WO2023204123A1 - Compound, acid generator comprising said compound, photoresist, and method for manufacturing electronic device using said photoresist - Google Patents

Abstract

Provided is a novel compound which has such acid generating capability that the compound is decomposed by the irradiation with i line to generate a sulfonic acid and which can keep the acid generating capability thereof at a satisfactory level in the whole area of a resist layer even when the thickness of the resist layer is increased.　The compound (1) according to the present invention is represented by formula (1). In formula (1), R¹ and R² each independently represent a hydrocarbon group that may have a substituent. R³ represents a hydrogen atom, a OR¹³ group or a R¹³ group, in which the R¹³ represents a hydrocarbon group that may have a substituent. R⁴ represents a hydrogen atom or R¹⁴, in which the R¹⁴ represents a hydrocarbon group that may have a substituent. The case where each of R³ and R⁴ represents a hydrogen atom at the same time is excluded.

Description

Compound, acid generator containing the compound, photoresist, and method for manufacturing an electronic device using the photoresist

The present invention relates to a novel compound, an acid generator containing the compound, a photoresist containing the compound, and a method for manufacturing an electronic device using the photoresist.

Conventionally, in the field of microfabrication, typified by semiconductor manufacturing, photolithography has been carried out using exposure light that is selected depending on the application. When it is required to process a fine pattern with high precision, i-line (365 nm) is used as the exposure light.

The resist material used in photolithography includes an acid generator that decomposes to generate acid when exposed to light, and a photosensitive resin whose solubility in a developer changes depending on the acid.

Patent Document 1 describes an acid generator containing a compound represented by the following formula (x) (hereinafter sometimes referred to as "compound X").

International Publication No. 2016/072049

The compound X has an extremely high i-line molar extinction coefficient. Therefore, when the resist layer containing compound X is thickened, most of the i-rays are absorbed at the surface, and only a small amount of the i-rays reach the deep layer. Therefore, there has been a problem that the acid generating ability of compound X is significantly reduced in the deep layer.

Therefore, an object of the present invention is to provide a compound having an acid-generating ability that decomposes and generates sulfonic acid when irradiated with i-rays, and which has good acid-generating ability in the entire resist layer even when the resist layer is thickened. The objective is to provide a new compound that maintains this ability.
Another object of the present invention is to provide a compound having an acid-generating ability that decomposes when irradiated with i-rays and generates sulfonic acid, which has excellent solvent solubility and which can be used even when the resist layer is thickened. The object of the present invention is to provide a new compound that can maintain good acid-generating ability overall.
Another object of the present invention is to provide an acid generator containing the above-mentioned novel compound.
Another object of the present invention is to provide a photoresist containing the acid generator.
Another object of the present invention is to provide a method for manufacturing an electronic device using the photoresist.

As a result of intensive studies to solve the above problems, the present inventors found that a compound represented by the following formula (1) (hereinafter sometimes referred to as "compound (1)") is sensitive to i-line. When irradiated with i-line, it easily decomposes to generate sulfonic acid, which is a strong acid (in other words, it has excellent acid-generating ability), and the molar absorption coefficient of i-line is not too high but is moderate. Therefore, even if the resist layer containing compound (1) is thickened, the i-line can penetrate deep into the layer, and the entire resist layer can exhibit good acid generation ability, and the solvent solubility The present inventors have discovered that, by using the above-mentioned compound, a photoresist with excellent stability over time can be prepared. The present invention was completed based on these findings.

That is, the present invention provides a compound represented by the following formula (1).

(In the formula, R ¹ and R ² are the same or different and represent a hydrocarbon group which may have a substituent. R ³ represents a hydrogen atom, OR ¹³ or R ¹³ , and R ¹³ is a substituent. is a hydrocarbon group which may have a substituent.R ⁴ represents a hydrogen atom or R ¹⁴ , and R ¹⁴ is a hydrocarbon group which may have a substituent. However, R ³ and R ⁴ (Except when both represent hydrogen atoms)

The present invention also provides the above compound having an i-line molar extinction coefficient of 100 to 5000 (L/mol·cm).

The present invention also provides the compound having a solubility in propylene glycol monomethyl ether acetate of 5% by weight or more at 25°C.

The present invention also provides an acid generator containing the above compound.

The present invention also provides the above acid generator, which is an i-line acid generator.

The present invention also provides a photoresist containing the acid generator and a photosensitive resin.

The present invention also provides the photoresist, which is a thick film photoresist used to form a thick film photoresist layer of 15 μm or more.

The present invention also provides a method for manufacturing an electronic device, including a step of forming a pattern by photolithography using the photoresist.

The present invention also provides a step of applying and drying the photoresist to form a thick photoresist layer of 15 μm or more, and forming a pattern on the formed thick photoresist layer by photolithography. A method for manufacturing a device is provided.

Compound (1) has photosensitivity to i-rays, and when irradiated with i-rays, it easily decomposes to generate sulfonic acid, which is a strong acid. Even if the photoresist layer containing compound (1) is thick, the i-line can reach the deep layer, and compound (1) exhibits good acid generation ability in the entire photoresist layer. be able to. Therefore, compound (1) is preferably used as an acid generator for a photoresist for forming a thick photoresist layer (ie, a thick film photoresist).
Furthermore, compound (1) has excellent solvent solubility. Therefore, when compound (1) is added to a photoresist, it is uniformly dispersed and can impart good fine pattern forming properties to the photoresist. Further, it is possible to suppress a decrease in sensitivity due to precipitation of the acid generator over time, and a photoresist with excellent storage stability can be obtained.

[Compound (1)]
The compound (1) of the present invention is a compound represented by the following formula (1).

(In the formula, R ¹ and R ² are the same or different and represent a hydrocarbon group which may have a substituent. R ³ represents a hydrogen atom, OR ¹³ or R ¹³ , and R ¹³ is a substituent. is a hydrocarbon group which may have a substituent.R ⁴ represents a hydrogen atom or R ¹⁴ , and R ¹⁴ is a hydrocarbon group which may have a substituent. However, R ³ and R ⁴ (Except when both represent hydrogen atoms)

The compound (1) includes compounds represented by the following formulas (1a) to (1e). R ¹ , R ² , R ¹³ and R ¹⁴ in the following formula are the same as above.

As the compound (1), at least one selected from the compounds represented by the above formulas (1a), (1b), and (1c) is preferable because it has excellent solvent solubility and acid-generating ability.

