JP7673669B2 - Silphenylene skeleton-containing polymer, photosensitive resin composition, pattern forming method, and method for manufacturing optical semiconductor device - Google Patents

Description

The present invention relates to a silphenylene skeleton-containing polymer, a photosensitive resin composition, a pattern forming method, and a method for producing an optical semiconductor device.

Transparent epoxy resins have traditionally been used as sealing and protective materials and adhesives in various optical devices, such as light-emitting diodes (LEDs) and CMOS image sensors. In recent years, many optical devices require microfabrication, so resist materials using epoxy resins are often used.

In recent years, optical devices such as LEDs have become increasingly powerful, and they are required to be microfabricated and have higher transparency and light resistance than conventional materials in order to suppress gas generation, discoloration, etc. An example of a material that can be microfabricated and has particularly high transparency and light resistance is a photosensitive material that uses an epoxy-modified silicone resin that has been introduced with isocyanuric acid and a norbornene skeleton (Patent Document 1).

Recently, in addition to transparency and light resistance, further improvements in properties are being demanded for such photosensitive materials, and in particular, low-temperature curing is required. However, the epoxy-modified silicone resin mentioned above is not a material that can be cured at a low temperature of around 130°C. Therefore, there has been a demand for photosensitive materials that use resins that contain not only epoxy groups but also other highly reactive functional groups. Introducing other highly reactive functional groups into epoxy resins not only enables low-temperature curing, but is also expected to contribute to improved processability. Therefore, it will be a high-added-value material that can be finely processed and cured at low temperatures.

JP 2020-90649 A

The present invention has been made in consideration of the above circumstances, and aims to provide a polymer that can form fine patterns over a wide wavelength range while also being curable at low temperatures and capable of providing a film having high transparency and high light resistance, a photosensitive resin composition containing the polymer, a pattern formation method using the photosensitive resin composition, and a method for manufacturing a semiconductor element.

As a result of extensive investigations to achieve the above object, the present inventors discovered that a polymer containing a silphenylene skeleton, an isocyanuric acid skeleton, and a hydroxyl-substituted alkyl ether skeleton in the main chain and an epoxy group in the side chain can be cured at low temperatures to give a film having high transparency and high light resistance, and that a photosensitive resin composition containing the polymer of the present invention and a photoacid generator can be cured at low temperatures to give a film having high transparency and high light resistance while being capable of forming fine patterns over a wide wavelength range, and thus completed the present invention.

（式中、ａ、ｂ及びｃは、０＜ａ＜１、０≦ｂ＜１、０＜ｃ＜１、及びａ＋ｂ＋ｃ＝１を満たす正数である。Ｘ¹は、下記式（Ｘ１）で表される２価の基である。Ｘ²は、下記式（Ｘ２）で表される２価の基である。Ｘ³は、下記式（Ｘ３）で表される２価の基である。）

（式中、Ｒ¹¹及びＲ¹²は、それぞれ独立に、水素原子又はメチル基である。Ｒ¹³は、炭素数１～８のヒドロカルビレン基であり、その炭素－炭素結合間にエステル結合又はエーテル結合が介在していてもよい。ｎ¹及びｎ²は、それぞれ独立に、０～７の整数である。破線は、結合手である。）

（式中、Ｒ²¹及びＲ²²は、それぞれ独立に、水素原子又はヘテロ原子を含んでいてもよい炭素数１～２０の飽和ヒドロカルビル基である。ｍは、０～１０の整数である。破線は、結合手である。）

（式中、Ｒ³¹及びＲ³²は、それぞれ独立に、水素原子又はメチル基である。Ｒ³³は、水素原子又はヘテロ原子を含んでいてもよい炭素数１～２０の飽和ヒドロカルビル基であり、Ｒ³³が飽和ヒドロカルビル基のとき、置換基として１級又は２級アルコール性ヒドロキシ基を含んでいてもよい。Ｒ³⁴は、ヒドロキシ基又はヘテロ原子を含んでいてもよい炭素数１～２０の飽和ヒドロカルビル基であり、Ｒ³⁴が飽和ヒドロカルビル基のとき、置換基として１級又は２級アルコール性ヒドロキシ基を含んでいてもよい。Ｒ³³が水素原子かつＲ³⁴が飽和ヒドロカルビル基のとき、Ｒ³⁴は置換基として少なくとも１つの１級又は２級アルコール性ヒドロキシ基を含む。Ｒ³³及びＲ³⁴がともに飽和ヒドロカルビル基のとき、その一方又は両方に置換基として少なくとも１つの１級又は２級アルコール性ヒドロキシ基を含む。ｐ¹及びｐ²は、それぞれ独立に、１～７の整数である。ｑ¹及びｑ²は、それぞれ独立に、１～７の整数である。破線は、結合手である。）
４．ａ、ｂ及びｃが、０＜ａ＜１、０＜ｂ＜１、０＜ｃ＜１、及びａ＋ｂ＋ｃ＝１を満たす正数である３のポリマー。
５．Ｒ³⁴が、末端にヒドロキシ基を有する直鎖アルキル基である、３又は４のポリマー。
６．Ｒ³¹及びＲ³²が、水素原子である３～５のいずれかのポリマー。
７．ｐ¹及びｐ²が、１である３～６のいずれかのポリマー。
８．ｑ¹及びｑ²が、１である３～７のいずれかのポリマー。
９．前記ポリマーからなる膜厚１０μｍの膜の波長４００ｎｍの光の透過率が、９５％以上である１～８のいずれかのポリマー。
１０．１～９のいずれかのポリマー及び（Ｂ）光酸発生剤を含む感光性樹脂組成物。
１１．更に、（Ｃ）カチオン重合性架橋剤を含む１０の感光性樹脂組成物。
１２．（ｉ）１０又は１１の感光性樹脂組成物を用いて基板上に感光性樹脂皮膜を形成する工程、
（ii）前記感光性樹脂皮膜を露光する工程、及び
（iii）前記露光した感光性樹脂皮膜を、現像液を用いて現像する工程
を含むパターン形成方法。
１３．１２のパターン形成方法を含む、感光性樹脂皮膜を備える光半導体素子の製造方法。 That is, the present invention provides the following silphenylene skeleton-containing polymer, photosensitive resin composition, pattern forming method, and method for producing an optical semiconductor element.
1. A polymer containing a silphenylene skeleton, an isocyanuric acid skeleton and a hydroxyl-substituted alkyl ether skeleton in the main chain and containing an epoxy group in the side chain.
2. The polymer of 1, wherein the hydroxy group-substituted alkyl ether skeleton has 9 to 20 carbon atoms.
3. The polymer according to 1 or 2, which contains a repeating unit represented by the following formula (A1), a repeating unit represented by the following formula (A2), and a repeating unit represented by the following formula (A3).

(In the formula, a, b, and c are positive numbers satisfying 0<a<1, 0≦b<1, 0<c<1, and a+b+c=1. ^X1 is a divalent group represented by the following formula (X1). ^X2 is a divalent group represented by the following formula (X2). ^X3 is a divalent group represented by the following formula (X3).)

(In the formula, R ¹¹ and R ¹² are each independently a hydrogen atom or a methyl group. R ¹³ is a hydrocarbylene group having 1 to 8 carbon atoms, and an ester bond or an ether bond may be present between the carbon-carbon bonds. n ¹ and n ² are each independently an integer of 0 to 7. The dashed lines represent bonds.)

(In the formula, R ²¹ and R ²² each independently represent a hydrogen atom or a saturated hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. m represents an integer of 0 to 10. The dashed line represents a bond.)

