JP7730960B2 - Polymer, positive photosensitive resin composition, insulating film, and method for producing the same - Google Patents

Description

The present invention relates to a polymer containing a structure derived from an isocyanuric acid derivative in which a protecting group is bonded to the nitrogen atom of the isocyanuric acid skeleton, a positive-type photosensitive composition containing the polymer, an insulating film, and a method for producing the same.

Positive photosensitive compositions are used in the manufacture of display devices, semiconductor elements, integrated circuits, and more. Positive photosensitive compositions contain a base polymer and a photoacid generator. The base polymer of a positive photosensitive composition contains a structure that increases its alkaline solubility when exposed to acid, and the acid generated from the photoacid generator upon exposure increases its alkaline solubility. When alkaline development is performed after exposure, the exposed areas are selectively dissolved in the alkali, resulting in a patterned film.

Examples of structures whose alkaline solubility increases with the action of acid include structures in which acidic groups such as carboxyl groups and phenolic hydroxyl groups are protected with protecting groups. When the protecting groups are eliminated in the presence of acid, acidic groups are generated, thereby increasing the alkaline solubility of the base polymer.

Positive-type photosensitive materials used as permanent resists require higher durability because the cured film after patterning remains on the device as a functional film, and positive-type photosensitive compositions based on polyimide or silicone polymers have been proposed. Patent Document 1 discloses a positive-type photosensitive composition based on a polymer with a siloxane structure.

WO2014/007231

Polymers with phenolic hydroxyl groups protected by protecting groups, which have a structure that increases alkaline solubility under the action of acid, inevitably absorb light in the short wavelength region of visible light (near 400 nm wavelength) due to the conjugated structure of the phenol. Furthermore, polymers with phenolic structures tend to have a lower visible light transmittance after heating, leaving room for improvement in transparency.

In light of the above, the present invention aims to provide a polymer that is alkali-soluble in the presence of an acid and has excellent transparency, and a positive-type photosensitive composition containing the polymer.

One embodiment of the present invention is an isocyanuric acid derivative used in the preparation of a polymer, having a structure represented by the following general formula (I):

In general formula (I), ^R1 is a protecting group that generates an NH group upon elimination, ^R2 is a substituent having a polymerizable functional group, and ^R3 is a halogen or a monovalent group and may be the same as either ^R1 or ^R2 .

The protecting group ^R1 is eliminated in the presence of an acid to generate an NH group of the isocyanuric acid skeleton, and examples thereof include a tertiary alkyl group, an acyl group, a tertiary alkoxycarbonyl group, a C _1-6 alkoxyalkyl group, a tertiary alkoxycarbonylalkyl group, a tri(C _1-6 alkyl)silyl group, a cyclic ether group, etc. As the protecting group ^R1 , a tert-butoxycarbonyl group is particularly preferred.

Examples of the polymerizable functional group contained in ^R2 include an alkenyl group, a (meth)acryloyl group, an epoxy group, an oxetane group, a hydrosilyl group, a silanol group, an alkoxysilyl group, a carboxy group, an amino group, an isocyanate group, a mercapto group, and a halogen atom. ^R2 may be an allyl group.

Examples of the isocyanuric acid derivative in which ^R2 is an allyl group include a compound represented by the following general formula (Ia) or a compound represented by the following general formula (Ib).

One embodiment of the present invention is a polymer having a structure represented by the following general formula (X1) and/or a structure represented by the following general formula (X2): ^R1 is the same as the protecting group ^R1 in the above general formula (I), and is preferably a tert-butoxycarbonyl group.

The polymer may contain a polysiloxane skeleton. The polymer may also contain crosslinkable functional groups, such as epoxy groups or oxetane groups, that can form crosslinked structures upon heating. The weight-average molecular weight of the polymer is, for example, approximately 1,000 to 200,000.

One embodiment of the present invention is a positive-type photosensitive composition containing (A) the above-described polymer and (B) a photoacid generator. The photosensitive composition may further contain (C) a photosensitizer, (D) a crosslinking agent, (E) a thermosetting resin, etc. Examples of crosslinking agents include compounds containing two or more functional groups per molecule that can react with the crosslinkable functional groups of the above-described polymer.

An insulating film can be obtained by applying a solution containing the above polymer to a substrate and then drying and removing the solvent. Alternatively, a patterned insulating film can be formed by applying the above positive photosensitive composition to a substrate and then patterning it through exposure and alkaline development. After alkaline development, the insulating film can be cured by heating (post-baking).

By using the above polymer or positive photosensitive composition, an insulating film with excellent transparency can be formed.

One embodiment of the present invention is a compound having a functionally protected isocyanuric acid structure, which is an isocyanuric acid derivative represented by the following general formula (I):

In general formula (I), ^R1 is a protecting group that generates an NH group upon elimination, ^R2 is a substituent having a polymerizable functional group, and ^R3 is a halogen or any monovalent group, and may be the same as ^R1 or ^R2 .

The above compound can form a polymer containing a structure in which a protecting group ^R1 is bonded to a nitrogen atom of an isocyanuric acid skeleton ("Structure X" described below) by reacting with the polymerizable functional group ^R2 . This polymer becomes alkali-soluble when the protecting group ^R1 is eliminated to generate an NH group, which is an acidic group. This polymer can be used, for example, as a base polymer in a positive-type photosensitive composition.

Examples of the protecting group ^R1 that generates an NH group upon elimination include an alkyl group, an aralkyl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an aralkyloxycarbonyl group, an alkoxyalkyl group, a trialkylsilyl group, and a cyclic ether group.

In a positive-working photosensitive composition, a protecting group ^R1 is bonded to the nitrogen atom of the isocyanuric acid skeleton, protecting the acidic group, and the composition is therefore insoluble in alkali before exposure. Upon exposure, the protecting group ^R1 is eliminated by the action of an acid generated from a photoacid generator, increasing the solubility of the polymer in an aqueous alkaline solution. Therefore, it is preferable that the protecting group ^R1 is unlikely to be eliminated from the nitrogen atom in an alkaline environment, but can be eliminated in an acidic environment to generate an NH group.