The hydrocarbon group includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a bonded group thereof.

The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 20 carbon atoms (=C _1-20 ), such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s - Alkyl group having about 1 to 20 carbon atoms (preferably 1 to 10, particularly preferably 1 to 3) such as butyl group, t-butyl group, pentyl group, hexyl group, decyl group, dodecyl group; vinyl group, allyl group alkenyl groups having about 2 to 20 carbon atoms (preferably 2 to 10, particularly preferably 2 to 3), such as 1-butenyl groups; , particularly preferably about 2 to 3) alkynyl groups.

The alicyclic hydrocarbon group is preferably a C _3-20 alicyclic hydrocarbon group, such as a 3 to 20 membered (preferably 3 ~15 members, particularly preferably 5 to 8 members) cycloalkyl group; 3 to 20 members (preferably 3 to 15 members, particularly preferably 5 to 8 members) such as cyclopentenyl group, cyclohexenyl group Cycloalkenyl group; perhydronaphthalen-1-yl group, norbornyl group, adamantyl group, tricyclo[5.2.1.0 ^2,6 ]decane-8-yl group, tetracyclo[4.4.0.1 ^{2, 5} . Examples include bridged cyclic hydrocarbon groups such as 1 ^7,10 ]dodecane-3-yl group.

The aromatic hydrocarbon group is preferably a C _6-14 (particularly C _6-10 ) aromatic hydrocarbon group, such as a phenyl group or a naphthyl group.

The hydrocarbon group in which an aliphatic hydrocarbon group and an alicyclic hydrocarbon group are bonded includes a cycloalkyl-substituted alkyl group such as a cyclopentylmethyl group, a cyclohexylmethyl group, and a 2-cyclohexylethyl group (for example, a C _3-20 cyclo alkyl-substituted C _1-4 alkyl groups, etc.). In addition, hydrocarbon groups in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded include aralkyl groups (for example, C _7-18 aralkyl groups, etc.), alkyl-substituted aryl groups (for example, about 1 to 4 phenyl group or naphthyl group substituted with C _1-4 alkyl group).

The above hydrocarbon group may have various substituents [for example, an oxo group, an alkoxy group, an aryloxy group, an aralkyloxy group, an acyloxy group, etc.].

The number of carbon atoms in the hydrocarbon group of R ¹ is, for example, 1 to 20. The lower limit of the number of carbon atoms is preferably 5, particularly preferably 5, from the viewpoint of suppressing the mobility of sulfonic acid generated by photolysis in the photoresist, thereby increasing the resolution of photolithography. is 7. The upper limit of the number of carbon atoms is preferably 18, particularly preferably 15.

Furthermore, when R ¹ is a bulky group having an alicyclic or aromatic ring structure, the mobility of sulfonic acid generated by photolysis in the photoresist is suppressed. Therefore, the effect of increasing the resolution of photolithography can be obtained.

Furthermore, when R ¹ is a chain hydrocarbon group, solubility in organic solvents tends to be particularly excellent.

As R ² , an aliphatic hydrocarbon group is preferable, and an alkyl group (linear or branched alkyl group) is particularly preferable. Further, the number of carbon atoms in the hydrocarbon group of R ² is preferably 1 to 5, particularly preferably 1 to 3.

Among these, R ¹³ is preferably an aliphatic hydrocarbon group, and particularly preferably a linear or branched alkyl group.

The number of carbon atoms in R ¹³ is, for example, 1 to 12. The upper limit of the number of carbon atoms in R ¹³ is preferably 10, more preferably 8, even more preferably 7, particularly preferably 6, most preferably 5, particularly preferably from the viewpoint of particularly excellent solvent solubility and acid generating ability. is 3.

Among these, R ¹⁴ is preferably an aliphatic hydrocarbon group, more preferably a linear or branched alkyl group, and particularly preferably a branched alkyl group.

The number of carbon atoms in R ¹⁴ is, for example, 1 to 12. The lower limit of the number of carbon atoms in R ¹⁴ is preferably 2, since it has particularly excellent acid generating ability. Further, the upper limit of the number of carbon atoms in R ¹⁴ is preferably 10, more preferably 8, particularly preferably 7, most preferably 6, particularly preferably 5, from the viewpoint of improving solvent solubility.

The compound (1) has the above groups at the 6th and/or 8th positions of the coumarin ring, but it also has substituents (for example, C _1-12 alkyl group, C _1-12 alkoxy group) at other positions of the coumarin ring. etc.).

The compound (1) has high photosensitivity to i-line, and has a molar absorption coefficient of i-line of, for example, 100 to 5000 (L/mol·cm). The lower limit of the i-line molar extinction coefficient is preferably 300 (L/mol·cm), particularly preferably 350 (L/mol·cm), most preferably 400 ( L/mol·cm), particularly preferably 450 (L/mol·cm). Further, the upper limit value of the molar extinction coefficient is preferably 4000 (L/mol·cm), more preferably 3500 (L/mol·cm), more preferably 3000 (L/mol·cm), particularly preferably 2000 (L/mol·cm), most preferably 1000 (L/mol·cm), particularly preferably 800 ( L/mol·cm).

Further, the compound (1) has excellent solubility in organic solvents, and its solubility in organic solvents (for example, propylene glycol monomethyl ether acetate) at 25°C is, for example, 5% by weight or more (for example, 5 to 50% by weight). ), preferably 10% by weight or more, particularly preferably 15% by weight or more.

Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; carbonates such as propylene carbonate, ethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate, and diethyl carbonate; ethyl acetate, butyl acetate, Ethyl lactate, etc., linear or cyclic esters such as β-propiolactone, β-butyrolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone;; ethylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monobutyl ether; Glycol diethers such as dipropylene glycol dimethyl ether, triethylene glycol diethyl ether, tripropylene glycol dibutyl ether; glycol monoethers such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, etc. Monoester; Ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone can be mentioned. These can be used alone or in combination of two or more.

The organic solvent preferably contains at least one selected from ketones, chain esters, and glycol monoether monoesters.

Since the compound (1) has the above characteristics, it can be suitably used as an acid generator (for example, a photoacid generator, a nonionic acid generator, or a nonionic photoacid generator).