(In the formula, R ³¹ and R ³² are each independently a hydrogen atom or a methyl group. R ³³ is a hydrogen atom or a saturated hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, and when R ³³ is a saturated hydrocarbyl group, it may contain a primary or secondary alcoholic hydroxy group as a substituent. R ³⁴ is a saturated hydrocarbyl group having 1 to 20 carbon atoms which may contain a hydroxy group or a heteroatom, and when R ³⁴ is a saturated hydrocarbyl group, it may contain a primary or secondary alcoholic hydroxy group as a substituent. When R ³³ is a hydrogen atom and R ³⁴ is a saturated hydrocarbyl group, R ³⁴ contains at least one primary or secondary alcoholic hydroxy group as a substituent. When ^{R 33} and R ³⁴ are both saturated hydrocarbyl groups, one or both of them contain at least one primary or secondary alcoholic hydroxy group as a substituent. p ¹ and p ² are each independently an integer of 1 to 7. q ¹ and q Each of ² is independently an integer from 1 to 7. The dashed lines represent bonds.
4. The polymer of 3, where a, b, and c are positive numbers such that 0<a<1, 0<b<1, 0<c<1, and a+b+c=1.
5. The polymer of 3 or 4, wherein R ³⁴ is a linear alkyl group having a terminal hydroxy group.
6. The polymer of any one of 3 to 5, wherein R ³¹ and R ³² are hydrogen atoms.
7. The polymer of any of 3 to 6, wherein p ¹ and p ² are 1.
8. The polymer of any of 3 to 7, wherein q ¹ and q ² are 1.
9. The polymer according to any one of 1 to 8, wherein a film of the polymer having a thickness of 10 μm has a transmittance of 95% or more at a light having a wavelength of 400 nm.
10. A photosensitive resin composition comprising any one of the polymers according to 1 to 9 and (B) a photoacid generator.
11. The photosensitive resin composition of 10, further comprising (C) a cationically polymerizable crosslinking agent.
12. (i) forming a photosensitive resin film on a substrate using the photosensitive resin composition of 10 or 11;
(ii) a step of exposing the photosensitive resin film to light; and (iii) a step of developing the exposed photosensitive resin film with a developer.
13. A method for producing an optical semiconductor element having a photosensitive resin film, comprising the pattern formation method according to 12.

The polymer of the present invention can be cured at low temperatures, particularly at temperatures below 130°C, and gives a film with high transparency and high light resistance. The polymer of the present invention can be easily synthesized. Furthermore, by using a photosensitive resin composition containing the polymer of the present invention, fine patterns can be formed using light of a wide range of wavelengths. Furthermore, the film obtained from the photosensitive resin composition of the present invention has excellent transparency and light resistance, can be cured at low temperatures below 130°C, and can be suitably used for protecting and sealing optical semiconductor elements.

[Silphenylene skeleton-containing polymer]
The polymer of the present invention is a polymer containing a silphenylene skeleton, an isocyanuric acid skeleton, and a hydroxyl-substituted alkyl ether skeleton in the main chain, and containing an epoxy group in the side chain. The number of carbon atoms in the hydroxyl-substituted alkyl ether skeleton is preferably 9 to 20. The polymer may further contain a norbornene skeleton in the main chain.

Such a polymer preferably contains a repeating unit represented by the following formula (A1), a repeating unit represented by the following formula (A2) and a repeating unit represented by the following formula (A3).

In formulas (A1) to (A3), a, b, and c are positive numbers that satisfy 0<a<1, 0≦b<1, 0<c<1, and a+b+c=1.

（破線は、結合手である。） In formula (A1), ^X1 is a divalent group represented by the following formula (X1): The divalent group represented by the following formula (X1) is a group having an isocyanuric acid skeleton.

(The dashed lines represent bonds.)

In formula (X1), R ¹¹ and R ¹² each independently represent a hydrogen atom or a methyl group.

In formula (X1), R ¹³ is a hydrocarbylene group having 1 to 8 carbon atoms, and an ester bond or an ether bond may be interposed between the carbon-carbon bonds. The hydrocarbylene group represented by R ¹³ may be linear, branched, or cyclic, and specific examples thereof include alkanediyl groups such as a methylene group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,2-diyl group, a butane-1,3-diyl group, and a butane-1,4-diyl group. Of these, R ¹³ is preferably a methylene group or an ethylene group, and more preferably a methylene group. In addition, an ester bond or an ether bond may be interposed between the carbon-carbon bonds of the hydrocarbylene group.

In formula (X1), n ¹ and n ² each independently represent an integer of 0 to 7.

（破線は、結合手である。） In formula (A2), ^X2 is a divalent group represented by the following formula (X2): The divalent group represented by the following formula (X2) is a group having a norbornene skeleton.

(The dashed lines represent bonds.)

In formula (X2), R ²¹ and R ²² are each independently a saturated hydrocarbyl group having 1 to 20 carbon atoms, which may contain a hydrogen atom or a heteroatom. The saturated hydrocarbyl group may be linear, branched, or cyclic, and specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, or an n-decyl group; and cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group. The saturated hydrocarbyl group may contain a heteroatom. Specifically, some or all of the hydrogen atoms of the saturated hydrocarbyl group may be substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., and a carbonyl group, an ether bond, a thioether bond, etc. may be present between the carbon-carbon atoms.

In formula (X2), m is an integer from 0 to 10, preferably 0.

（破線は、結合手である。） In formula (A3), ^X3 is a divalent group represented by the following formula (X3): The divalent group represented by the following formula (X3) is a group having a hydroxy group-substituted alkyl ether skeleton.

(The dashed lines represent bonds.)

In formula (X3), R ³¹ and R ³² each independently represent a hydrogen atom or a methyl group, and preferably a hydrogen atom.

In formula (X3), R ³³ is a saturated hydrocarbyl group having 1 to 20 carbon atoms which may contain a hydrogen atom or a heteroatom, and when R ³³ is a saturated hydrocarbyl group, it may contain a primary or secondary alcoholic hydroxyl group as a substituent. R ³⁴ is a saturated hydrocarbyl group having 1 to 20 carbon atoms which may contain a hydroxyl group or a heteroatom, and when R ³⁴ is a saturated hydrocarbyl group, it may contain a primary or secondary alcoholic hydroxyl group as a substituent. The saturated hydrocarbyl groups represented by R ³³ and R ³⁴ may be linear, branched, or cyclic, and specific examples thereof include the same as those exemplified as the saturated hydrocarbyl groups represented by R ²¹ and R ²² in the explanation of formula (X2). The saturated hydrocarbyl group may contain a heteroatom. Specifically, some or all of the hydrogen atoms of the saturated hydrocarbyl group may be substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., and a carbonyl group, an ether bond, a thioether bond, etc. may be present between the carbon-carbon atoms.

When R ³³ is a hydrogen atom and R ³⁴ is a saturated hydrocarbyl group, R ³⁴ contains at least one primary or secondary alcoholic hydroxy group as a substituent. When R ³³ and R ³⁴ are both saturated hydrocarbyl groups, one or both of them contain at least one primary or secondary alcoholic hydroxy group as a substituent. When R ³³ and R ³⁴ contain an alcoholic hydroxy group, R ³³ and R ³⁴ are preferably linear alkyl groups containing a primary alcoholic hydroxy group at the terminal.

In formula (X3), ^p1 and ^p2 each independently represent an integer of 1 to 7, preferably 1. ^q1 and ^q2 each independently represent an integer of 1 to 7, preferably 1. The number of carbon atoms contained in the divalent group represented by formula (X3) is preferably 9 to 20.

The polymer of the present invention preferably has a weight average molecular weight (Mw) of 3,000 to 500,000, and more preferably 5,000 to 200,000. If the Mw is within the above range, the polymer can be obtained in a solid form, and film-forming properties can be ensured. In the present invention, Mw is a polystyrene-equivalent measured value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as an elution solvent.

The polymer of the present invention may be a polymer in which the repeating units represented by formula (A1), the repeating units represented by formula (A2), and the repeating units represented by formula (A3) are randomly or alternately bonded, and may contain multiple blocks of each unit.

In the polymer of the present invention, a, b, and c in formula (1) are positive numbers that satisfy 0<a<1, 0≦b<1, 0<c<1, and a+b+c=1, but preferably 0<a<1, 0<b<1, and 0<c<1, more preferably 0.1<a<0.8, 0.1<b<0.8, and 0.1<c<0.8, and even more preferably 0.15<a<0.65, 0.15<b<0.65, and 0.15<c<0.65.