Examples of the protective group R ¹ that can be removed under an acidic environment include tertiary alkyl groups such as a tert-butyl group and a tert-pentyl group; aralkyl groups such as a trityl group, a diphenylmethyl group and a 4,4'-dimethoxytrityl group; acyl groups such as a formyl group, an acetyl group, a propionyl group, a butyryl group and a benzoyl group; fluorinated acyl groups in which some or all of the hydrogen atoms of the above-mentioned acyl groups have been substituted with fluorine atoms; tertiary alkoxycarbonyl groups such as a tert-butoxycarbonyl group and a tert-pentyloxycarbonyl group; lower (C _1-6 ) alkyl groups such as a methoxymethyl group, a 1-ethoxy-1-ethyl group and a 1-methoxy-1-propyl group; tertiary alkoxycarbonylalkyl groups such as tert-butoxycarbonylmethyl group, tert-butoxycarbonylethyl group, tert-pentyloxycarbonylmethyl group, and tert-pentyloxycarbonylethyl group; tri(C _1-6 alkyl)silyl groups such as trimethylsilyl group, dimethylethylsilyl group, triethylsilyl group, and tert-butyldimethylsilyl group; and cyclic ether groups such as tetrahydropyranyl group and tetrahydrofuranyl group. Among these, tert-butyl group, tert-butoxycarbonyl group, acetyl group, trifluoroacetyl group, trityl group, methoxymethyl group, trimethylsilyl group, tert-butyldimethylsilyl group, tetrahydropyranyl group, and tetrahydrofuranyl group are preferred, with tert-butyl group and tert-butoxycarbonyl group being particularly preferred, because they have high storage stability, can be easily deprotected in the presence of acid, and have excellent photosensitivity.

The polymerizable functional group contained in ^R2 may be either one that is reactive with the same type of functional group (typically, a chain-polymerizable reactive group such as radical polymerization or ionic polymerization), or one that is reactive with different types of functional groups (typically, a step-growth polymerizable reactive group). The polymerization reaction caused by the polymerizable functional group may be addition polymerization, ring-opening polymerization, polycondensation, polyaddition, addition-condensation, or the like. Examples of the polymerizable functional group include alkenyl groups (vinyl groups, allyl groups, butenyl groups, hexenyl groups, etc.), (meth)acryloyl groups, epoxy groups, oxetane groups, hydrosilyl groups, silanol groups, alkoxysilyl groups, carboxy groups, amino groups, isocyanate groups, mercapto groups, halogens, and the like.

The polymerizable functional group of ^R2 may be bonded directly to the nitrogen atom of the isocyanuric acid skeleton, or may be bonded via a divalent organic group such as alkylene or oxyalkylene. Specific examples of ^R2 include a vinyl group, an allyl group, a carboxyethyl group, a hydroxyethyl group, a tri(methoxysilyl)propyl group, a glycidyl group, an acryloyloxyethyl group, and a halogen (a chlorine atom, a bromine atom, an iodine atom). For example, when ^R2 is a functional group having an ethylenically unsaturated group such as a vinyl group, an allyl group, an acryloyloxyethyl group, or a (meth)acryloyl group, a Si-C bond is formed by a hydrosilylation reaction between a compound having a hydrosilyl (SiH) group and the ethylenically unsaturated group, thereby obtaining a polymer.

^R3 is any group and may be the same as the protecting group ^R1 or the same as the reactive functional group ^R2 . ^R3 may also have a polymerizable functional group different from ^R2 . For example, ^R2 may be a substituent having an ethylenically unsaturated group such as an allyl group, and ^R3 may be a substituent having a polymerizable functional group such as a glycidyl group. Examples of ^R3 that are different from ^R1 and do not have a polymerizable functional group include primary alkyl groups such as methyl, ethyl, and propyl, secondary alkyl groups such as isopropyl and isobutyl, phenyl, and benzyl. The selection of ^R3 can adjust the ease of deprotection of the protecting group ^R1 , the acidity of the NH group generated by deprotection, and the alkaline solubility after deprotection.

Examples of the isocyanuric acid derivative include a compound in which ^R2 and ^R3 in general formula (I) are allyl groups (general formula (Ia) below); and a compound in which ^R2 in general formula (I) is an allyl group and ^R3 is the same protecting group as ^R1 (general formula (Ib) below).

The method for synthesizing the compound represented by general formula (I) is not particularly limited. For example, an isocyanuric acid derivative in which one or two hydrogen atoms of three NH groups of isocyanuric acid are substituted with a substituent ^R2 containing a polymerizable functional group is prepared, and the hydrogen atoms of the remaining one or two NH groups are substituted with a protecting group, thereby obtaining the isocyanuric acid derivative represented by general formula (I).

For example, the compound represented by the general formula (Ia) can be obtained by reacting diallyl isocyanurate with a protecting group introduction reagent. The compound represented by the general formula (Ib) can be obtained by reacting monoallyl isocyanurate with a protecting group introduction reagent. When a Boc reagent such as di-tert-butyl dicarbonate is used as the protecting group introduction reagent, an isocyanuric acid derivative having a tert-butoxycarbonyl group as the protecting group ^R1 can be obtained. When an acylating reagent such as acetyl halide is used as the protecting group introduction reagent, an isocyanuric acid derivative having an acyl group such as an acetyl group as the protecting group ^R1 can be obtained.

[polymer]
The above isocyanuric acid derivative can form a polymer having a structure in which a protecting group ^R1 is bonded to a nitrogen atom of an isocyanuric acid skeleton by reacting with the polymerizable functional group ^R2 . Examples of the structure in which a protecting group ^R1 is bonded to a nitrogen atom of an isocyanuric acid skeleton include the following X1 and X2.

Hereinafter, the structure represented by general formula X1 and the structure represented by general formula X2 will be referred to as "Structure X". When the protecting group ^R1 is eliminated from a polymer having Structure X, an NH group, which is an acidic group, is generated, and the polymer becomes alkali-soluble. That is, Structure X is a structure in which the NH group of the isocyanuric acid skeleton, which is an alkali-solubility-imparting group, is protected by the protecting group ^R1 . A polymer containing Structure X can be used as a photosensitive resin capable of forming a positive pattern because the protecting group is removed (deprotected) by reaction with an acid generated from a photoacid generator, increasing its alkali-solubility.

The polymer of this embodiment preferably includes, in addition to the above-described structure X, a polymer backbone structure other than structure X. Examples of polymer backbone structures include polyacrylic, polyphenol, polyamide, polyanhydride, polycarbonate, polydiene, polyester, polyhaloolefin, polyimide, polyimine, polyketone, polyolefin, polyether, polyphenylene, polyphosphazene, polysiloxane, polysilane, polystyrene, polysulfide, polysulfone, polyurethane, polyurea, and polyvinyl.

For example, polymers having a polysiloxane skeleton in addition to structure X are expected to have excellent heat resistance and a low dielectric constant. From the standpoint of achieving high heat resistance and a low dielectric constant, cyclic polysiloxane structures are particularly preferred.

In this specification, "polysiloxane structure" refers to a structural skeleton having siloxane units Si-O-Si, and "cyclic polysiloxane structure" refers to a cyclic molecular structural skeleton having siloxane units (Si-O-Si) as ring components. A positive photosensitive resin containing a polysiloxane structure is a polymer having Structure X (i.e., Structure X1 and/or Structure X2) with a "compound having siloxane units" as the main skeleton.

When a permanent resist is prepared using a positive-tone photosensitive composition, the polymer preferably has polymerizable functional groups. When the composition is heated (post-baked) after exposure and development, crosslinked structures are introduced through reactions between the polymerizable functional groups of the polymer and between the polymerizable functional groups of the polymer and the crosslinking agent (component (D) described below), resulting in a patterned cured film.

