represents a methyl group.
n ′ represents an integer of 0 to 10.
Z ″ represents the same meaning as in formula (IIa). ]

  Specific examples of the monomer for deriving the structural unit represented by the formula (III) include the following.

  Among these, for example, (meth) acrylic acid 3-hydroxy-1-adamantyl, (meth) acrylic acid 3, 5-dihydroxy-1-adamantyl, methacrylic acid 1- (3-hydroxy-1-adamantyloxycarbonyl) methyl Preferred examples include 1- (3,5-dihydroxy-1-adamantyloxycarbonyl) methyl methacrylate and the like.

  As the structural unit represented by the formula (II), for example, a plurality of structural units having a lactone structure in the side chain (but different from the structural unit represented by the formula (I)) may be included. Specific examples include a compound having a β-butyrolactone structure, a compound having a γ-butyrolactone structure, and a compound having a lactone structure added to a cycloalkyl skeleton or a norbornane skeleton.

  Among these, for example, a structural unit represented by any one of the formula (IVa), the formula (IVb), and the formula (IVc) can be preferably exemplified.

[In Formula (IVa) to Formula (IVc), R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁹ represents a hydrogen atom or a methyl group.
l represents an integer of 1 to 5. When l is 2 or more, the plurality of R ⁹ may be the same as or different from each other.
R ¹⁰ and R ¹¹ each independently represent a carboxyl group, a cyano group, or a hydrocarbon group having 1 to 4 carbon atoms.
l ′ represents an integer of 0 to 3. When l ′ is 2 or more, the plurality of R ¹⁰ and R ¹¹ may be the same as or different from each other.
Z ″ represents the same meaning as in formula (IIa). ]

  Specific examples of the monomer for deriving the structural unit represented by the formula (IVa) include the following.

  Specific examples of the monomer for deriving the structural unit represented by the formula (IVb) include the following.

  Specific examples of the monomer for deriving the structural unit represented by the formula (IVc) include the following.

  Among these, for example, (meth) acrylic acid hexahydro-2-oxo-3,5-methano-2H-cyclopenta [b] furan-6-yl, (meth) acrylic acid tetrahydro-2-oxo-3-furyl, Preferred examples include resins obtained from 2- (5-oxo-4-oxatricyclo [4.2.1.03.7] nonan-2-yloxy) -2-oxoethyl (meth) acrylate.

  Moreover, as resin, you may have structural units other than the structural unit represented, for example by Formula (II). Examples of the structural unit other than the structural unit represented by the formula (II) include a structural unit derived from 2-norbornene. 2-norbornene may be introduced into the main chain during polymerization by radical polymerization using, for example, an aliphatic unsaturated dicarboxylic acid anhydride such as maleic anhydride or itaconic anhydride in addition to the corresponding 2-norbornene. Good. The structural unit derived from 2-norbornene is formed by opening a double bond of the norbornene structure and can be represented by the formula (d). The structural unit derived from maleic anhydride and itaconic anhydride is formed by opening a double bond of maleic anhydride and itaconic anhydride, and can be represented by the formulas (e) and (f), respectively.

Here, R ²⁵ and R ²⁶ in the formula (d) are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a carboxyl group, a cyano group, or —COOU (U is an alcohol residue) Or a carboxylic acid anhydride residue in which R ²⁵ and R ²⁶ are bonded to each other to form a ring containing —C (═O) OC (═O) —.
The —COOU is an ester of a carboxyl group, and examples of the alcohol residue corresponding to U include an aliphatic hydrocarbon group having 1 to 8 carbon atoms which may have a substituent. -Oxooxolane-3- or -4-yl group and the like can be mentioned. Here, as a substituent of the aliphatic hydrocarbon group, a hydroxyl group or a saturated cyclic hydrocarbon residue having 3 to 36 carbon atoms may be bonded.
Examples of the aliphatic hydrocarbon group for R ²⁵ and R ²⁶ include a methyl group, an ethyl group, and a propyl group. Examples of the aliphatic hydrocarbon group to which a hydroxyl group is bonded include a hydroxymethyl group and a 2-hydroxyethyl group. Etc.

Specific examples of the monomer for deriving the structural unit having norbornene represented by the formula (d) include the following.
2-norbornene,
2-hydroxy-5-norbornene,
5-norbornene-2-carboxylic acid,
Methyl 5-norbornene-2-carboxylate,
2-hydroxy-1-ethyl 5-norbornene-2-carboxylate,
5-norbornene-2-methanol,
5-norbornene-2,3-dicarboxylic anhydride.

  In addition, as for U of —COOU in the formula (d), a norbornene structure is used as long as it is an acid-labile group such as a saturated cyclic ester in which the carbon atom bonded to —O— of the carboxyl group is a quaternary carbon atom. Is a structural unit having an acid labile group. Examples of the monomer containing a norbornene structure and an acid labile group include, for example, 5-norbornene-2-carboxylic acid-t-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5- 1-methylcyclohexyl norbornene-2-carboxylate, 2-methyl-2-adamantyl 5-norbornene-2-carboxylate, 2-ethyl-2-adamantyl 5-norbornene-2-carboxylate, 5-norbornene-2-carboxyl Acid 1- (4-methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1 -(4-oxocyclohexyl) ethyl, 5-norbornene-2-carboxylic acid 1- (1-adap Pentyl) -1-methylethyl and the like.

