JP7249198B2 - ONIUM SALT, COMPOSITION, AND DEVICE MANUFACTURING METHOD USING THE SAME - Google Patents

Description

One aspect of the invention relates to onium salts. Another aspect of the present invention relates to a composition containing the onium salt, and a method for manufacturing a device using the composition.

2. Description of the Related Art In recent years, photolithography techniques using photoresist have been actively used to manufacture display devices such as liquid crystal displays (LCDs) and organic EL displays (OLEDs) and to form semiconductor elements. Light such as i-line with a wavelength of 365 nm, h-line (405 nm) and g-line (436 nm) with longer wavelengths are widely used as active energy rays for the above-mentioned electronic parts and packages of electronic products.

As devices become more highly integrated, the demand for miniaturization of lithography technology increases. EB) and particle beams tend to be used for exposure. Since lithographic techniques using these short-wavelength light, especially EUV or electron beams, can be manufactured by single patterning, there is a need for a resist composition that exhibits high sensitivity to EUV, electron beams, or the like. It is thought that it will increase further in the future.

Along with the shortening of the wavelength of the exposure light source, resist compositions are required to have improved lithography properties such as sensitivity to the exposure light source and resolution capable of reproducing fine-dimensional patterns. A chemically amplified resist is known as a resist composition that satisfies such requirements (Patent Document 1).
However, conventional chemically amplified resist compositions for EUV or electron beams have low absorption of EUV or electron beams, and it is difficult to satisfy the characteristics of sensitivity, resolution and pattern performance at the same time. In particular, it is necessary to overcome the decrease in throughput due to low sensitivity due to small absorption, and the deterioration of resist pattern collapse and linewise roughness (LWR) of line patterns that occur as the resolution line width of the resist becomes finer. difficult.

In order to improve the throughput of EUV or electron beam lithography, to solve the above problems, an acid and a sensitizer are generated by lithography using a first active energy beam such as EUV or an electron beam, and then visible light or ultraviolet light or the like is used. proposed a photosensitized chemically amplified resist composition for irradiation with a second actinic energy ray. (Patent Documents 2-3 and Non-Patent Document 1)

JP-A-9-90637 Japanese Patent No. 5881093 JP 2015-172741 A

Proc. of SPIE Vol. 9776 977607

However, when the resist reaction is promoted by the second active energy ray using the photosensitized chemically amplified resist composition utilizing the photosensitizing reaction, the sensitizer (electron donor) and the photoacid generator ( (electron acceptor), acid may be generated by the electron transfer reaction of several nm in some cases. This may cause unintended diffusion of the generated acid without reacting with the acid diffusion control agent even when the acid diffusion control agent is contained in the resist composition. As a result, pattern deterioration such as deterioration of LWR may occur. On the other hand, when a large amount of the acid diffusion control agent is added to suppress pattern deterioration, the amount of photosensitizer produced in the process of producing the photosensitizer by the action of the acid produced by the first active energy ray is small. Since the amount is small, the sensitization reaction is difficult to occur, and there is a problem that even if a large amount of energy, for example, 1 J/cm ² , is irradiated, the effect of promoting the resist reaction is small.

In view of such circumstances, it is an object of some embodiments of the present invention to provide a photoacid generator and a composition that are excellent in pattern properties such as sensitivity and LWR. More specifically, the object is to provide an onium salt that is most suitable as a photoacid generator for use in irradiation with particle beams, electromagnetic waves, or the like. Another object of the present invention is to provide a composition containing the onium salt and a specific resin whose solubility in a developer changes under the action of an acid.
A further object of the present invention is to provide an onium salt that is most suitable as a photoacid generator for exposure to a second active energy ray such as ultraviolet rays or visible light after irradiation with a first active energy ray such as an electron beam or extreme ultraviolet rays. do. Another object of some embodiments of the present invention is to provide a photoacid generator containing the onium salt and a composition containing the photoacid generator. Another object of the present invention is to provide a method for manufacturing a device using the composition.

As a result of intensive studies by the present inventors in order to solve the above problems, the onium salt having a specific structure does not have significant absorption in the second active energy ray such as ultraviolet rays or visible light, and the above second It was found that the acid generated by the first active energy ray, such as having a wavelength shorter than that of the active energy ray, changes the structure to convert it into a ketone derivative that absorbs the second active energy ray. was completed.
More specifically, the present inventors have found that by having at least one amino group or heterocyclic structure in a specific site of the onium salt, it has high absorption of the second activation energy and excellent acid generation efficiency. have completed several aspects of the present invention.
By using a photoacid generator containing the above onium salt in a resist composition, compared with the resist composition described in Patent Document 3 using a photosensitizing reaction occurring between an electron donor and an electron acceptor, the second It was found that since acid is generated with high efficiency by two active energy rays, it is excellent in pattern characteristics such as high sensitivity and LWR.

One aspect of the present invention for solving the above problems is an onium salt represented by any one selected from the following general formula (1) and the following general formula (2).

In the above formula (1), R ¹¹ and R ¹² are independently each an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; an optionally linear, branched or cyclic alkenyl group having 1 to 12 carbon atoms; an aryl group having 6 to 14 carbon atoms which may have a substituent; any one selected from the group consisting of a heteroaryl group having 4 to 12 carbon atoms;
Any two or more of the above R ¹¹ , R ¹² and the aryl group to which the sulfonium group is bonded are selected from the group consisting of a single bond directly or an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group. may form a ring structure together with the sulfur atom to which they are bonded via any
At least one methylene group in R ¹¹ and R ¹² may be substituted with a divalent heteroatom-containing group.

R ¹³ and R ¹⁴ each independently represent an alkyl group, a hydroxy group, a mercapto group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylsulfanylcarbonyl group, an arylsulfanyl group, alkylsulfanyl group, aryl group, heteroaryl group, aryloxy group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, (meth)acryloyloxy group, hydroxy(poly)alkyleneoxy group, amino group, cyano is any one selected from the group consisting of groups, nitro groups and halogen atoms, has 1 to 12 carbon atoms when it contains carbon, and may have a substituent.
At least one of R ¹⁴ is an amino group, or R ¹⁴ is selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom-containing group, together with an aryl group to which the R ¹⁴ is bonded They form a heterocyclic structure with each other.

R ¹⁵ and R ¹⁶ are each independently an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; an optionally substituted linear chain; A branched or cyclic alkenyl group having 1 to 12 carbon atoms; an aryl group having 6 to 14 carbon atoms which may have a substituent; and an optionally substituted aryl group having 4 to 12 carbon atoms any one selected from the group consisting of a heteroaryl group;
The above R ¹⁵ and R ¹⁶ may be bonded to each other directly with a single bond or through any one selected from the group consisting of an oxygen atom, a sulfur atom and an alkylene group to form a ring structure.
At least one methylene group in R ¹⁵ and R ¹⁶ may be substituted with a divalent heteroatom-containing group.

L ¹ is a direct bond; a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms; an alkenylene group having 1 to 12 carbon atoms; an arylene group having 6 to 14 carbon atoms; any one selected from the group consisting of a heteroarylene group; and a group in which these groups are bonded via an oxygen atom, sulfur atom or nitrogen atom-containing group.
L ⁴ and L ⁵ are each independently selected from the group consisting of a direct bond, an alkenylene group having 2 carbon atoms, an alkynylene group having 2 carbon atoms, and a carbonyl group.

Y is an oxygen atom or a sulfur atom.
h and i are each independently an integer from 1 to 3;
j is an integer of 0 to 4 when h is 1, 0 to 6 when h is 2, and 0 to 8 when h is 3.
k is an integer of 0 to 5 when i is 1, 0 to 7 when i is 2, and 0 to 9 when i is 3.
X ⁻ represents a monovalent counter anion.

In formula (2) above, R ¹¹ to R ¹⁶ , L ¹ , L ⁴ to L ⁵ , Y, hk and X ^- are each independently R ¹¹ to R ¹⁶ , L ¹ , L ⁴ -L ⁵ , Y, hk and X ^- selected from the same options as each.
R ¹⁷ is any one selected from the group consisting of an aryl group optionally having a substituent; and a heteroaryl group optionally having a substituent, and R ¹⁷ and an iodonium group are bonded The aryl groups may be bonded together to form a ring structure with the iodine atom to which they are bonded.

Moreover, one aspect of the present invention is the above onium salt represented by the following general formula (3). In addition, although a monocation is shown below, a polycation may be used.

In formula (3) above, R ¹³ to R ¹⁶ , Y and X ^- are each independently selected from the same options as each of R ¹³ to R ¹⁶ , Y and X ^- in formula (1) above.
R ¹⁸ is an alkyl group, hydroxy group, mercapto group, alkoxy group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, arylsulfanylcarbonyl group, alkylsulfanyl group, arylsulfanyl group, aryl group, hetero aryl group, aryloxy group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, (meth)acryloyloxy group, hydroxy(poly)alkyleneoxy group, amino group, cyano group, nitro group and halogen atom is any one selected from the group consisting of 1 to 12 carbon atoms when containing carbon, and may have a substituent.

L ² and L ³ are each independently selected from the group consisting of a direct bond; a methylene group; an oxygen atom; a sulfur atom;
The methylene group may have a substituent, and either one of ^L2 and ^L3 is an oxygen atom-, sulfur atom- or nitrogen atom-containing group.
e is an integer of 0-4 and f is an integer of 0-3. g is an integer from 0 to 4;

In another aspect of the present invention, a photoacid generator (hereinafter referred to as "photoacid generator (A) is also referred to as ""). The photoacid generator (A) generates an acid upon exposure.

One aspect of the present invention for solving the above problems is a composition containing the photoacid generator (A) and an acid-reactive compound.

Preferably, the composition further comprises an acid diffusion control agent.

Preferably, the acid-reactive compound is a resin (B) whose solubility in a developer changes under the action of an acid,
The resin (B) is a composition having at least one of units represented by the following (4a) to (4d). In addition, although the onium salt contained in the photoacid generator (A) is a monocation in the above description, it may be a polycation.

In formulas (4a) to (4d) above, R ¹ is any one selected from the group consisting of a hydrogen atom, an alkyl group and a halogenated alkyl group.
R ² and R ³ are each independently a linear, branched or cyclic alkyl group.
^R4 is a linear, branched or cyclic alkyl group which may have a substituent.
two or more of R ² , R ³ , and R ⁴ are either directly with a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group, and a methylene group; , may form a ring structure.
L ⁶ is any one selected from the group consisting of a direct bond, a carbonyloxy group, a carbonylamino group, a linear, branched or cyclic alkylenecarbonyloxy group optionally having a substituent, and an alkylenecarbonylamino group is.

In formula (4b) above, R ¹ and L ⁶ are selected from the same options as each of R ¹ and L ⁶ in formula (4a) above.
^R5 and ^R6 are each independently selected from the group consisting of a hydrogen atom and a linear, branched or cyclic alkyl group.
^R7 is a linear, branched or cyclic alkyl group which may have a substituent.
two or more of R ⁵ , R ⁶ and R ⁷ are either directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group, A ring structure may be formed.

In formula (4c) above, R ¹ to R ⁴ and L ⁶ are selected from the same options as each of R ¹ to R ⁴ and L ⁶ in formula (4a) above.
R ⁸ is independently selected from the group consisting of an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an alkylsulfanyl group, an alkylsulfinyl group, an alkylsulfonyl group, an amino group, a cyano group, a nitro group, and a halogen atom; Either selected.
Two or more of R ⁸ may form a ring structure directly with a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group. good.
l is an integer of 1-2.
m is an integer of 0 to 4 when l is 1, and 0 to 6 when l is 2;
n is an integer of 1 to 5 when l is 1, and an integer of 1 to 7 when l is 2;
m+n is 1 to 5 when l is 1, and 1 to 7 when l is 2.

In formula (4d) above, R ¹ , R ⁵ to R ⁷ , R ⁸ , L ⁶ , l and n are R ¹ , R ⁵ to R ⁷ , R ⁸ and L in formulas (4a) to (4c) above. ⁶ , l and n are selected from the same options as each.

Further, another aspect of the present invention includes the steps of applying the composition on a substrate to form a resist film, irradiating the resist film with a first active energy ray, and after irradiating the first active energy ray. and a step of developing the resist film after being irradiated with the second active energy ray to obtain a pattern.

According to some aspects of the present invention, it is suitably used as a resist composition for a lithographic process using a first active energy ray such as particle beams or electromagnetic waves and a second active energy ray such as ultraviolet light or visible light. , an onium salt having high sensitivity and excellent pattern characteristics such as LWR can be provided. Also, a resist composition containing the onium salt as an acid generator and having high sensitivity to the first activation energy such as particle beams or electromagnetic waves, especially electron beams or extreme ultraviolet rays, and a method for manufacturing a device using the same. can provide

FIG. 1 shows the UV absorption spectrum.

The present invention will be specifically described below, but the present invention is not limited thereto.
<1> Onium Salt and Photoacid Generator The onium salt according to one aspect of the present invention is represented by any one selected from the general formula (1) and the general formula (2). Moreover, the photoacid generator (A) contains at least one of the onium salts. The onium salt is a sulfonium salt or an iodonium salt.

The onium salt according to one aspect of the present invention has a specific structure such as acetal or thioacetal, and does not have significant absorption of the second active energy ray such as ultraviolet light or visible light. On the other hand, the acid generated by the first active energy beam such as a particle beam or an electromagnetic wave, particularly an electron beam or extreme ultraviolet rays converts the onium salt into an acetal or The thioacetal is deprotected and converted to a ketone derivative. The ketone derivative has absorption in the first active energy ray and the second active energy ray. Since the ketone derivative is generated in the exposed portion irradiated with the first active energy ray in the resist film, the amount of acid generated in the exposed portion by the first active energy ray is further irradiated with the second active energy. can be increased.
Moreover, the onium salt according to one aspect of the present invention has at least one amino group or heterocyclic structure at a specific site, so that it has high absorption of the second activation energy and excellent acid generation efficiency.

In the above formula (1), R ¹¹ and R ¹² are independently each an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; an optionally linear, branched or cyclic alkenyl group having 1 to 12 carbon atoms; an aryl group having 6 to 14 carbon atoms which may have a substituent; Any one selected from the group consisting of a heteroaryl group having 4 to 12 carbon atoms is preferred.

Specific examples of linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms for R ¹¹ and R ¹² are methyl, ethyl, n-propyl, n-butyl, isopropyl, t-butyl, cyclo Alkyl groups such as propyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, adamantan-1-yl group, adamantan-2-yl group, norbornan-1-yl group and norbornan-2-yl group can be mentioned.

-O-, -CO-, -COO-, -OCO-, -O-CO-O-, -NHCO-, -CONH- in place of at least one methylene group in the alkyl groups of R ¹¹ and R ¹² , -NH-CO-O-, -O-CO-NH-, -NH-, -N(R)-, -N(Ar)-, -S-, -SO- and -SO ₂ - The skeleton may contain one divalent heteroatom-containing group selected from the above. However, the sulfur atom (S ⁺ ) of the sulfonium group is preferably bonded to the above divalent hydrocarbon group without directly bonding to the heteroatom-containing group. R and Ar will be described later.
Examples of alkenyl groups for R ¹¹ and R ¹² include those in which at least one carbon-carbon single bond of the above alkyl group is replaced with a carbon-carbon double bond.

The optionally substituted aryl group having 6 to 14 carbon atoms for R ¹¹ and R ¹² specifically includes a monocyclic aromatic hydrocarbon group and at least 2 monocyclic aromatic hydrocarbon groups. Ring-condensed condensed polycyclic aromatic hydrocarbon groups and the like can be mentioned. These aryl groups may have a substituent.
Examples of the monocyclic aromatic hydrocarbon group include groups having a skeleton such as benzene.
Examples of the condensed polycyclic aromatic hydrocarbon group include groups having skeletons such as indene, naphthalene, azulene, anthracene, and phenanthrene.