[Method for producing compound (1)]
The compound (1) can be produced, for example, through the following reactions [I] and [II]. In the following formula, R ¹ , R ² , R ³ and R ⁴ are as defined above. X is the same or different and represents a halogen atom.

[I]
Reaction [I] consists of a compound represented by formula (2) (hereinafter sometimes referred to as "compound (2)") and a compound represented by formula (3) (hereinafter referred to as "compound (3)"). This is a reaction in which a compound represented by formula (4) (hereinafter sometimes referred to as "compound (4)") is obtained by reacting a compound (hereinafter sometimes referred to as "compound (4)").

The amount of compound (3) to be used is, for example, 0.5 to 5 mol, preferably 1 to 3 mol, per 1 mol of compound (2).

Compound (2) is preferably dissolved in a solvent before being added to the reaction system, and examples of the solvent include ethers such as tetrahydrofuran, diethyl ether, dibutyl ether, dimethoxyethane, and dioxane; methylene chloride, chloroform, etc. Halogenated hydrocarbons and the like can be used. These can be used alone or in combination of two or more.

Further, it is preferable that the compound (3) is also dissolved in a solvent before being added to the reaction system. Examples of the solvent include alcohols such as methanol and ethanol; halogenated hydrocarbons such as methylene chloride and chloroform. can do. These can be used alone or in combination of two or more.

The reaction temperature is, for example, about 0 to 60°C. The reaction time is, for example, about 0.5 to 5 hours. Further, the reaction can be carried out by any method such as a batch method, a semi-batch method, or a continuous method.

As the reaction proceeds, hydrochloric acid is produced in the reaction system. Therefore, a basic compound such as potassium hydroxide, sodium hydroxide, sodium hydrogen carbonate, pyridine, triethylamine, etc. may be added as a dehydrochlorination agent into the reaction system. These can be used alone or in combination of two or more.

The reaction atmosphere is not particularly limited as long as it does not inhibit the reaction, and may be any of air atmosphere, nitrogen atmosphere, argon atmosphere, etc.

After completion of the reaction, the obtained reaction product can be separated and purified, for example, by separation means such as filtration, concentration, distillation, extraction, crystallization, adsorption, recrystallization, column chromatography, or a combination of these separation means.

[II]
Reaction [II] is a reaction in which compound (4) and the compound represented by formula (5) (hereinafter sometimes referred to as "compound (5)") are reacted to obtain compound (1).

The amount of compound (5) to be used is, for example, 0.5 to 5 mol, preferably 1 to 3 mol, per 1 mol of compound (4).

As the reaction proceeds, hydrochloric acid is produced in the reaction system. Therefore, a basic compound such as potassium hydroxide, sodium hydroxide, pyridine, triethylamine, etc. may be added as a dehydrochlorination agent into the reaction system. These can be used alone or in combination of two or more.

The reaction between compound (4) and compound (5) can be carried out in the presence of a solvent. As the solvent, for example, halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, and bromobenzene can be used. These can be used alone or in combination of two or more.

The amount of the solvent used is, for example, about 50 to 300% by weight based on the total amount of compound (4) and compound (5).

The reaction temperature is, for example, about 30 to 70°C. The reaction time is, for example, about 1 to 12 hours. Further, the reaction can be carried out by any method such as a batch method, a semi-batch method, or a continuous method.

The reaction atmosphere is not particularly limited as long as it does not inhibit the reaction, and may be any of air atmosphere, nitrogen atmosphere, argon atmosphere, etc.

After completion of the reaction, the obtained reaction product can be separated and purified, for example, by separation means such as filtration, concentration, distillation, extraction, crystallization, adsorption, recrystallization, column chromatography, or a combination of these separation means.

In addition, compound (2) can be produced, for example, through the following reactions [III] and [IV]. In the following formula, R ³ and R ⁴ are as defined above. X represents a halogen atom.

[III]
Reaction [III] consists of a compound represented by formula (6) (hereinafter sometimes referred to as "compound (6)") and a compound represented by formula (7) (hereinafter referred to as "compound (7)"). This is a reaction in which a compound represented by formula (8) (hereinafter sometimes referred to as "compound (8)") is obtained by reacting a compound (hereinafter sometimes referred to as "compound (8)").

The amount of compound (7) to be used is, for example, 0.5 to 3 mol, preferably 0.5 to 2 mol, per 1 mol of compound (6).

The reaction between compound (6) and compound (7) can be carried out in the presence of a solvent. As the solvent, for example, water; alcohol such as methanol, ethanol, etc. can be used. These can be used alone or in combination of two or more.

The reaction temperature is, for example, about 50 to 120°C. The reaction time is, for example, about 0.5 to 5 hours. Further, the reaction can be carried out by any method such as a batch method, a semi-batch method, or a continuous method.

The reaction atmosphere is not particularly limited as long as it does not inhibit the reaction, and may be any of air atmosphere, nitrogen atmosphere, argon atmosphere, etc.

After completion of the reaction, the obtained reaction product can be separated and purified, for example, by separation means such as filtration, concentration, distillation, extraction, crystallization, adsorption, recrystallization, column chromatography, or a combination of these separation means.

[IV]
Reaction [IV] is a reaction in which compound (8) is halogenated to obtain compound (2).

A halogenating agent can be used for halogenation. As the halogenating agent, for example, thionyl chloride can be used.

The amount of the halogenating agent used is, for example, 1 to 5 mol per 1 mol of compound (8).

The reaction temperature is, for example, about 50 to 120°C. The reaction time is, for example, about 0.5 to 5 hours. Further, the reaction can be carried out by any method such as a batch method, a semi-batch method, or a continuous method.

The reaction atmosphere is not particularly limited as long as it does not inhibit the reaction, and may be any of air atmosphere, nitrogen atmosphere, argon atmosphere, etc.

After completion of the reaction, the obtained reaction product can be separated and purified, for example, by separation means such as filtration, concentration, distillation, extraction, crystallization, adsorption, recrystallization, column chromatography, or a combination of these separation means.

[Acid generator]
The acid generator of the present invention contains at least the compound (1). The acid generator may contain one kind of the above compound (1) alone, or may contain two or more kinds in combination. Further, the acid generator may contain components other than the compound (1), but the compound ( The proportion of 1) is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, most preferably 90% by weight or more, Particularly preferably, it is 95% by weight or more. That is, it may contain an acid generator other than the compound (1), but the content of the other acid generator is, for example, 50% by weight with respect to all the compounds that decompose and generate acid upon irradiation with light. % or less, more preferably 40% by weight or less, still more preferably 30% by weight or less, particularly preferably 20% by weight or less, most preferably 10% by weight or less, particularly preferably 5% by weight or less.