[Method of producing a polymer containing a silphenylene skeleton]
The polymer can be produced by addition polymerization of a compound represented by the following formula (1), a compound represented by the following formula (2), a compound represented by the following formula (4), and, if necessary, a compound represented by the following formula (3) in the presence of a metal catalyst.

（式中、Ｒ¹¹～Ｒ¹³、ｎ¹及びｎ²は、前記と同じ。）

(In the formula, R ¹¹ to R ¹³ , n ¹ and n ² are the same as defined above.)

（式中、Ｒ²¹、Ｒ²²及びｍは、前記と同じ。）

(In the formula, R ²¹ , R ²² and m are the same as defined above.)

（式中、Ｒ³¹～Ｒ³⁴、ｐ¹、ｐ²、ｑ¹及びｑ²は、前記と同じ。）

(In the formula, R ³¹ to R ³⁴ , p ¹ , p ² , q ¹ and q ² are the same as defined above.)

The metal catalyst may be, for example, a platinum group _metal such as _platinum (including platinum black) _, rhodium, _{or palladium ; H2PtCl4.xH2O} , _{H2PtCl6.xH2O , NaHPtCl6.xH2O , KHPtCl6.xH2O , Na2PtCl6.xH2O , K2PtCl4.xH2O} , _{PtCl4.xH2O , PtCl2 , Na2HPtCl4.xH2O ;} O (wherein x is preferably an integer of 0 to 6, particularly preferably 0 or 6), platinum chloride, chloroplatinic acid, and chloroplatinic acid salts; alcohol-modified chloroplatinic acid (e.g., as described in U.S. Pat. No. 3,220,972); complexes of chloroplatinic acid and olefins (e.g., as described in U.S. Pat. Nos. 3,159,601, 3,159,662, and 3,775,452); platinum group metals such as platinum black and palladium supported on carriers such as alumina, silica, and carbon; rhodium-olefin complexes; chlorotris(triphenylphosphine)rhodium (the so-called Wilkinson's catalyst); complexes of platinum chloride, chloroplatinic acid, or chloroplatinic acid salts and vinyl group-containing siloxanes (particularly vinyl group-containing cyclic siloxanes);

The amount of catalyst used is a catalytic amount, and is usually preferably 0.001 to 0.1 mass% of the platinum group metal relative to the total amount of the reaction polymer. In the polymerization reaction, a solvent may be used as necessary. Examples of the solvent are hydrocarbon solvents such as toluene and xylene. As the polymerization conditions, from the viewpoint of not deactivating the catalyst and being able to complete the polymerization in a short time, the polymerization temperature is preferably, for example, 40 to 150°C, particularly 60 to 120°C. The polymerization time depends on the type and amount of the polymer, but is preferably completed within about 0.5 to 100 hours, particularly 0.5 to 30 hours, to prevent moisture from entering the polymerization system. After the polymerization reaction is completed in this manner, if a solvent is used, it can be distilled off to obtain the polymer.

The reaction method is not particularly limited, but it is preferable to first mix and heat the compound represented by formula (2) and the compound represented by formula (4), and if necessary, the compound represented by formula (3), and then add a metal catalyst to the mixed solution, and then dropwise add the compound represented by formula (1) over a period of 0.1 to 5 hours.

The raw material compounds are preferably blended so that the molar ratio of the hydrosilyl groups in the compound represented by formula (1) to the total of the alkenyl groups in the compound represented by formula (2), the compound represented by formula (3), and the compound represented by formula (4) is preferably 0.67 to 1.67, more preferably 0.83 to 1.25. The Mw of the polymer of the present invention can be controlled by using a monoallyl compound such as o-allylphenol, or a monohydrosilane or monohydrosiloxane such as triethylhydrosilane as a molecular weight regulator.

The polymer of the present invention is preferably one in which a film of the polymer having a thickness of 10 μm has a transmittance of 95% or more for light having a wavelength of 400 nm.

[Photosensitive resin composition]
The photosensitive resin composition of the present invention contains (A) the above-mentioned silphenylene skeleton-containing polymer and (B) a photoacid generator.

[(B) Photoacid generator]
The photoacid generator (B) is not particularly limited as long as it is decomposed by irradiation with light and generates an acid, but it is preferable that it generates an acid by irradiation with light having a wavelength of 190 to 500 nm. The photoacid generator (B) is used as a curing catalyst. Examples of the photoacid generator include onium salts, diazomethane derivatives, glyoxime derivatives, β-ketosulfone derivatives, disulfone derivatives, nitrobenzylsulfonate derivatives, sulfonate ester derivatives, imido-yl-sulfonate derivatives, oxime sulfonate derivatives, iminosulfonate derivatives, and triazine derivatives.

The onium salt includes a sulfonium salt represented by the following formula (B1) or an iodonium salt represented by the following formula (B2).

In formulae (B1) and (B2), R ¹⁰¹ to R ¹⁰⁵ each independently represent a saturated hydrocarbyl group having 1 to 12 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, or an aralkyl group having 7 to 12 carbon atoms which may have a substituent. A ⁻ represents a non-nucleophilic counter ion.

The saturated hydrocarbyl group may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl groups. Examples of the aryl group include phenyl, naphthyl, and biphenylyl groups. Examples of the aralkyl group include benzyl and phenethyl groups.

The substituents include an oxo group, a saturated hydrocarbyl group having 1 to 12 carbon atoms, a saturated hydrocarbyloxy group having 1 to 12 carbon atoms, an aryl group having 6 to 24 carbon atoms, an aralkyl group having 7 to 25 carbon atoms, an aryloxy group having 6 to 24 carbon atoms, and an arylthio group having 6 to 24 carbon atoms.

R ¹⁰¹ to R ¹⁰⁵ are preferably a saturated hydrocarbyl group which may have a substituent such as a methyl group, an ethyl group, a propyl group, a butyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, or a 2-oxocyclohexyl group; an aryl group which may have a substituent such as a phenyl group, a naphthyl group, a biphenylyl group, a 2-, 3-, or 4-methoxyphenyl group, a 2-, 3-, or 4-ethoxyphenyl group, a 3- or 4-tert-butoxyphenyl group, a 2-, 3-, or 4-methylphenyl group, a 2-, 3-, or 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-butylphenyl group, a dimethylphenyl group, a terphenylyl group, a biphenylyloxyphenyl group, or a biphenylylthiophenyl group; or an aralkyl group which may have a substituent such as a benzyl group or a phenethyl group. Of these, an aryl group which may have a substituent and an aralkyl group which may have a substituent are more preferable.

The non-nucleophilic counter ions include halide ions such as chloride ion and bromide ion; fluoroalkanesulfonate ions such as triflate ion, 1,1,1-trifluoroethanesulfonate ion, and nonafluorobutanesulfonate ion; arylsulfonate ions such as tosylate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion, and 1,2,3,4,5-pentafluorobenzenesulfonate ion; alkanesulfonate ions such as mesylate ion and butanesulfonate ion; fluoroalkanesulfonimide ions such as trifluoromethanesulfonimide ion; fluoroalkanesulfonylmethide ions such as tris(trifluoromethanesulfonyl)methide ion; and borate ions such as tetrakisphenylborate ion and tetrakis(pentafluorophenyl)borate ion.

The diazomethane derivative includes a compound represented by the following formula (B3).

In formula (B3), R ¹¹¹ and R ¹¹² each independently represent a saturated hydrocarbyl group or a halogenated saturated hydrocarbyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms which may have a substituent, or an aralkyl group having 7 to 12 carbon atoms.

Examples of the saturated hydrocarbyl group include the same as those exemplified as the saturated hydrocarbyl groups represented by R ¹⁰¹ to R ^105. Examples of the halogenated saturated hydrocarbyl group include a trifluoromethyl group, a 1,1,1-trifluoroethyl group, a 1,1,1-trichloroethyl group, a nonafluorobutyl group, and the like.

The aryl group, which may have a substituent, includes a phenyl group; an alkoxyphenyl group such as a 2-, 3-, or 4-methoxyphenyl group, a 2-, 3-, or 4-ethoxyphenyl group, or a 3- or 4-tert-butoxyphenyl group; an alkylphenyl group such as a 2-, 3-, or 4-methylphenyl group, a 2-, 3-, or 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-butylphenyl group, or a dimethylphenyl group; and a halogenated aryl group such as a fluorophenyl group, a chlorophenyl group, or a 1,2,3,4,5-pentafluorophenyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group.