The optionally substituted heteroaryl group having 4 to 12 carbon atoms of R ¹¹ and R ¹² is selected from an oxygen atom, a nitrogen atom and a sulfur atom in place of at least one carbon atom of the above aryl group. and at least one of which is included in the skeleton.

The heteroaryl group includes a monocyclic aromatic heterocyclic group, and a condensed polycyclic aromatic heterocyclic group in which at least one of the monocyclic aromatic heterocycles is condensed with the above aromatic hydrocarbon group or aliphatic heterocyclic group. A cyclic group and the like can be mentioned. These aromatic heterocyclic groups may have a substituent.
Examples of the monocyclic aromatic heterocyclic group include groups having skeletons such as furan, pyrrole, imidazole, pyran, pyridine, pyrimidine and pyrazine.

Condensed polycyclic aromatic heterocyclic groups include groups having skeletons such as indole, purine, quinoline, isoquinoline, chromene, phenoxazine, xanthene, acridine, phenazine and carbazole.

Substituents that R ¹¹ and R ¹² may have (hereinafter also referred to as "first substituents") include a hydroxy group, a cyano group, a mercapto group, a carboxy group, a carbonyl group, an alkyl group (-R), Alkoxy group (-OR), acyl group (-COR), alkoxycarbonyl group (-COOR), aryl group (-Ar), aryloxy group (-OAr), amino group, alkylamino group (-NHR), dialkylamino group (-N(R) ₂ ), arylamino group (-NHAr), diarylamino group (-N(Ar) ₂ ), N-alkyl-N-arylamino group (-NRAr) phosphino group, silyl group, halogen atom , a trialkylsilyl group (—Si—(R) ₃ ), a silyl group in which at least one alkyl group of the trialkylsilyl group is substituted with Ar, an alkylsulfanyl group (—SR) and an arylsulfanyl group (—SAr) etc., but are not limited to these. R and Ar will be described later.

Further, as the first substituent, the above group may be a group having a polymerizable group such as a (meth)acryloyl group.

any two or more of the above R ¹¹ , R ¹² and the aryl group to which the sulfonium group is bonded are selected from the group consisting of a single bond directly or an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group; may form a ring structure together with the sulfur atom (S ⁺ ) of the sulfonium group to which they are bonded via any one of However, the sulfur atom (S ⁺ ) of the sulfonium group is preferably bonded to the above divalent hydrocarbon group without directly bonding to the heteroatom-containing group.
Examples of the above-mentioned "nitrogen atom-containing group" include divalent groups containing a nitrogen atom such as an aminodiyl group (-NH-), an alkylaminodiyl group (-NR-), and an arylaminodiyl group (-NAr-). be done. R and Ar will be described later.
In the above formula (1), the aryl group to which the sulfonium group is bonded is the portion indicated by the arrow below.

Preferably, R in the first substituent and the like is an alkyl group having 1 or more carbon atoms. Moreover, it is more preferable that the number of carbon atoms is 20 or less. Specific examples of alkyl groups having 1 or more carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl and n-decyl. linear alkyl groups such as groups; branched alkyl groups such as isopropyl group, isobutyl group, tert-butyl group, isopentyl group, tert-pentyl group, 2-ethylexyl group; cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl alicyclic alkyl groups such as groups, adamantan-1-yl groups, adamantan-2-yl groups, norbornan-1-yl groups and norbornan-2-yl groups; A silyl group-substituted alkyl group substituted with a trialkylsilyl group such as a dimethylethylsilyl group; an alkyl group in which at least one of these hydrogen atoms is substituted with a cyano group, a fluoro group, or the like; and the like. A carbon-carbon single bond in the above alkyl group may be replaced with a carbon-carbon double bond.

Ar in the first substituent and the like is preferably an aryl group or a heteroaryl group. A heteroaryl group is an aryl group that contains one or more heteroatoms in the ring structure. Specific examples of Ar include a phenyl group, biphenyl group, terphenyl group, quaterphenyl group, naphthyl group, anthryl group, phenanthrenyl group, pentalenyl group, indenyl group, indacenyl group, acenaphthyl group, fluorenyl group, heptalenyl group, naphthacenyl group, pyrenyl group, chrysenyl group, tetracenyl group, furanyl group, thienyl group, pyranyl group, sulfanylpyranyl group, pyrrolyl group, imidazoyl group, oxazolyl group, thiazolyl group, pyrazolyl group, pyridyl group, isobenzofuranyl group , a benzofuranyl group, an isochromenyl group, a chromenyl group, an indolyl group, an isoindolyl group, a benzimidazolyl group, a xanthenyl group, an aquazinyl group and a carbazoyl group having 20 or less carbon atoms.
When R ¹¹ and R ¹² have the first substituent and the onium salt is a low-molecular-weight compound, the number of carbon atoms in R ¹¹ and R ¹² includes the number of carbon atoms in the first substituent. It is preferably 1-20.

Incidentally, the onium salt in one aspect of the present invention may be a polymer component bonded to a part of a polymer as one unit of the resin, that is, a unit containing an onium salt structure, or a polymer unit It may be a polymer component contained as. When it is a polymer component, the first substituent group includes the main chain of the polymer. When the first substituents of R ¹¹ and R ¹² are the main chain of the polymer, the number of carbon atoms of R ¹¹ and R ¹² excludes the number of carbon atoms of the main chain of the polymer. When the onium salt in one embodiment of the present invention is the polymer component, it is preferable to adjust the weight average molecular weight of the entire polymer component to 2000 to 200000.
In the present invention, a low-molecular compound has a weight-average molecular weight of less than 2,000, and a polymer component has a weight-average molecular weight of 2,000 or more.

R ¹¹ and R ¹² are preferably aryl groups from the viewpoint of improving stability.

R ¹³ and R ¹⁴ each independently represent an alkyl group, a hydroxy group, a mercapto group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylsulfanylcarbonyl group, an arylsulfanyl group, alkylsulfanyl group, aryl group, heteroaryl group, aryloxy group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, arylsulfonyl group, (meth)acryloyloxy group, hydroxy(poly)alkyleneoxy group, Any one selected from the group consisting of an amino group, a cyano group, a nitro group and a halogen atom, preferably having 1 to 12 carbon atoms when having carbon, and these are substituents (hereinafter referred to as "second (also referred to as "substituent"). Also, the carbon-carbon single bond in the alkyl groups of R ¹³ and R ¹⁴ may be replaced with a carbon-carbon double bond.
Examples of the second substituent that R ¹³ and R ¹⁴ may have include those similar to the above first substituent.
When R ¹³ and R ¹⁴ have the second substituent and the onium salt is a low-molecular-weight compound, the number of carbon atoms in R ¹³ and R ¹⁴ includes the number of carbon atoms in the second substituent. It is preferably 1-12. When the second substituent of R ¹³ and R ¹⁴ is the polymer backbone, the number of carbon atoms of R ¹³ and R ¹⁴ excludes the polymer backbone.

However, in the onium salt that is one embodiment of the present invention, at least one of R ¹⁴ is an amino group, or R ¹⁴ is any selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom-containing group. It forms a heterocyclic structure together with the aryl group to which R ¹⁴ is bonded via .
In a preferred onium salt that is one embodiment of the present invention, at least one of R ¹⁴ is an amino group, or R ¹⁴ is a heterocyclic ring together with an aryl group to which said R ¹⁴ is bonded via a nitrogen atom-containing group. It is what forms the structure.
A more preferred onium salt that is one aspect of the present invention is one in which R ¹⁴ forms a heterocyclic structure together with an aryl group to which R ¹⁴ is bonded via a nitrogen atom-containing group. The nitrogen atom-containing group includes a divalent group such as -N(H)- or a trivalent group such as =N-, and the hydrogen atom may be substituted with the second substituent.
With R ¹⁴ having the above structure, when the acetal group or thioacetal group is deprotected and converted to a ketone derivative, it absorbs the second active energy ray such as ultraviolet light or visible light.
Hereinafter, R ¹⁴ that is an amino group will be referred to as "R ^14a ", and other R ¹⁴ will also be referred to as "R ^14b ".

The alkyl group for R ¹³ and R ^14b may be linear, branched or cyclic, and specific examples include the same alkyl groups for R as the first substituent. The aryl group and heteroaryl group for R ¹³ and R ^14b include the same aryl group and heteroaryl group for Ar as the first substituent for R ¹¹ and R ¹² . Examples of the alkoxy group for R ¹³ and R ^14b include the same alkoxy groups (--OR) for the first substituent.
Examples of the hydroxy(poly)alkyleneoxy group for R ¹³ and R ^14b include a polyethyleneoxy group and a polypropyleneoxy group.
Halogen atoms for R ¹³ and R ^14b include fluorine, chlorine and iodine atoms.

The alkyl group for R ¹³ and R ^14b may contain a group similar to the heteroatom-containing group for R ¹¹ and R ¹² above instead of at least one methylene group in the skeleton. However, it is preferable not to have a continuous connection of heteroatoms such as -O-O-, -S-S- and -OS-.
R ^14b is preferably an alkyl group. Also, aryl, alkoxy, alkylsulfanyl, aryloxy, arylsulfanyl, amino and alkylamino when ortho or para to the quaternary carbon bonded to the arylene bearing Y and R ¹⁴ . Electron-donating groups such as groups are also preferred. These are preferable from the viewpoint of improving the absorbance at 365 nm.

optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms as R ¹⁵ and R ¹⁶ ; optionally substituted linear, branched or cyclic carbon atom an alkenyl group having a number of 1 to 12; an aryl group having 6 to 14 carbon atoms which may have a substituent; and a heteroaryl group having 4 to 12 carbon atoms which may have a substituent; Preferably, they are selected from the same options as each of R ¹¹ and R ¹² above.
Substituents for R ¹⁵ and R ¹⁶ (hereinafter also referred to as "third substituents") include the same substituents as the first substituents.
The above R ¹⁵ and R ¹⁶ may be directly bonded to each other via a single bond or through any one selected from the group consisting of an oxygen atom, a sulfur atom and an alkylene group to form a ring structure.
From a synthetic point of view, R ¹⁵ and R ¹⁶ are preferably the same.

L ¹ is a linear, branched or cyclic C 1-12 alkylene group; C 1-12 alkenylene group; C 6-12 arylene group; C 4-12 heteroarylene group. and a group to which these groups are bonded via an oxygen atom, sulfur atom or nitrogen atom-containing group; Examples of the alkylene group, alkenylene group, arylene group and heteroarylene group for L ¹ include divalent alkyl, alkenyl, aryl and heteroaryl groups for R ¹¹ . Examples of the nitrogen atom-containing group for L ¹ include the same nitrogen atom-containing groups as those for R ¹¹ .
When L ¹ is "a group in which these groups are bonded via an oxygen atom, a sulfur atom or a nitrogen atom-containing group", any of the above alkylene group, alkenylene group, arylene group and heteroarylene group is oxygen It is the case where the sulfonium group is bonded to the aryl group to which the sulfonium group is bonded via an atom, a sulfur atom or a nitrogen atom-containing group.
In general formula (1) above, k and j are preferably each independently 0 to 3, and more preferably independently each 0 to 2, for ease of synthesis. .

In general formula (2) above, R ¹³ to R ¹⁶ , X ⁻ , Y, L ¹ , L ⁴ to L ⁵ , h to k are each independently R ¹³ to R ¹⁶ and X in formula (1) above. ⁻ , Y, L ¹ , L ⁴ to L ⁵ , and selected from the same choices as each of h to k.

R ¹⁷ is preferably an optionally substituted C 6-12 aryl group and an optionally substituted C 4-12 heteroaryl group. R ¹⁷ and an iodonium group-bonded aryl group may bond together to form a ring structure together with the iodine atom to which they bond. The aryl and heteroaryl groups for R ¹⁷ are selected from the same options as the aryl and heteroaryl groups for R ¹¹ above, respectively. Substituents for R ¹⁷ include those similar to the first substituent.
In the general formula (2), the aryl group to which the iodonium group is bonded is the portion indicated by the arrow below.

L ⁴ and L ⁵ are each independently selected from the group consisting of a direct bond, an alkenylene group having 2 carbon atoms, an alkynylene group having 2 carbon atoms, and a carbonyl group. That is, the quaternary carbon atom to which the two Y are directly bonded and the two aryl groups may be directly bonded via an alkenylene group having 2 carbon atoms or an alkynylene group having 2 carbon atoms. However, the structure includes at least one bond via an alkenylene group having 2 carbon atoms or an alkynylene group having 2 carbon atoms.

L ⁴ and L ⁵ are each independently selected from the group consisting of a direct bond, an alkenylene group having 2 carbon atoms, an alkynylene group having 2 carbon atoms, and a carbonyl group. That is, the quaternary carbon atom to which the two Y are directly bonded and the two aryl groups may be directly bonded via an alkenylene group having 2 carbon atoms or an alkynylene group having 2 carbon atoms. However, the structure includes at least one bond via an alkenylene group having 2 carbon atoms or an alkynylene group having 2 carbon atoms.

In formula (1) or (2) above, Y is an oxygen atom or a sulfur atom.
h and i are each independently an integer from 1 to 3;
j is an integer of 0 to 4 when h is 1, 0 to 6 when h is 2, and 0 to 8 when h is 3.
k is an integer of 0 to 5 when i is 1, 0 to 7 when i is 2, and 0 to 9 when i is 3.
For example, when i and/or h are 2 in the formula (1) or (2), the onium salt has a naphthalene ring. The naphthalene ring may be bonded to the quaternary carbon to which Y is bonded at any position of the 1- to 8-positions.
Further, for example, when i and/or h are 3 in the formula (1) or (2), the onium salt has at least one of an anthracene ring, a phenanthrene ring and a naphthacene ring. Also in this case, the phenanthrene ring and the naphthacene ring may be bonded to the quaternary carbon to which Y is bonded at any position of 1-10 positions.

Examples of onium salts in some embodiments of the present invention include those having sulfonium cations and iodonium cations shown below. However, some aspects of the invention are not so limited.

One aspect of the present invention is preferably a sulfonium salt represented by the following formula (3). An iodonium salt that is an iodonio group is also preferable in place of the sulfonio group in the following formula (3). Specific examples of the iodonio group include -I ⁺ R ¹⁷ in the above formula (2).

In formula (3) above, R ¹³ -R ¹⁶ , Y and X ^- are each independently selected from the same options as each of R ¹³ -R ¹⁶ , Y and X ^- in formula (1) above.

R ¹⁸ is an alkyl group, hydroxy group, mercapto group, alkoxy group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, arylsulfanylcarbonyl group, arylsulfanyl group, alkylsulfanyl group, aryl group, heteroaryl group, aryloxy group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, arylsulfonyl group, (meth)acryloyloxy group, hydroxy(poly)alkyleneoxy group, amino group, cyano group, nitro group and It is any one selected from the group consisting of halogen atoms, preferably has 1 to 12 carbon atoms when it contains carbon, and may have a substituent. A carbon-carbon single bond in the alkyl group of R ¹⁸ may be replaced with a carbon-carbon double bond.

L ² and L ³ are each independently selected from the group consisting of a direct bond; a methylene group; an oxygen atom; a sulfur atom; a nitrogen atom-containing group; and either one of L ² and L ³ is an oxygen atom-, sulfur atom- or nitrogen atom-containing group. A preferred embodiment of the above formula (3) is a case where ^L2 is a direct bond and ^L3 is a nitrogen atom-containing group. A specific preferred embodiment of the above formula (3) is the case of having a carbazole skeleton.

e is an integer of 0-4, f is an integer of 0-4, and g is an integer of 0-5.