It is preferable that the acid generator (A) represented by the formula (I) and the resin (B) having the structural unit represented by the formula (II) include a ring having the same skeleton. Since the rings have the same skeleton, the compatibility between the resin and the acid generator is improved, and the diffusion of the acid is reduced. Therefore, a chemically amplified photoresist composition containing the resin and the acid generator. When forming a pattern using, an effect that an excellent pattern can be formed is shown.
A ring in which a hydrogen atom contained in the ring is substituted is included in a ring having the same skeleton regardless of the type of the substituent.
A ring in which —CH ₂ — contained in a ring is replaced with another skeleton is not included in a ring of the same skeleton.

  The resin (B) is preferably a resin containing 3 or more types of structural units, and more preferably a resin containing 4 or more types of structural units.

  In addition to the resin (B), a resin known in the technical field of ArF resist can be used in combination with the resin in the present invention.

  In producing the resist composition of the present invention, a basic compound, preferably a basic nitrogen-containing organic compound, particularly preferably an amine or ammonium salt can be contained together with the resin and the acid generator. By adding a basic compound as a quencher, it is possible to improve the performance degradation due to the deactivation of the acid accompanying the holding after exposure. As a basic compound used for a quencher, the following are mentioned, for example.

In the formula, T ¹ , T ² and T ⁷ are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a saturated cyclic hydrocarbon group having 5 to 10 carbon atoms or a carbon atom having 6 to 20 carbon atoms. Represents an aromatic hydrocarbon group. The hydrogen atom of the aliphatic hydrocarbon group, the hydrogen atom of the saturated cyclic hydrocarbon group, and the hydrogen atom of the aromatic hydrocarbon group may be substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. The hydrogen atom of the amino group may be substituted with an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

T ^{3 to} T ⁵ are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a saturated cyclic hydrocarbon group having 5 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or An alkoxy group having 1 to 6 carbon atoms is represented. The hydrogen atom of the aliphatic hydrocarbon group, the hydrogen atom of the saturated cyclic hydrocarbon group, the hydrogen atom of the aromatic hydrocarbon group and the hydrogen atom of the alkoxy group are independently of each other a hydroxyl group, an amino group, or a carbon number. It may be substituted with 1 to 6 alkoxy groups. The hydrogen atom of the amino group may be substituted with an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

T ⁶ represents an aliphatic hydrocarbon group having 1 to 6 carbon atoms or a saturated cyclic hydrocarbon group having 5 to 10 carbon atoms. The hydrogen atom of the aliphatic hydrocarbon group and the hydrogen atom of the saturated cyclic hydrocarbon group may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. The hydrogen atom of the amino group may be substituted with an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

  A represents an alkylene group having 1 to 6 carbon atoms, a carbonyl group, an imino group, a sulfide group or a disulfide group.

  Specific examples of such compounds include hexylamine, heptylamine, octylamine, nonylamine, decylamine, aniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, 1- or 2-naphthylamine. , Ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3 '-Diethyldiphenylmethane, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, N-methylaniline, piperidine, diphenylamine, triethylamine, trimethylamine, tripropylamine, tripropylamine Tylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine Methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, N, N-dimethylaniline, 2,6-isopropylaniline, imidazole, Gin, 4-methylpyridine, 4-methylimidazole, bipyridine, 2,2'-dipyridylamine, di-2-pyridyl ketone, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ) Ethane, 1,3-di (4-pyridyl) propane, 1,2-bis (2-pyridyl) ethylene, 1,2-bis (4-pyridyl) ethylene, 1,2-bis (4-pyridyloxy) Ethane, 4,4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 1,2-bis (4-pyridyl) ethylene, 2,2′-dipiconylamine, 3,3′-dipiconylamine, tetramethyl Ammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetra-n-hexylammonium hydroxide, tet Examples include la-n-octylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethylammonium hydroxide, and choline.

  Furthermore, a hindered amine compound having a piperidine skeleton as disclosed in JP-A-11-52575 can be used as a quencher.

  More preferable quenchers include compounds represented by the formula (XII). Specifically, for example, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-trifluoromethyl-phenyltrimethylammonium hydroxide, etc. Can be mentioned.

  The resist composition of the present invention may generally contain a resin in the range of about 80 to 99% by weight and an acid generator in the range of about 1 to 20% by weight based on the total solid content.

  Further, when the resist composition of the present invention contains a basic compound as a quencher, the content of the basic compound is usually 0.01 to 5% by weight based on the total solid content of the resist composition of the present invention. The range of the degree.

The resist composition of the present invention is usually provided in a state where each of the above components is dissolved in a solvent.
Examples of the solvent include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate, esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate, acetone, methyl Examples thereof include ketones such as isobutyl ketone, 2-heptanone and cyclohexanone, cyclic esters such as γ-butyrolactone, and propylene glycol monomethyl ether. These solvents can be used alone or in combination of two or more.

  The resist composition of the present invention can further contain small amounts of various additives such as sensitizers, dissolution inhibitors, other resins, surfactants, stabilizers, and dyes as necessary.

The present invention also provides a pattern forming method including the following steps.