The glyoxime derivative includes a compound represented by the following formula (B4).

In formula (B4), R ¹²¹ to R ¹²⁴ are each independently a saturated hydrocarbyl group or a halogenated saturated hydrocarbyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms which may have a substituent, or an aralkyl group having 7 to 12 carbon atoms. R ¹²³ and R ¹²⁴ may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and when they form a ring, the group formed by bonding of R ¹²³ and R ¹²⁴ is an alkanediyl group having 1 to 12 carbon atoms.

Examples of the saturated hydrocarbyl group, the halogenated saturated hydrocarbyl group, the aryl group which may have a substituent, and the aralkyl group include the same as those exemplified as the saturated hydrocarbyl group, the halogenated saturated hydrocarbyl group, the aryl group which may have a substituent, and the aralkyl group represented by R ¹¹¹ and R ¹¹² , respectively. Examples of the alkanediyl group include a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a hexanediyl group.

Specific examples of the onium salt include diphenyliodonium trifluoromethanesulfonate, (p-tert-butoxyphenyl)phenyliodonium trifluoromethanesulfonate, diphenyliodonium p-toluenesulfonate, (p-tert-butoxyphenyl)phenyliodonium p-toluenesulfonate, triphenylsulfonium trifluoromethanesulfonate, (p-tert-butoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, bis(p-tert-butoxyphenyl)phenylsulfonium trifluoromethanesulfonate, tris( p-tert-butoxyphenyl)sulfonium, triphenylsulfonium p-toluenesulfonate, (p-tert-butoxyphenyl)diphenylsulfonium p-toluenesulfonate, bis(p-tert-butoxyphenyl)phenylsulfonium p-toluenesulfonate, tris(p-tert-butoxyphenyl)sulfonium p-toluenesulfonate, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium butanesulfonate, trimethylsulfonium trifluoromethanesulfonate, trimethylsulfonium p-toluenesulfonate, cyclotrifluoromethanesulfonate cyclohexylmethyl(2-oxocyclohexyl)sulfonium, cyclohexylmethyl(2-oxocyclohexyl)sulfonium p-toluenesulfonate, dimethylphenylsulfonium trifluoromethanesulfonate, dimethylphenylsulfonium p-toluenesulfonate, dicyclohexylphenylsulfonium trifluoromethanesulfonate, dicyclohexylphenylsulfonium p-toluenesulfonate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, 4-(phenylthio)phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphate , diphenyl(4-thiophenoxyphenyl)sulfonium hexafluoroantimonate, [4-(4-biphenylylthio)phenyl]-4-biphenylylphenylsulfonium tris(trifluoromethanesulfonyl)methide, triphenylsulfonium tetrakis(fluorophenyl)borate, tris[4-(4-acetylphenyl)thiophenyl]sulfonium tetrakis(fluorophenyl)borate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, tris[4-(4-acetylphenyl)thiophenyl]sulfonium tetrakis(pentafluorophenyl)borate, etc.

Specific examples of the diazomethane derivatives include bis(benzenesulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(xylenesulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(cyclopentylsulfonyl)diazomethane, bis(n-butylsulfonyl)diazomethane, bis(isobutylsulfonyl)diazomethane, bis(sec-butylsulfonyl)diazomethane, bis(n-propylsulfonyl)diazomethane, bis(isopropylsulfonyl)diazomethane, bis( tert-butylsulfonyl)diazomethane, bis(n-pentylsulfonyl)diazomethane, bis(isopentylsulfonyl)diazomethane, bis(sec-pentylsulfonyl)diazomethane, bis(tert-pentylsulfonyl)diazomethane, 1-cyclohexylsulfonyl-1-(tert-butylsulfonyl)diazomethane, 1-cyclohexylsulfonyl-1-(tert-pentylsulfonyl)diazomethane, 1-tert-pentylsulfonyl-1-(tert-butylsulfonyl)diazomethane, etc.

Specific examples of the glyoxime derivatives include bis-o-(p-toluenesulfonyl)-α-dimethylglyoxime, bis-o-(p-toluenesulfonyl)-α-diphenylglyoxime, bis-o-(p-toluenesulfonyl)-α-dicyclohexylglyoxime, bis-o-(p-toluenesulfonyl)-2,3-pentanedione glyoxime, bis-(p-toluenesulfonyl)-2-methyl-3,4-pentanedione glyoxime, bis-o-(n-butanesulfonyl)-α-dimethylglyoxime, bis-o-(n-butanesulfonyl)-α-diphenylglyoxime, bis-o-(n-butanesulfonyl)-α-dicyclohexylglyoxime, bis-o-(n-butanesulfonyl)-2,3-pentanedione glyoxime, bis-o-(n-butanesulfonyl)-2-methyl-3,4-pentanedione glyoxime, bis- Examples include o-(methanesulfonyl)-α-dimethylglyoxime, bis-o-(trifluoromethanesulfonyl)-α-dimethylglyoxime, bis-o-(1,1,1-trifluoroethanesulfonyl)-α-dimethylglyoxime, bis-o-(tert-butanesulfonyl)-α-dimethylglyoxime, bis-o-(perfluorooctanesulfonyl)-α-dimethylglyoxime, bis-o-(cyclohexanesulfonyl)-α-dimethylglyoxime, bis-o-(benzenesulfonyl)-α-dimethylglyoxime, bis-o-(p-fluorobenzenesulfonyl)-α-dimethylglyoxime, bis-o-(p-tert-butylbenzenesulfonyl)-α-dimethylglyoxime, bis-o-(xylenesulfonyl)-α-dimethylglyoxime, and bis-o-(camphorsulfonyl)-α-dimethylglyoxime.

Specific examples of the β-ketosulfone derivatives include 2-cyclohexylcarbonyl-2-(p-toluenesulfonyl)propane, 2-isopropylcarbonyl-2-(p-toluenesulfonyl)propane, etc.

Specific examples of the disulfone derivatives include diphenyl disulfone, dicyclohexyl disulfone, etc.

Specific examples of the nitrobenzyl sulfonate derivative include 2,6-dinitrobenzyl p-toluenesulfonate and 2,4-dinitrobenzyl p-toluenesulfonate.

Specific examples of the sulfonic acid ester derivatives include 1,2,3-tris(methanesulfonyloxy)benzene, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, 1,2,3-tris(p-toluenesulfonyloxy)benzene, etc.

Specific examples of the imido-yl sulfonate derivatives include phthalimido-yl triflate, phthalimido-yl tosylate, 5-norbornene-2,3-dicarboximido-yl triflate, 5-norbornene-2,3-dicarboximido-yl tosylate, 5-norbornene-2,3-dicarboximido-yl n-butylsulfonate, and n-trifluoromethylsulfonyloxynaphthylimide.

Specific examples of the oxime sulfonate derivative include α-(benzenesulfonium oxyimino)-4-methylphenylacetonitrile.

Specific examples of the iminosulfonate derivative include (5-(4-methylphenyl)sulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile, (5-(4-(4-methylphenylsulfonyloxy)phenylsulfonyloxyimino)-5H-thiophen-2-ylidene)-(2-methylphenyl)-acetonitrile, etc.

2-Methyl-2-[(4-methylphenyl)sulfonyl]-1-[(4-methylthio)phenyl]-1-propane and the like can also be suitably used.

The content of component (B) is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 5 parts by weight, per 100 parts by weight of component (A). If the content of component (B) is within the above range, sufficient photocurability is easily obtained, and deterioration of curability in a thick film due to light absorption by the photoacid generator itself can be effectively prevented. In order to obtain the transparency and light resistance that are the characteristics of the present invention, it is preferable that the amount of the photoacid generator (B), which has light absorption properties, is small as long as it does not inhibit photocurability. The photoacid generator (B) may be used alone or in combination of two or more types.