X ⁻ is an anion. The anion is not particularly limited, and includes anions such as sulfonate anion, carboxylate anion, imide anion, methide anion, carbanion, borate anion, halogen anion, phosphate anion, antimonate anion and arsenate anion.

More specifically, anions such as ZA ^a− , (Rf) _b PF _(6-b) ⁻ , R ¹⁹ _c BA _(4-c) ⁻ , R ¹⁹ _c GaA _(4-c) ⁻ , R ²⁰ SO ₃ ⁻ , (R ²⁰ SO ₂ ) ₃ C ^— or (R ²⁰ SO ₂ ) ₂ N ^— are preferred. When two or more of Rf, R ¹⁹ and R ²⁰ are present, two of Rf, two of R ¹⁹ and two of R ²⁰ may combine with each other to form a ring.

Z represents a phosphorus atom, a boron atom or an antimony atom. A represents a halogen atom (preferably a fluorine atom).
P represents a phosphorus atom, F a fluorine atom, B a boron atom, and Ga a gallium atom.
S represents a sulfur atom, O represents an oxygen atom, C represents a carbon atom, and N represents a nitrogen atom.

Rf is preferably an alkyl group in which 80 mol % or more of the hydrogen atoms are substituted with fluorine atoms, and the alkyl group is preferably an alkyl group having 1 to 8 carbon atoms. Alkyl groups to be Rf by fluorine substitution include straight-chain alkyl groups (methyl, ethyl, propyl, butyl, pentyl, octyl, etc.), branched-chain alkyl groups (isopropyl, isobutyl, sec-butyl, tert-butyl, etc.) and cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.) and the like. The ratio of hydrogen atoms of these alkyl groups substituted with fluorine atoms in Rf is preferably 80 mol% or more, more preferably 90 mol%, based on the number of moles of hydrogen atoms possessed by the original alkyl groups. % or more, particularly preferably 100%.

Particularly preferred examples of Rf include CF ₃ ⁻ , CF ₃ CF ₂ ⁻ , (CF ₃ ) ₂ CF ⁻ , CF ₃ CF ₂ CF ₂ ⁻ , CF ₃ CF 2 CF _{2 CF 2} ⁻ , (CF ₃ ) ₂ CFCF ₂ ⁻ , CF ₃ CF ₂ (CF ₃ )CF ^— and (CF ₃ ) ₃ C ^— . The b Rf's are independent of each other and therefore may be the same or different.

R ¹⁹ represents a phenyl group in which a portion of hydrogen atoms are substituted with at least one halogen atom or electron-withdrawing group. A halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and the like. Electron-withdrawing groups include trifluoromethyl, nitro and cyano groups. Among these, a phenyl group in which one hydrogen atom is substituted with a fluorine atom or a trifluoromethyl group is preferred. The c R ^19s are independent of each other and therefore may be the same or different.

R ²⁰ represents an alkyl group having 1 to 20 carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms, or an aryl group having 6 to 20 carbon atoms, and the alkyl group may be linear or branched. It may be branched or cyclic, and the aryl group may be unsubstituted or substituted.
a represents an integer of 4 to 6; b represents an integer of 1 to 5, preferably 2 to 4, particularly preferably 2 or 3; c represents an integer of 1 to 4, preferably 4;
Examples of anions represented by ZA _a ^- include anions represented by SbF ₆ ^- , PF ₆ ^- and BF ₄ ^- .

Anions represented by (Rf) _b PF _(6-b) ^- include (CF ₃ CF ₂ ) ₂ PF ₄ ^- , (CF ₃ CF ₂ ) ₃ PF ₃ ^- , ((CF ₃ ) ₂ CF) ₂ PF ₄ ⁻ , ((CF ₃ ) ₂ CF) ₃ PF ₃ ⁻ , (CF ₃ CF ₂ CF ₂ ) ₂ PF ₄ ⁻ , (CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ⁻ , ((CF ₃ ) ₂ CFCF ₂ ) _{2PF 4} ^- , ((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ^- , (CF ₃ CF ₂ CF ₂ CF ₂ ) ₂ PF ₄ ^- and (CF ₃ CF ₂ CF ₂ CF ₂ ) ₃ PF ₃ ^- The anion etc. which are represented by are mentioned. Of these, (CF ₃ CF ₂ ) ₃ PF ₃ ⁻ , (CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ⁻ , ((CF ₃ ) ₂ CF) ₃ PF ₃ ⁻ , ((CF ₃ ) ₂ CF) ₂ The anions represented by PF ₄ ^- , ((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ^- and ((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ^- are preferred.

Examples of anions represented by R ¹⁹ cBA _(4-c) ^- include (C ₆ F ₅ ) ₄ B ^- , ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ B ^- , (CF ₃ C ₆ H ₄ ) Anions represented by ₄ B ⁻ , (C ₆ F ₅ ) ₂ BF ₂ ⁻ , C ₆ F ₅ BF ₃ ⁻ and (C ₆ H ₃ F ₂ ) ₄ B ⁻ are exemplified. Among these, anions represented by (C ₆ F ₅ ) ₄ B ^— and ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ B ^— are preferred.

Examples of anions represented by R ¹⁹ _c GaA _(4-c) ^- include (C ₆ F ₅ ) ₄ Ga ^- , ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ Ga ^- , (CF ₃ C ₆ H ₄ ) ₄ Ga ⁻ , (C ₆ F ₅ ) ₂ GaF ₂ ⁻ , C ₆ F ₅ GaF ₃ ⁻ and (C ₆ H ₃ F ₂ ) ₄ Ga ⁻ and the like. Among these, anions represented by (C ₆ F ₅ ) ₄ Ga ^— and ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ Ga ^— are preferred.

Anions represented by R ²⁰ SO ₃ ^— include trifluoromethanesulfonate anion, pentafluoroethanesulfonate anion, heptafluoropropanesulfonate anion, nonafluorobutanesulfonate anion, pentafluorophenylsulfonate anion, and p-toluene. Examples include sulfonate anion, benzenesulfonate anion, camphorsulfonate anion, methanesulfonate anion, ethanesulfonate anion, propanesulfonate anion and butanesulfonate anion. Among these, trifluoromethanesulfonate anion, nonafluorobutanesulfonate anion, methanesulfonate anion, butanesulfonate anion, benzenesulfonate anion and p-toluenesulfonate anion are preferred.

Examples of anions represented by (R ²⁰ SO ₂ ) ₃ C ⁻ include (CF ₃ SO ₂ ) ₃ C ⁻ , (C ₂ F ₅ SO ₂ ) ₃ C ⁻ , (C ₃ F ₇ SO ₂ ) ₃ C ⁻ and anions represented by (C ₄ F ₉ SO ₂ ) ₃ ^C- .

Anions represented by (R ²⁰ SO ₂ ) ₂ N ⁻ include (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (C ₃ F ₇ SO ₂ ) ₂ N ⁻ and anions represented by (C ₄ F ₉ SO ₂ ) ₂ ^N- . Cyclic imides in which two moieties corresponding to (R ²⁰ SO ₂ ) are bonded to each other to form a ring structure are also included as anions represented by (R ²⁰ SO ₂ ) ₂ N ^— .

Examples of monovalent anions other than the above anions include perhalate ions (ClO ₄ ⁻ , BrO ₄ ⁻ etc.), halogenated sulfonate ions (FSO ₃ ⁻ , ClSO ₃ ⁻ etc.), sulfate ions (CH ₃ SO ₄ ^- , CF ₃ SO ₄ ^- , HSO ₄ ^- etc.), carbonate ion (HCO ₃ ^- , CH ₃ CO ₃ ^- etc.), aluminate ion (AlCl ₄ ^- , AlF ₄ ^- etc.), hexafluorobismuthate ion (BiF ₆ ⁻ ), carboxylate ions (CH ₃ COO ⁻ , CF ₃ COO ⁻ , C ₆ H ₅ COO ⁻ , CH ₃ C ₆ H ₄ COO ⁻ , C ₆ F ₅ COO ⁻ , CF ₃ C ₆ H ₄ COO ⁻ etc. ), aryl borate ions (B(C ₆ H ₅ ) ₄ ⁻ , CH ₃ CH ₂ CH ₂ CH ₂ B(C ₆ H ₅ ) ₃ ⁻ etc.), thiocyanate ions (SCN ⁻ ) and nitrate ions (NO ₃ ⁻ ) can be used.

These anions may have a substituent, and the substituents are an alkyl group, a hydroxy group, a mercapto group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylsulfanylcarbonyl group, arylsulfanyl group, alkylsulfanyl group, aryl group, heteroaryl group, aryloxy group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, arylsulfonyl group, (meth)acryloyloxy group, hydroxy(poly) An alkyleneoxy group, an amino group, a cyano group, a nitro group, a halogen atom and the like are included.
Among these anions, sulfonate anions and carboxylate anions are preferred.

The onium salt according to one aspect of the present invention may be, as one aspect of the photoacid generator (A), an acid generator unit-containing resin in which an anion moiety is bonded to a part of a polymer. Examples of such onium salts include resins in which X 1 ^- in the above formulas (1) and (2) has a unit represented by the following general formula (6). When the onium salt is contained in the composition as one unit of the acid generator unit-containing resin, diffusion of the acid generated during exposure is suppressed, thereby suppressing LWR.
In addition, the unit represented by the general formula (6) may be contained in the resin (B), or may be contained in a resin different from the resin (B).

In formula (6) above, R ¹ and L ⁶ are each independently selected from the same options as R ¹ and L ⁶ in formula (4a) above.
Z ¹ is a straight or branched alkyl group having 1 to 12 carbon atoms, a straight or branched alkenyl group having 1 to 12 carbon atoms, or a straight or branched aryl group having 6 to 14 carbon atoms. Also, some or all of the hydrogen atoms of these alkyl groups, alkenyl groups and aryl groups may be substituted with fluorine atoms. At least one methylene group in these groups may be substituted with a divalent heteroatom-containing group.

Examples of the anion moiety represented by the formula (6) are shown below. However, the invention is not so limited.

Onium salts according to some aspects of the present invention preferably have a molar extinction coefficient at 365 nm of less than 1.0×10 ⁵ cm ² /mol, preferably less than 1.0×10 ⁴ cm ² /mol. is more preferred.
Further, the ketone derivative obtained by deprotecting the acetal of the onium salt or the thioacetal according to some aspects of the present invention preferably has a molar absorption coefficient at 365 nm of 1.0×10 ⁵ cm ² /mol or more. It is more preferably 0×10 ⁶ cm ² /mol or more.
The molar absorption coefficient at 365 nm of the ketone derivative is preferably 5 times or more, more preferably 10 times or more, more preferably 20 times the molar absorption coefficient at 365 nm of the onium salt according to some embodiments of the present invention. It is more preferable to be above.
In order to obtain the above characteristics, the onium salt represented by the above formula (1) or (2) may be used.

<2> Method for Synthesizing the Above Onium Salt Of the onium salts according to one aspect of the present invention, methods for synthesizing the sulfonium salt and the iodonium salt will be described. The present invention is not limited to this.

When the desired sulfonium salt has an alkyl group in the sulfonio group moiety (when R ¹¹ and R ¹² in the above formula (1) are alkyl groups), for example, the following methods may be mentioned. First, an alkylsulfanyl group-containing benzoyl chloride (h = 1 in the following formula (10a), and the aryl group may have an R ¹³ group) and a bromobenzene derivative having a specific R ¹⁴ group (the following formula i=1 in (10b)) is reacted with a Grignard reagent to give an alkylsulfanylbenzophenone derivative (10c).
The R ¹⁴ group forms a heterocyclic structure with an optionally substituted amino group or an aryl group to which the R ¹⁴ group is bonded. Such bromobenzene derivatives (10b) are readily available or can be synthesized at will.
Then, an alkylating agent (R ¹² ₂ SO ₄ ) such as dimethylsulfuric acid is added to form a sulfonium salt, followed by salt exchange with a salt having a corresponding anion to obtain a dialkyl-arylsulfonium salt (10d). Then, the target sulfonium salt (10e) is obtained by acetalizing the carbonyl group using an acid catalyst and an alcohol (R ¹⁵ OH).

When the desired sulfonium salt has an aryl group in the sulfonio group portion (when R ¹¹ and R ¹² are aryl groups in the above formula (1)), for example, the following methods may be mentioned. First, a bromobenzene derivative having a specific R ¹⁴ group (i = 1 in the following formula (11a)) and an arylsulfanyl group-containing benzoyl chloride (h = 1 in the following formula (11b), and the aryl group is R (which may have ¹³ groups) is subjected to a Friedel-Crafts reaction using a Lewis acid to obtain a bromobenzophenone derivative (11c).
The R ¹⁴ group in the following formula (11a) forms a heterocyclic structure with an optionally substituted amino group or an aryl group to which the R ¹⁴ group is bonded. Such bromobenzene derivatives (11a) are readily available or can be synthesized at will.
Then, the carbonyl group is acetalized using an acid catalyst and an alcohol (R ¹⁵ OH) to obtain the acetal form (11d). Then, a Grignard reagent is used to react with a sulfoxide body (11e) having R ¹¹ and R ¹² groups to obtain a sulfonium salt, and then a salt having a corresponding anion is used for salt exchange to obtain the desired sulfonium salt ( 11f).

In the case of iodonium salts, for example, the methods shown below can be mentioned. First, a specific R ¹⁴ group-containing benzene (m = 1 in the following formula (12a)) and iodobenzoyl chloride (n = 1 in the following formula (12b), and the aryl group may have an R ¹³ group) is subjected to a Friedel-Crafts reaction using a Lewis acid to obtain an iodobenzophenone derivative (12c).
The R ¹⁴ group in the following formula (12a) forms a heterocyclic structure with an optionally substituted amino group or an aryl group to which the R ¹⁴ group is bonded. Such bromobenzene derivatives (12a) are readily available or can be synthesized at will.
Then, after reacting with an oxidizing agent such as meta-chloroperbenzoic acid (mCPBA) in the presence of an acid such as trifluoromethanesulfonic acid, the iodonium salt (12e) is formed by reaction with the aromatic compound R ¹⁷ H (12d), and then After acetalizing the carbonyl group using an acid catalyst and an alcohol (R ¹⁵ OH) to obtain the acetal form (12f), the desired iodonium salt is obtained by salt exchange using a salt having the corresponding anion if necessary. (12 g) is obtained.

When the anion portion of the onium salt is a polymer component bound to a part of the polymer, for example, the synthesis method shown below can be used. First, the sulfonium salt ((10e) or (11f) or iodonium salt (12 g) is salt-exchanged with a commercially available or optionally synthesized sulfonate having a polymerizable functional group to obtain an onium salt ( Then, the polymerizable onium salt thus obtained and an acid dissociable compound or the like are copolymerized using a radical initiator to obtain the desired polymer component.

When the desired onium salt has an alkenylene group in L ⁴ or L ⁵ , for example, the synthesis method shown below can be mentioned. An unsaturated ketone compound (d) is obtained by subjecting an acetyl compound (b) having an R ¹³ group or an R ¹⁴ group and an aldehyde compound (c) to an aldol reaction using sodium hydroxide.
The R ¹⁴ group in the following formula (b) forms a heterocyclic structure with an optionally substituted amino group or an aryl group to which the R ¹⁴ group is bonded. Such acetyl compounds (b) are readily available or can be synthesized at will.
Next, the unsaturated ketone compound and the sulfoxide compound having ^R11 and ^R12 groups are reacted with a strong acid such as methanesulfonic acid and a dehydrating agent to obtain a sulfonium salt. After that, the target sulfonium salt can be obtained by acetalizing the carbonyl group using an acid catalyst and an alcohol (R ¹⁵ OH).

<3> Composition One aspect of the present invention relates to a composition containing the photoacid generator (A) and an acid-reactive compound. Preferably, the composition further comprises an acid diffusion inhibitor.