Polysiloxane-based polymers can be obtained, for example, by a hydrosilylation reaction. A hydrosilylation reaction is a reaction between a polysiloxane compound having at least two SiH groups (hydrosilyl groups) per molecule and a compound having a carbon-carbon double bond that is reactive with the SiH groups. When at least one of these compounds (starting materials) has Structure X in addition to the above functional groups, a polysiloxane-based polymer having Structure X is obtained.

For example, a polysiloxane polymer having the structure X can be obtained by a hydrosilylation reaction using the following compounds (α) and (β) as starting materials.
Compound (α): an isocyanuric acid derivative represented by the above general formula (I), in which ^R2 has a carbon-carbon double bond (ethylenically unsaturated group) as a polymerizable functional group;
Compound (β): A polysiloxane compound having at least two SiH groups in one molecule.

(Compound (α): Isocyanuric acid derivative)
Compound (α) is an isocyanuric acid derivative represented by the general formula (I) in which ^R2 has a carbon-carbon double bond (ethylenically unsaturated group) as a polymerizable functional group. Examples of the ethylenically unsaturated group reactive with SiH groups include vinyl, allyl, methallyl, acrylic, methacrylic, 2-hydroxy-3-(allyloxy)propyl, 2-allylphenyl, 3-allylphenyl, 4-allylphenyl, 2-(allyloxy)phenyl, 3-(allyloxy)phenyl, 4-(allyloxy)phenyl, 2-(allyloxy)ethyl, 2,2-bis(allyloxymethyl)butyl, 3-allyloxy-2,2-bis(allyloxymethyl)propyl, and vinyl ether groups.

Compound (α) may have multiple (two) ethylenically unsaturated groups per molecule, as in the compound represented by general formula (Ia) above, or may have one ethylenically unsaturated group per molecule, as in the compound represented by general formula (Ib) above. When an isocyanuric acid derivative having two ethylenically unsaturated groups per molecule is used as compound (α), a polymer having structure X1 is obtained. When an isocyanuric acid derivative having one ethylenically unsaturated group per molecule is used as compound (α), a polymer having structure X2 is obtained.

When compound (α) having multiple ethylenically unsaturated groups in one molecule is used, multiple polysiloxane compounds (compound (β)) are crosslinked by a hydrosilylation reaction, which increases the molecular weight of component (A) and tends to improve film-forming properties and the mechanical strength, heat resistance, and chemical resistance of the insulating film. Compound (α) may also be used in combination with an isocyanuric acid derivative having multiple ethylenically unsaturated groups in one molecule and an isocyanuric acid derivative having one ethylenically unsaturated group in one molecule.

(Compound (β): Polysiloxane compound)
Compound (β) is a polysiloxane compound having at least two SiH groups per molecule. For example, compounds described in WO96/15194 having at least two SiH groups per molecule can be used. Specific examples of compound (β) include hydrosilyl group-containing polysiloxanes having a linear structure, polysiloxanes having hydrosilyl groups at the molecular terminals, and cyclic polysiloxanes containing hydrosilyl groups. The cyclic polysiloxane may have a polycyclic structure, and the polycyclic ring may have a polyhedral structure. In order to form an insulating film with high heat resistance and mechanical strength, it is preferable to use a cyclic polysiloxane compound having at least two SiH groups per molecule as compound (β). Compound (β) preferably contains three or more SiH groups per molecule. From the viewpoint of heat resistance and light resistance, the group present on the Si atom is preferably either a hydrogen atom or a methyl group.

Examples of hydrosilyl group-containing polysiloxanes with a linear structure include copolymers of dimethylsiloxane units, methylhydrogensiloxane units, and terminal trimethylsiloxy units, copolymers of diphenylsiloxane units, methylhydrogensiloxane units, and terminal trimethylsiloxy units, copolymers of methylphenylsiloxane units, methylhydrogensiloxane units, and terminal trimethylsiloxy units, and polysiloxanes end-blocked with dimethylhydrogensilyl groups.

Examples of polysiloxanes having hydrosilyl groups at the molecular terminals include polysiloxanes whose terminals are blocked with dimethylhydrogensilyl groups, and polysiloxanes composed of dimethylhydrogensiloxane units (H( _CH3 ) _{2SiO1 /2} units) and at least one siloxane unit selected from the group consisting of _SiO2 units, SiO3 _/2 units, and SiO units.

Cyclic polysiloxanes are, for example, represented by the following general formula (II):

In the formula, R ⁴ , R ⁵ and R ⁶ each independently represent an organic group having 1 to 20 carbon atoms. m represents an integer of 2 to 10, and n represents an integer of 0 to 10. m is preferably 3 or more. m+n is preferably 3 to 12.

R ⁴ , R ⁵ , and R ⁶ are preferably organic groups composed of an element selected from the group consisting of C, H, and O. Examples of R ⁴ , R ⁵ , and R ⁶ include alkyl groups, hydroxyalkyl groups, alkoxyalkyl groups, oxyalkyl groups, and aryl groups. Among these, chain alkyl groups such as methyl, ethyl, propyl, hexyl, octyl, decyl, and dodecyl groups, cyclic alkyl groups such as cyclohexyl and norbornyl groups, and phenyl groups are preferred. From the viewpoint of availability of compound (β), R ⁴ , R ⁵ , and R ⁶ are preferably methyl, propyl, hexyl, or phenyl groups. ^{R 4} and R ⁵ are more preferably chain alkyl groups having 1 to 6 carbon atoms, and a methyl group is particularly preferred.

Examples of the cyclic polysiloxane compound represented by general formula (II) include 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane, 1-propyl-3,5,7-trihydrogen-1,3,5,7-tetramethylcyclotetrasiloxane, 1,5-dihydrogen-3,7-dihexyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5-trihydrogen-1,3,5-trimethylcyclosiloxane, 1,3,5,7,9-pentahydrogen-1,3,5,7,9-pentamethylcyclosiloxane, and 1,3,5,7,9,11-hexahydrogen-1,3,5,7,9,11-hexamethylcyclosiloxane. Among these, 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane (a compound in which m=4, n=0, and ^R4 is a methyl group in general formula (II)) is preferred from the viewpoints of availability and reactivity of the SiH group.