[(C) Cationic Polymerizable Crosslinking Agent]
The photosensitive resin composition of the present invention may further contain a cationic polymerizable crosslinking agent as component (C), which is capable of undergoing a cationic polymerization reaction with the epoxy group of component (A) and is a component that facilitates the formation of a pattern and further increases the strength of the resin film after photocuring.

The crosslinking agent is preferably a compound with a molecular weight of 100 to 15,000, more preferably a compound with a molecular weight of 200 to 1,000. If the molecular weight is 100 or more, sufficient photocurability can be obtained, and if it is 15,000 or less, it is preferable because there is no risk of deteriorating the heat resistance of the composition after photocuring. The compound may be a resin (polymer), in which case the molecular weight is the weight average molecular weight (Mw).

As the cationic polymerizable crosslinking agent, a compound having a functional group selected from an epoxy group, an oxetane group, and a vinyl ether group is preferable. These compounds may be used alone or in combination of two or more.

The content of component (C) is 0 to 100 parts by mass relative to 100 parts by mass of component (A), but if it is contained, it is preferably 0.5 to 100 parts by mass, more preferably 0.5 to 60 parts by mass, and even more preferably 1 to 50 parts by mass. If the content of component (C) is 0.5 parts by mass or more, sufficient curing properties are obtained upon light irradiation, and if it is 100 parts by mass or less, the proportion of component (A) in the photosensitive resin composition does not decrease, so that the cured product can fully exhibit the effects of the present invention. Component (C) can be used alone or in combination of two or more types.

[(D) Solvent]
The photosensitive resin composition of the present invention may contain a solvent as component (D) in order to improve its coatability. The solvent (D) is not particularly limited as long as it can dissolve the above-mentioned components (A) to (C), the below-mentioned component (E), and other various additives.

(D) The solvent is preferably an organic solvent, and specific examples thereof include ketones such as cyclohexanone, cyclopentanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; and esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono-tert-butyl ether acetate, and γ-butyrolactone. These may be used alone or in combination of two or more.

(D) As the solvent, ethyl lactate, cyclohexanone, cyclopentanone, propylene glycol monomethyl ether acetate, gamma-butyrolactone, and mixed solvents thereof are preferred, as they have particularly excellent solubility for the photoacid generator.

From the viewpoint of compatibility and viscosity of the photosensitive resin composition, the content of component (D) is preferably 50 to 2,000 parts by mass, more preferably 50 to 1,000 parts by mass, and even more preferably 50 to 100 parts by mass, per 100 parts by mass of component (A).

[(E) Antioxidant]
The photosensitive resin composition of the present invention may contain an antioxidant as an additive. By containing an antioxidant, the heat resistance can be improved. Examples of the antioxidant include hindered phenol compounds and hindered amine compounds.

The hindered phenol compound is not particularly limited, but the following are preferred. For example, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (trade name: IRGANOX 1330), 2,6-di-tert-butyl-4-methylphenol (trade name: Sumilizer BHT), 2,5-di-tert-butyl-hydroquinone (trade name: Nocrac NS-7), 2,6-di-tert-butyl-4-ethylphenol (trade name: Nocrac M-17), 2,5-di-tert-pentylhydroquinone (trade name: Nocrac DAH), 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (trade name: Nocrac NS-6), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester (trade name: IRGANOX 1330), 2,6-di-tert-butyl-4-methylphenol (trade name: Sumilizer BHT), 2,5-di-tert-butyl- ... 1222), 4,4'-thiobis(3-methyl-6-tert-butylphenol) (trade name: Nocrac 300), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol) (trade name: Nocrac NS-5), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol) (trade name: Adekastab AO-40), 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (trade name: Sumilizer GM), 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate (trade name: Sumilizer GS), 2,2'-methylenebis[4-methyl-6-(α-methyl-cyclohexyl)phenol], 4,4'-methylenebis(2,6-di-tert-butylphenol) (trade name: Seenox 226M), 4,6-bis(octylthiomethyl)-o-cresol (trade name: IRGANOX 1520L), 2,2'-ethylenebis(4,6-di-tert-butylphenol), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (trade name: IRGANOX 1076), 1,1,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (trade name: Adeka STAB AO-30), tetrakis[methylene-(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane (trade name: Adeka STAB AO-60), triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate] (trade name: IRGANOX 245), 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine (trade name: IRGANOX 565), N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide) (trade name: IRGANOX 1098), 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (trade name: IRGANOX 259), 2,2-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (trade name: IRGANOX 1035), 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]1,1-dimethylethyl]2,4,8,10-tetraoxaspiro[5.5]undecane (trade name: Sumilizer GA-80), tris-(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate (trade name: IRGANOX 3114), bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl) calcium/polyethylene wax mixture (50:50) (trade name: IRGANOX 1425WL), isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (trade name: IRGANOX 1135), 4,4'-thiobis(6-tert-butyl-3-methylphenol) (trade name: Sumilizer WX-R), 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenz[d,f][1,3,2]dioxaphosphepine (trade name: Sumilizer GP), etc.

The hindered amine compounds are not particularly limited, but the following are preferred: For example, p,p'-dioctyldiphenylamine (trade name: IRGANOX 5057), phenyl-α-naphthylamine (trade name: Nocrac PA), poly(2,2,4-trimethyl-1,2-dihydroquinoline) (trade names: Nocrac 224, 224-S), 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (trade name: Nocrac AW), N,N'-diphenyl-p-phenylenediamine (trade name: Nocrac DP), N,N'-di-β-naphthyl-p-phenylenediamine (trade name: Nocrac White), N-phenyl-N'-isopropyl-p-phenylenediamine (trade name: Nocrac 810NA), N,N'-diallyl-p-phenylenediamine (trade name: Nonflex TP), 4,4'-(α,α-dimethylbenzyl)diphenylamine (trade name: Nocrac CD), p,p-toluenesulfonylaminodiphenylamine (trade name: Nocrac TD), N-phenyl-N'-(3-methacloryloxy-2-hydroxypropyl)-p-phenylenediamine (trade name: Nocrac G1), N-(1-methylheptyl)-N'-phenyl-p-phenylenediamine (trade name: Ozonon 35), N,N'-di-sec-butyl-p-phenylenediamine (trade name: Sumilizer BPA), N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (trade name: Antigene 6C), alkylated diphenylamine (trade name: Sumilizer 9A), dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate (trade name: Tinuvin 622LD), poly[[6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]] (trade name: CHIMASSORB 944), N,N'-bis(3-aminopropyl)ethylenediamine-2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine condensate (trade name: CHIMASSORB 119FL), bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate (trade name: TINUVIN 123), bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (trade name: TINUVIN 770), 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl) (trade name: TINUVIN 144), bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (trade name: TINUVIN 765), tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)1,2,3,4-butanetetracarboxylate (trade name: LA-57), tetrakis(2,2,6,6-tetramethyl-4-piperidyl)1,2,3,4-butanetetracarboxylate (trade name: LA-52), mixed ester of 1,2,3,4-butanetetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol and 1-tridecanol (trade name: LA-62), mixed ester of 1,2,3,4-butanetetracarboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and 1-tridecanol (trade name: LA-67), mixed ester of 1,2,3,4-butanetetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol Examples include a mixed ester of 1,2,3,4-butanetetracarboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (trade name: LA-63P), a mixed ester of 1,2,3,4-butanetetracarboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (trade name: LA-68LD), (2,2,6,6-tetramethylene-4-piperidyl)-2-propylene carboxylate (trade name: Adekastab LA-82), and (1,2,2,6,6-pentamethyl-4-piperidyl)-2-propylene carboxylate (trade name: Adekastab LA-87).

The content of component (E) is not particularly limited as long as it does not impair the effects of the present invention, but if it is contained, it is preferably 0.01 to 1 mass % in the photosensitive resin composition of the present invention. The antioxidant of component (E) may be used alone or in combination of two or more types.

[Other additives]
The photosensitive resin composition of the present invention may contain other additives in addition to the above-mentioned components. Examples of the additives include surfactants commonly used to improve coatability.