(1) The process of apply | coating the composition in any one of 1-6 on a board | substrate (2) The process of removing a solvent from the composition after application | coating, and forming a composition layer (3) In a composition layer Step of exposing using exposure machine (4) Step of heating composition layer after exposure (5) Step of developing composition layer after heating using developing device

Coating on the substrate is performed by a commonly used apparatus such as a spin coater.
Next, the solvent is removed by boiling the solvent using a heating device such as a hot plate, or a composition layer from which the solvent is removed is formed using a decompression device.
The obtained composition layer is exposed using an exposure machine. At this time, exposure is usually performed by meeting a mask corresponding to a required pattern.
Next, the composition layer after exposure is subjected to heat treatment for promoting the deprotection group reaction.
Subsequently, it develops normally with an alkaline developing solution using a developing device. The alkaline developer used here can be various alkaline aqueous solutions used in this field, for example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline). Is mentioned.
After development, the substrate is rinsed with ultrapure water, and water remaining on the substrate and the pattern is removed to obtain a pattern.
Since the resist composition of the present invention can be suitably used for dry exposure, immersion exposure, and double imaging, the present invention is industrially useful.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
In Examples and Comparative Examples, “%” and “part” representing content or use amount are based on mass unless otherwise specified.

  The weight average molecular weight is a value determined by gel permeation chromatography using polystyrene as a standard product. The measurement conditions are as follows.

Apparatus: HLC-8120GPC (manufactured by Tosoh Corporation)
Column: 3 TSKgel Multipore HXL-M + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μL
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

  The structure of the compound is NMR (GX-270 type or EX-270 type; manufactured by JEOL Ltd.), mass spectrometry (LC is Agilent 1100 type, MASS is Agilent LC / MSD type or LC / MSD TOF. Type).

(Synthesis of acid generator AA1)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 150 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting solution was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.4 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.7%). To 1.9 parts (purity 62.7%) of difluorosulfoacetic acid sodium salt and 9.5 parts of N, N-dimethylformamide, 1.0 part of 1,1′-carbonyldiimidazole was added for 2 hours. A mixture was prepared by stirring.
On the other hand, 0.2 part of sodium hydride was added to 1.1 parts of 3-hydroxyadamantyl methanol and 5.5 parts of N, N-dimethylformamide, and stirred for 2 hours. To this solution was added the above mixture. After the resulting mixture was stirred for 15 hours, the resulting solution containing difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt was used as it was in the next reaction. To the resulting solution containing difluorosulfoacetate-3-hydroxy-1-adamantyl methyl ester sodium salt, 17.2 parts of chloroform and 0.5 part of 4-adamantylphenyldiphenylsulfonium bromide were added. After stirring for 24 hours, liquid separation was performed to recover the organic layer. Subsequently, the remaining aqueous layer was extracted with 6.5 parts of chloroform to recover the organic layer. The organic layers were combined, washed with ion-exchanged water, and then the obtained organic layer was concentrated. As a concentrate, 0.3 part of 4-adamantylphenyldiphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate (AA1) was obtained.

(Synthesis of acid generator AA2)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 150 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.4 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.7%). To 1.9 parts (purity 62.7%) of difluorosulfoacetic acid sodium salt and 9.5 parts of N, N-dimethylformamide, 1.0 part of 1,1′-carbonyldiimidazole was added for 2 hours. A mixture was prepared by stirring.
On the other hand, 0.2 parts of sodium hydride was added to 1.1 parts of -hydroxyadamantylmethanol and 5.5 parts of N, N-dimethylformamide, and added to the solution stirred for 2 hours. To this solution was added the above mixture. The resulting mixture was stirred for 15 hours, and the resulting difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt was used as such for the next reaction. To the obtained solution containing difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt, 17.2 parts of chloroform and 0.5 part of 4- (1-adamantylmethoxymethyl) phenyldiphenylsulfonium bromide were added. The resulting mixture was stirred for 18 hours and then separated to recover the organic layer. Subsequently, the remaining aqueous layer was extracted with 6.5 parts of chloroform to recover the organic layer. The organic layers were combined, washed with ion-exchanged water, and then the obtained organic layer was concentrated to give 4- (1-adamantylmethoxymethyl) phenyldiphenylsulfonium 1-((3-hydroxyadamantyl) 0.3 part of methoxycarbonyl) difluoromethanesulfonate (AA2) was obtained.

(Synthesis of acid generator AA3)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 150 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.4 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.7%). To 1.9 parts (purity 62.7%) of difluorosulfoacetic acid sodium salt and 9.5 parts of N, N-dimethylformamide, 1.0 part of 1,1′-carbonyldiimidazole was added for 2 hours. A mixture was prepared by stirring.
On the other hand, 0.2 part of sodium hydride was added to 1.1 parts of 3-hydroxyadamantyl methanol and 5.5 parts of N, N-dimethylformamide, and stirred for 2 hours. To this solution was added the above mixture. After the resulting mixture was stirred for 15 hours, the resulting solution containing difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt was used as it was in the next reaction. To the obtained solution containing difluorosulfoacetic acid-3-hydroxy-1-adamantyl methyl ester sodium salt, 17.2 parts of chloroform and 0.7 parts of tri (4-adamantylphenyl) sulfonium bromide were added. After stirring for 24 hours, liquid separation was performed to recover the organic layer. Next, the remaining aqueous layer was extracted with 7.5 parts of chloroform to recover the organic layer. The above organic layers were combined, washed with ion exchange water, and then the obtained organic layer was concentrated to tri (4-adamantylphenyl) sulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethane. 0.1 part of sulfonate (AA3) was obtained.