Compound (β) may be a polycyclic polysiloxane. The polycyclic ring may have a polyhedral structure. Polysiloxanes having a polyhedral skeleton preferably have 6 to 24 silicon atoms constituting the polyhedral skeleton, and more preferably 6 to 10 silicon atoms. Specific examples of polysiloxanes having a polyhedral skeleton include silsesquioxanes (number of silicon atoms = 8) represented by the following general formula (III):

In the above formula, R ¹⁰ to R ¹⁷ are each independently a monovalent group selected from the group consisting of a hydrogen atom, a chain alkyl group (such as a methyl group, an ethyl group, a propyl group, or a butyl group), a cycloalkyl group (such as a cyclohexyl group), an aryl group (such as a phenyl group or a tolyl group), groups in which some or all of the hydrogen atoms bonded to carbon atoms of these groups have been substituted with halogen atoms or cyano groups (such as a chloromethyl group, a trifluoropropyl group, or a cyanoethyl group), an alkenyl group (such as a vinyl group, an allyl group, a butenyl group, or a hexenyl group), a (meth)acryloyl group, an epoxy group, and an organic group containing a mercapto group or an amino group. The number of carbon atoms in the hydrocarbon group is preferably 1 to 20, and more preferably 1 to 10. The cyclic polysiloxane having a polyhedral skeleton has two or more hydrosilyl groups, which are reactive groups in a hydrosilylation reaction. Therefore, at least two of R ¹⁰ to R ¹⁷ are hydrogen atoms.

The cyclic polysiloxane may be a silylated silicate having a polyhedral skeleton. Specific examples of silylated silicates having a polyhedral skeleton include compounds represented by the following general formula (IV) (number of Si atoms = 8):

In the above formula, R ¹⁸ to R ⁴¹ are the same as the specific examples of R ¹⁰ to R ¹⁷ in the above general formula (III), and at least two of R ¹⁸ to R ⁴¹ are hydrogen atoms.

Polysiloxanes can be obtained by known synthesis methods. For example, cyclic polysiloxanes represented by general formula (II) can be synthesized by methods such as those described in WO96/15194. Polysiloxanes with polyhedral skeletons, such as silsesquioxanes, and silylated silicas with polyhedral skeletons can be synthesized by methods such as those described in JP-A-2004-359933, JP-A-2004-143449, and JP-A-2006-269402. Commercially available polysiloxane compounds may also be used as compound (β).

(Other Starting Materials)
In preparing the polymer by the hydrosilylation reaction, other starting materials may be used in addition to the above-mentioned compound (α) and compound (β). For example, an ethylenically unsaturated group-containing compound other than the above-mentioned compound (α) may be used as the starting material.

For example, in addition to compound (α) and compound (β), a compound having two or more ethylenically unsaturated groups per molecule (hereinafter referred to as "compound (γ)") may be used as a starting material. When compound (γ) is used, the polysiloxane compound (compound (β)) is crosslinked by a hydrosilylation reaction, which increases the molecular weight of the polymer and tends to improve film-forming properties and the heat resistance of the insulating film.

The compound (γ) may be either an organic polymer compound or an organic monomer compound. Examples of organic polymer compounds include polyether, polyester, polyarylate, polycarbonate, saturated hydrocarbon, unsaturated hydrocarbon, polyacrylic ester, polyamide, phenol-formaldehyde (phenolic resin), and polyimide compounds. Examples of organic monomer compounds include phenol, bisphenol, aromatic hydrocarbons such as benzene or naphthalene; aliphatic hydrocarbons such as linear and alicyclic compounds; and heterocyclic compounds.

Specific examples of compound (γ) include diallyl phthalate, triallyl trimellitate, diethylene glycol bisallyl carbonate, trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, pentaerythritol triallyl ether, pentaerythritol tetraallyl ether, 1,1,2,2-tetraallyloxyethane, diarylidene pentaerythritol, triallyl cyanurate, triallyl isocyanurate, diallyl monobenzyl isocyanurate, diallyl monomethyl isocyanurate, 1,2,4-trivinylcyclohexane, 1,4-butanediol divinyl ether, nonanediol divinyl ether, 1,4-cyclohexane dimethanol divinyl ether, triethylene glycol divinyl ether, trimethylolpropane trivinyl ether, pentaerythritol tetravinyl ether, bisphenol A Diallyl ether of bisphenol S, divinylbenzene, divinylbiphenyl, 1,3-diisopropenylbenzene, 1,4-diisopropenylbenzene, 1,3-bis(allyloxy)adamantane, 1,3-bis(vinyloxy)adamantane, 1,3,5-tris(allyloxy)adamantane, 1,3,5-tris(vinyloxy)adamantane, dicyclopentadiene, vinylcyclohexene, 1,5-hexadiene, 1,9-decadiene, diallyl ether, bisphenol A diallyl ether, 2,5-diallylphenol allyl ether, and oligomers thereof, 1,2-polybutadiene (1,2 ratio of 10 to 100%, preferably 1,2 ratio of 50 to 100%), allyl ether of novolak phenol, allylated polyphenylene oxide, and other conventionally known epoxy resins in which all of the glycidyl groups have been replaced with allyl groups. Additionally, compounds in which the allyl groups in the above-exemplified compounds are replaced with (meth)acryloyl groups (e.g., polyfunctional (meth)acrylates) can also be suitably used as compound (γ).

Compound (γ) may be a polysiloxane compound having two or more ethylenically unsaturated groups. Specific examples of polysiloxane compounds having two or more ethylenically unsaturated groups include compounds in which some or all of the hydrogen atoms bonded to Si in compound (β) have been replaced with ethylenically unsaturated groups. Of these, cyclic polysiloxane compounds having two or more ethylenically unsaturated groups are preferred from the perspective of improving the heat resistance of the insulating film.

A specific example of a cyclic polysiloxane compound having two or more ethylenically unsaturated groups is a cyclic polysiloxane in which a vinyl group is bonded to a Si atom as an ethylenically unsaturated group. Examples of cyclic polysiloxane compounds having two or more vinyl groups bonded to Si atoms include 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1-propyl-3,5,7-trivinyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1,5-divinyl-3,7-dihexyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5-trivinyl-trimethylcyclosiloxane, 1,3,5,7,9-pentavinyl-1,3,5,7,9-pentamethylcyclosiloxane, and 1,3,5,7,9,11-hexavinyl-1,3,5,7,9,11-hexamethylcyclosiloxane.

A compound containing only one functional group that participates in the hydrosilylation reaction per molecule (hereinafter referred to as "compound (δ)") may be used as the starting material for the hydrosilylation reaction. The functional group that participates in the hydrosilylation reaction is an SiH group or an ethylenically unsaturated group. By using a compound containing only one functional group that participates in the hydrosilylation reaction, a specific functional group can be introduced at the end of a polymer.

For example, by using a siloxane compound having one SiH group as compound (δ), a siloxane structural moiety can be introduced into the terminal of the polymer. Specific examples of siloxane compounds having one SiH group include cyclic polysiloxane compounds in which m = 1 in the above-mentioned general formula (II), polyhedral polysiloxane compounds in which one of R ¹⁰ to R ¹⁷ in the above-mentioned general formula (III) is a hydrogen atom, and silylated silicate compounds in which one of R ¹⁸ to R ⁴¹ in the above-mentioned general formula (IV) is a hydrogen atom. The siloxane compound having one SiH group may be a chain siloxane compound.