The surfactant is preferably a nonionic one, and examples thereof include fluorine-based surfactants, specifically perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl esters, perfluoroalkylamine oxides, fluorine-containing organosiloxane compounds, etc. Commercially available surfactants can be used, such as Fluorad (registered trademark) "FC-430" (manufactured by 3M), Surflon (registered trademark) "S-141" and "S-145" (manufactured by AGC Seimi Chemical Co., Ltd.), Unidyne (registered trademark) "DS-401", "DS-4031" and "DS-451" (manufactured by Daikin Industries, Ltd.), Megafac (registered trademark) "F-8151" (manufactured by DIC Corporation), and "X-70-093" (manufactured by Shin-Etsu Chemical Co., Ltd.). Among these, Fluorad "FC-430" and "X-70-093" are preferred. The content of the surfactant is not particularly limited as long as it does not impair the effects of the present invention, but if it is contained, it is preferably 0.01 to 1% by mass in the photosensitive resin composition of the present invention.

A silane coupling agent can also be used as an additive. By including a silane coupling agent, the adhesion of the photosensitive resin composition to the adherend can be further improved. Examples of the silane coupling agent include epoxy silane coupling agents and aromatic-containing amino silane coupling agents. These can be used alone or in combination of two or more. The content of the silane coupling agent is not particularly limited as long as it does not impair the effects of the present invention, but if it is included, it is preferably 0.01 to 5 mass % in the photosensitive resin composition of the present invention.

The method for preparing the photosensitive resin composition of the present invention is not particularly limited, but an example of the method is to stir and mix the above-mentioned components, and then filter the mixture with a filter or the like to remove solids as necessary.

[Pattern formation method]
The pattern forming method of the present invention uses the photosensitive resin composition,
(i) forming a photosensitive resin film on a substrate using the photosensitive resin composition;
(ii) a step of exposing the photosensitive resin film to light, and (iii) a step of developing the exposed photosensitive resin film with a developer. By this method, a fine pattern can be obtained.

Step (i) is a step of forming a photosensitive resin film on a substrate using the photosensitive resin composition. Examples of the substrate include a silicon wafer, a glass wafer, a quartz wafer, a plastic circuit board, a ceramic circuit board, and the like.

The photosensitive resin film can be formed by a known method. For example, the photosensitive resin composition can be applied to a substrate by a dip method, a spin coating method, a roll coating method, or the like. The amount of coating can be appropriately selected depending on the purpose, but an amount that results in a film thickness of 0.1 to 100 μm is preferable.

Here, in order to efficiently carry out the photocuring reaction, the solvent, etc. may be evaporated in advance by preheating as necessary. Preheating can be carried out, for example, at 40 to 160°C for about 1 minute to 1 hour.

Next, in step (ii), the photosensitive resin film is exposed to light. At this time, it is preferable to expose to light having a wavelength of 240 to 500 nm. Examples of the light having a wavelength of 240 to 500 nm include light of various wavelengths generated by a radiation generator, such as ultraviolet light such as g-line and i-line, and far ultraviolet light (248 nm). The exposure dose is preferably 10 to 5,000 mJ/ ^cm2 .

The exposure may be performed through a photomask. The photomask may be, for example, hollowed out to have a desired pattern. The material of the photomask is preferably one that blocks light with a wavelength of 240 to 500 nm, and chromium is preferably used, but is not limited to this.

Furthermore, to increase the development sensitivity, post-exposure heat treatment (PEB) may be performed. The PEB can be performed, for example, at 40 to 160°C for 5 to 30 minutes.

Step (iii) is a step of developing the photosensitive resin film using a developer after exposure or PEB. The developer is preferably an organic solvent-based developer used as a solvent, such as isopropyl alcohol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, etc. By developing using the organic solvent-based developer, a negative pattern is obtained in which the non-exposed areas are dissolved and removed. Development can be performed by a conventional method, such as immersing the substrate on which the pattern is formed in the developer. Thereafter, washing, rinsing, drying, etc. are performed as necessary to obtain a film having the desired pattern.

The method for forming a pattern is as described above. However, when it is not necessary to form a pattern, for example when it is desired to simply form a uniform film, in step (ii) of the pattern formation method, the film can be formed by exposing the film to light of an appropriate wavelength without using the photomask.

If necessary, (iv) the patterned film may be further heated in an oven or on a hot plate at 80 to 300°C for 10 minutes to 10 hours to increase the crosslink density and remove any remaining volatile components (post-curing).

[Optical semiconductor element]
By forming a fine pattern by the method using the photosensitive resin composition, an optical semiconductor element can be manufactured. In addition, the film obtained from the photosensitive resin composition has excellent transparency, light resistance and heat resistance, and the optical semiconductor element having the film is suitably used for optical devices such as light emitting elements such as light emitting diodes, photodiodes, optical sensors, light receiving elements such as CMOS image sensors, and optical transmission devices such as optical waveguides. The film preferably has a transmittance of 92% or more, more preferably 96% or more, and particularly preferably 98% or more, for light with a wavelength of 400 nm.

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following examples, Mw was measured by GPC using a TSKGEL Super HZM-H (manufactured by Tosoh Corporation) as a GPC column under analysis conditions of a flow rate of 0.6 mL/min, an elution solvent of THF, and a column temperature of 40°C, with monodisperse polystyrene as the standard.

[1] Synthesis of Polymer and Evaluation Thereof The compounds used in the synthesis of the polymer are shown below.

[Example 1-1] Synthesis of Polymer 1 53.0 g (0.20 mol) of the compound represented by formula (S-2), 48.1 g (0.40 mol) of the compound represented by formula (S-3a), and 85.7 g (0.40 mol) of the compound represented by formula (S-4a) were added to a 10 L flask equipped with a stirrer, a thermometer, a nitrogen replacement device, and a reflux condenser, and then 700 g of toluene was added and heated to 70 ° C. Then, 1.0 g of a chloroplatinic acid toluene solution (platinum concentration 0.5 mass%) was added, and 192 g (0.99 mol) of the compound represented by formula (S-1) was added dropwise over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99: 1 (molar ratio)). After the dropwise addition, the mixture was heated to 100 ° C. and aged for 8 hours, and then toluene was distilled off from the reaction solution under reduced pressure to obtain Polymer 1. The Mw of Polymer 1 was 16,000. Polymer 1 was confirmed by ¹ H-NMR (Bruker) to be a polymer containing repeating units represented by formula (A1), repeating units represented by formula (A2) and repeating units represented by formula (A3).

[Example 1-2] Synthesis of Polymer 2 In a 10L flask equipped with a stirrer, a thermometer, a nitrogen replacement device and a reflux condenser, 159g (0.60 mol) of the compound represented by formula (S-2), 24.0g (0.20 mol) of the compound represented by formula (S-3a) and 42.9g (0.20 mol) of the compound represented by formula (S-4a) were added, followed by adding 700g of toluene and heating to 70°C. Then, 1.0g of a chloroplatinic acid toluene solution (platinum concentration 0.5% by mass) was added, and 192g (0.99 mol) of the compound represented by formula (S-1) was added dropwise over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99: 1 (molar ratio)). After completion of the dropwise addition, the reaction solution was heated to 100°C and aged for 8 hours, and then toluene was distilled off under reduced pressure from the reaction solution to obtain Polymer 2. The Mw of Polymer 2 was 15,000. Polymer 2 was confirmed by ¹ H-NMR (Bruker) to be a polymer containing repeating units represented by formula (A1), repeating units represented by formula (A2) and repeating units represented by formula (A3).

[Example 1-3] Synthesis of Polymer 3 92.8g (0.35 mol) of the compound represented by formula (S-2), 56.8g (0.35 mol) of the compound represented by formula (S-3b), and 64.3g (0.30 mol) of the compound represented by formula (S-4a) were added to a 10L flask equipped with a stirrer, a thermometer, a nitrogen replacement device, and a reflux condenser, and then 700g of toluene was added and heated to 70°C. Then, 1.0g of a chloroplatinic acid toluene solution (platinum concentration 0.5 mass%) was added, and 192g (0.99 mol) of the compound represented by formula (S-1) was added dropwise over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99: 1 (molar ratio)). After the dropwise addition, the mixture was heated to 100°C and aged for 8 hours, and then toluene was distilled off from the reaction solution under reduced pressure to obtain Polymer 3. The Mw of Polymer 3 was 12,000. Polymer 3 was confirmed by ¹ H-NMR (Bruker) to be a polymer containing repeating units represented by formula (A1), repeating units represented by formula (A2) and repeating units represented by formula (A3).