(Photoacid generator)
The content of the photoacid generator in the composition of one embodiment of the present invention is preferably 0.1 to 50 parts by mass with respect to 100 parts by mass of the resist composition components excluding the photoacid generator. It is more preferably 1 to 30 parts by mass, even more preferably 3 to 15 parts by mass.

In calculating the content of the photoacid generator, the organic solvent is not included in 100 parts by mass of the resist composition components.

When the photoacid generator is contained in the resin as one unit, that is, when the photoacid generator is a polymer component, the weight is based on the weight excluding the main chain of the polymer. In addition, the photoacid generator is a polymer component, and units represented by general formulas (5a) to (5b) described later (hereinafter also referred to as "unit C") and general formulas (4a) to When it is included as a unit of the same polymer together with at least one unit selected from the group consisting of units represented by (4d) (hereinafter also referred to as "unit B"), the unit acting as the photoacid generator (hereinafter referred to as , also referred to as “unit A”) is preferably 0.1 to 40 mol%, more preferably 1 to 30 mol%, and further preferably 3 to 20 mol% of the total polymer units. preferable.
In the resist composition, the photoacid generator may be used alone or in combination of two or more, regardless of whether it is a polymer component or a low-molecular-weight component, and may be used in combination with other photoacid generators.

Photoacid generators other than the photoacid generator containing the onium salt include general-purpose ionic photoacid generators and nonionic photoacid generators. Examples of the ionic photoacid generator include onium salt compounds such as iodonium salts and sulfonium salts other than the above. Nonionic photoacid generators include N-sulfonyloxyimide compounds, oxime sulfonate compounds, organic halogen compounds and sulfonyldiazomethane compounds.
When a photoacid generator other than the photoacid generator containing the above onium salt is included, the content is 0.1 to 50 parts by mass with respect to 100 parts by mass of the resist composition components excluding the total amount of the photoacid generator. is preferred.

(acid-reactive compound)
The acid-reactive compound is at least one selected from the group consisting of a compound having a protective group that is deprotected by an acid, a compound having a polymerizable group that is polymerized by an acid, and a cross-linking agent having a cross-linking action by an acid. Preferably.
A compound having a protective group that can be deprotected by an acid is a compound whose protective group is deprotected by an acid to generate a polar group and change its solubility in a developer. For example, in the case of aqueous development using an alkaline developer or the like, the protective group is insoluble in the alkaline developer, but the protective group is deprotected from the compound in the exposed area by the acid generated from the photoacid generator upon exposure. , is a compound that becomes soluble in an alkaline developer.

In one aspect of the present invention, it is particularly preferred that the acid-reactive compound is a resin (B) whose solubility in a developer changes under the action of acid.
(Resin (B))
The resin (B) has at least one of the units B represented by the above (4a) to (4d) having a protective group that can be deprotected by an acid.
The above unit B is a unit contained in the resin (B) having a protective group that is deprotected by an acid, and a unit in which the protective group is deprotected by an acid to generate a polar group and change the solubility in a developer. is. For example, in the case of aqueous development using an alkaline developer or the like, the protective group is deprotected from the unit B in the exposed area by the acid generated from the photoacid generator upon exposure, although it is insoluble in the alkaline developer. It is a compound that becomes soluble in an alkaline developer.

In the present invention, the developer is not limited to an alkaline developer, and may be an aqueous neutral developer or an organic solvent developer. Therefore, when an organic solvent developer is used, a compound having a protective group that can be deprotected by an acid is deprotected from the compound in the exposed area by the acid generated from the photoacid generator upon exposure. It is a compound that produces a group and lowers the solubility in an organic solvent developer.

Examples of the polar group include a hydroxy group, a carboxy group, an amino group and a sulfo group. Among these, a polar group having —OH in the structure is preferred, and a hydroxy group or a carboxy group is preferred.
Specific examples of protective groups that can be deprotected with an acid include groups that form tertiary alkyl ester groups with carboxy groups; alkoxyacetal groups; tetrahydropyranyl groups; siloxy groups and benzyloxy groups. As the compound having the protective group, a compound having a styrene skeleton, a methacrylate or an acrylate skeleton to which these protective groups are pendant, and the like are preferably used.

The resin (B) may be a protective group-containing low-molecular-weight compound instead of a polymer component having a unit B having a protective group that can be deprotected by acid.

The protective group-containing low-molecular-weight compound has at least one of the units represented by (4a) to (4d), as in the resin (B).

In formulas (4a) to (4d) above, R ¹ is any one selected from the group consisting of a hydrogen atom, an alkyl group and a halogenated alkyl group.
Examples of the alkyl group include methyl, ethyl, n-propyl, n-butyl, isopropyl, t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups, and some of these hydrogen atoms are halogen may be replaced with Among them, a hydrogen atom, a methyl group, and a trifluoromethyl group are particularly preferred.

In the above general formulas (4a) to (4d), the sites represented by the following formulas (a-1) or (a-2) are protecting groups that are deprotected by acid (hereinafter also referred to as "acid-labile groups"). It is decomposed by the action of acid to form carboxylic acid or phenolic hydroxyl groups, which changes the solubility in the developer.
The dashed lines in the following formulas (a-1) and (a-2) indicate the bond with ^L1 or the oxygen atom in the above formulas (4a) to (4d). R ² to R ⁷ in formulas (a-1) and (a-2) below are preferably selected from the same options as R ² to R ⁷ in formulas (4a) to (4d) above.

In the above formula (a-1), R ² and R ³ are each independently a linear, branched or cyclic alkyl group such as methyl, ethyl, n-propyl, n-butyl, isopropyl, t-butyl , cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, adamantan-1-yl group, adamantan-2-yl group, norbornan-1-yl group and norbornan-2-yl group.

^R4 is a linear, branched or cyclic alkyl group which may have a substituent, the alkyl group is selected from the same options as the alkyl groups for ^R2 , and some of these hydrogen atoms are It may be substituted with a hydroxyl group, an alkoxy group, an oxo group, an amino group, an alkylamino group, or the like. The above R ⁵ , R ⁶ and R ⁷ may form a ring structure with a single bond either directly or through any one selected from the group consisting of methylene groups.

In formula (a-2) above, R ⁵ and R ⁶ are each independently a hydrogen atom and a linear or cyclic alkyl group, and the alkyl group is the same as the alkyl group for R ² . is selected from

R ⁷ is a linear, branched or cyclic alkyl group which may have a substituent, and the alkyl group is selected from the same options as the alkyl group for R ² , and some of these hydrogen atoms are hydroxyl groups. , an alkoxy group, an oxo group, an amino group, an alkylamino group, or the like. R ⁵ , R ⁶ and R ⁷ may form a ring structure with a single bond either directly or through any one selected from the group consisting of methylene groups.

Specific examples of the above formulas (a-1) and (a-2) include the structures shown below. However, the invention is not so limited.

R ⁸ in the above general formulas (4c) to (4d) is an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an alkylsulfanyl group, an alkylsulfinyl group, an alkylsulfonyl group, an amino group, a cyano group, a nitro group and a halogen Any one selected from the group consisting of atoms. These are selected from the same options as each of ^R13 .

L ⁶ in the above general formulas (4a) to (4d) is a direct bond, a carbonyloxy group, a carbonylamino group, an optionally substituted linear, branched or cyclic alkylenecarbonyloxy group or an alkylenecarbonylamino group. and a carbonyloxy group or a carbonylamino group is bonded to the acid-labile group.
In the above formulas (4a) to (4d), l is an integer of 1 to 2, m is an integer of 0 to 4 when l is 1, and 0 to 6 when l is 2, and n is l is 1, it is an integer of 1 to 5; when l is 2, it is an integer of 1 to 7; when l is 1, m+n is 1 to 5;

Specific examples of units B represented by formulas (4a) to (4d) are shown below. However, the invention is not so limited.

Instead of or in addition to the resin (B), the composition may contain a compound having a polymerizable group capable of being polymerized by an acid and/or a cross-linking agent having a cross-linking action by an acid. A compound having a polymerizable group that is polymerized by an acid is a compound that changes solubility in a developer by being polymerized by an acid. For example, in the case of aqueous development, it acts on a compound soluble in an aqueous developer to reduce the solubility of the compound in the aqueous developer after polymerization. Specific examples include compounds having an epoxy group, a vinyloxy group, an oxetanyl group, and the like.

The compound having a polymerizable group that is polymerized by an acid may be a polymerizable low-molecular-weight compound or a unit-containing polymer component having a polymerizable group.
A cross-linking agent having a cross-linking action with an acid is a compound that changes the solubility in a developer by cross-linking with an acid. For example, in the case of aqueous development, it acts on a compound soluble in an aqueous developer to reduce the solubility of the compound in the aqueous developer after polymerization or crosslinking. Specific examples include cross-linking agents having cross-linkable groups such as epoxy groups, vinyloxy groups, 1-alkoxyamino groups and oxetanyl groups. When the compound is a cross-linking agent having a cross-linking action, examples of the compound to be cross-linked, that is, the compound that reacts with the cross-linking agent to change the solubility in the developer include compounds having a phenolic hydroxyl group.

The compound having a cross-linking action with an acid may be a cross-linkable low-molecular-weight compound or a unit-containing polymer component having a cross-linkable group.
In addition to at least one of the units B represented by the formulas (4a) to (4d), the resin (B) may contain other units commonly used in resist compositions in the polymer component. good. Other units include, for example, units having at least one skeleton selected from the group consisting of a lactone skeleton, a sultone skeleton, a sulfolane skeleton, a lactam skeleton, and the like; units having at least one structure selected from the group consisting of structures, etc.; hydroxyaryl group-containing units; and the like. Furthermore, the resin (B) may contain the unit A described above.

The resin (B) is a homopolymer containing the unit B, or at least one unit C selected from the group consisting of the unit B, the unit A, and general formulas (5a) to (5b) described later. and may be included in the composition as a copolymer having When the resin (B) is a copolymer, the unit B in the resin (B) is preferably 3 to 50 mol%, more preferably 5 to 35 mol%, of the total polymer units. More preferably ~30 mol%.

(Resin (C))
In one aspect of the present invention, the composition contains a resin (C) containing one or more units C represented by the following formulas (5a) to (5b), or the resin (B) is the above At least one of the units C is preferably further included.

In formulas (5a) and (5b) above, R ¹ , R ⁸ and L ⁶ are each independently selected from the same options as each of R ¹ , R ⁸ and L ⁶ in formulas (4a) to (4d) above. be done.
R ⁹ is a cyclic group containing at least one selected from the group consisting of -C(O)-O-, -SO ₂ - and -O-SO ₂ -.
p is an integer of 0-4 and q is an integer of 1-5.
Examples of the cyclic group include groups containing a lactone skeleton, a sultone skeleton, and a sulfolane skeleton.

The unit C represented by the formulas (5a) to (5b) is contained in a copolymer containing at least one of the units A and/or the units B represented by the formulas (4a) to (4d). may also be units of another polymer.
The unit represented by the above formula (5a) is a hydroxyaryl group-containing unit (hereinafter also referred to as "unit C1"), and the unit represented by the above formula (5b) is a lactone skeleton; a sultone skeleton; a sulfolane skeleton-containing unit. (hereinafter also referred to as “unit C2”).

When a polymer having hydroxyaryl group-containing units C1 is used, it can serve as a hydrogen source when the photoacid generator decomposes, and the acid generation efficiency can be further improved, resulting in high sensitivity, which is preferable. In addition, since the polymer having a hydroxyaryl group-containing unit C1 has a low ionization potential, when an electron beam or extreme ultraviolet (EUV) is used as the first active energy beam described later, secondary electrons are easily generated, and the photoacid generation It is preferable because it improves the acid generation efficiency of the agent and provides high sensitivity.

Examples of the hydroxyaryl group-containing unit C1 are shown below. However, the invention is not so limited.

When the hydroxyaryl group-containing unit C1 is included as a unit of the same polymer together with at least one selected from the group consisting of the unit A and the unit B, the hydroxyaryl group-containing unit C1 is a positive type for aqueous development. For resist compositions, the content is preferably 3 to 90 mol %, more preferably 5 to 80 mol %, even more preferably 7 to 70 mol %, based on the total polymer units. In the case of a negative resist composition for aqueous development, the content is preferably 60 to 99 mol%, more preferably 70 to 98 mol%, even more preferably 75 to 98 mol%, based on the total polymer units.

The lactone skeleton, sultone skeleton, and sulfolane skeleton-containing unit C2 are exemplified below. However, the invention is not so limited.

When a sultone skeleton-containing unit or a sulfolane skeleton-containing unit is used as the unit C2, an acid is generated by ionization by electron beam or extreme ultraviolet (EUV) irradiation as the first active energy ray. can contribute to the deprotection reaction of the onium salt acetal in and produce more ketone derivatives having absorption in the second active energy ray. In addition, it is preferable because it contributes to polarity conversion due to the reaction with the resin (B) containing the above unit B, and the solubility of the resin in the developer is further changed, resulting in high sensitivity.

When the unit C2 includes a lactone skeleton-containing unit, a sultone skeleton-containing unit, and a sulfolane skeleton-containing unit together with at least one selected from the group consisting of the unit A and the unit B as units of the same polymer, the unit C2 is It is preferably 3 to 70 mol %, more preferably 5 to 50 mol %, even more preferably 7 to 40 mol % of the total polymer units.

In the composition of one aspect of the present invention, in addition to the above unit A, the above unit B, and the above unit C, other compounds are included in the resin (B) and/or the resin (C) as units of the same polymer. good too. Other compounds are not particularly limited as long as they are compounds generally used as resin compositions for ArF lithography, KrF 2 lithography, electron beam lithography, EUV lithography, and the like.

(Low-molecular-weight compound containing sulfone or sulfonic acid ester, or polymer)
The composition of one embodiment of the invention may contain a low molecular weight compound or polymer containing a sulfone or sulfonate ester.

The above sulfone or sulfonic acid ester is not particularly limited, but preferably has a linear, branched or cyclic alkyl or aryl group. More preferably, some or all of the hydrogen atoms in the alkyl or aryl group are substituted with fluorine atoms. When the compound is contained, it is ionized by irradiation with an electron beam or extreme ultraviolet rays to generate an acid, so that the sensitivity of the resist can be increased.
The content of the compound containing sulfone or sulfonic acid ester is preferably 0.1 to 50 parts by weight per 100 parts by weight of the resist composition components excluding the total amount of the photoacid generator.

Specific examples of compounds containing sulfones or sulfonate esters include dimethylsulfone, isopropylmethylsulfone, methylphenylsulfone, diphenylsulfone, phenyltrifluoromethylsulfone, bis(4-fluorophenyl)sulfone, bis(phenylsulfonyl)methane, methyl methanesulfonate, isopropyl methanesulfonate, ethyl trifluoromethanesulfonate, methyl benzenesulfonate, 1,3-propanesultone, 1-propene 1,3-sultone, 1,4-butanesultone, 1,2-bis(tosyloxy ) ethane, 1,8-naphthosultone, and the like, each of which may be used alone or in combination of two or more.

(Fluorine-containing water-repellent polymer)
The composition of one aspect of the present invention may contain a fluorine-containing water-repellent polymer.

The fluorine-containing water-repellent polymer is not particularly limited, but includes those commonly used in the immersion exposure process, and preferably has a fluorine atom content higher than that of the above polymer. When a resist film is formed using a composition containing a fluorine-containing water-repellent polymer, the fluorine-containing water-repellent polymer is unevenly distributed on the surface of the resist film due to the water repellency of the fluorine-containing water-repellent polymer. can be made
As for the fluorine content of the fluorine water-repellent polymer, it is preferable that 25 mol % or more of the hydrogen atoms in the hydrocarbon groups in the fluorine water-repellent polymer are fluorinated, and 50 mol % or more is fluorinated. is more preferred.