(Synthesis of acid generator AA4)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.8 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.6%). To a mixture of 5.0 parts (purity 62.6%) of the obtained sodium difluorosulfoacetate, 2.6 parts of 4-oxo-1-adamantanol and 100 parts of ethylbenzene, 0.8 part of concentrated sulfuric acid was added, Heated to reflux for hours. The obtained mixture was cooled and then filtered, and the filtration residue was washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of purity analysis by ¹ H-NMR, the purity was 35.6%. 16 parts of acetonitrile and 16 parts of ion-exchanged water were added to 5.4 parts (purity 35.6%) of the obtained difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. To this, 1.9 parts of 4-adamantylphenyldiphenylsulfonium bromide, 5 parts of acetonitrile and 5 parts of ion-exchanged water were added. The resulting mixture was stirred for 24 hours and then concentrated, and the concentrate was extracted with 142 parts of chloroform. The organic layer recovered by the extraction was washed with ion-exchanged water, and then the obtained organic layer was concentrated to give 4-adamantylphenyldiphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (AA4). 5 parts were obtained.

(Synthesis of acid generator AA5)
To 20 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 30 parts of ion-exchanged water, 46 parts of 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 17.5 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 32.82 parts of sodium difluorosulfoacetate (inorganic content was not removed, so the content was 63.5%). To a mixture of the obtained difluorosulfoacetic acid sodium salt 3.9 parts (content 63.5%), 1-adamantane methanol 2.1 parts and dichloroethane 20 parts, p-toluenesulfonic acid (p-TsOH) 2.4. The mixture was added and heated to reflux for 7 hours. Then, it concentrated, the dichloroethane was distilled off, 25 parts of tert-butyl methyl ether was added to the concentration residue, and after repulping, it filtered. To the filtration residue, 25 parts of acetonitrile was added, stirred, filtered, and the obtained filtrate was concentrated to obtain 3.3 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt. The obtained 3.3 parts of difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt was dissolved in 10 parts of ion-exchanged water. To this solution, 3.0 parts of 4-adamantylphenyldiphenylsulfonium bromide and 14 parts of methanol were added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting concentrate was extracted twice with 20 parts of chloroform. The organic layers recovered by the two extractions were combined, and washing with ion-exchanged water was repeated until it became neutral. The obtained organic layer was concentrated to obtain 2.5 parts of 4-adamantylphenyldiphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (AA5).

(Synthesis of acid generator AA6)
10.4 parts of lithium aluminum hydride and 120 parts of anhydrous tetrahydrofuran were charged and stirred at 23 ° C. for 30 minutes. Next, a solution obtained by dissolving 62.2 parts of sodium ethyldifluorosulfoacetate in 900 parts of anhydrous THF was added dropwise under ice cooling, and the mixture was stirred at 23 ° C. for 5 hours. To the reaction mass, 50.0 parts of ethyl acetate and 50.00 parts of 6N hydrochloric acid were added, followed by liquid separation. After concentration of the organic layer, separation of the column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) was performed to obtain 84.7 g of sodium salt of 2,2-difluoro-2-sulfoethanol. (Purity 60%).
Further, 4.5 parts of 4-oxo-1-adamantanecarboxylic acid and 90 parts of anhydrous THF were added and dissolved by stirring at room temperature for 30 minutes. To this solution, a mixed solution of 3.77 parts of carbonyldiimidazole and 45 parts of anhydrous THF was added dropwise at room temperature, followed by stirring at 23 ° C. for 4 hours. The obtained reaction solution was added dropwise at 54 ° C. to 60 ° C. for 30 minutes while mixing 7.87 parts (purity 60%) of sodium salt of 2,2-difluoro-2-sulfoethanol and 50 parts of anhydrous THF. The reaction solution was heated at 65 ° C. for 18 hours, cooled and then filtered. The obtained filtrate was concentrated, and the concentrate was fractionated into a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain sodium 4-oxo-1-adamantylcarbonyloxymethyldifluoromethanesulfone. 4.97 parts of narate (yield 59%) were obtained.
Next, 1.0 part of sodium 4-oxo-1-adamantylcarbonyloxymethyldifluoromethanesulfonate and 20 parts of chloroform were charged, stirred at 23 ° C. for 30 minutes, and further 1.19 parts of 4-adamantylphenyldiphenylsulfonium chloride were added to 23 parts. Added at ° C. After stirring at room temperature for 12 hours, liquid separation was performed. 10 parts of ion-exchanged water was added to the organic layer, followed by liquid separation washing. This operation was performed three times. Thereafter, 1 part of magnesium sulfate was added and stirred at 23 ° C. for 30 minutes, followed by filtration. The filtrate was concentrated to obtain 0.66 part of compound (AA6).

(Synthesis of acid generator AA7)
3.51 parts of 3-hydroxy-1-adamantanecarboxylic acid and 75 parts of anhydrous THF were charged and stirred at 23 ° C. for 30 minutes. Next, a mixed solution of 2.89 parts of carbonyldiimidazole and 50 parts of anhydrous THF was added dropwise at 23 ° C., and the mixture was stirred at 23 ° C. for 4 hours. The obtained reaction solution was dropped into a mixed solution of 2,2-difluoro-2-sulfoethanol sodium salt 6.04 parts (purity 60%) and anhydrous THF 50 parts at 54-60 ° C. over 25 minutes, Heated at 65 ° C. for 18 hours, cooled and filtered. The obtained filtrate was concentrated, and the concentrate was fractionated into a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain sodium 3-hydroxy-1-adamantylcarbonyloxymethyldifluoromethanesulfone. 2.99 parts of nat were obtained.
Sodium 3-hydroxy-1-adamantylcarbonyloxymethyldifluoromethanesulfonate (1.0 part) and chloroform (30 parts) were charged and stirred at 23 ° C. for 30 minutes. Subsequently, 1.19 parts of 4-adamantylphenyldiphenylsulfonium chloride was stirred at 23 ° C. for 12 hours and then separated. 10 parts of ion-exchanged water was added to the organic layer, followed by liquid separation washing. This operation was performed three times. Thereafter, 1 part of magnesium sulfate was added and stirred at 23 ° C. for 30 minutes, followed by filtration. The filtrate was concentrated to obtain 0.81 part of compound (AA7).