[Example 1-4] Synthesis of Polymer 4 In a 10L flask equipped with a stirrer, a thermometer, a nitrogen replacement device and a reflux condenser, 106g (0.40 mol) of the compound represented by formula (S-2), 32.5g (0.20 mol) of the compound represented by formula (S-3b) and 85.7g (0.40 mol) of the compound represented by formula (S-4a) were added, followed by adding 700g of toluene and heating to 70°C. Then, 1.0g of a toluene solution of chloroplatinic acid (platinum concentration 0.5% by mass) was added, and 192g (0.99 mol) of the compound represented by formula (S-1) was added dropwise over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99:1 (molar ratio)). After completion of the dropwise addition, the mixture was heated to 100°C and aged for 8 hours, after which toluene was distilled off from the reaction solution under reduced pressure to obtain Polymer 4. The Mw of Polymer 4 was 13,000. Polymer 4 was confirmed by ¹ H-NMR (Bruker) to be a polymer containing repeating units represented by formula (A1), repeating units represented by formula (A2) and repeating units represented by formula (A3).

[Example 1-5] Synthesis of Polymer 5 In a 10L flask equipped with a stirrer, a thermometer, a nitrogen replacement device and a reflux condenser, 53.0g (0.20 mol) of the compound represented by formula (S-2), 24.0g (0.20 mol) of the compound represented by formula (S-3a) and 103g (0.60 mol) of the compound represented by formula (S-4b) were added, followed by adding 700g of toluene and heating to 70°C. Then, 1.0g of a chloroplatinic acid toluene solution (platinum concentration 0.5 mass%) was added, and 192g (0.99 mol) of the compound represented by formula (S-1) was added dropwise over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99: 1 (molar ratio)). After completion of the dropwise addition, the mixture was heated to 100°C and aged for 8 hours, after which toluene was distilled off from the reaction solution under reduced pressure to obtain Polymer 5. The Mw of Polymer 5 was 9,000. Polymer 5 was confirmed by ¹ H-NMR (Bruker) to be a polymer containing repeating units represented by formula (A1), repeating units represented by formula (A2) and repeating units represented by formula (A3).

[Example 1-6] Synthesis of Polymer 6 79.5g (0.30 mol) of the compound represented by formula (S-2), 32.5g (0.20 mol) of the compound represented by formula (S-3b), and 86.1g (0.50 mol) of the compound represented by formula (S-4b) were added to a 10L flask equipped with a stirrer, a thermometer, a nitrogen replacement device, and a reflux condenser, and then 700g of toluene was added and heated to 70°C. Then, 1.0g of a chloroplatinic acid toluene solution (platinum concentration 0.5 mass%) was added, and 192g (0.99 mol) of the compound represented by formula (S-1) was added dropwise over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99: 1 (molar ratio)). After the dropwise addition, the mixture was heated to 100°C and aged for 8 hours, and then toluene was distilled off from the reaction solution under reduced pressure to obtain Polymer 6. The Mw of Polymer 6 was 8,000. Polymer 6 was confirmed by ¹ H-NMR (Bruker) to be a polymer containing repeating units represented by formula (A1), repeating units represented by formula (A2) and repeating units represented by formula (A3).

[Example 1-7] Synthesis of Polymer 7 In a 10L flask equipped with a stirrer, a thermometer, a nitrogen replacement device, and a reflux condenser, 106 g (0.40 mol) of the compound represented by formula (S-2) and 129 g (0.60 mol) of the compound represented by formula (S-4a) were added, followed by adding 700 g of toluene and heating to 70°C. Then, 1.0 g of a toluene solution of chloroplatinic acid (platinum concentration 0.5 mass%) was added, and 192 g (0.99 mol) of the compound represented by formula (S-1) was added dropwise over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99: 1 (molar ratio)). After completion of the dropwise addition, the reaction solution was heated to 100°C and aged for 8 hours, and then toluene was distilled off under reduced pressure from the reaction solution to obtain Polymer 7. The Mw of Polymer 7 was 11,000. Polymer 7 was confirmed by ¹ H-NMR (manufactured by Bruker) to be a polymer containing a repeating unit represented by formula (A1) and a repeating unit represented by formula (A3).

[Comparative Example 1-1] Synthesis of Comparative Polymer 1 In a 10L flask equipped with a stirrer, a thermometer, a nitrogen replacement device and a reflux condenser, 53.0g (0.20 mol) of the compound represented by formula (S-2), 48.1g (0.40 mol) of the compound represented by formula (S-3a) and 56.5g (0.40 mol) of the compound represented by formula (S-5a) were added, and then 700g of toluene was added and heated to 70°C. Then, 1.0g of a chloroplatinic acid toluene solution (platinum concentration 0.5% by mass) was added, and 192g (0.99 mol) of the compound represented by formula (S-1) was added dropwise over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99: 1 (molar ratio)). After completion of the dropwise addition, the mixture was heated to 100°C and aged for 8 hours, and then toluene was distilled off from the reaction solution under reduced pressure to obtain Comparative Polymer 1. The Mw of Comparative Polymer 1 was 10,000.

[Comparative Example 1-2] Synthesis of Comparative Polymer 2 92.8 g (0.35 mol) of the compound represented by formula (S-2), 56.8 g (0.35 mol) of the compound represented by formula (S-3b), and 59.8 g (0.30 mol) of the compound represented by formula (S-5b) were added to a 10 L flask equipped with a stirrer, a thermometer, a nitrogen replacement device, and a reflux condenser, and then 700 g of toluene was added and heated to 70 ° C. Then, 1.0 g of a chloroplatinic acid toluene solution (platinum concentration 0.5 mass%) was added, and 192 g (0.99 mol) of the compound represented by formula (S-1) was dropped over 1 hour (total of hydrosilyl groups: total of alkenyl groups = 0.99: 1 (molar ratio)). After the dropwise addition was completed, the reaction solution was heated to 100 ° C. and aged for 8 hours, and then toluene was distilled off under reduced pressure from the reaction solution to obtain Comparative Polymer 2. The Mw of Comparative Polymer 2 was 12,000.

[Light transmittance test 1]
Polymers 1 to 7 and Comparative Polymers 1 and 2 were each dissolved in cyclopentanone to a concentration of 50% by mass to prepare a polymer solution. Each polymer solution was applied onto a glass substrate, and heated at 60°C for 30 minutes and then at 190°C for 2 hours in a nitrogen atmosphere to prepare a film (thickness 10 μm). The transmittance of light with a wavelength of 400 nm was measured for each of the obtained films. The results are shown in Table 1. The film thickness was measured using an optical interference film thickness measuring device manufactured by SCREEN, and was the film thickness of a film previously formed on a silicon wafer under the same conditions.

[Light transmittance test 2]
A sample consisting of the film on the glass wafer obtained by the above method was continuously irradiated with a 400 nm, 1 W laser in an oven at 50° C., and the rate of change in light transmittance after 100 hours and 1,000 hours was measured, with the initial value (before laser irradiation) being taken as 100%. The results are shown in Table 2.

[Curing temperature measurement test 1]
To 100 parts by mass of polymers 1 to 7 and comparative polymers 1 and 2, 3 parts by mass of CPI-210S (manufactured by San-Apro Co., Ltd.) was added as a photoacid generator, and cyclopentanone was added so that the solid concentration became 50% by mass, and the solution was dissolved until it was uniform. 2 g of each solution was placed in an aluminum petri dish, and the solution was dried by heating at a temperature of 100°C for 15 minutes. After exposing the remaining solid to 3,000 mJ of 365 nm light, differential scanning calorimetry was performed, and the curing temperature was evaluated based on the exothermic peak. The results are shown in Table 3. The differential scanning calorimetry was performed using a TA Instruments Q2000, and the curing temperature was measured by increasing the temperature from 0°C to 200°C at a rate of 10°C per minute.