The content of the fluorine water-repellent polymer in the composition should be 0.5 to 10 parts by mass with respect to 100 parts by mass of the polymer (not the fluorine water-repellent polymer) of one embodiment of the present invention. is preferable from the viewpoint of improving the hydrophobicity of the resist film. The fluorine water-repellent polymer may be used alone or in combination of two or more.

(Photosensitizer and its precursor)
The composition of one aspect of the invention may comprise a photosensitizer and its precursors. Hereinafter, the photosensitizer and its precursor are collectively referred to as a "sensitizing compound".
The sensitizing compound is not particularly limited as long as it does not reduce the effect of the onium salt according to some embodiments of the present invention, and includes thioxanthone derivatives and their acetalized compounds, benzophenone derivatives and their acetalized compounds, naphthalene derivatives, Examples include anthracene derivatives, alkyl alcohols and aryl alcohols.
Moreover, as a sensitizing compound, for example, a photosensitizer precursor represented by the following general formula (7) may be included. By containing the photosensitizer precursor, a photosensitizer is generated from the photosensitizer precursor by irradiating the first active energy ray, and then by irradiating the second active energy. Since the sensitization reaction that occurs between the photosensitizer and the onium salt according to some embodiments of the present invention can be utilized, the sensitivity of the resist can be increased, which is preferable.

In the above formula (7), Ar ¹¹ and Ar ¹² are each independently a phenylene group which may have a substituent, and R ²¹ is an alkylsulfanyl group which may have a substituent. , an arylsulfanyl group and an alkylsulfanylphenyl group, W is any one selected from the group consisting of a sulfur atom, an oxygen atom and a direct bond, and R ²² is a substituent Y is independently each either an oxygen atom or a sulfur atom, and R ²³ and R ²⁴ are each independently , a linear, branched or cyclic alkyl group, an alkenyl group, an alkynyl group and an aralkyl group which may have a substituent, and the above R ²³ and R ²⁴ are It may be bonded to each other to form a ring structure with two Y in the formula.

Ar ¹¹ and Ar ¹² in the above formula (7) are each a phenylene group, and substituents other than R ²¹ or -WR ²² (hereinafter, the substituents of Ar ¹¹ and Ar ¹² are referred to as "fourth substituents group"). From the viewpoint of synthesis, Ar ¹¹ and Ar ¹² are preferably not indirectly bonded to form a ring.
An electron donating group is mentioned as said 4th substituent. Specific examples of the electron-donating group include alkyl groups, alkenyl groups, alkoxy groups, alkoxyphenyl groups, alkylsulfanyl groups, arylsulfanyl groups and alkylsulfanylphenyl groups. A fourth substituent also includes a long chain alkoxy group having a polyethylene glycol chain (-(CO ₂ H ₄ ) _n -). Also, when the fourth substituent is bonded to the para-position of Ar ¹¹ or Ar ¹² , it may have an OH group as the fourth substituent.

In the present invention, the substitution position such as the “para position” of Ar ¹¹ or Ar ¹² is the position relative to the group to which the quaternary carbons bonded to two Ys and Ar ¹¹ and Ar ¹² in the above formula (7) are bonded. Say. Not only for the fourth substituent but also for other groups, the standard of the substitution position such as "para position" is the position relative to the group bonded to the quaternary carbon.
The alkyl group and alkenyl group as the fourth substituent are selected from the same options as the alkyl group and alkenyl group for R ¹¹ in formula (1) above. The alkoxy group as the fourth substituent is selected from the same options as those for the alkoxy group (--OR) in the first substituent.
The alkylsulfanyl group, arylsulfanyl group and alkylsulfanylphenyl group as the fourth substituent include those similar to the alkylsulfanyl group, arylsulfanyl group and alkylsulfanylphenyl group for R ²¹ described later.

Any methylene group of the alkyl group in the fourth substituent may be a group substituted with a -C(=O)- group or a -OC(=O)- group. However, the -C(=O)- group and the -OC(=O)- group are preferably not directly bonded to Ar ¹¹ and Ar ¹² in the above four substituents. In addition, in the above-mentioned fourth substituent, it is preferable that the heteroatoms such as —O—O, —S—S— and —S—O— are not connected continuously.
When the fourth substituent is an alkoxy group, an alkoxyphenyl group, an alkylsulfanyl group, an arylsulfanyl group or an alkylsulfanylphenyl group, the phenylene group represented by Ar ¹¹ and Ar ¹² is bonded to the ortho and/or para positions of the phenylene group. preferably. In that case, the number of substituents is preferably three or less.

R ²¹ in the above formula (7) is any one selected from the group consisting of optionally substituted alkylsulfanyl groups, arylsulfanyl groups and alkylsulfanylphenyl groups.
Specifically, the alkylsulfanyl group for R ²¹ is preferably an alkylsulfanyl group having 1 to 20 carbon atoms such as methylsulfanyl group, ethylsulfanyl group, n-propylsulfanyl group, n-butylsulfanyl group, and 1 to 12 carbon atoms. is more preferred.
Specific examples of the arylsulfanyl group for R ²¹ include a phenylsulfanyl group and a naphthylsulfanyl group.

Specific examples of the alkylsulfanylphenyl group for R ²¹ preferably include a phenyl group to which an alkylsulfanyl group having 1 to 20 carbon atoms such as a methylsulfanylphenyl group, an ethylsulfanylphenyl group, a propylsulfanylphenyl group, and a butylsulfanylphenyl group are bonded. and more preferably a phenyl group to which an alkylsulfanyl group having 1 to 12 carbon atoms is attached. The substitution position of the alkylsulfanyl group bonded to the phenylene group in R ²¹ is not particularly limited, but the para-position is preferred from the viewpoint of increasing the electron-donating property and the molar absorption coefficient at 365 nm. The above R ²¹ is preferably bonded to the ortho- or para-position of the phenylene group Ar ¹¹ .

R ²² in the above formula (7) is either an optionally substituted alkyl group or an aryl group, and is selected from the same options as for each of R ¹¹ above.

R ²¹ and R ²² in the above formula (7) may have a substituent, and the substituent (hereinafter, the substituent of R ²¹ and R ²² is referred to as a “fifth substituent”) is particularly Examples include, but are not limited to, an electron-withdrawing group in addition to the fourth substituent. A nitro group, a sulfonyl group, etc. are mentioned as an electron withdrawing group. A polymerizable group may be introduced into R ²¹ or R ²² above, and the polymer obtained by polymerizing the polymer may be used as the polymer imparted with a sensitizing effect, or the fifth substituent may include the main chain of the polymer. Examples of the polymerizable group include a (meth)acryloyloxy group, an epoxy group, and a vinyl group.

When W in the above formula (7) is an oxygen atom or a sulfur atom, it is preferred that the above W is at the ortho- or para-position of Ar ¹² . When said W is a direct bond, said W is preferably at the ortho or para position of Ar ¹² .

The total carbon number of R ²¹ in the above formula (7) is not particularly limited, and when R ²¹ has a substituent, the total carbon number is preferably 1-20. The total carbon number of R ²² in the above formula (7) is not particularly limited, and when R ²² has a substituent, it preferably has a total carbon number of 1-20.
When the photosensitizer precursor is a polymer, the total carbon number of R ²¹ and R ²² excluding the portion containing the polymer main chain serving as the fifth substituent is preferably 1-20.

Y is each independently either an oxygen atom or a sulfur atom.
R ²³ and R ²⁴ are independently selected from the group consisting of linear, branched or cyclic alkyl groups, alkenyl groups and alkynyl groups, and aralkyl groups, each of which may have a substituent. Either. The alkyl group and alkenyl group for R ²³ and R ²⁴ are selected from the same options as the alkyl group and alkenyl group for R ¹¹ in formula (1) above.
The alkynyl group for R ²³ and R ²⁴ is selected from those in which part of the alkyl groups for R ²³ and R ²⁴ are triple bonds. The aralkyl group for R ²³ and R ⁴ is selected from those in which some of the hydrogen atoms in the alkyl groups for R ²³ and R ²⁴ are substituted with aryl groups such as phenyl and naphthyl groups.

R ²³ and R ²⁴ in the above formula (7) may have a substituent, and the substituent (hereinafter, the substituent of R ²³ and R ²⁴ is referred to as a “sixth substituent”) is particularly Although not limited, in addition to the above fifth substituent, aryl groups such as phenyl group and naphthyl group, and the like can also be mentioned.
The total carbon number of R ²³ and R ²⁴ in the above formula (7) is not particularly limited, and the photosensitizer precursor may be a constituent component of a polymer, but R ²³ or R ²⁴ may be a substituent. When it has, it is preferable that each has a total carbon number of 1 to 20.

The above R ²³ and R ²⁴ may combine with each other to form a ring structure with two Y in the formula.
That is, the photosensitizer precursor according to one aspect of the present invention is represented by the following formula (8). In the following formula (8), -R ²⁵ -R ²⁶ - is preferably -(CH ₂ ) _n -, where n is an integer of 2 or more. Although n is not particularly limited as long as it is 2 or more, it is preferably 8 or less for ease of synthesis. R ²⁵ and R ²⁶ correspond to R ²³ and R ²⁴ in the above formula (7) combined to form a ring.

In formula (8) above, R ²⁵ and R ²⁶ may have the same sixth substituent as R ²³ and R ²⁴ above. A polymerizable group may be introduced into the above R ²³ or R ²⁴ , and a polymer obtained by polymerizing this may be used as a polymer imparted with a sensitizing action.
The total carbon number of R ²³ and R ²⁴ is preferably 1-20. When the photosensitizer precursor is a polymer, the total carbon number of R ²³ and R ²⁴ excluding the portion containing the polymer main chain serving as the sixth substituent is preferably 1-20.

After the acid treatment of the photosensitizer precursor, that is, the photosensitizer having a carbonyl group generated when the photosensitizer precursor is deprotected by acid has a molar absorption coefficient of 1 at 365 nm. It is preferably 0×10 ⁵ cm ² /mol or more. A higher molar extinction coefficient at 365 nm is preferable, but a realistic value is 1.0×10 ¹⁰ cm ² /mol or less. In order to make the molar extinction coefficient within the above range, the photosensitizer precursor contains, for example, one or more alkylsulfanyl groups, arylsulfanyl groups, alkylsulfanylphenyl groups, or two or more alkoxy groups or aryloxy groups. A configuration including
In the present invention, the molar extinction coefficient is at 365 nm measured with a UV-VIS spectrophotometer using chloroform as a solvent.
In addition, the photosensitizer precursor according to one aspect of the present invention has -YR ²³ and -YR ²⁴ in the whole photosensitizer precursor in terms of ease of synthesis and light absorption characteristics or 4 or less groups selected from the group consisting of alkylsulfanyl groups, arylsulfanyl groups, alkoxyphenyl groups, alkylsulfanylphenyl groups, alkoxy groups and aryloxy groups other than -YR ²⁵ -R ²⁶ -Y- is preferably

Examples of the photosensitizer precursor represented by formula (7) or (8) include the following photosensitizer precursors. In the following examples, those shown in parentheses represent polymer units. Photosensitizer precursors in some embodiments of the present invention are not limited to this.

A method for synthesizing a photosensitizer precursor according to one aspect of the present invention will now be described. The present invention is not limited to this.
When the photosensitizer precursor according to one aspect of the present invention has a structure represented by the following formula (9), it can be synthesized, for example, by the following method. First, one selected from the group consisting of alkoxybenzoyl chlorides, alkylbenzoyl chlorides, thioalkoxybenzoyl chlorides and thioalkylbenzoyl chlorides having —WR ²² groups, and those in which these alkyl groups are aryl groups; , with a benzene halide having an R ²¹ group, via a Grignard reaction to give the benzophenone derivative. Then, the benzophenone derivative is reacted with an alcohol and, if necessary, an orthoester such as trialkyl orthoformate (R ²³ , R ²⁴ =alkyl group) as a dehydrating agent at 0° C. to reflux temperature for 1 to 120 hours. can obtain a derivative represented by the following formula (9).

(other ingredients)
In addition to the above components, the composition according to one aspect of the present invention may optionally further contain an acid diffusion control agent, a surfactant, an organic carboxylic acid, an organic solvent, and a dissolution inhibitor, which are used in ordinary resist compositions. , stabilizers and dyes, polymers other than those described above, and the like.

The acid diffusion control agent has the effect of controlling the diffusion phenomenon of the acid generated from the photo-acid generator in the resist film and controlling undesirable chemical reactions in the non-exposed regions. Therefore, the storage stability of the obtained resist composition is further improved, and the resolution as a resist is further improved, and the line width change of the resist pattern due to the variation of the holding time from exposure to development can be suppressed. , a resist composition having excellent process stability can be obtained.

Examples of the acid diffusion control agent include compounds having one nitrogen atom, compounds having two nitrogen atoms, compounds having three nitrogen atoms in the same molecule, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like. be done. As the acid diffusion control agent, a photodegradable base that is sensitized by exposure to generate a weak acid can also be used. Photodegradable bases include, for example, onium salt compounds and iodonium salt compounds which are decomposed by exposure to lose acid diffusion controllability.

Specifically, as the acid diffusion control agent, Japanese Patent No. 3577743, JP-A-2001-215689, JP-A-2001-166476, JP-A-2008-102383, JP-A-2010-243773, JP-A-2011-37835 and JP-A-2011-37835. compounds described in JP-A-2012-173505.

The content of the acid diffusion control agent is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, more preferably 0.05 to 0.05 parts by mass, based on 100 parts by mass of the resist composition components. More preferably, it is 3 parts by mass.
The surfactant is preferably used to improve coatability. Examples of surfactants include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene polyoxypropylene block copolymers, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters. agents, fluorine-based surfactants, organosiloxane polymers, and the like.
The content of the surfactant is preferably 0.0001 to 2 parts by mass, more preferably 0.0005 to 1% by mass, per 100 parts by mass of the resist composition components.

Examples of the organic carboxylic acids include aliphatic carboxylic acids, alicyclic carboxylic acids, unsaturated aliphatic carboxylic acids, oxycarboxylic acids, alkoxycarboxylic acids, ketocarboxylic acids, benzoic acid derivatives, phthalic acid, terephthalic acid, isophthalic acid, 2 -naphthoic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid and the like. When electron beam exposure is performed in a vacuum, there is a risk of volatilization from the resist film surface and contamination of the writing chamber. 1-Hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid are preferred.
The content of the organic carboxylic acid is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, and still more preferably 0.01 to 3 parts by mass with respect to 100 parts by mass of the resist composition components. is.

Examples of organic solvents include ethylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether propionate, and propylene glycol monoethyl ether. Acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl β-methoxyisobutyrate, ethyl butyrate, propyl butyrate, methyl isobutyl ketone, ethyl acetate, isoamyl acetate, ethyl lactate, toluene, xylene, cyclohexyl acetate, diacetone Alcohol, N-methylpyrrolidone, N,N-dimethylformamide, γ-butyrolactone, N,N-dimethylacetamide, propylene carbonate, ethylene carbonate and the like are preferred. These organic solvents are used alone or in combination.

The resist composition components are preferably dissolved in the above-mentioned container solvent at a solid content concentration of 1 to 40% by mass. More preferably 1 to 30 mass %, still more preferably 3 to 20 mass %. By setting the solid content concentration in such a range, the above film thickness can be achieved.

When the resist composition of one aspect of the present invention contains a polymer, the polymer preferably has a weight average molecular weight of 2000 to 200000, more preferably 2000 to 50000, and further preferably 2000 to 15000. preferable. The preferred dispersity (molecular weight distribution) (Mw/Mn) of the polymer is 1.0 to 1.7, more preferably 1.0 to 1.2, from the viewpoint of sensitivity. The weight-average molecular weight and dispersity of the polymer are defined as polystyrene-equivalent values by GPC measurement.