Further, the acid generator has high photosensitivity to i-line, and has a molar absorption coefficient of i-line of, for example, 100 to 5000 (L/mol·cm). The lower limit of the i-line molar extinction coefficient is preferably 300 (L/mol·cm), particularly preferably 350 (L/mol·cm), most preferably 400 ( L/mol·cm), particularly preferably 450 (L/mol·cm). Further, the upper limit value of the molar extinction coefficient is preferably 4000 (L/mol·cm), more preferably 4000 (L/mol·cm), in order to improve the resolution of the pattern shape obtained by subjecting the thickened photoresist layer to photolithography treatment. Preferably 3500 (L/mol·cm), more preferably 3000 (L/mol·cm), particularly preferably 2000 (L/mol·cm), most preferably 1000 (L/mol·cm), particularly preferably 800 (L/mol·cm).

Furthermore, the acid generator has excellent solubility in organic solvents, and the amount of the acid generator that dissolves in 100 parts by weight of the organic solvent at 25° C. is, for example, 5 parts by weight or more, preferably 10 parts by weight or more, Particularly preferably 15 parts by weight or more, most preferably 20 parts by weight or more. Incidentally, examples of the organic solvent include the same organic solvents in which compound (1) exhibits solubility.

When the acid generator is irradiated with i-rays, it easily decomposes and generates sulfonic acid (R ¹ --SO ₃ H), which is a strong acid.

Since the acid generator has the above characteristics, it can be suitably used as an acid generator for photoresists.

[Photoresist]
The photoresist of the present invention contains the acid generator (or the compound (1)) and a photosensitive resin.

The content of the acid generator (or the compound (1)) is, for example, 0.001 to 20% by weight, preferably 0.01 to 15% by weight, particularly preferably 0.001 to 15% by weight, based on the total amount of the photosensitive resin. 05 to 7% by weight.

If the content of the acid generator (or the compound (1)) is 0.001% by weight or more, excellent photosensitivity to i-line can be exhibited. Further, if the content is 20% by weight or less, the effect of improving the resolution of the photoresist can be obtained.

The photosensitive resins include negative photosensitive resins (QN) whose solubility decreases (or unexposed areas are removed) upon irradiation with light, and negative photosensitive resins (QN) whose solubility increases upon irradiation with light (or whose exposed areas are removed). positive-working photopolymer (QP) that is selectively removed. These can be selected and used depending on the purpose.

Negative photosensitive resin (or negative chemically amplified resin; QN) is made by, for example, phenolic hydroxyl group-containing resin (QN1) and crosslinking agent (QN2), each alone or in combination of two or more. It is a composition containing.

The phenolic hydroxyl group-containing resin (QN1) is not particularly limited as long as it contains a phenolic hydroxyl group, and examples include novolak resin, polyhydroxystyrene, a copolymer of hydroxystyrene, a copolymer of hydroxystyrene and styrene, Hydroxystyrene, copolymers of styrene and (meth)acrylic acid derivatives, phenol-xylylene glycol condensation resins, cresol-xylylene glycol condensation resins, polyimides containing phenolic hydroxyl groups, polyamic acids containing phenolic hydroxyl groups, phenol -dicyclopentadiene condensation resins, etc.

The phenolic hydroxyl group-containing resin (QN1) may contain a phenolic low molecular compound as a part of the components.

The polystyrene equivalent weight average molecular weight (Mw) of the phenolic hydroxyl group-containing resin (QN1) measured by GPC is, for example, 2,000 to 20,000.

The crosslinking agent (QN2) may be any compound that can crosslink the phenolic hydroxyl group-containing resin (QN1) with the acid generated from the acid generator, such as bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, and bisphenol S. epoxy compounds, novolak resin epoxy compounds, resol resin epoxy compounds, poly(hydroxystyrene) epoxy compounds, oxetane compounds, melamine compounds containing methylol groups, benzoguanamine compounds containing methylol groups, urea compounds containing methylol groups, phenols containing methylol groups Compound, alkoxyalkyl group-containing melamine compound, alkoxyalkyl group-containing benzoguanamine compound, alkoxyalkyl group-containing urea compound, alkoxyalkyl group-containing phenol compound, carboxymethyl group-containing melamine resin, carboxymethyl group-containing benzoguanamine resin, carboxymethyl group-containing urea resin , a carboxymethyl group-containing phenol resin, a carboxymethyl group-containing melamine compound, a carboxymethyl group-containing benzoguanamine compound, a carboxymethyl group-containing urea compound, and a carboxymethyl group-containing phenol compound. These can be used alone or in combination of two or more.

The content of the crosslinking agent (QN2) is, for example, 10 to 40 mol% based on the total acidic functional groups in the phenolic hydroxyl group-containing resin (QN1) from the viewpoint of forming a pattern with high precision.

Examples of positive photosensitive resins (or positive chemically amplified resins; QP) include alkali-soluble resins into which acid-dissociable groups are introduced as protecting groups (protecting group-introduced resins; QP1).

The protecting group-introduced resin (QP1) is a resin in which some or all of the hydrogen atoms of acidic functional groups (for example, phenolic hydroxyl groups, carboxyl groups, sulfonyl groups, etc.) in an alkali-soluble resin are substituted with acid-dissociable groups. be.

The protecting group-introduced resin (QP1) itself is an alkali-insoluble or slightly alkali-soluble resin, and when the acid-dissociable group is dissociated by the acid generated from the acid generator, an alkali-soluble resin that is easily soluble in an alkaline developer is generated. do.

The alkali-soluble resin is, for example, a resin with an HLB value of 4 to 19 (preferably 5 to 18, particularly preferably 6 to 17).

Alkali-soluble resins include phenolic hydroxyl group-containing resins, carboxyl group-containing resins, and sulfonic acid group-containing resins.

Examples of the phenolic hydroxyl group-containing resin include the same resins as the above-mentioned phenolic hydroxyl group-containing resin (QN1).

The carboxyl group-containing resin is not particularly limited as long as it is a polymer having a carboxyl group, for example, a homopolymer of a carboxyl group-containing vinyl monomer (Ba), or a carboxyl group-containing vinyl monomer (Ba) and a hydrophobic group-containing vinyl monomer. A homopolymer with (Bb) can be mentioned.