[2] Preparation of photosensitive resin composition and its evaluation [Examples 2-1 to 2-11, Comparative Examples 2-1 to 2-8]
Photosensitive resin compositions were prepared by mixing polymers 1 to 7 as component (A), comparative polymers 1 and 2, photoacid generators B-1 and B-2 as component (B), crosslinking agents C-1, C-2 and C-3 as component (C), and cyclopentanone (CP) as a solvent for component (D) so as to obtain the compositions shown in Tables 4 and 5 below, stirring to dissolve the mixture, and then microfiltration was performed using a 0.2 μm Teflon (registered trademark) filter.

（式中、Ｒｆは、パーフルオロアルキル基である。ｂは０～６である。） In Tables 4 and 5, the photoacid generators B-1 and B-2, and the crosslinking agents C-1, C-2 and C-3 are as follows.
Photoacid generators B-1 and B-2:

(In the formula, Rf is a perfluoroalkyl group. b is 0 to 6.)

Crosslinking agents C-1, C-2, C-3:

[Pattern formation evaluation]
Each photosensitive resin composition was coated on an 8-inch silicon wafer primed with hexamethyldisilazane with a spin coater to a film thickness of 10 μm. In order to remove the solvent from the composition, the wafer was placed on a hot plate, heated at 110° C. for 3 minutes, and dried. In order to form a line and space pattern and a contact hole pattern on the obtained photosensitive resin film, the wafer was exposed to light through a mask using a contact aligner type exposure device under exposure conditions of 365 nm. After light irradiation, PEB was performed on a hot plate at 120° C. for 3 minutes and then cooled, and the wafer was spray-developed with propylene glycol monomethyl ether acetate (PGMEA) for 300 seconds to form a pattern.

The photosensitive resin film on the wafer on which the pattern was formed by the above method was post-cured in an oven at 190°C for 2 hours while purging with nitrogen. The cross sections of the 50 μm, 30 μm, 20 μm, 10 μm, and 5 μm contact hole patterns formed were then observed using a scanning electron microscope (SEM), and the smallest hole pattern in which the holes penetrated to the bottom of the film was determined to be the limiting resolution. Furthermore, the perpendicularity of the 50 μm contact hole pattern was evaluated from the cross-sectional photographs obtained, with a perpendicular pattern being rated as ◎, a slightly reverse tapered shape being ◯, a reverse tapered shape being △, and poor opening being ×. The results are shown in Tables 6 and 7.

[Light transmittance test 1]
Each photosensitive resin composition was coated on an 8-inch glass wafer with a film thickness of 20 μm using a spin coater. In order to remove the solvent from the composition, the glass wafer was placed on a hot plate and heated at 110° C. for 3 minutes to dry. The entire surface of the composition applied to the glass wafer was irradiated with light from a high-pressure mercury lamp (wavelength 360 nm) without a mask using a mask aligner MA8 from SUSS MicroTec, and then PEB was performed and immersed in PGMEA. The film remaining after this operation was further heated in an oven at 190° C. for 2 hours to obtain a film. The transmittance of light with a wavelength of 400 nm was measured for this film using a spectrophotometer U-3900H (manufactured by Hitachi High-Tech Science Co., Ltd.). The results are shown in Tables 8 and 9.

[Light transmittance test 2]
A sample of the coating on a glass wafer obtained by the above method was continuously irradiated with a 400 nm laser of 1 W in an oven at 50° C., and the rate of change in light transmittance after 100 hours and 1,000 hours was measured, with the initial value (before laser irradiation) being taken as 100%. The results are shown in Tables 10 and 11.

[Curing temperature measurement test]
2 g of each photosensitive resin composition was placed in an aluminum petri dish, heated at 100°C for 15 minutes, and dried. The remaining solid was exposed to 3,000 mJ of 365 nm light, and then differential scanning calorimetry was performed to evaluate the curing temperature based on the exothermic peak. The differential scanning calorimetry was performed using a TA Instruments Q2000, and the curing temperature was measured by increasing the temperature from 0°C to 200°C at a rate of 10°C per minute. The results are shown in 12 and 13.

From the above results, the polymer of the present invention, which contains a silphenylene skeleton, an isocyanuric acid skeleton, and a hydroxyl-substituted alkyl ether skeleton in the main chain and an epoxy group in the side chain, has excellent low-temperature curing properties. In addition, the film obtained from the polymer of the present invention is a film with high transparency and high light resistance. Furthermore, the photosensitive resin composition containing the polymer of the present invention can be finely processed, has excellent low-temperature curing properties, and gives a film with high transparency and high light resistance.

Claims (12)

A polymer containing a silphenylene skeleton, an isocyanuric acid skeleton, and a hydroxyl group-substituted alkyl ether skeleton in its main chain and containing an epoxy group in its side chain ,
A polymer comprising a repeating unit represented by the following formula (A1), a repeating unit represented by the following formula (A2), and a repeating unit represented by the following formula (A3) .

(In the formula, a, b, and c are positive numbers satisfying 0<a<1, 0≦b<1, 0<c<1, and a+b+c=1. ^X1 is a divalent group represented by the following formula (X1). ^X2 is a divalent group represented by the following formula (X2). ^X3 is a divalent group represented by the following formula (X3).)

(In the formula, R ¹¹ and R ¹² are each independently a hydrogen atom or a methyl group. R ¹³ is a hydrocarbylene group having 1 to 8 carbon atoms, and an ester bond or an ether bond may be present between the carbon-carbon bonds. n ¹ and n ² are each independently an integer of 0 to 7. The dashed lines represent bonds.)

(In the formula, R ²¹ and R ²² each independently represent a hydrogen atom or a saturated hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. m represents an integer of 0 to 10. The dashed line represents a bond.)

(In the formula, R ³¹ and R ³² are each independently a hydrogen atom or a methyl group. R ³³ is a hydrogen atom or a saturated hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, and when R ³³ is a saturated hydrocarbyl group, it may contain a primary or secondary alcoholic hydroxy group as a substituent. R ³⁴ is a saturated hydrocarbyl group having 1 to 20 carbon atoms which may contain a hydroxy group or a heteroatom, and when R ³⁴ is a saturated hydrocarbyl group, it may contain a primary or secondary alcoholic hydroxy group as a substituent. When R ³³ is a hydrogen atom and R ³⁴ is a saturated hydrocarbyl group, R ³⁴ contains at least one primary or secondary alcoholic hydroxy group as a substituent. When ^{R 33} and R ³⁴ are both saturated hydrocarbyl groups, one or both of them contain at least one primary or secondary alcoholic hydroxy group as a substituent. p ¹ and p ² are each independently an integer of 1 to 7. q ¹ and q Each of ² is independently an integer from 1 to 7. The dashed lines represent bonds. The polymer according to claim 1, wherein the divalent group represented by formula (X3) contains 9 to 20 carbon atoms . 3. The polymer according to claim 1, wherein a, b and c are positive numbers satisfying 0<a<1, 0<b<1, 0<c<1, and a+b+c=1. 4. The polymer according to claim 1, wherein R ³⁴ is a linear alkyl group having a terminal hydroxyl group. 5. The polymer according to claim 1 , wherein R ³¹ and R ³² are hydrogen atoms. The polymer according to any one of claims 1 to 5 , wherein p ¹ and p ² are 1. The polymer according to any one of claims 1 to 6 , wherein ^q1 and ^q2 are 1. 8. The polymer according to claim 1 , wherein a 10 μm-thick film made of the polymer has a transmittance of 95% or more for light having a wavelength of 400 nm. A photosensitive resin composition comprising the polymer according to any one of claims 1 to 8 and (B) a photoacid generator. The photosensitive resin composition according to claim 9 , further comprising (C) a cationic polymerizable crosslinking agent. (i) forming a photosensitive resin film on a substrate using the photosensitive resin composition according to claim 9 or 10 ;
(ii) a step of exposing the photosensitive resin film to light; and (iii) a step of developing the exposed photosensitive resin film with a developer. A method for producing an optical semiconductor element having a photosensitive resin film, comprising the pattern forming method according to claim 11 .