(Synthesis of acid generator AA8)
5-hydroxymethyl-2-adamantanone 1.00 part of ethylene ketal, 2.47 parts of pyridine and 5 parts of anhydrous methylene chloride were added and stirred at 23 ° C for 30 minutes. Next, a solution of 2.37 parts of trifluoromethanesulfonic anhydride and 5 parts of methylene chloride was added dropwise under ice cooling, and the mixture was stirred at 3 to 5 ° C. for 2 hours. To the reaction solution, 10 parts of methylene chloride and 10 parts of ion exchange water were added, followed by separation and washing with water. This operation was performed three times. Thereafter, 1 part of magnesium sulfate was added, and the mixture was stirred at 23 ° C. for 30 minutes and then filtered. The filtrate was concentrated, and the concentrate was separated into a column (Merck silica gel 60-200 mesh developing solvent: hexane / ethyl acetate = 1/1). By taking, 1.19 parts of 5-trifluoromethanesulfonylmethyl-2-adamantanone ethylene ketal was obtained.
0.2285 parts of sodium hydride and 3 parts of anhydrous dimethyl sulfoxide were added and stirred at 60 ° C. for 30 minutes. Next, 0.62 part of sodium salt of 2,2-difluoro-2-sulfoethanol was added and stirred at 60 ° C. for 1 hour. Further, a solution of 1.00 part of 5-trifluoromethanesulfonylmethyl-2-adamantanone ethylene ketal and 9 parts of anhydrous dimethyl sulfoxide was added dropwise and stirred at 60 ° C. for 5 hours. After cooling, the reaction mass is separated from a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain sodium spiro {adamantane-4,4 ′-[1,3] dioxolane} -1. 0.28 parts of -yl-methoxymethyldifluoromethanesulfonate were obtained.
Sodium spiro {adamantane-4,4 ′-[1,3] dioxolane} -1-yl-methoxymethyldifluoromethanesulfonate (0.2 parts) and chloroform (10 parts) were added and stirred at 23 ° C. for 30 minutes. Subsequently, 0.28 parts of 4-adamantylphenyldiphenylsulfonium chloride was stirred at 23 ° C. for 36 hours, followed by liquid separation. 10 parts of ion-exchanged water was added to the organic layer, followed by liquid separation washing. This operation was performed three times. Thereafter, 1 part of magnesium sulfate was added and stirred at 23 ° C. for 30 minutes, followed by filtration. The filtrate was concentrated to obtain 0.15 part of compound (AA8).

(Synthesis of acid generator A1)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 150 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. This was refluxed at 100 ° C. for 3 hours, cooled, and then neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.4 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.7%). To 1.9 parts (purity 62.7%) of difluorosulfoacetic acid sodium salt and 9.5 parts of N, N-dimethylformamide, 1.0 part of 1,1′-carbonyldiimidazole was added for 2 hours. Stir to give a mixture.
On the other hand, 0.2 part of sodium hydride was added to 1.1 parts of 3-hydroxyadamantyl methanol and 5.5 parts of N, N-dimethylformamide, and stirred for 2 hours to prepare a solution. To this solution was added the above mixture. After the resulting mixture was stirred for 15 hours, the resulting solution containing difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt was used as it was in the next reaction. To the obtained solution containing difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt, 17.2 parts of chloroform and 2.9 parts of 14.8% aqueous triphenylsulfonium chloride were added. After stirring for 15 hours, the organic layer was recovered by liquid separation. Subsequently, the remaining aqueous layer was extracted with 6.5 parts of chloroform to recover the organic layer. The organic layers were combined, washed with ion-exchanged water, and then the obtained organic layer was concentrated. To the concentrate, 5.0 parts of tert-butyl methyl ether was added, stirred and filtered to give triphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate (A1) as a white solid. Two parts were obtained.

(Synthesis of acid generator A2)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.8 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.6%). To 5.0 parts (purity 62.6%) of difluorosulfoacetic acid salt obtained, 2.6 parts of 4-oxo-1-adamantanol and 100 parts of ethylbenzene, 0.8 part of concentrated sulfuric acid is added and heated for 30 hours. Refluxed. The obtained mixture was cooled and then filtered, and the filtration residue was washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of purity analysis by ¹ H-NMR, the purity was 35.6%. 16 parts of acetonitrile and 16 parts of ion-exchanged water were added to 5.4 parts (purity 35.6%) of the obtained difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. To the obtained mixture, 1.7 parts of triphenylsulfonium chloride, 5 parts of acetonitrile, and 5 parts of ion-exchanged water were added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting mixture was extracted with 142 parts of chloroform to recover the organic layer. The collected organic layer was washed with ion-exchanged water, and then the obtained organic layer was concentrated. The concentrate was repulped with 24 parts of tert-butyl methyl ether to obtain 1.7 parts of triphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (A2) as a white solid.