By using a compound containing one ethylenically unsaturated group as compound (δ), the desired functional group can be introduced at the end of the polymer. In addition to the above, compounds that participate in hydrosilylation reactions, such as linear polysiloxanes containing two or more SiH groups, may also be included in the starting materials.

The above compounds (α), (β), (γ), and (δ) may also be compounds that contain, in one molecule, a polymerizable reactive group (crosslinking reactive group) that does not participate in the hydrosilylation reaction, in addition to an ethylenically unsaturated group or SiH group, which is a polymerizable reactive group that participates in the hydrosilylation reaction. Examples of polymerizable reactive groups that do not participate in the hydrosilylation reaction include epoxy groups, oxetane groups, silanol groups, alkoxysilyl groups, carboxy groups, amino groups, isocyanate groups, and mercapto groups. The crosslinking reactive group is preferably one that can form a crosslinked structure by heating (post-baking) after exposing and developing the coating film of the photosensitive composition, and epoxy groups, oxetane groups, etc. are preferred.

Examples of compounds that have an alkenyl group and an epoxy group as a crosslinking reactive group in one molecule include allyl glycidyl ether and vinylcyclohexyl epoxide. Examples of compounds that have an alkenyl group and an oxetane group as a crosslinking reactive group in one molecule include 3-[(allyloxy)methyl]-3-methyloxetane and 3-[(allyloxy)methyl]-3-ethyloxetane.

(Hydrosilylation Reaction)
The order and method of the hydrosilylation reaction are not particularly limited. From the viewpoint of simplifying the synthesis process, a method in which all starting materials are charged into one pot, the hydrosilylation reaction is carried out, and unreacted compounds are finally removed is preferred. The hydrosilylation reaction may be carried out in two or more stages. For example, from the viewpoint of suppressing the formation of low molecular weight compounds, a method in which a compound containing multiple ethylenically unsaturated groups (e.g., an isocyanuric acid derivative represented by general formula (Ia) and compound (γ)) and a compound containing multiple SiH groups (e.g., compound (β)) are hydrosilylated using an excess amount of one of them, and after removing the unreacted compounds as necessary, a compound having only one functional group participating in the hydrosilylation reaction per molecule (e.g., an isocyanuric acid derivative represented by general formula (Ib) and compound (δ)) is added to carry out the hydrosilylation reaction is preferred.

While there are no particular restrictions on the proportions of each compound in the hydrosilylation reaction, it is preferable that the total amount of ethylenically unsaturated groups, A, and the total amount of SiH groups, B, in the starting materials satisfy the relationship 1≦B/A≦30, and more preferably 1≦B/A≦10. When B/A is 1 or greater, unreacted ethylenically unsaturated groups are less likely to remain, and when B/A is 30 or less, unreacted compound (β) is less likely to remain, thereby improving the properties of the insulating film.

The hydrosilylation reaction may be carried out using a hydrosilylation catalyst such as chloroplatinic acid, a platinum-olefin complex, or a platinum-vinylsiloxane complex. The hydrosilylation catalyst may be used in combination with a co-catalyst. The amount of the hydrosilylation catalyst added is not particularly limited, but is preferably 10 ⁻⁸ to 10 ⁻¹ times, and more preferably 10 ⁻⁶ to 10 ⁻² times, the total number (number of moles) of ethylenically unsaturated groups contained in the starting material.

The hydrosilylation reaction temperature may be set appropriately, preferably between 30 and 200°C, and more preferably between 50 and 150°C. An appropriate solvent may be used in the hydrosilylation reaction. A gelation inhibitor may also be used in the hydrosilylation reaction, if necessary.

The weight-average molecular weight of the polymer, calculated in terms of polystyrene, is, for example, approximately 1,000 to 200,000, and preferably 2,000 to 150,000. Having a polymer molecular weight within this range allows for the formation of an insulating film (cured film) that has excellent solubility in organic solvents and in the developer used during patterning, as well as excellent mechanical strength, film-forming properties, heat resistance, chemical resistance, etc.

In the above, a hydrosilylation reaction between a compound (α) having Structure X and an ethylenically unsaturated group in one molecule and a polysiloxane compound (β) having at least two SiH groups in one molecule was described as an example of a method for obtaining a polysiloxane polymer having Structure X. However, the method for synthesizing a polymer having Structure X is not limited to this. A polymer having Structure X can also be obtained by a hydrosilylation reaction using a starting material other than those described above.

For example, a polysiloxane polymer having Structure X may be prepared using an isocyanuric acid derivative having an SiH group as the reactive group of the substituent ^R2 as a starting material, instead of Compound (α). In this case, a polysiloxane polymer having Structure X is obtained by a hydrosilylation reaction between the isocyanuric acid derivative having an SiH group and a polysiloxane compound having an ethylenically unsaturated group. The polysiloxane compound having an ethylenically unsaturated group may contain multiple ethylenically unsaturated groups.

Examples of cyclic siloxane compounds containing ethylenically unsaturated groups include 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1-propyl-3,5,7-trivinyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1,5-divinyl-3,7-dihexyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5-trivinyl-1,3,5-trimethylcyclosiloxane, 1,3,5,7,9-pentavinyl-1,3,5,7,9-pentamethylcyclosiloxane, and 1,3,5,7,9,11-hexavinyl-1,3,5,7,9,11-hexamethylcyclosiloxane. In terms of heat resistance and light resistance, it is preferable that the organic group present on the Si atom in a cyclic polysiloxane compound having an ethylenically unsaturated group be a vinyl group or a methyl group.

The polymer having Structure X is not limited to a polysiloxane-based polymer. Furthermore, the polymer having Structure X may have a structure in which an acidic group (alkali-solubility-imparting group) other than the NH group of Structure X (isocyanuric acid skeleton) is protected with a protecting group. Examples of the acidic group other than the NH group of the isocyanuric acid skeleton include acidic groups such as carboxylic acid and phenolic hydroxyl groups. By including a structure in which the acidic group of a carboxylic acid or phenolic hydroxyl group is protected in addition to Structure X, an increase in exposure sensitivity can be expected.

Protecting groups for phenolic hydroxyl groups include tert-butoxycarbonyl and trialkylsilyl groups. For example, phenolic hydroxyl groups can be protected with tert-butoxycarbonyl groups by reaction with a Boc reagent. Protecting groups for carboxylic acids include tertiary alkyl esters and acetals. Examples of tertiary alkyl groups in tertiary alkyl esters of carboxylic acids include tert-butyl, adamantyl, tricyclodecyl, and norbornyl groups. Acidic groups bearing these protecting groups can be introduced into polymers using various known methods.