An example of the carboxyl group-containing vinyl monomer (Ba) is (meth)acrylic acid.

Examples of hydrophobic group-containing vinyl monomers (Bb) include (meth)acrylic acid esters (Bb1) such as C _1-20 alkyl (meth)acrylates and alicyclic group-containing (meth)acrylates, and hydrocarbon monomers having a styrene skeleton. Examples include aromatic hydrocarbon monomers (Bb2) such as vinylnaphthalene.

The sulfonic acid group-containing resin is not particularly limited as long as it is a polymer having a sulfonic acid group. For example, a sulfonic acid group-containing vinyl monomer (Bc) such as vinyl sulfonic acid or styrene sulfonic acid, and if necessary, a hydrophobic group-containing vinyl It is obtained by vinyl polymerizing the monomer (Bb).

Examples of the acid-dissociable group possessed by the protecting group-introduced resin (QP1) include 1-substituted methyl groups such as methoxymethyl group, benzyl group, and tert-butoxycarbonylmethyl group; 1-methoxyethyl group, 1-ethoxyethyl group; 1-substituted ethyl groups such as; 1-branched alkyl groups such as tert-butyl groups; silyl groups such as trimethylsilyl groups; germyl groups such as trimethylgermyl groups; alkoxycarbonyl groups such as tert-butoxycarbonyl groups; acyl groups; Examples include cyclic acid dissociable groups such as a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, and a tetrahydrothiofuranyl group. These may contain one type alone or a combination of two or more types.

Introduction rate of acid-dissociable groups in the protecting group-introduced resin (QP1) {ratio of the number of acid-dissociable groups to the total number of unprotected acidic functional groups and acid-dissociable groups in the protecting group-introduced resin (QP1) } cannot be absolutely defined depending on the acid-dissociable group or the type of alkali-soluble resin into which the group is introduced, but it is preferably 10 to 100%, more preferably 15 to 100%.

The polystyrene equivalent weight average molecular weight (Mw) of the protecting group-introduced resin (QP1) measured by GPC is, for example, 1,000 to 150,000, preferably 3,000 to 100,000.

The photoresist of the present invention can be prepared, for example, by dissolving the acid generator (or the compound (1)) in an organic solvent and mixing this with a photosensitive resin.

In addition to the acid generator (or the compound (1)) and the photosensitive resin, the photoresist may contain one or more other components as necessary. Other components include, for example, organic solvents, pigments, dyes, photosensitizers, dispersants, surfactants, fillers, leveling agents, antifoaming agents, antistatic agents, ultraviolet absorbers, pH adjusters, surface Examples include modifiers, plasticizers, drying accelerators, and the like.

The organic solvent may be any solvent that can dissolve the photosensitive resin and impart good coating properties to the photoresist, but among them, those having a boiling point of 200° C. or lower are used. This is preferable in that the photoresist can be easily dried after coating. Examples of such organic solvents include aromatic hydrocarbons such as toluene; alcohols such as ethanol and methanol; ketones such as cyclohexanone, methyl ethyl ketone, and acetone; esters such as ethyl acetate, butyl acetate, and ethyl lactate; propylene glycol monomethyl ether acetate, etc. Glycol monoether monoesters and the like are preferred. These can be used alone or in combination of two or more.

The photoresist contains a compound (1) having an appropriate molar extinction coefficient for i-line. Therefore, even if the photoresist layer is made thicker (for example, 15 μm or more, preferably 20 μm or more), the i-line can reach the deep part of the resist layer, and photolithography can increase the thickness of the photoresist layer. An etching mask having a pattern shape with high resolution can be formed with high precision. Therefore, the photoresist can be suitably used as a thick film photoresist used to form a thick film photoresist layer (layer thickness, for example, 15 μm or more).

[Manufacturing method of electronic device]
The method for manufacturing an electronic device of the present invention includes a step of forming a pattern by photolithography using the photoresist.

The step of forming a pattern by photolithography using the photoresist is preferably a step of forming an etching mask on the substrate through steps 1 to 3 below.

Step 1: Forming a photoresist layer on a substrate using the photoresist Step 2: Irradiating the photoresist layer with light in a pattern Step 3: Performing alkali development

In the method of the present invention, since a photoresist containing compound (1) having an appropriate molar absorption coefficient for i-line is used, the photoresist layer is made thick (for example, 15 μm or more, preferably 20 μm or more. Even if the upper limit of the thickness is, for example, 50 μm, preferably 30 μm, an etching mask having a pattern shape with high resolution can be formed with high precision.

Therefore, the method for manufacturing the electronic device includes a step of coating and drying the photoresist to form a thick photoresist layer of 15 μm or more, and forming a pattern on the formed thick photoresist layer by photolithography. A method including:

(Step 1)
This step is a step of forming the photoresist layer on the substrate to be etched. The photoresist layer can be formed by applying the photoresist onto a substrate using a known method such as spin coating, curtain coating, roll coating, spray coating, or screen printing, and then drying it.

(Step 2)
This step is a step in which the photoresist layer obtained through Step 1 is irradiated with light in a patterned manner, such as by irradiating light through a photomask having a pattern. The light beam used for light irradiation is not particularly limited as long as it can decompose the compound (1) and generate acid, but it is preferable to use i-line.

After light irradiation, it is preferable to heat at a temperature of 60 to 200° C. for about 0.1 to 120 minutes because it can increase the difference in solubility in an alkaline developer between the exposed and unexposed areas.

(Step 3)
This step is a step in which the photoresist layer that has undergone step 2 is subjected to an alkali development treatment.

Examples of the alkaline developer used in the alkaline development treatment include an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous sodium bicarbonate and tetramethylammonium salt solution, and the like.

Methanol, ethanol, isopropyl alcohol, tetrahydrofuran, N-methylpyrrolidone, etc. may be added to the alkaline developer.

The alkaline development treatment is performed by applying the alkaline developer to the photoresist layer by a method such as a dip method, a shower method, or a spray method.

The temperature of the alkaline developer is, for example, 25 to 40°C. Further, the alkaline development time is appropriately determined depending on the thickness of the resist, and is, for example, about 1 to 5 minutes.