(Synthesis of acid generator A3)
To 200 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 300 parts of ion-exchanged water, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of difluorosulfoacetic acid sodium salt (content of 63.5% because inorganic salts were not removed). To a mixture of the obtained sodium difluorosulfoacetate salt 39.4 parts (content 63.5%), 1-adamantane methanol 21.0 parts and dichloroethane 200 parts, p-toluenesulfonic acid (p-TsOH) 24.0 was added. Was added and this was heated to reflux for 7 hours. Thereafter, the mixture was concentrated to distill off dichloroethane, 250 parts of tert-butyl methyl ether was added to the concentrated residue, repulped and filtered. To the residue, 250 parts of acetonitrile was added and stirred, followed by filtration. The obtained filtrate was concentrated to obtain 32.8 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt. To a solution obtained by dissolving 32.8 parts of the obtained difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt in 100 parts of ion-exchanged water, a solution of 28.3 parts of triphenylsulfonium chloride and 140 parts of methanol was added. Added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting concentrate was extracted twice with 200 parts of chloroform. The recovered organic layers obtained by the extraction twice were combined, and the washing operation using ion-exchanged water was repeated until the organic layer became neutral, and then the obtained organic layer was concentrated. To the concentrated solution, 300 parts of tert-butyl methyl ether was added, stirred, and then filtered to collect a white precipitate, which was dried under reduced pressure to give triphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfone as white crystals. Nate (A3) 39.7 parts was obtained.

(Synthesis of acid generator A4)
To 200 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 300 parts of ion-exchanged water, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. This was refluxed at 100 ° C. for 2.5 hours, cooled, and then neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.8%). To a mixture of the obtained difluorosulfoacetic acid sodium salt 123.3 parts (purity 62.8%), 1-adamantane methanol 65.7 parts and dichloroethane 600 parts, p-toluenesulfonic acid (p-TsOH) 75.1 parts. And heated at reflux for 12 hours. Thereafter, the mixture was concentrated to distill off dichloroethane, and 400 parts of tert-butyl methyl ether was added to the concentrated residue, followed by repulping and filtration. 400 parts of acetonitrile was added to the residue, and after stirring, filtration was repeated twice and concentrated to obtain 99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt.
Next, 150 parts of 2-bromoacetophenone was dissolved in 375 parts of acetone, and 66.5 parts of tetrahydrothiophene was added dropwise thereto. After stirring the resulting mixture at room temperature for 24 hours, the white precipitate formed was collected by filtration, washed with acetone, and then dried to give 1- (2-oxo-2-phenyl) as white crystals. 207.9 parts of ethyl) tetrahydrothiophenium bromide were obtained.
99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt obtained above was dissolved in 298 parts of acetonitrile. To the obtained solution, 79.5 parts of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide obtained above and 159 parts of ion-exchanged water were added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting concentrate was extracted twice with 500 parts of chloroform. The organic layers recovered by the two extractions were combined, washed with ion-exchanged water, and the obtained organic layer was concentrated. To the concentrate, 250 parts of tert-butyl methyl ether was added, stirred, and then filtered to collect a white precipitate, which was dried under reduced pressure to give 1- (2-oxo-2-phenylethyl as white crystals. ) 116.9 parts of tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (A4) were obtained.

(Synthesis of acid generator A5)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.8 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.6%). To 5.0 parts of the obtained sodium difluorosulfoacetate (purity 62.8%), 2.6 parts of 4-oxo-1-adamantanol and 100 parts of ethylbenzene, 0.8 part of concentrated sulfuric acid was added, Heated to reflux for hours. The obtained mixture was cooled and then filtered, and the filtration residue was washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of purity analysis by ¹ H-NMR, the purity was 35.6%. 30 parts of acetonitrile and 20 parts of ion-exchanged water were added to 10.0 parts (purity 55.2%) of the obtained difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. To this, 5.0 parts of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide, 10 parts of acetonitrile and 5 parts of ion-exchanged water were added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting concentrate was extracted with 98 parts of chloroform. The organic layer recovered by the extraction was washed with ion-exchanged water, and the obtained organic layer was concentrated. The concentrate is repulped with 70 parts of ethyl acetate to give 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (A5) 5.2 as a white solid. Got a part.

(Synthesis of acid generator A6)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 158.4 parts of sodium difluorosulfoacetate (containing inorganic salt, purity: 65.1%). 31.26 parts of p-toluenesulfonic acid was added to 50.0 parts (purity 65.1%) of difluorosulfoacetic acid sodium salt, 18.76 parts of cyclohexylmethanol and 377 parts of dichloroethane, and this was heated to reflux for 6 hours. did. Then, after concentrating the obtained mixture and distilling dichloroethane off, 200 parts of n-heptane was added thereto, followed by repulping and filtration. 200 parts of acetonitrile was added to the obtained filtration residue and stirred, followed by filtration. The collected filtrate was concentrated to obtain 39.03 parts of difluorosulfoacetic acid-1-cyclohexylmethyl ester sodium salt. The obtained 39.03 parts of difluorosulfoacetic acid-1-cyclohexylmethyl ester sodium salt was dissolved in 195.2 parts of ion-exchanged water. To this solution, 39.64 parts of triphenylsulfonium chloride and 196.4 parts of ion-exchanged water were added, and 500 parts of acetonitrile was further added. The resulting mixture was stirred for 15 hours, then concentrated, and the resulting concentrate was extracted twice with 250 parts of chloroform. The organic layers recovered by the two extractions were combined, washed with ion-exchanged water, and the obtained organic layer was concentrated. The concentrate was repulped with 200 parts of tert-butyl methyl ether to obtain 40.16 parts of triphenylsulfonium (1-cyclohexylmethoxycarbonyl) difluoromethanesulfonate difluoromethanesulfonate (A6) as a white solid.

  Then, the synthesis example of resin is described below. The monomers used in this example are as follows. Hereinafter, unless otherwise specified, parts represent parts by weight.