In the polymer having Structure X, the amount of NH groups generated upon elimination of the protecting group ^R1 in Structure X in the presence of an acid is preferably 0.1 mmol/g or more. In the presence of an acid, the protecting group ^R1 in Structure X1 is eliminated to generate one NH group, and the protecting group ^R1 in Structure X2 is eliminated to generate two NH groups. Therefore, the amount of NH groups generated upon elimination of the protecting group ^R1 in the presence of an acid is equal to the sum of twice the amount of Structure X2 and the amount of Structure X1.

The greater the amount of NH groups generated by elimination of the protecting group ^R1 in the presence of an acid, the higher the alkali solubility of the polymer tends to be. Furthermore, when a polymer containing Structure X is used as the base polymer of a positive-type photosensitive composition, the greater the amount of NH groups generated by elimination of the protecting group ^R1 in the presence of an acid, the higher the exposure sensitivity tends to be. The amount of NH groups generated by elimination of the protecting group ^R1 in the presence of an acid is more preferably 0.3 mmol/g or more, even more preferably 0.5 mmol/g or more, and may be 0.8 mmol/g or more, 1 mmol/g or more, 1.2 mmol/g or more, or 1.4 mmol/g or more.

Although there is no particular upper limit to the amount of NH groups generated by elimination of the protecting group R ¹ in the presence of an acid, an excessively large content of the structure X may make it difficult to adjust the exposure dose or may cause a decrease in the heat resistance, transparency, etc. of the polymer. Therefore, the amount of NH groups generated by elimination of the protecting group R ¹ in the presence of an acid in the polymer is preferably 15 mmol/g or less, more preferably 10 mmol/g or less, still more preferably 5 mmol/g or less, and may be 3 mmol/g or less, 2 mmol/g or less, or 1.8 mmol/g or less.

[Photosensitive composition]
The polymer having the above-mentioned Structure X can be used as a positive-type photosensitive resin because the protecting group ^R1 is eliminated by the action of an acid to generate an NH group, which is an acidic group, and the alkali solubility is increased. One embodiment of the present invention is a positive-type photosensitive composition containing (A) the above-mentioned polymer having Structure X and (B) a photoacid generator. In addition to components (A) and (B), the photosensitive composition may also contain a photosensitizer as component (C) and a crosslinker as component (D).

<(B) Photoacid Generator>
The photosensitive composition contains a photoacid generator as component (B). When the photoacid generator is exposed to active energy rays, an acid is generated. Examples of active energy rays include visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays. The action of the acid generated from the photoacid generator causes the protecting group ^R1 of component (A) to be eliminated, thereby increasing alkali solubility.

The photoacid generator contained in the photosensitive composition is not particularly limited as long as it generates a Lewis acid upon exposure. Specific examples of photoacid generators include ionic photoacid generators such as sulfonium salts, iodonium salts, ammonium salts, _and other onium salts; and nonionic photoacid generators such as imidosulfonates, oxime sulfonates, _and sulfonyldiazomethanes. Examples of anions contained in ^ionic photoacid generators include _{B ( C6F5 ) 4-} ^{, PF6-} , _{SbF6- , CH3SO3-} ^{, C2H5SO3-} _{, C3H7SO3- , camphorsulfonic} acid anion _{, CH3C6H5SO3-} ^, _CF3SO3- ^, _C4F9SO3- ^, _{amic acid} anion, ^and methide _acid anion _. As the photoacid generator, sulfonium salts, iodonium salts, imide sulfonates and oxime sulfonates are preferred due to their high photosensitivity, with imide sulfonates and oxime sulfonates being particularly preferred.

The content of the photoacid generator in the photosensitive composition is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 7 parts by weight, and even more preferably 0.5 to 5 parts by weight, per 100 parts by weight of component (A). When the amount of photoacid generator is within the above range, the alkali solubility of component (A) in the exposed area is sufficiently increased, improving patterning properties, and suppressing a decrease in contrast caused by excess acid.

<(C) Sensitizer>
The photosensitive composition may contain a sensitizer. The use of a sensitizer improves the exposure sensitivity during patterning. Examples of sensitizers for positive photosensitive compositions include naphthalene-based compounds, anthracene-based compounds, and thioxanthone-based compounds. Among these, anthracene-based sensitizers are preferred because of their excellent photosensitizing effect. Specific examples of the anthracene-based sensitizer include anthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-dimethylanthracene, 9,10-dibutoxyanthracene (DBA), 9,10-dipropoxyanthracene, 9,10-diethoxyanthracene, 9,10-bis(octanoyloxy)anthracene, 1,4-dimethoxyanthracene, 9-methylanthracene, 2-ethylanthracene, 2-tert-butylanthracene, 2,6-di-tert-butylanthracene, and 9,10-diphenyl-2,6-di-tert-butylanthracene. Among these, 9,10-dibutoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diethoxyanthracene, 9,10-bis(octanoyloxy)anthracene, and the like are preferred from the viewpoint of compatibility with the photosensitive composition.

The amount of sensitizer in the photosensitive composition is not particularly limited and may be adjusted as appropriate within a range that achieves the sensitizing effect. In order to balance the sensitizing effect and the properties of the insulating film, the amount of sensitizer is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 40 parts by weight, even more preferably 0.5 to 35 parts by weight, and particularly preferably 1 to 30 parts by weight, per 100 parts by weight of component (A). Furthermore, to achieve the sensitizing effect, the molar ratio (C/B) of the sensitizer (C) to the photoacid generator (B) is preferably 0.01 to 300, more preferably 0.1 to 100.

<(D) Crosslinking Agent>
The photosensitive composition may contain, as a crosslinking agent, a compound having a functional group capable of reacting (bonding) with the crosslinkable functional group of the component (A) to introduce a crosslinked structure. The crosslinking agent is preferably a compound having two or more functional groups per molecule capable of reacting with the crosslinkable reactive group of the component (A).

For example, if component (A) has a polysiloxane skeleton and contains SiH groups that were not used in the hydrosilylation reaction, a crosslinked structure can be introduced by the hydrosilylation reaction between component (A) and the crosslinking agent by adding a compound having two or more ethylenically unsaturated groups per molecule to the photosensitive composition. Examples of compounds having two or more ethylenically unsaturated groups per molecule that can be used include compounds similar to compound (γ) exemplified in the synthesis of component (A) above.

When the photosensitive composition contains a crosslinking agent, the content of the crosslinking agent is preferably 0.1 to 40 parts by weight, more preferably 0.5 to 35 parts by weight, and even more preferably 1 to 30 parts by weight, per 100 parts by weight of component (A). When the photosensitive composition contains a crosslinking agent, after patterning by exposure and development, it is preferable to introduce a crosslinked structure by reacting component (A) with the crosslinking agent through heating (post-baking). The introduction of a crosslinked structure hardens the patterned film, thereby improving the insulating properties, heat resistance, solvent resistance, etc. of the patterned film.