A composition according to one aspect of the present invention is obtained by mixing each component of the above composition, and the mixing method is not particularly limited.

<4> Device manufacturing method One aspect of the present invention includes the steps of forming a resist film by applying the composition onto a substrate, and irradiating the resist film with a first active energy ray; A method of manufacturing a device, comprising the steps of: irradiating a resist film after being irradiated with the first active energy ray with a second active energy ray; and developing the resist film after being irradiated with the second active energy ray to obtain a pattern. is.

One embodiment of the present invention includes the steps of forming a resist film, irradiating with a first active energy ray, irradiating with a second active energy, and forming a pattern using the above composition, It may be a method for manufacturing a substrate having a pattern before obtaining singulated chips.
One form of the present invention is a step of forming a coating film on a substrate using the above composition, exposing the coating film using a first active energy ray and a second active energy ray, and forming an interlayer insulating film. It may be a device manufacturing method including the step of obtaining

The first active energy ray and the second active energy ray are not particularly limited as long as the onium salt according to some embodiments of the present invention does not have significant absorption in the second active energy ray. Preferably, the wavelength of the radiation is shorter than that of the second active energy radiation, or the energy of the photon or particle radiation is higher. Each actinic energy ray is exemplified below, but is not limited thereto if the wavelength of the first actinic energy ray is shorter than that of the second actinic energy ray, or if the energy of the photon or particle beam is high.
The first active energy ray is not particularly limited as long as it can generate active species such as acid in the resist film after irradiation of the resist film. Ultraviolet rays (EUV) are preferred.

As the second active energy ray, a ketone produced by deprotecting the acetal or thioacetal portion of the onium salt according to some embodiments of the present invention with an acid generated in the resist film after irradiation with the first active energy ray. Any light may be used as long as it can activate the derivative to generate an active species such as an acid. For example, it means KrF excimer laser light, UV, visible light, etc. Among UV light, it is particularly preferable to use light in the range of 365 nm (i-line) to 436 nm (g-line).

A method for manufacturing a device according to one aspect of the present invention may include a step of heating with a heating wire or laser between the step of irradiating with the first activation energy and the step of irradiating with the second activation energy ray. preferable. By having this step, the decomposition efficiency of the onium salt is improved, which can lead to further improvement in sensitivity. The heating step can be performed with a hot plate or the like, and in the device manufacturing method, the implementation of prebaking corresponds to this step.

The substrate is not particularly limited, and known substrates can be used. Examples include metal substrates such as silicon, silicon nitride, titanium, tantalum, palladium, copper, chromium, and aluminum; glass substrates; and the like.
In one aspect of the present invention, the active energy beam used for exposure in the photolithography process used to obtain an interlayer insulating film for LSI fabrication includes UV, KrF excimer laser light, ArF excimer laser light, electron beam, or Extreme ultraviolet rays (EUV) are preferred.

The irradiation amount of the first active energy ray varies depending on the type and blending ratio of each component in the photocurable composition, the film thickness of the coating film, etc., but it should be 1 J/cm ² or less or 1000 μC/cm ² or less. is preferred.
In one aspect of the present invention, the thickness of the resist film formed from the resist composition is preferably 10 to 200 nm. The above resist composition is applied onto a substrate by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc., and is heated at 60 to 150° C. for 1 to 20 minutes, preferably 80 to 80 minutes. A thin film is formed by pre-baking at 120° C. for 1 to 10 minutes. The film thickness of this coating film is 5 to 200 nm, preferably 10 to 100 nm.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

<1> Synthesis of sulfonium salt <Synthesis of sulfonium salt 1>
(Synthesis Example 1) Synthesis of 3-(4-bromobenzoyl)-9-ethylcarbazole 5.1 g of aluminum chloride is added to 48 g of methylene chloride and the temperature is adjusted to 0°C. 6.8 g of 9-ethylcarbazole is added thereto, 8.4 g of 4-bromobenzoyl chloride dissolved in 17 g of methylene chloride is added dropwise over 30 minutes, and the mixture is stirred at 25° C. for 1 hour. After that, 40 g of pure water is added, and after stirring, liquid separation is performed to recover the organic layer. Add 35 g of pure water to the organic layer, add 5.2 g of a 25% by mass sodium hydroxide aqueous solution with stirring until the aqueous layer becomes basic, collect the organic layer, wash with 40 g of pure water three times, By distilling off the methylene chloride from the organic layer, 8.3 g of 3-(4-bromobenzoyl)-9-ethylcarbazole is obtained.

(Synthesis Example 2) Synthesis of 3-[(4-bromophenyl)dimethoxymethyl]-9-ethylcarbazole 8.0 g of 3-(4-bromobenzoyl)-9-ethylcarbazole and 1.8 g of trimethyl orthoformate were mixed with methanol. After dissolving in 20 g, 200 mg of 95% by mass sulfuric acid is added and stirred at 60° C. for 3 hours. After cooling to room temperature and adding 1.0 g of triethylamine, methanol is distilled off. 48 g of methylene chloride is dissolved in the residue, washed with 32 g of pure water three times, and methylene chloride is distilled off to obtain 8.8 g of 3-[(4-bromophenyl)dimethoxymethyl]-9-ethylcarbazole.

(Synthesis Example 3) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldiphenylsulfonium nonafluorobutanesulfonate (sulfonium salt 1) 2.0 g of tetrahydrofuran and 360 mg of magnesium were placed in a pre-dried flask. 50 mg of 1,2-dibromoethane are added to activate the magnesium. After confirming activation, the solution was heated to 50° C., and 4.0 g of 3-[(4-bromophenyl)dimethoxymethyl]-9-ethylcarbazole obtained in Synthesis Example 2 above was added to 6.0 g of THF. Add dropwise the solution dissolved in After dropping, the mixture is stirred at 50° C. for 2 hours to obtain a THF solution of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenylmagnesium bromide. 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenylmagnesium bromide was added to a solution of 2.2 g of diphenyl sulfoxide, 1.5 g of trimethylsilyl chloride and 1.5 g of triethylamine dissolved in 9.5 g of methylene chloride. is added dropwise at a temperature of 10° C. or lower, and then stirred at 25° C. for 1 hour. After stirring, 30 g of a 10% by mass ammonium chloride aqueous solution is added at 5°C or less, and the mixture is further stirred for 10 minutes. Then, 40 g of methylene chloride and 3.8 g of potassium nonafluorobutanesulfonate are added, and the mixture is stirred at 25°C for 2 hours. After liquid separation and washing with pure water three times, methylene chloride is distilled off to obtain crude crystals. The crude crystals are purified by silica gel column chromatography (methylene chloride/methanol=90/10 (volume ratio)) to give 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldiphenylsulfonium nonafluorobutanesulfonate. 4.7 g of (sulfonium salt 1) are obtained.

<Synthesis of sulfonium salt 2>
(Synthesis Example 4) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldiphenylsulfonium benzoate (sulfonium salt 2) The above except that sodium benzoate is used instead of potassium nonafluorobutanesulfonate. By performing the same operation as in Synthesis Example 3, 3.5 g of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldiphenylsulfonium benzoate (sulfonium salt 2) is obtained.

<Synthesis of sulfonium salt 3>
(Synthesis Example 5) Synthesis of 3-[2-(4-bromobenzoyl)-1,3-dioxolan-2-yl]-9-ethylcarbazole Same as Synthesis Example 2 except that ethylene glycol is used instead of methanol. to obtain 8.6 g of 3-[2-(4-bromobenzoyl)-1,3-dioxolan-2-yl]-9-ethylcarbazole.

(Synthesis Example 6) Synthesis of diphenyl-4-[2-(9-ethylcarbazol-3-yl)-1,3-dioxolan-2-yl]phenylsulfonium nonafluorobutanesulfonate (sulfonium salt 3) 3-[( The above synthesis example except that 3-[2-(4-bromobenzoyl)-1,3-dioxolan-2-yl]-9-ethylcarbazole is used in place of 4-bromophenyl)dimethoxymethyl]-9-ethylcarbazole. Diphenyl-4-[2-(9-ethylcarbazol-3-yl)-1,3-dioxolan-2-yl]phenylsulfonium nonafluorobutanesulfonate (sulfonium salt 3) was obtained in 4 by performing the same operation as in 3. .5 g.

<Synthesis of sulfonium salt 4>
(Synthesis Example 7) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldibenzothiophenium nonafluorobutanesulfonate (sulfonium salt 4) Except for using dibenzothiophene oxide instead of diphenyl sulfoxide By performing the same operation as in Synthesis Example 3 above, 3.1 g of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldibenzothiophenium nonafluorobutanesulfonate (sulfonium salt 4) is obtained.

<Synthesis of sulfonium salt 5>
(Synthesis Example 8) 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldibenzothiophenium-4-(3-hydroxyadamantylcarbonyloxy)-1,1,2-trifluorobutanesulfonate ( Synthesis of sulfonium salt 5) Using dibenzothiophene oxide instead of diphenyl sulfoxide and 4-(3-hydroxyadamantylcarbonyloxy)-1,1,2-trifluorobutanesulfonic acid instead of potassium nonafluorobutanesulfonate 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldibenzothiophenium-4-(3-hydroxyadamantylcarbonyloxy)-4-(3-hydroxyadamantylcarbonyloxy) was obtained by the same procedure as in Synthesis Example 3 above, except that sodium was used. 3.3 g of -1,1,2-trifluorobutanesulfonate (sulfonium salt 5) are obtained.

<Synthesis of sulfonium salt 6>
(Synthesis Example 9) Synthesis of 3-(4-bromobenzoyl)dibenzothiophene 3-(4-bromobenzoyl) was obtained by performing the same operation as in Synthesis Example 1 above, except that dibenzothiophene was used in place of 9-ethylcarbazole. 8.1 g of dibenzothiophene are obtained.

(Synthesis Example 10) Synthesis of 3-[(4-bromophenyl)dimethoxymethyl]dibenzothiophene Except for using 3-(4-bromobenzoyl)dibenzothiophene instead of 3-(4-bromobenzoyl)-9-ethylcarbazole 8.6 g of 3-[(4-bromophenyl)dimethoxymethyl]dibenzothiophene was obtained by the same procedure as in Synthesis Example 2 above.

(Synthesis Example 11) Synthesis of 4-[(dibenzothiophen-3-yl)dimethoxymethyl]phenyldiphenylsulfonium nonafluorobutanesulfonate (sulfonium salt 6) 3-[(4-bromophenyl)dimethoxymethyl]-9-ethylcarbazole 4-[(dibenzothiophen-3-yl)dimethoxymethyl]phenyldiphenylsulfonium was obtained in the same manner as in Synthesis Example 3 except that 3-[(4-bromophenyl)dimethoxymethyl]dibenzothiophene was used instead of 4.5 g of nonafluorobutanesulfonate (sulfonium salt 6) are obtained.

<Synthesis of sulfonium salt 7>
(Synthesis Example 12) Synthesis of 3-(4-bromobenzoyl)dibenzofuran 3-(4-bromobenzoyl)dibenzofuran was prepared in the same manner as in Synthesis Example 1 above, except that dibenzofuran was used in place of 9-ethylcarbazole. 8.1 g is obtained.

(Synthesis Example 13) Synthesis of 3-[(4-bromophenyl)dimethoxymethyl]dibenzofuran The above procedure was performed except that 3-(4-bromobenzoyl)dibenzofuran was used in place of 3-(4-bromobenzoyl)-9-ethylcarbazole. By performing the same operation as in Synthesis Example 2, 8.4 g of 3-[(4-bromophenyl)dimethoxymethyl]dibenzofuran is obtained.

(Synthesis Example 14) Synthesis of 4-[(dibenzofuran-3-yl)dimethoxymethyl]phenyldiphenylsulfonium nonafluorobutanesulfonate (sulfonium salt 7) 3-[(4-bromophenyl)dimethoxymethyl]-9-ethylcarbazole 4-[(dibenzofuran-3-yl)dimethoxymethyl]phenyldiphenylsulfonium nonafluorobutane was obtained in the same manner as in Synthesis Example 3 except that 3-[(4-bromophenyl)dimethoxymethyl]dibenzofuran was used instead. 4.1 g of sulfonate (sulfonium salt 7) are obtained.

<Synthesis of sulfonium salt 8>
(Synthesis Example 15) Synthesis of 4-(4-bromobenzoyl)phenylmethylphenylamine 4-(4- 8.0 g of bromobenzoyl)phenylmethylphenylamine are obtained.

(Synthesis Example 16) Synthesis of 4-[(4-bromophenyl)dimethoxymethyl]phenylmethylphenylamine 4-(4-bromobenzoyl)phenylmethylphenyl instead of 3-(4-bromobenzoyl)-9-ethylcarbazole 8.2 g of 4-[(4-bromophenyl)dimethoxymethyl]phenylmethylphenylamine is obtained in the same manner as in Synthesis Example 2 except that an amine is used.

(Synthesis Example 17) Synthesis of 4-[dimethoxy-[4-(methylphenylamino)phenyl]methyl]phenyldiphenylsulfonium nonafluorobutanesulfonate (sulfonium salt 8) 3-[(4-bromophenyl)dimethoxymethyl]-9 4-{dimethoxy-[4-(methylphenylamino)] was prepared in the same manner as in Synthesis Example 3 above, except that 4-[(4-bromophenyl)dimethoxymethyl]methylphenylamine was used in place of -ethylcarbazole. 3.9 g of phenyl]methyl}phenyldiphenylsulfonium nonafluorobutanesulfonate (sulfonium salt 8) are obtained.

<Synthesis of sulfonium salt 9>
(Synthesis Example 18) Synthesis of 9-ethyl-3-(4-phenylsulfanylbenzoyl)carbazole 46 g of 3-(4-bromobenzoyl)-9-ethylcarbazole, 20 g of benzenethiol and 25 g of calcium carbonate were mixed with N,N-dimethyl Add to 117 g of formamide (DMF) and stir at 60° C. for 5 hours. Thereafter, 312 g of pure water and 312 g of ethyl acetate are added to separate the layers, and the organic layer is recovered. The organic layer is washed twice with 150 g of pure water, and ethyl acetate is distilled off to obtain crude crystals. After dispersing it in 150 g of isopropyl ether, it is recovered to give 40 g of 9-ethyl-3-(4-phenylsulfanylbenzoyl)carbazole.

(Synthesis Example 19) Synthesis of 9-ethyl-3-(4-phenylsulfinylbenzoyl)carbazole After dissolving 38 g of 9-ethyl-3-(4-phenylsulfinylbenzoyl)carbazole in 228 g of formic acid, 35% by mass of hydrogen peroxide was added. Add 9.0 g of water and stir at room temperature for 17 hours. The reaction solution is added dropwise to 1100 g of pure water, and the resulting crude crystals are collected. After dissolving the crude crystals in 228 g of methylene chloride, 152 g of pure water is added, and 20 g of a 25 mass % sodium hydroxide aqueous solution is added while stirring until the water layer becomes basic. After washing the organic layer with 132 g of pure water, the methylene chloride is distilled off to obtain crude crystals. The crude crystals are dispersed in 152 g of diisopropyl ether and then collected to obtain 36 g of 9-ethyl-3-(4-phenylsulfinylbenzoyl)carbazole.

(Synthesis Example 20) Synthesis of 3-[dimethoxy-(4-phenylsulfinylphenyl)methyl]-9-ethylcarbazole Instead of 3-(4-bromobenzoyl)-9-ethylcarbazole, 9-ethyl-3-(4 9.0 g of 3-[dimethoxy-(4-phenylsulfinylphenyl)methyl]-9-ethylcarbazole is obtained in the same manner as in Synthesis Example 2 except that -phenylsulfinylbenzoyl)carbazole is used.