After Step 3, an etching mask can be formed on the substrate. By etching a substrate using the etching mask obtained in this manner, a highly accurate electronic device can be manufactured.

The electronic devices include, for example, display devices such as organic EL displays and liquid crystal displays; input devices such as touch panels; light emitting devices; sensor devices; optical scanners, optical switches, acceleration sensors, pressure sensors, gyroscopes, microchannels, This includes MEMS (Micro Electro Mechanical Systems) devices such as inkjet heads.

The configurations and combinations thereof of the present invention described above are merely examples, and additions, omissions, substitutions, and changes to the configurations can be made as appropriate without departing from the gist of the present invention. Furthermore, the present invention is not limited by the embodiments, but only by the claims.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1
14.7 g (0.097 mol) of 2-hydroxy-3-methoxybenzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to water, and while stirring, 15.3 g (0.1.6 mol) of Meldrum's acid was added. . After stirring at 100° C. for 2 hours while refluxing, the mixture was returned to room temperature and the solid was collected. By washing this with a mixed solvent of water and methanol, 13.8 g (0.063 mol) of 8-methoxycoumarin-3-carboxylic acid was obtained.
13.8 g (0.063 mol) of 8-methoxycoumarin-3-carboxylic acid was dissolved in thionyl chloride (100 mL) and stirred at 80° C. for 2 hours. Thereafter, thionyl chloride and hydrochloric acid generated in the system were distilled off under reduced pressure at 80° C. to obtain 15.0 g (0.063 mol) of 8-methoxycoumarin-3-carboxylic acid chloride.

7.8 g (0.094 mol) of N-methylhydroxylammonium hydrochloride was dissolved in methanol (50 mL), and 60 g of a 10% methanol solution of potassium hydroxide was added dropwise while stirring at 0°C. Furthermore, a solution of 15.0 g (0.063 mol) of 8-methoxycoumarin-3-carboxylic acid chloride in THF (35 mL) was added, and the mixture was stirred for 1 hour. After the reaction solution was returned to room temperature and further stirred for 1 hour, the reaction solution was distilled off using an evaporator. The residue was extracted with ethyl acetate and saturated brine, the organic layer was separated, and the solvent was distilled off using an evaporator to recover a white solid.

7.8 g of the obtained solid and 7.0 g (0.033 mol) of 1-octanesulfonyl chloride were dissolved in chloroform (50 mL), and 3.5 g (0.034 mol) of triethylamine was added dropwise while stirring at 0°C. did. After stirring at 50° C. for 8 hours, the reaction solution was extracted with chloroform-water, the organic layer was removed under reduced pressure, and the solvent was removed to obtain a brown oil. Further recrystallization with methanol yielded 10.0 g (0.023 mol) of a compound represented by the following formula (1-1) [nonionic photoacid generator (1)].

Example 2
9.1 g (0.377 mol) of a 60% liquid paraffin dispersion of sodium hydride was added to dimethyl sulfoxide, stirred, and replaced with nitrogen. 12.5 g (0.091 mol) of 2,3-dihydroxybenzaldehyde was added, and further 14.9 g (0.109 mol) of 1-bromobutane was added dropwise, followed by stirring at room temperature. After 6 hours, the reaction solution was poured into cold water, and after adding hydrochloric acid, the mixture was extracted with dichloromethane. After separating the organic layer, the solvent was distilled off using an evaporator to recover a white solid, thereby obtaining 15.8 g (0.081 mol) of 2-hydroxy-3-butoxybenzaldehyde.

15.8 g (0.081 mol) of the obtained 2-hydroxy-3-butoxybenzaldehyde was poured into water, and while stirring, 12.9 g (0.089 mol) of Meldrum's acid was added. After stirring at 100° C. for 2 hours while refluxing, the mixture was returned to room temperature and the solid was collected. By washing this with a mixed solvent of water and methanol, 13.9 g (0.053 mol) of 8-butoxycoumarin-3-carboxylic acid was obtained.
13.9 g (0.053 mol) of 8-butoxycoumarin-3-carboxylic acid was dissolved in thionyl chloride (100 mL) and stirred at 80° C. for 2 hours. Thereafter, thionyl chloride and hydrochloric acid generated in system 8 were distilled off under reduced pressure at 80° C. to obtain 14.8 g (0.053 mol) of 8-butoxycoumarin-3-carboxylic acid chloride.

6.6 g (0.080 mol) of N-methylhydroxylammonium hydrochloride was dissolved in methanol (50 mL), and 60 g of a 10% methanol solution of potassium hydroxide was added dropwise while stirring at 0°C. Furthermore, a solution of 14.8 g (0.053 mol) of 8-butoxycoumarin-3-carboxylic acid chloride in THF (35 mL) was added, and the mixture was stirred for 1 hour. After the reaction solution was returned to room temperature and further stirred for 1 hour, the reaction solution was distilled off using an evaporator. The residue was extracted with ethyl acetate and saturated brine, the organic layer was separated, and the solvent was distilled off using an evaporator to recover a white solid.

7.7 g of the obtained solid and 7.0 g (0.028 mol) of (+)-10-camphorsulfonyl chloride were dissolved in chloroform (50 mL), and while stirring at 0°C, 2.9 g (0.029 mol) of triethylamine was added. ) was added dropwise. After stirring at 50° C. for 8 hours, the reaction solution was extracted with chloroform-water, the organic layer was removed under reduced pressure, and the solvent was removed to obtain a brown oil. Further recrystallization with methanol yielded 10.0 g (0.020 mol) of a compound represented by the following formula (1-2) [nonionic photoacid generator (2)].

Example 3
10.9 g (0.115 mol) of magnesium chloride and 13.0 g (0.095 mol) of 2-n-propylphenol were added to acetonitrile, stirred, and cooled. Thereafter, 24.1 g (0.239 mol) of triethylamine was added, the temperature was raised to 60° C., 8.6 g (0.286 mol) of paraformaldehyde was added, and the mixture was aged for 3 hours. After the reaction solution was returned to room temperature, hydrochloric acid was added and extracted with ethyl acetate. After separating the organic layer, the solvent was distilled off using an evaporator to recover a brown solid, thereby obtaining 14.1 g (0.086 mol) of 2-hydroxy-3-n-propylbenzaldehyde.