<(E) Thermosetting resin>
The photosensitive composition may contain a polymerizable compound (thermosetting resin) that is not reactive with the above-mentioned component (A) and can be thermoset independently. Examples of the thermosetting resin include epoxy resins, oxetane resins, isocyanate resins, blocked isocyanate resins, bismaleimide resins, bisallylnadimide resins, acrylic resins, allyl-cured resins, and unsaturated polyester resins. The thermosetting resin may be a side-chain reactive group-type thermosetting polymer having a reactive group such as an allyl group, a vinyl group, an alkoxysilyl group, or a hydrosilyl group at the side chain or end of the polymer chain.

The content of the thermosetting resin is preferably 0.1 to 40 parts by weight, more preferably 0.5 to 35 parts by weight, and even more preferably 1 to 30 parts by weight, per 100 parts by weight of component (A). When the photosensitive composition contains a thermosetting resin that is not reactive with component (A), post-baking forms a polymer network of the thermosetting resin surrounding component (A), hardening the pattern film and improving the insulating properties, heat resistance, solvent resistance, etc. of the pattern film.

The photosensitive resin composition may contain both the above-mentioned components (D) and (E). Component (E) may be reactive with component (D).

<Solvent>
The photosensitive composition can be obtained by dissolving or dispersing the above-mentioned components (A) and (B), and optionally the components (C), (D), and (E) in a solvent. The photosensitive composition may be prepared by mixing the components immediately before film formation, or may be stored in the form of a single liquid in which all components have been mixed in advance.

Any solvent capable of dissolving component (A) may be used. Specific examples include hydrocarbon solvents such as benzene, toluene, hexane, and heptane; ether solvents such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, and diethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; glycol solvents such as propylene glycol-1-monomethyl ether-2-acetate (PGMEA), propylene glycol diacetate (PGDA), diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, and diethylene glycol diethyl ether; ester solvents such as ethyl acetate, butyl acetate, isobutyl isobutyrate, and isobutyl butyrate; and halogenated solvents such as chloroform, methylene chloride, and 1,2-dichloroethane. From the perspective of film formation stability, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol diacetate, and diethylene glycol diethyl ether are preferred. The amount of solvent used can be determined appropriately. The preferred amount of solvent used per 1 g of solids in the photosensitive composition is 0.1 to 10 mL.

<Other ingredients>
The photosensitive composition may contain resin components and additives other than the above (A) to (E). For example, the photosensitive composition may contain various thermoplastic resins for the purpose of modifying properties, etc. Examples of thermoplastic resins include acrylic resins, polycarbonate resins, cycloolefin resins, olefin-maleimide resins, polyester resins, polyethersulfone resins, polyarylate resins, polyvinyl acetal resins, polyethylene resins, polypropylene resins, polystyrene resins, polyamide resins, silicone resins, fluororesins, and rubber-like resins such as natural rubber and EPDM. The thermoplastic resin may have a crosslinkable group such as an epoxy group, an amino group, a radically polymerizable unsaturated group, a carboxy group, an isocyanate group, a hydroxy group, or an alkoxysilyl group.

The photosensitive composition may contain an alkali-soluble component other than component (A) to improve solubility in an alkaline developer. Examples of alkali-soluble components include resins having alkali-soluble functional groups. Examples of resins include phenolic resins, acrylic resins, amide resins, and polysiloxane resins.

In addition to the above, the photosensitive composition may contain adhesion improvers, coupling agents such as silane coupling agents, antidegradants, hydrosilylation reaction inhibitors, polymerization inhibitors, polymerization catalysts (crosslinking accelerators), release agents, flame retardants, flame retardant aids, surfactants, defoamers, emulsifiers, leveling agents, anti-repellent agents, ion trapping agents, thixotropy-imparting agents, tackifiers, storage stability improvers, light stabilizers, thickeners, plasticizers, reactive diluents, antioxidants, thermal stabilizers, conductivity-imparting agents, antistatic agents, radiation shielding agents, nucleating agents, phosphorus-based peroxide decomposers, lubricants, metal deactivators, thermal conductivity-imparting agents, and physical property adjusters, as long as the purpose and effects of the present invention are not impaired.

The photosensitive composition may contain fillers and colorants. Fillers include silica-based fillers (quartz, fume silica, precipitated silica, silicic anhydride, fused silica, crystalline silica, and ultrafine amorphous silica), silicon nitride, silver powder, alumina, aluminum hydroxide, titanium oxide, glass fiber, carbon fiber, mica, carbon black, graphite, diatomaceous earth, clay, talc, calcium carbonate, magnesium carbonate, barium sulfate, and inorganic balloons. Colorants include organic pigments, inorganic pigments, and dyes.

The total amount of components (A), (B), (C), (D), and (E) is preferably 50% by weight or more, more preferably 60% by weight or more, and even more preferably 70% by weight or more of the total solids content of the photosensitive composition.

[Formation of insulating film]
An insulating film can be formed by coating a substrate with a solution containing a polymer having Structure X to form a coating film. Alternatively, a patterned film can be formed by coating a substrate with the above-described positive photosensitive composition to form a coating film, exposing the coating through a mask of a predetermined shape, and dissolving and removing the exposed portion by alkaline development. A patterned cured film can be obtained by post-baking after development.

<Formation of coating film>
The method for applying the photosensitive composition to the substrate is not particularly limited as long as it allows for uniform application, and common coating methods such as spin coating, slit coating, and screen coating can be used. The thickness of the coating film is not particularly limited. When the pattern film is a permanent resist, from the viewpoint of reliability, the thickness is preferably 0.05 to 100 μm, more preferably 0.1 to 80 μm, and even more preferably 0.2 to 50 μm.

<Pre-bake>
Before exposure, heating (pre-baking) may be performed to dry the solvent. The heating temperature can be set appropriately, but is preferably 50 to 200°C, more preferably 60 to 150°C. Furthermore, vacuum devolatilization may be performed before exposure. Vacuum devolatilization may be performed simultaneously with heating. Photosensitive compositions containing thermosetting components (for example, the above-mentioned component (D) and/or component (E)) may have reduced developability as curing proceeds due to heating. Therefore, the heating temperature in pre-baking is preferably 120°C or less.

<Exposure>
The light source for exposure may be selected depending on the wavelength sensitivity of the photoacid generator and sensitizer contained in the photosensitive composition, and typically, a light source having a wavelength in the range of 200 to 450 nm (e.g., a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a high-power metal halide lamp, a xenon lamp, a carbon arc lamp, or a light-emitting diode) is used.

The exposure dose is not particularly limited, but is preferably 1 to 5000 mJ/cm ² , more preferably 5 to 1000 mJ/cm ² , and even more preferably 10 to 500 mJ/cm ^2. If the exposure dose is too low, curing may be insufficient, resulting in a decrease in pattern contrast, whereas if the exposure dose is too high, the takt time may increase, resulting in an increase in production costs.