(Synthesis Example 21) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-fluorophenylphenylsulfonium nonafluorobutanesulfonate (sulfonium salt 9) Tetrahydrofuran2. Add 0 g and 330 mg magnesium. 1.4 g of 1-bromo-4-fluorobenzene is added dropwise thereto. After dropping, the mixture is stirred at 50° C. for 1 hour to obtain a THF solution of 4-fluorophenylmagnesium bromide. 4-fluorophenylmagnesium bromide was added to a solution prepared by dissolving 2.0 g of 3-[dimethoxy-(4-phenylsulfinylphenyl)methyl]-9-ethylcarbazole obtained in Synthesis Example 20 above and 920 mg of trimethylsilyl chloride in 10 g of tetrahydrofuran. is added dropwise at a temperature of 10° C. or lower, and then stirred at 25° C. for 1 hour. After stirring, 860 mg of triethylamine is added, 30 g of a 10% by mass ammonium chloride aqueous solution is added at 5° C. or lower, and the mixture is stirred for 10 minutes. After distilling off tetrahydrofuran and ethyl acetate, 15 g of methylene chloride, 10 g of pure water and 1.7 g of potassium nonafluorobutanesulfonate are added and stirred at 25° C. for 2 hours. After liquid separation and washing with pure water three times, methylene chloride is distilled off to obtain crude crystals. The crude crystals are purified by silica gel column chromatography (methylene chloride/methanol=90/10 (volume ratio)) to give 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-fluorophenylphenyl. 2.1 g of sulfonium nonafluorobutanesulfonate (sulfonium salt 9) are obtained.

<Synthesis of sulfonium salt 10>
(Synthesis Example 22) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-fluorophenylphenylsulfonium-p-styrenesulfonate (sulfonium salt 10) Instead of potassium nonafluorobutanesulfonate 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-fluorophenylphenylsulfonium-p was obtained in the same manner as in Synthesis Example 21 except that sodium p-styrenesulfonate was used as - 2.1 g of styrene sulfonate (sulfonium salt 10) are obtained.

<Synthesis of sulfonium salt 11>
(Synthesis Example 23) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-methylsulfanylphenylphenylsulfonium nonafluorobutanesulfonate 1- in place of 1-bromo-4-fluorobenzene 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-methylsulfanylphenylphenylsulfonium nonamic acid was obtained by the same procedure as in Synthesis Example 21 except that bromo-4-methylsulfanylbenzene was used. 2.2 g of fluorobutanesulfonate are obtained.

(Synthesis Example 24) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-methylsulfonylphenylphenylsulfonium nonafluorobutanesulfonate (sulfonium salt 11) 4 obtained in Synthesis Example 23 above -[Dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-methylsulfanylphenylphenylsulfonium nonafluorobutanesulfonate 200 mg was dissolved in formic acid 1.2 g, and then 60 mg of 35 mass% hydrogen peroxide solution was added. and stir at 60° C. for 17 hours. 10 g of dichloromethane and 6 g of pure water are added to the reaction solution, and the organic layer is recovered. After distilling off the dichloromethane, 10 g of methanol and 10 mg of sulfuric acid are added, and the mixture is stirred at 60° C. for 3 hours. After cooling to room temperature and adding 23 mg of triethylamine, methanol is distilled off. The residue was dissolved in 10 g of methylene chloride and washed with 6 g of pure water three times. 200 mg of phenylphenylsulfonium nonafluorobutanesulfonate (sulfonium salt 11) are obtained.

<Synthesis of sulfonium salt 12>
(Synthesis Example 25) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-(1-ethoxyethoxy)phenylphenylsulfonium camphorsulfonate Camphorsulfone instead of potassium nonafluorobutanesulfonate 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-(1-ethoxyethoxy)phenylphenylsulfonium camphorsulfonate was obtained by the same procedure as in Synthesis Example 21 except that sodium phosphate was used. 2.0 g of

(Synthesis Example 26) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-4-hydroxyphenylphenylsulfonium camphorsulfonate (sulfonium salt 12) 4-[dimethoxy-(9-ethylcarbazole- After dissolving 2.0 g of 3-yl)methyl]phenyl-4-(1-ethoxyethoxy)phenylphenylsulfonium camphorsulfonate in 20 g of methanol, 100 mg of camphorsulfonic acid is added and stirred at 60° C. for 3 hours. After cooling to room temperature and adding 5 g of a 1% by mass sodium hydroxide aqueous solution, methanol is distilled off. 48 g of the residue was dissolved in methylene chloride and washed with 32 g of pure water three times. 1.4 g of phenylsulfonium camphorsulfonate (sulfonium salt 12) are obtained.

<Synthesis of sulfonium salt 13>
(Synthesis Example 27) Synthesis of 3-[4-(methylphenylamino)phenylcarbonyl]dibenzothiophene By performing the same operation as in Synthesis Example 18 except that N-methylaniline is used instead of benzenethiol, 3-[4 28 g of -(methylphenylamino)phenylcarbonyl]dibenzothiophene are obtained.

(Synthesis Example 28) Synthesis of 3-[4-(methylphenylamino)phenylcarbonyl]dibenzothiophene-9-oxide 9-ethyl-3-(4-phenylsulfanylbenzoyl) 3-[4-(methyl 20 g of 3-[4-(methylphenylamino)phenylcarbonyl]dibenzothiophene-9-oxide is obtained in the same manner as in Synthesis Example 19 except that phenylamino)phenylcarbonyl]dibenzothiophene is used.

(Synthesis Example 29) Synthesis of 3-[dimethoxy-4-(methylphenylamino)phenylmethyl]dibenzothiophene-9-oxide 3-(4-bromobenzoyl)-9-ethylcarbazole is replaced with 3-[4-( 3-[dimethoxy-4-(methylphenylamino)phenylmethyl]dibenzothiophene-9-oxide was obtained in the same manner as in Synthesis Example 2 except that methylphenylamino)phenylcarbonyl]dibenzothiophene-9-oxide was used. Gain 20g.

(Synthesis Example 30) Synthesis of phenyl-3-[dimethoxy-(4-methylphenylamino)phenylmethyl]dibenzothiophenium nonafluorobutanesulfonate (sulfonium salt 13) 3-[dimethoxy-(4-phenylsulfinylphenyl)methyl ]-9-ethylcarbazole is replaced by 3-[dimethoxy-4-(methylphenylamino)phenylmethyl]dibenzothiophene-9-oxide and 1-bromo-4-fluorobenzene is replaced by bromobenzene. By performing the same operation as in Synthesis Example 21, 3.1 g of phenyl-3-[dimethoxy-(4-methylphenylamino)phenylmethyl]dibenzothiophenium nonafluorobutanesulfonate (sulfonium salt 13) is obtained.

<Synthesis of sulfonium salt 14>
(Synthesis Example 31) Synthesis of diphenyl-4-(9-ethylcarbazol-3-ylcarbonyl)phenylsulfonium-4-methacryloxy-1,1,2-trifluorobutanesulfonate Instead of potassium nonafluorobutanesulfonate, 4- Diphenyl-4-(9-ethylcarbazol-3-ylcarbonyl)phenylsulfonium-4-methacryloxy-4-(9-ethylcarbazol-3-ylcarbonyl)phenylsulfonium-4-methacryloxy-4-methacryloxy-4-(9-ethylcarbazol-3-ylcarbonyl)phenyl- 1.5 g of 1,1,2-trifluorobutanesulfonate are obtained.

<Synthesis of sulfonium salt 15>
(Synthesis Example 32) Synthesis of 4-methylsulfanylbenzoyl chloride To 24.7 g of 4-methylsulfanylbenzoyl benzoic acid, 148 g of thionyl chloride is added, and the mixture is stirred at 60°C for 4 hours. After stirring, thionyl chloride is distilled off under reduced pressure to obtain 27.5 g of 4-methylsulfanylbenzoyl chloride.

(Synthesis Example 33) Synthesis of 9-ethyl-3-(4-methylsulfanylbenzoyl)carbazole The same procedure as in Synthesis Example 1 was performed except that 4-methylsulfanylbenzoyl chloride was used instead of 4-bromobenzoyl chloride. 34 g of 9-ethyl-3-(4-methylsulfanylbenzoyl)carbazole are obtained.

(Synthesis Example 34) Synthesis of dimethyl-4-(9-ethylcarbazol-3-ylcarbonyl)phenylsulfonium nonafluorobutanesulfonate 9-ethyl-3-(4-methylsulfanylbenzoyl)carbazole obtained in Synthesis Example 33 above 1.0 g is dissolved in 7.0 g of acetonitrile, 920 mg of dimethyl sulfate is added thereto, and the mixture is stirred at 70° C. for 4 hours. After stirring, 20 g of pure water is added, and the mixture is further stirred for 10 minutes, and 13 g of toluene is added for washing. 1.5 g of potassium nonafluorobutanesulfonate and 10 g of methylene chloride are added to the resulting aqueous layer, and the mixture is stirred for about 1 hour. After liquid separation and washing with water three times, methylene chloride is distilled off to obtain crude crystals. Dimethyl-4-(9-ethylcarbazol-3-ylcarbonyl)phenylsulfonium nonafluorobutanesulfonate was obtained by purifying the crude crystals by silica gel column chromatography (methylene chloride/methanol=90/10 (volume ratio)). You get 6g.

(Synthesis Example 35) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyldimethylsulfonium nonafluorobutanesulfonate (sulfonium salt 15) To 3-(4-bromobenzoyl)-9-ethylcarbazole 4-[dimethoxy-(9-ethylcarbazole- 1.7 g of 3-yl)methyl]phenyldimethylsulfonium nonafluorobutanesulfonate (sulfonium salt 15) are obtained.

<Synthesis of iodonium salt 1>
(Synthesis Example 36) Synthesis of 9-ethyl-3-(4-iodobenzoyl)carbazole 9 by performing the same operation as in Synthesis Example 1 above except that 4-iodobenzoyl chloride is used in place of 4-bromobenzoyl chloride. - 9.1 g of ethyl-3-(4-iodobenzoyl)carbazole are obtained.

(Synthesis Example 37) Synthesis of 4-(9-ethylcarbazol-3-ylcarbonyl)phenylphenyliodonium nonafluorobutanesulfonate 9-ethyl-3-(4-iodobenzoyl)carbazole obtained in Synthesis Example 36 was added to 16 g of sulfuric acid. 4 g is added, and then 10 g of potassium persulfate is added little by little at 10° C. or less and stirred for 30 minutes. After stirring, 9.8 g of benzene is added and further stirred at 25° C. for 3 hours. After stirring, 30 g of pure water is added at 10° C. or lower, then 40 g of methylene chloride and 4.7 g of potassium nonafluorobutanesulfonate are added, and the mixture is stirred at 25° C. for about 2 hours. After liquid separation and washing with water three times, the methylene chloride is distilled off to obtain a crude product. The crude product was purified by silica gel column chromatography (methylene chloride/methanol=90/10 (volume ratio)) to give 4.5 g of 4-(9-ethylcarbazol-3-ylcarbonyl)phenylphenyliodonium nonafluorobutanesulfonate. obtain.

(Synthesis Example 38) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenylphenyliodonium nonafluorobutanesulfonate (iodonium salt 1) To 3-(4-bromobenzoyl)-9-ethylcarbazole 4-[dimethoxy-(9-ethylcarbazole-3 4.2 g of -yl)methyl]phenylphenyliodonium nonafluorobutanesulfonate (iodonium salt 1) are obtained.

<Synthesis of iodonium salt 2>
(Synthesis Example 39) Synthesis of 4-(9-ethylcarbazol-3-ylcarbonyl)phenyl-2,4,6-trimethylphenyliodonium nonafluorobutanesulfonate Same as Synthesis Example 38 except that mesitylene is used in place of benzene. 4.4 g of 4-(9-ethylcarbazol-3-ylcarbonyl)phenyl-2,4,6-trimethylphenyliodonium nonafluorobutanesulfonate is obtained.

(Synthesis Example 40) Synthesis of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-2,4,6-trimethylphenyliodonium nonafluorobutanesulfonate (iodonium salt 2) 3-(4-bromo The same procedure as in Synthesis Example 2 above except that 4-(9-ethylcarbazol-3-ylcarbonyl)phenyl-2,4,6-trimethylphenyliodonium nonafluorobutanesulfonate is used in place of benzoyl)-9-ethylcarbazole. to obtain 4.6 g of 4-[dimethoxy-(9-ethylcarbazol-3-yl)methyl]phenyl-2,4,6-trimethylphenyliodonium nonafluorobutanesulfonate (iodonium salt 1).

<Synthesis of polymer A>
(Synthesis Example 41) Synthesis of Polymer A 8.0 g of polyhydroxystyrene (weight average molecular weight: 8000) and 0.010 g of 35% by mass hydrochloric acid aqueous solution are dissolved in 28 g of dehydrated dioxane. 2.73 g of cyclohexyl vinyl ether is dissolved in 2.80 g of dehydrated dioxane and added dropwise to the polyhydroxystyrene solution over 30 minutes. After dropping, the mixture is heated to 40° C. and stirred for 2 hours. After stirring, 0.014 g of dimethylaminopyridine are added after cooling. After that, the polymer is precipitated by dropping the solution into 260 g of pure water. The solid obtained by separating this by filtration under reduced pressure is washed twice with 300 g of pure water, and then vacuum-dried to obtain 9.2 g of polymer A shown below as a white solid. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of Polymer B>
(Synthesis Example 42) Synthesis of Polymer B 7.0 g of acetoxystyrene, 3.1 g of t-butyl methacrylate, 0.022 g of butyl mercaptan, and 0.0 g of dimethyl-2,2′-azobis(2-methylpropionate) (AIBN). 40 g are dissolved in 35 g of tetrahydrofuran (THF) to deoxygenate. This is added dropwise over 4 hours into 20 g of THF which has been brought to the reflux temperature by nitrogen gas flow in advance. After dropping, the mixture is stirred for 2 hours and then cooled to room temperature. The polymer is precipitated by dropping this into a mixed solvent of 149 g of hexane and 12 g of THF. The solid obtained by separating this by filtration under reduced pressure is washed with 52 g of hexane and then vacuum-dried to obtain 10.3 g of polymer B represented by the following formula as a white solid. A weight-average molecular weight of 9,200 is obtained by polystyrene conversion using gel permeation chromatography. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

(Synthesis Example 43) Synthesis of Polymer C 6.0 g of polymer B, 6.0 g of triethylamine, 6.0 g of methanol and 1.5 g of pure water are dissolved in 30 g of propylene glycol monomethyl ether and stirred at reflux temperature for 6 hours. After cooling to 25° C., the obtained solution is added dropwise to a mixture of 30 g of acetone and 30 g of pure water to precipitate the polymer. The solid obtained by separating this by filtration under reduced pressure is washed twice with 30 g of pure water, and then vacuum-dried to obtain 4.3 g of polymer C represented by the following formula as a white solid. A weight-average molecular weight of 9,100 is obtained by polystyrene conversion using gel permeation chromatography. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of polymer D>
(Synthesis Example 44) Synthesis of Polymer D 5.0 g of α-methacryloxy-γ-butyrolactone, 6.0 g of 2-methyladamantane-2-methacrylate, 4.3 g of 3-hydroxyadamantane-1-methacrylate, and dimethyl-2,2 0.51 g of '-azobis(2-methylpropionate) is dissolved in 26 g of propylene glycol-1-monomethyl ether acetate (PGMEA) to deoxygenate. This is added dropwise over 4 hours to 7.5 g of PGMEA preheated to 85°C. After stirring for 2 hours, cool. After cooling, it is reprecipitated by adding dropwise to 180 g of hexane. This is filtered, dispersed and washed with 70 g of hexane, filtered again, and then vacuum-dried to obtain 8.5 g of a polymer D represented by the following formula as a compound that reacts with an acid. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of Polymer E>
(Synthesis Example 45) Synthesis of Polymer E
10.1 g of Polymer E represented by the following formula is obtained in the same manner as in Synthesis Example 42 except that pt-butoxystyrene is used instead of t-butyl methacrylate. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