14.1 g (0.086 mol) of the obtained 2-hydroxy-3-n-propylbenzaldehyde was poured into water, and while stirring, 13.6 g (0.094 mol) of Meldrum's acid was added. After stirring at 100° C. for 2 hours while refluxing, the mixture was returned to room temperature and the solid was collected. By washing this with a mixed solvent of water and methanol, 13.0 g (0.056 mol) of 8-n-propylcoumarin-3-carboxylic acid was obtained.
13.0 g (0.056 mol) of 8-n-propylcoumarin-3-carboxylic acid was dissolved in thionyl chloride (100 mL) and stirred at 80° C. for 2 hours. Thereafter, thionyl chloride and hydrochloric acid generated in the system were distilled off under reduced pressure at 80° C. to obtain 14.0 g (0.056 mol) of 8-n-propylcoumarin-3-carboxylic acid chloride.

7.0 g (0.084 mol) of N-methylhydroxylammonium hydrochloride was dissolved in methanol (50 mL), and 60 g of a 10% methanol solution of potassium hydroxide was added dropwise while stirring at 0°C. Furthermore, a solution of 14.0 g (0.056 mol) of 8-n-propylcoumarin-3-carboxylic acid chloride in THF (35 mL) was added, and the mixture was stirred for 1 hour. After the reaction solution was returned to room temperature and further stirred for 1 hour, the reaction solution was distilled off using an evaporator. The residue was extracted with ethyl acetate and saturated brine, the organic layer was separated, and the solvent was distilled off using an evaporator to recover a white solid.

7.3 g of the obtained solid and 7.4 g (0.029 mol) of (+)-10-camphorsulfonyl chloride were dissolved in chloroform (50 mL), and while stirring at 0°C, 3.1 g (0.031 mol) of triethylamine was added. ) was added dropwise. After stirring at 50° C. for 8 hours, the reaction solution was extracted with chloroform-water, the organic layer was removed under reduced pressure, and the solvent was removed to obtain a brown oil. Further recrystallization with methanol yielded 10.0 g (0.021 mol) of a compound represented by the following formula (1-3) [nonionic photoacid generator (3)].

Example 4
The following formula (1- 11.1 g (0.020 mol) of the compound represented by 4) [nonionic photoacid generator (4)] was obtained.

Example 5
Represented by the following formula (1-5) in the same manner as in Example 1 except that 7.8 g (0.080 mol) of N-ethylhydroxylammonium hydrochloride was used instead of N-methylhydroxylammonium hydrochloride. 10.3 g (0.020 mol) of the compound [nonionic photoacid generator (5)] was obtained.

Example 6
10.3 g (0.108 mol) of magnesium chloride and 12.3 g (0.090 mol) of 4-isopropylphenol were added to acetonitrile, stirred, and cooled. Thereafter, 22.8 g (0.226 mol) of triethylamine was added, the temperature was raised to 60° C., 8.1 g (0.271 mol) of paraformaldehyde was added, and the mixture was aged for 3 hours. After the reaction solution was returned to room temperature, hydrochloric acid was added and extracted with ethyl acetate. After separating the organic layer, the solvent was distilled off using an evaporator to collect a brown solid, thereby obtaining 13.3 g (0.081 mol) of 2-hydroxy-5-isopropylbenzaldehyde.

13.3 g (0.081 mol) of the obtained 2-hydroxy-5-isopropylbenzaldehyde was poured into water, and while stirring, 12.9 g (0.089 mol) of Meldrum's acid was added. After stirring at 100° C. for 2 hours while refluxing, the mixture was returned to room temperature and the solid was collected. By washing this with a mixed solvent of water and methanol, 12.2 g (0.053 mol) of 6-isopropylcoumarin-3-carboxylic acid was obtained.
12.2 g (0.053 mol) of 6-butoxycoumarin-3-carboxylic acid was dissolved in thionyl chloride (100 mL) and stirred at 80° C. for 2 hours. Thereafter, thionyl chloride and hydrochloric acid generated in the system were distilled off under reduced pressure at 80° C. to obtain 13.3 g (0.053 mol) of 6-isopropylcoumarin-3-carboxylic acid chloride.

6.6 g (0.080 mol) of N-methylhydroxylammonium hydrochloride was dissolved in methanol (50 mL), and 60 g of a 10% methanol solution of potassium hydroxide was added dropwise while stirring at 0°C. Furthermore, a solution of 13.3 g (0.053 mol) of 6-isopropylcoumarin-3-carboxylic acid chloride in THF (35 mL) was added, and the mixture was stirred for 1 hour. After the reaction solution was returned to room temperature and further stirred for 1 hour, the reaction solution was distilled off using an evaporator. The residue was extracted with ethyl acetate and saturated brine, the organic layer was separated, and the solvent was distilled off using an evaporator to recover a white solid.

6.9 g of the obtained solid and 7.0 g (0.028 mol) of (+)-10-camphorsulfonyl chloride were dissolved in chloroform (50 mL), and while stirring at 0°C, 2.9 g (0.029 mol) of triethylamine was added. ) was added dropwise. After stirring at 50° C. for 8 hours, the reaction solution was extracted with chloroform-water, the organic layer was removed under reduced pressure, and the solvent was removed to obtain a brown oil. Further recrystallization with methanol yielded 9.4 g (0.020 mol) of a compound represented by the following formula (1-6) [nonionic photoacid generator (6)].

Comparative example 1
Represented by the following formula (x) in the same manner as in Example 1 except that 17.1 g (0.112 mol) of 2-hydroxy-4-methoxybenzaldehyde was used instead of 2-hydroxy-5-butoxybenzaldehyde. 11.6 g (0.027 mol) of the compound [nonionic photoacid generator (7)] was obtained.

(evaluation)
The nonionic photoacid generators obtained in Examples and Comparative Examples were evaluated for solvent solubility, molar extinction coefficient, and acid generation ability using the following methods. The results are summarized in the table below.

<Solvent solubility>
0.1 g of the nonionic photoacid generator was placed in a test tube, and 0.2g of organic solvent was added under temperature control at 25°C until the nonionic photoacid generator was completely dissolved. The concentration of the nonionic photoacid generator at the time was determined. The higher the concentration, the better the solvent solubility. Note that propylene glycol monomethyl ether acetate was used as the organic solvent.