[Synthesis of Resin B1]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 15: 20: 30, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 77 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8100 in a yield of 78%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B1.

[Synthesis of Resin B2]
Monomer F, monomer E, monomer B, monomer C and monomer D are charged in a molar ratio of 30: 15: 5: 20: 30, and then 1.5 mass times dioxane with respect to the total mass of all monomers. Was added. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 73 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent for precipitation three times to obtain a copolymer having a weight average molecular weight of about 8500 in a yield of 73%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B2.

[Synthesis of Resin B3]
Resin B3 was synthesized according to the same synthesis method except that the charge ratio of monomer F, monomer E, monomer B, monomer C, and monomer D was changed to a molar ratio of 35: 5: 15: 20: 30 in the synthesis of resin B2. Was synthesized to obtain a copolymer having a weight average molecular weight of about 8600 in a yield of 70%.

[Synthesis of Resin B4]
Monomer F, monomer E, monomer B, monomer C and monomer I are charged in a molar ratio of 35: 5: 15: 30: 5, and then 1.2 mass times dioxane with respect to the total amount of all monomers. Was added. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 7600 in a yield of 72%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B4.

[Synthesis of Resin B5]
Monomer A, monomer B and monomer D were charged in a molar ratio of 50:25:25, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 77 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8000 in a yield of 60%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B5.

[Synthesis of Resin B6]
Monomer G, monomer B and monomer D were charged at a molar ratio of 40:20:40, and then 1.5 mass times dioxane was added to the total mass of all monomers. Into the resulting mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were 1.2 mol% and 3.6 mol%, respectively, with respect to the total number of moles of all monomers. And heated at 78 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 6300 in a yield of 68%. This copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B6.

Examples After mixing the following components, the obtained mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

＜樹脂＞
樹脂合成例参照Ｂ１〜６
＜クエンチャー＞
Ｑ１：２、６−ジイソプロピルアニリン
＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ２６５部
２−ヘプタノン ２０．０部
プロピレングリコールモノメチルエーテル ２０．０部
γ−ブチロラクトン ３．５部 <Acid generator>
Acid generator; AA1 to AA8, A1 to 6
C1:

<Resin>
See resin synthesis examples B1-6
<Quencher>
Q1: 2,6-diisopropylaniline <solvent>
Propylene glycol monomethyl ether acetate 265 parts 2-heptanone 20.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.5 parts

An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic antireflective coating having a thickness of 780 mm. Formed. Next, the resist solution was spin-coated on the organic antireflection film so that the film thickness after drying was 0.15 μm. After applying the resist solution, it was pre-baked (also referred to as PB in some cases) at 95 ° C. for 60 seconds on a direct hot plate. Each wafer having the resist film thus formed was exposed to a line-and-space pattern using an ArF immersion excimer stepper (XT: 1900 Gi; manufactured by ASML, NA = 1.35) while changing the exposure stepwise.
After exposure, post-exposure baking (may be referred to as PEB) at 95 ° C. for 60 seconds on a hot plate, followed by 60-second paddle development with an aqueous 2.38 wt% tetramethylammonium hydroxide solution. went.
The dark field pattern after development on the organic antireflection film substrate was observed with a scanning electron microscope. The results are shown in Table 2. The dark field pattern referred to here is obtained by exposure and development through a reticle having a glass surface (translucent portion) formed in a line form on the outside with a chromium layer (light-shielding layer) as a base, and thus exposure development. The rest is a pattern in which the resist layer around the line and space pattern is left. Effective sensitivity: 70 nm line and space pattern is shown as an exposure amount that becomes 1: 1.
Shape evaluation: 70 nm line and space pattern is exposed at an exposure amount of 1: 1, and the resist pattern is observed with a scanning electron microscope. The case where round or skirting was seen was judged as x.
Line edge roughness evaluation (LER): The surface of the resist pattern after the lithography process is observed with a scanning electron microscope, the surface of the resist pattern after the lithography process is observed with a scanning electron microscope, and the irregularities on the side walls of the resist pattern are touched. A sample having a width of 9 nm or less was evaluated as ◯, and a sample having a width exceeding 9 nm was evaluated as ×.