(Synthesis Example 46) Synthesis of Polymer F By performing the same operation as in Synthesis Example 43 except that Polymer E was used instead of Polymer B, 4.1 g of Polymer F represented by the following formula was obtained. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of polymer G>
(Synthesis Example 47) Synthesis of Polymer G As monomers, 5.5 g of 5-methacryloyloxynorbornane 2,6-lactone, 6.2 g of 4-(1-ethoxyethoxy)phenyl methacrylate, and 4.4 g of 4-hydroxyphenyl methacrylate are used. 8.0 g of polymer G represented by the following formula is obtained by performing the same operation as in Synthesis Example 44 except for the above. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of polymer H>
(Synthesis Example 48) Synthesis of Polymer H 1-acetoxy-4-vinylnaphthalene was used in place of acetoxystyrene, and 1-(2-tetrahydropyranyloxy)-4-vinylnaphthalene was used in place of t-butyl methacrylate. 10.5 g of polymer H represented by the following formula is obtained by performing the same operation as in Synthesis Example 42 except that the polymer is used. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

(Synthesis Example 49) Synthesis of Polymer I By performing the same operation as in Synthesis Example 43 except that polymer H is used instead of polymer B, 4.3 g of polymer I represented by the following formula is obtained. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of polymer J>
(Synthesis Example 50) Synthesis of Polymer J The same procedure as in Synthesis Example 44 was performed except that 2-methacryloyloxy-1,3-propanesultone was used in place of α-methacryloxy-γ-butyrolactone. 8.0 g of polymer J shown in . In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of polymer K>
(Synthesis Example 51) Synthesis of Polymer K Using 2-methacryloyloxy-1,3-propanesultone instead of α-methacryloxy-γ-butyrolactone, and 1-ethoxyethyl methacrylate in place of 2-methyladamantane-2-methacrylate 8.2 g of polymer K represented by the following formula is obtained by performing the same operation as in Synthesis Example 44 except for using . In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of polymer L>
(Synthesis Example 52) Synthesis of Polymer L As monomers, 7.2 g of 5-methacryloyloxynorbornane 2,6-sultone, 5.9 g of 2-(1-ethoxyethoxy)-6-vinylnaphthalene and 2-hydroxy-6-vinylnaphthalene 8.0 g of polymer L represented by the following formula is obtained by performing the same operation as in Synthesis Example 44 except that 3.0 g of polymer is used. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

<Synthesis of polymer M>
(Synthesis Example 53) Synthesis of Polymer M 4.7 g of the sulfonium salt 14 obtained in Synthesis Example 31 above, 3.9 g of 5-methacryloyloxynorbornane 2,6-lactone, and 4-(1-ethoxyethoxy)phenyl methacrylate as monomers. 7.8 g of a polymer M represented by the following formula is obtained in the same manner as in Synthesis Example 44 except that 4.2 g of 4-hydroxyphenyl methacrylate and 3.2 g of 4-hydroxyphenyl methacrylate are used. In addition, the monomer ratio of the polymer unit in the present invention is not limited to the following.

[Examples 1 to 7 and Comparative Examples 1 to 2]
<Electron beam sensitivity evaluation 1>
Samples were prepared as follows. To 3000 mg of cyclohexanone, 500 mg of any resin selected from the above polymers A, C, D, J, K and M, photoacid generators (PAG) and sensitizing compounds are selected as appropriate. Composition samples 1 to 9 were prepared by adding 0.036 mmol of each acid diffusion controller and 0.0012 mmol of the acid diffusion control agent.
As the photoacid generator (PAG), the above sulfonium salts 1 and 4, and comparative sulfonium salts 1 and 2 shown below were used. Comparative sulfonium salt 1 was used together with comparative sensitizing compound 1'.
Trioctylamine was used as an acid diffusion controller.

Electron beam sensitivity evaluation is performed as follows. A silicon wafer modified with hexamethylenedisilazane in advance is spin-coated with the resist composition sample 1 above. By pre-baking this on a hot plate at 110° C. for 1 minute, a substrate with a coating film having a thickness of 200 nm is obtained. An electron beam lithography apparatus is used to draw a line-and-space pattern of 200 nm on the coating film of the substrate with an electron beam of 30 keV. After the electron beam irradiation, the substrate was subjected to PEB on a hot plate at 60°C for 30 seconds, then exposed to the entire surface with a UV exposure device (355 nm to 410 nm) with an exposure dose of 500 mJ/cm ² , and then on a hot plate at 110°C. Heat for 1 minute. Develop for 1 minute using a developer (product name: NMD-3, 2.38% by mass aqueous solution of tetramethylammonium hydroxide, manufactured by Tokyo Ohka Kogyo Co., Ltd.), then rinse with pure water to form a 200 nm line. Gets the ampersand space pattern. The electron beam irradiation dose at this time is defined as E _size [μC/cm ² ], and the sensitivity due to the electron beam irradiation is obtained. The other samples 2 to 9 are also subjected to sensitivity evaluation in the same manner as described above. Sample compositions and results are shown in Table 1.

In Table 1, the sensitivity of each sample is determined by setting the sensitivity of sample 8 (comparative example 1) to which comparative sulfonium salt 1 and comparative sensitizing compound 1' were added to 100, and the corresponding samples (examples 1 to 7 and comparative example The evaluation result of 2) was calculated as a relative value. A smaller sensitivity value indicates a better effect.

Examples 1 to 7, which are samples containing onium salts according to some aspects of the present invention in any polymer, are prepared according to Comparative Example 1 and Comparative Example 2 (Sample 9 of Comparative Example 2 is described, for example, in WO2018/074382. (a sample containing one of the disclosed onium salts) was found to be more sensitive after UV irradiation. The reason is as follows. Sulfonium salt 1 and sulfonium salt 4 show higher absorption in the vicinity of UV wavelengths (>365 nm) than comparative sulfonium salt 2, which is thought to be due to higher sensitivity after UV irradiation. It is presumed that the reason why the sulfonium salts 1 and 4 have high absorption in the vicinity of UV wavelengths is that they have an amino group and a condensed ring structure.
FIG. 1 shows the UV absorption coefficients of sulfonium salt 1 and comparative sulfonium salt 2. FIG. As shown in FIG. 1, sulfonium salt 1 absorbs more at UV wavelengths than comparative sulfonium salt 2. As the UV absorption coefficient increases, the efficiency of acid generation by UV irradiation improves, resulting in higher sensitivity.

Since the sulfonium salt 8 has an amino group, the absorption in the vicinity of the UV wavelength is higher than that of the comparative sulfonium salt 2, similarly to the sulfonium salt 1, and the sensitivity after UV irradiation is increased.
In addition, since the sulfonium salt 6 and the like also have a condensed ring structure of oxygen atoms and sulfur atoms, similar to the sulfonium salt 1, the absorption near the UV wavelength is higher than that of the comparative sulfonium salt 2. Increased sensitivity.

According to some aspects of the present invention, an onium salt is structurally changed into a ketone derivative by an active species generated by irradiation with a first active energy ray such as an electron beam or extreme ultraviolet rays, and the ketone derivative is converted into an active species by irradiation with a second active energy ray. It is possible to provide a resin composition containing an onium salt capable of generating When the onium salt has a specific substituent or a specific structure, specifically an amino group or a heterocondensed ring structure, the absorption of UV wavelengths to be irradiated is improved. Therefore, the resin composition containing the onium salt can be a highly sensitive resist composition that efficiently generates acid upon UV irradiation.

Claims (13)

An onium salt represented by the following general formula (3) .

(In the above formula ( 3 ), R ¹¹ and R ¹² are independently each an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; A linear, branched or cyclic alkenyl group having 2 to 12 carbon atoms which may be substituted; an aryl group having 6 to 14 carbon atoms which may have a substituent; any one selected from the group consisting of: a heteroaryl group having 4 to 12 carbon atoms;
Any two or more of the aryl groups to which R ¹¹ , R ¹² and the sulfonium group are bonded directly by a single bond or selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group may form a ring structure with the sulfur atom to which they are attached,
at least one methylene group in R ¹¹ and R ¹² may be substituted with a divalent heteroatom-containing group;
R ¹³ and R ¹⁴ each independently represent an alkyl group, a hydroxy group, a mercapto group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylsulfanylcarbonyl group, an arylsulfanyl group, alkylsulfanyl group, aryl group, heteroaryl group, aryloxy group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, (meth)acryloyloxy group, hydroxy(poly)alkyleneoxy group, amino group, cyano is selected from the group consisting of a group, a nitro group and a halogen atom, and has 1 to 12 carbon atoms when it has carbon, and these may have a substituent,
at least one of R ¹⁴ is an amino group, or R ¹⁴ is selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom-containing group together with an aryl group to which said R ¹⁴ is bonded It forms a heterocyclic structure,
R ¹⁵ and R ¹⁶ are each independently an optionally substituted linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; an optionally substituted linear chain; A branched or cyclic alkenyl group having 2 to 12 carbon atoms; an aryl group having 6 to 14 carbon atoms which may have a substituent; and an optionally substituted aryl group having 4 to 12 carbon atoms any one selected from the group consisting of a heteroaryl group;
R ¹⁵ and R ¹⁶ may be bonded to each other directly with a single bond or through any one selected from the group consisting of an oxygen atom, a sulfur atom and an alkylene group to form a ring structure,
at least one methylene group in R ¹⁵ and R ¹⁶ may be substituted with a divalent heteroatom-containing group;
R ¹⁸ is an alkyl group, hydroxy group, mercapto group, alkoxy group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, arylsulfanylcarbonyl group, alkylsulfanyl group, arylsulfanyl group, aryl group, hetero aryl group, aryloxy group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, (meth)acryloyloxy group, hydroxy(poly)alkyleneoxy group, amino group, cyano group, nitro group and halogen atom is any selected from the group consisting of 1 to 12 carbon atoms when having carbon, and these may have a substituent,
L ² and L ³ are each independently selected from the group consisting of a direct bond; a methylene group; an oxygen atom; a sulfur atom; a nitrogen atom-containing group; and either one of L ² and L ³ is an oxygen atom, a sulfur atom, or a nitrogen atom-containing group,
Y is an oxygen atom or a sulfur atom,
e is an integer from 0 to 4,
f is an integer from 0 to 3,
g is an integer from 0 to 4,
X ⁻ represents a monovalent counter anion. ) A photoacid generator containing at least the onium salt according to claim 1 . A composition comprising the photoacid generator of claim 2 and an acid-reactive compound. 4. The composition of claim 3 , further comprising an acid diffusion control agent. the acid-reactive compound is a resin (B) whose solubility in a developer changes under the action of an acid;
5. The composition according to claim 3 , wherein the resin (B) has at least one of units represented by the following (4a) to ( 4d ).

(In the above formula (4a),
R ¹ is any selected from the group consisting of a hydrogen atom, an alkyl group and a halogenated alkyl group,
R ² and R ³ are each independently a linear, branched or cyclic alkyl group;
R ⁴ is a linear, branched or cyclic alkyl group which may have a substituent,
two or more of R ² , R ³ , and R ⁴ are directly via a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group, and a methylene group; , may form a ring structure,
L ⁶ is any one selected from the group consisting of a direct bond, a carbonyloxy group, a carbonylamino group, a linear, branched or cyclic alkylenecarbonyloxy group optionally having a substituent, and an alkylenecarbonylamino group is.
In formula (4b), R ¹ and L ⁶ are selected from the same options as each of R ¹ and L ⁶ in formula (4a);
R ⁵ and R ⁶ are each independently selected from the group consisting of a hydrogen atom and a linear, branched or cyclic alkyl group;
^R7 is a linear, branched or cyclic alkyl group which may have a substituent,
two or more of R ⁵ , R ⁶ , and R ⁷ are directly through a single bond or through any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group, and a methylene group; , may form a ring structure.
In formula (4c), R ¹ to R ⁴ and L ⁶ are selected from the same options as each of R ¹ to R ⁴ and L ⁶ in formula (4a);
R ⁸ is independently selected from the group consisting of an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an alkylsulfanyl group, an alkylsulfinyl group, an alkylsulfonyl group, an amino group, a cyano group, a nitro group, and a halogen atom; is either selected,
Two or more of R ⁸ may form a ring structure directly with a single bond or via any one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom-containing group and a methylene group. often,
l is an integer from 1 to 2,
m is an integer of 0 to 4 when l is 1 and 0 to 6 when l is 2;
n is an integer of 1 to 5 when l is 1 and 1 to 7 when l is 2;
m+n is 1 to 5 when l is 1, and 1 to 7 when l is 2.
In formula (4d), R ¹ , R ⁵ to R ⁷ , R ⁸ , L ⁶ , l and n are R ¹ , R ⁵ to R ⁷ , R ⁸ and L in formulas (4a) to (4c). ⁶ , l and n are selected from the same options as each. ) The resin (B) contains at least one of units represented by the following general formulas (5a) to (5b), or
6. The composition according to claim 5 , further comprising a resin (C) containing at least one of units represented by the following general formulas (5a) to (5b).

(In formula (5a) above, R ¹ , R ⁸ and L ⁶ are each independently selected from the same choices as each of R ¹ , R ⁸ and L ⁶ in formula (4a) above,
p is an integer of 0-4 and q is an integer of 1-5.
In formula (5b), R ¹ and L ⁶ are each independently selected from the same options as each of R ¹ and L ⁶ in formula (4a);
R ⁹ is a cyclic group containing at least one selected from the group consisting of -C(O)-O-, -SO ₂ - and -O-SO ₂ -. ) The composition according to any one of claims 3 to 6 , wherein the photoacid generator is an acid generator unit-containing resin in which X ^- in the onium salt has a unit represented by the following general formula (6): thing.

(In formula (6), R ¹ and L ⁶ are each independently selected from the same options as R ¹ and L ⁶ in formula (4a),
Z ¹ is selected from the group consisting of a linear or branched alkylene group having 1 to 12 carbon atoms, a linear or branched alkenylene group having 2 to 12 carbon atoms, and an arylene group having 6 to 14 carbon atoms. is either
Some or all of the hydrogens of the alkylene group, alkenylene group and arylene group may be substituted with fluorine atoms,
At least one methylene group in the alkylene group, alkenylene group and arylene group may be substituted with a divalent heteroatom-containing group. ) A step of applying the composition according to any one of claims 3 to 7 onto a substrate to form a resist film;
a step of irradiating the resist film with a first active energy ray;
a step of irradiating a second active energy ray onto the resist film after the irradiation of the first active energy ray;
and obtaining a pattern by developing the resist film after being irradiated with the second active energy ray. 9. The method of manufacturing a device according to claim 8 , wherein the wavelength of said first active energy ray is shorter than the wavelength of said second active energy ray. 10. The device manufacturing method according to claim 8 , wherein the first active energy ray is an electron beam or extreme ultraviolet rays. 11. The method according to any one of claims 8 to 10 , comprising a step of heating with a heating wire or laser between the step of irradiating the first active energy ray and the step of irradiating the second active energy ray. device manufacturing method. generating a first active species from the composition in the resist film by irradiation with the first active energy ray;
structurally changing the photoacid generator with the first active species;
The device manufacturing method according to any one of claims 8 to 11 , wherein the second active energy ray irradiation generates a second active species from the structurally-changed photoacid generator. 13. The method of manufacturing a device according to claim 12 , wherein the structurally-changed photoacid generator is a ketone derivative.

Images