<Molar extinction coefficient>
A nonionic photoacid generator was diluted to 0.25 mmol/L using acetonitrile, and measured in a 1 cm cell in the range of 200 to 500 nm using a UV-visible spectrophotometer (manufactured by Shimadzu Corporation, UV-2550). The absorbance was measured over a long period of time. The i-line (365 nm) molar extinction coefficient (L/mol·cm) was calculated from the i-line (365 nm) absorbance.

<Acid generating ability>
A test in which a resist coating film was formed using the nonionic photoacid generator obtained in Examples and Comparative Examples, and the formed resist coating film was subjected to exposure and development treatment [see below (Photoresist Preparation) (Resist Coating film preparation) (Exposure) and (Development)] were carried out by changing the i-line exposure amount stepwise from 50 mJ/cm ² to 1000 mJ/cm ² until the exposed area of the resist coating was completely covered. The minimum exposure amount required to dissolve in the developer and leave no residue, that is, the minimum exposure amount necessary to form a resist pattern was determined.

(Photoresist preparation)
A membrane with a pore size of 1 μm was prepared by mixing 0.2 parts by weight of a nonionic photoacid generator, 100 parts by weight of a positive photosensitive resin represented by the following formula (Resin-1), and 200 parts by weight of propylene glycol monomethyl ether acetate. A photoresist was prepared by filtration through a filter.

(Resist coating film preparation)
The obtained photoresist was applied onto a 10 cm square glass substrate using a spin coater. Next, it was vacuum dried at 25° C. for 5 minutes, and then dried on a hot plate at 110° C. for 5 minutes to form a resist coating film with a thickness of 20 μm.

(exposure)
This resist coating film was exposed to i-line (light with a wavelength of 365 nm) using a 10 mm x 10 mm square pattern mask and an ultraviolet irradiation device (TME-150RSC, manufactured by Topcon Corporation).

(developing)
Next, post-exposure heating (PEB) was performed for 3 minutes on a 90° C. hot plate. Thereafter, the film was developed by immersing it in a 2.38% by weight aqueous tetramethylammonium hydroxide solution for 90 seconds, and immediately washed with water and dried.

The acid generation ability was evaluated using the following criteria from the minimum exposure amount determined by the above method. Note that the smaller the minimum exposure amount, the better the sensitivity of the nonionic photoacid generator and the better the acid generation ability.
<Evaluation criteria>
◎ (Excellent): Minimum exposure amount is 200 mJ/cm ² or less ○ (Good): Minimum exposure amount is greater than 200 mJ/cm ² and 500 mJ/cm ² or less × (Poor): Minimum exposure amount is 500 mJ/cm ² bigger

R ¹ to R ⁵ of the acid generator in the table are R ¹ to R ⁵ in the following formulas, respectively.

The abbreviations in the table are explained below.

Table 1 shows that the acid generator (or compound (1)) of the present invention has excellent solvent solubility.
Furthermore, if a photoresist containing the acid generator (or compound (1)) of the present invention is used, even when a thick film is formed, it is possible to form a pattern well by irradiating with i-rays. I understand.

As a summary of the above, the configuration of the present invention and its variations are additionally described below.
[1] A compound represented by formula (1).
(In the formula, R ¹ and R ² are the same or different and represent a hydrocarbon group which may have a substituent. R ³ represents a hydrogen atom, OR ¹³ or R ¹³ , and R ¹³ is a substituent. is a hydrocarbon group which may have a substituent.R ⁴ represents a hydrogen atom or R ¹⁴ , and R ¹⁴ is a hydrocarbon group which may have a substituent. However, R ³ and R ⁴ (Except when both represent hydrogen atoms)
[2] The compound according to [1], which has an i-line molar extinction coefficient of 100 to 5000 (L/mol·cm).
[3] The compound according to [1] or [2], which has a solubility in propylene glycol monomethyl ether acetate at 25° C. of 5% by weight or more.
[4] An acid generator containing the compound according to any one of [1] to [3].
[5] The acid generator according to [4], which is an i-ray acid generator.
[6] A photoresist containing the acid generator according to [4] or [5] and a photosensitive resin.
[7] The photoresist according to [6], which is a thick film photoresist used to form a thick film photoresist layer of 15 μm or more.
[8] A method for manufacturing an electronic device, including a step of forming a pattern by photolithography using the photoresist according to [6] or [7].
[9] Coating and drying the photoresist described in [6] or [7] to form a thick photoresist layer of 15 μm or more, and patterning the formed thick photoresist layer by photolithography. A method of manufacturing an electronic device, including the steps of:
[10] Use of the compound according to any one of [1] to [3] as an acid generator.
[11] Use of the compound according to any one of [1] to [3] as an acid generator used in a thick film photoresist.
[12] Use of the compound according to any one of [1] to [3] as an i-line acid generator.

Compound (1) is easily decomposed by i-ray irradiation to generate sulfonic acid, which is a strong acid. Even if the photoresist layer containing compound (1) is thick, the i-line can reach the deep layer, and compound (1) exhibits good acid generation ability in the entire photoresist layer. be able to. Therefore, compound (1) is preferably used as an acid generator for thick film photoresists.

Claims (9)

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

   

   (In the formula, R ¹ and R ² are the same or different and represent a hydrocarbon group which may have a substituent. R ³ represents a hydrogen atom, OR ¹³ or R ¹³ , and R ¹³ is a substituent. is a hydrocarbon group which may have a substituent.R ⁴ represents a hydrogen atom or R ¹⁴ , and R ¹⁴ is a hydrocarbon group which may have a substituent. However, R ³ and R ⁴ (Except when both represent hydrogen atoms)
2. The compound according to claim 1, which has an i-line molar extinction coefficient of 100 to 5000 (L/mol·cm).
3. The compound according to claim 1 or 2, having a solubility in propylene glycol monomethyl ether acetate at 25°C of 5% by weight or more.
4. An acid generator comprising the compound according to claim 1 or 2.
5. The acid generator according to claim 4, which is an i-line acid generator.
6. A photoresist comprising the acid generator according to claim 4 and a photosensitive resin.
7. The photoresist according to claim 6, which is a thick film photoresist used to form a thick film photoresist layer of 15 μm or more.
8. A method for manufacturing an electronic device, comprising a step of forming a pattern by photolithography using the photoresist according to claim 6.
9. An electronic device comprising the step of coating and drying the photoresist according to claim 6 to form a thick photoresist layer of 15 μm or more, and forming a pattern on the formed thick photoresist layer by photolithography. manufacturing method.