[Table 1]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example No. Resin Acid generator Quencher PB / PEB
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 B1 / 10 part AA1 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 2 B1 / 10 part AA1 / A1 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 3 B1 / 10 part AA1 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 4 B1 / 10 part AA2 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 5 B1 / 10 part AA3 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 6 B1 / 10 part AA4 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 7 B1 / 10 part AA5 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 8 B1 / 10 part AA2 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 9 B1 / 10 part AA3 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 10 B1 / 10 part AA4 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 11 B1 / 10 part AA5 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 12 B1 / 10 part AA4 / A2 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 13 B1 / 10 part AA5 / A3 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 14 B1 / 10 part AA5 / A4 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 15 B1 / 10 part AA4 / A5 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 16 B1 / 10 part AA5 / A6 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 17 B2 / 10 part AA1 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 18 B3 / 10 part AA1 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 19 B4 / 10 part AA1 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 20 B5 / 10 part AA1 / A1 = 0.20 / 0.50 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 21 B2 / 10 part AA6 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 22 B2 / 10 part AA7 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 23 B2 / 10 part AA8 = 0.7 part Q1 / 0.065 part 95 ° C./95° C.
Example 24 B2 / 10 part AA1 = 0.7 part Q1 / 0.065 part 95 ° C./95° C.
Example 25 B2 / 10 part AA2 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 26 B2 / 10 part AA3 = 0.7 part Q1 / 0.065 part 95 ° C./95° C.
Example 27 B2 / 10 part AA4 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 28 B2 / 10 part AA5 = 0.7 part Q1 / 0.065 part 95 ° C./95° C.
Example 29 B2 / 10 part AA1 / A1 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 30 B2 / 10 part AA1 / A1 = 0.40 / 0.10 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 31 B2 / 10 part AA1 / A1 = 0.30 / 0.10 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 32 B2 / 10 part AA1 / A1 = 0.10 / 0.10 part Q1 / 0.065 part 95 ° C / 95 ° C
Comparative Example 1 B6 / 10 part C1 = 0.5 part Q1 / 0.050 part 100 ° C / 120 ° C
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 2]
━━━━━━━━━━━━━━━━━━━━━━━━
Example No. Effective sensitivity pattern LER
(mJ / cm ² ) Shape ━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 34 ○ ○
Example 2 32 ○ ○
Example 3 31 ○ ○
Example 4 33 ○ ○
Example 5 25 ○ ○
Example 6 28 ○ ○
Example 7 27 ○ ○
Example 8 34 ○ ○
Example 9 31 ○ ○
Example 10 32 ○ ○
Example 11 32 ○ ○
Example 12 30 ○ ○
Example 13 29 ○ ○
Example 14 39 ○ ○
Example 15 41 ○ ○
Example 16 26 ○ ○
Example 17 35 ○ ○
Example 18 36 ○ ○
Example 19 34 ○ ○
Example 20 22 ○ ○
Example 21 28 ○ ○
Example 22 31 ○ ○
Example 23 28 ○ ○
Example 24 29 ○ ○
Example 25 30 ○ ○
Example 26 25 ○ ○
Example 27 26 ○ ○
Example 28 27 ○ ○
Example 29 32 ○ ○
Example 30 39 ○ ○
Example 31 42 ○ ○
Example 32 56 ○ ○
Comparative Example 1 30 × ×
━━━━━━━━━━━━━━━━━━━━━━━

  According to the chemically amplified photoresist composition of the present invention, a pattern having an excellent shape and line edge roughness can be obtained.

Claims (7)

A chemically amplified photoresist composition comprising an acid generator represented by formula (I) and a resin having a structural unit represented by formula (II).

[In Formula (I), Q < ¹ > and Q < ² > represent a fluorine atom or a C1-C6 perfluoroalkyl group mutually independently.
X ⁰ represents a divalent C _1-17 saturated hydrocarbon group, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Y ¹ represents a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Z ⁺ represents a cation represented by the formula (AA). ]

[In Formula (II), R ¹ represents a hydrogen atom or a methyl group.
X ² represents a single bond or — [CH ₂ ] _k —, and —CH ₂ — contained in — [CH ₂ ] _k — may be replaced by —O— or —CO—.
k represents an integer of 1 to 8.
Y ² represents a saturated cyclic hydrocarbon group having 4 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a halogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group. , An aromatic hydrocarbon group having 6 to 20 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidoxy group, or an acyl group having 2 to 4 carbon atoms, and is included in the saturated cyclic hydrocarbon group —CH ₂ — may be replaced by —CO— or —O—. ]

[In Formula (AA), A ¹ and A ² are each independently an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 21 carbon atoms. Or A ¹ and A ² may be bonded to each other to form a ring having 1 to 20 carbon atoms.
Ar ¹ represents an (m ₄ +1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 5 to 20 carbon atoms.
B ¹ represents a single bond or an alkylene group having 1 to 6 carbon atoms, and —CH ₂ — contained in the alkylene group may be replaced by —O—.
B ² represents a saturated cyclic hydrocarbon group having 6 to 36 carbon atoms.
m ₁ and m ₂ each independently represent an integer of 0 to 2.
m ₃ represents an integer of 1 to 3. _However, it is _{m 1 + m 2 + m 3} = 3.
m ₄ represents an integer of 1 to 3. ]
(However, an acid generator represented by the formula (I), such as an acid generator represented by the following formula rather nor salt represented by the formula (2).

[In formula (2), each R ¹ independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, and R ² represents a substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms. are shown, R ^f represents a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. L represents an integer of 0 to 4, n represents an integer of 0 to 10, and m represents an integer of 1 to 4. M ^{k +} represents a k-valent cation, and k represents an integer of 1 to 4. ) The composition according to claim 1, wherein the acid generator represented by the formula (I) is an acid generator represented by the formula (I-1).

[In formula (I-1), Q ¹ , Q ² , Y ¹ and Z ⁺ represent the same meaning as described above. X ¹ represents a single bond or — [CH ₂ ] _k1 —, and —CH ₂ — contained in — [CH ₂ ] _k1 — may be replaced by —O— or —CO—.
k1 represents an integer of 1 to 8. ] The composition according to claim 1 or 2, wherein B ² is a saturated polycyclic hydrocarbon group having 10 to 36 carbon atoms. The composition according to claim 1, wherein B ² and Y ² are rings having the same skeleton.   Furthermore, the composition in any one of Claims 1-4 containing the other acid generator different from the acid generator represented by a formula (I).   The composition according to any one of claims 1 to 5, wherein the resin having a structural unit represented by formula (II) is a resin containing three or more different structural units. A pattern forming method including the following steps.
(1) The process of apply | coating the composition in any one of Claims 1-6 on a board | substrate (2) The process of removing a solvent from the composition after application | coating, and forming a composition layer (3) In a composition layer Step of exposing using exposure machine (4) Step of heating composition layer after exposure (5) Step of developing composition layer after heating using developing device