<Post-exposure bake>
After exposure and before development, post-exposure baking (PEB) may be performed for the purpose of promoting the reaction between the acid and component (A), etc. The heating temperature in post-exposure baking is preferably 40 to 120°C, more preferably 50 to 110°C, and even more preferably 60 to 100°C.

<Developing>
The exposed coating film is brought into contact with an alkaline developer by immersion, spraying, or other methods to dissolve and remove the exposed areas of the coating film, thereby obtaining a patterned film. In the exposed areas, the alkali solubility of component (A) is increased by the action of the acid generated by irradiating the photoacid generator with active energy rays, and the coating film is therefore dissolved by alkaline development.

Any commonly used alkaline developer can be used without any particular restrictions. Specific examples of alkaline developers include organic alkaline aqueous solutions such as tetramethylammonium hydroxide (TMAH) aqueous solution and choline aqueous solution, and inorganic alkaline aqueous solutions such as potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, potassium carbonate aqueous solution, sodium carbonate aqueous solution, and lithium carbonate aqueous solution. The alkaline concentration of the developer is preferably 0.01 to 25% by weight, more preferably 0.1 to 10% by weight, and even more preferably 0.3 to 5% by weight. The developer may contain a surfactant or the like to adjust the dissolution rate, etc.

<Post-bake>
After dissolving and removing the exposed areas by development, post-baking may be performed to harden the composition of the film in the remaining unexposed areas. Post-baking conditions can be appropriately set. The post-baking temperature is preferably 100 to 400°C, more preferably 120 to 350°C.

For example, if component (A) contains SiH groups, post-baking will cause the SiH groups to react with each other, resulting in a cured film. If component (A) contains SiH groups and the photosensitive composition contains component (D), a compound with multiple ethylenically unsaturated groups, post-baking will cause curing (crosslinking) to occur through a hydrosilylation reaction between the SiH groups in component (A) and the ethylenically unsaturated groups in component (D), which tends to improve the insulating properties, heat resistance, solvent resistance, and other properties of the cured film.

If a polymer containing crosslinkable functional groups such as epoxy groups or oxetane groups is used as component (A) instead of or in addition to using component (D), a crosslinked structure is formed by post-baking, thereby hardening the insulating film. Furthermore, if the photosensitive composition contains a thermosetting resin such as an epoxy resin or oxetane resin as component (E), post-baking also promotes the thermal curing of component (E), thereby hardening the insulating film.

[Application]
The photosensitive composition of this embodiment can be used as an alkali-developable transparent resist. The photosensitive composition of this embodiment contains an isocyanuric acid skeleton structure X as the alkali-solubility-exerting structure (an acidic group protected by a protecting group) of the base polymer component (A). Therefore, compared to a polymer containing a phenol structure having a protecting group as the primary alkali-solubility-exerting structure, the photosensitive composition exhibits less light absorption in the short wavelength visible light region (near 400 nm wavelength) and superior transparency. Furthermore, polymers having an isocyanuric acid skeleton exhibit superior heat resistance compared to phenolic polymers, and exhibit smaller changes in light transmittance during a heat durability test.

For this reason, photosensitive compositions are particularly suitable as materials for FPDs. Examples of FPD materials include TFT passivation films, TFT gate insulating films, TFT interlayer insulating films, TFT transparent planarizing films, photospacer materials for liquid crystal cells, and transparent encapsulating materials for OLED elements. Photosensitive compositions can also be used as materials for colored films such as color filters and black matrices.

The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples.

[Synthesis Example: Synthesis of a compound having a protecting group bonded to the nitrogen atom of an isocyanuric acid skeleton]
<Synthesis Example 1>
A flask was charged with 100 g of diallyl isocyanurate (DAIC), 400 g of tetrahydrofuran (THF), and 13.2 g of pyridine, and the mixture was stirred and then heated to 70°C. A solution of 120 g of di-tert-butyl dicarbonate and 60 g of THF was added dropwise thereto, and after completion of the reaction, the solvent was removed. Recrystallization was carried out with hexane to obtain the following compound 1 (yield: 148 g), in which a tert-butoxycarbonyl group (Boc) was bonded to the nitrogen atom of the isocyanuric acid skeleton and two allyl groups were obtained.

<Synthesis Example 2>
10 g of DAIC, 40 g of THF, and 33 g of potassium carbonate were placed in a flask and stirred at room temperature. 60 g of tert-butyl bromide was added in two portions and reacted. After completion of the reaction, the liquid was separated and the solvent was removed. Recrystallization was carried out with hexane to obtain the following compound 2 (yield: 11 g), in which a tert-butyl group was bonded to the nitrogen atom of the isocyanuric acid skeleton and two allyl groups were present.

<Synthesis Example 3>
10 g of monoallyl isocyanurate (MAIC), 30 g of tetrahydrofuran (THF), and 1.8 g of pyridine were placed in a flask, stirred, and then heated to 70°C. A solution of 36 g of di-tert-butyl dicarbonate and 18 g of THF was added dropwise thereto, and after completion of the reaction, the solvent was removed. The resulting solid was dissolved in toluene to obtain a toluene solution of the following compound 3 (yield: 22 g), in which Boc groups are bonded to two nitrogen atoms of the isocyanuric acid skeleton and which has one allyl group.

<Comparative Synthesis Example: Synthesis of a compound in which a protecting group is bound to a phenolic hydroxyl group>
5 g of diallyl bisphenol S and 20 g of dioxane were placed in a flask and stirred. 2.5 g of hexamethyldisilazane was added thereto, and after the reaction was completed, the solvent was removed. The resulting solid was dissolved in toluene to obtain a toluene solution of the following compound 4, which has a bisphenol S structure protected with a trimethylsilyl group (yield: 6.5 g).

[Polymer Preparation]
Example 1
A flask was charged with 3.84 g of 1,3,5,7-tetramethylcyclotetrasiloxane (D4H) and an equal amount of toluene to that of D4H, and the gas phase was replaced with nitrogen. The internal temperature was then heated to 105° C. and the mixture was stirred. To the flask, 6.16 g of the above compound 1 and 5.2 mg of a platinum catalyst solution (a xylene solution of a platinum vinylsiloxane complex: platinum content 3 wt %) dissolved in dioxane in an amount four times the amount of compound 1 were added dropwise. After the reaction was completed, the solvent was distilled off under reduced pressure.

<Examples 2 to 4>
Polymers were prepared in the same manner as in Example 1, except that the amounts of Compound 1 and D4H charged were changed as shown in Table 1.

Example 5
A flask was charged with 4.68 g of D4H and the same amount of toluene as D4H, and the gas phase was replaced with nitrogen. The mixture was then heated to an internal temperature of 105° C. and stirred. A solution prepared by dissolving 4.92 g of the compound 1, 0.40 g of diallyl monomethyl isocyanurate (DAMMIC), and 5.3 mg of a platinum catalyst solution in dioxane in an amount four times the total amount of compound 1 and DAMMIC was added dropwise thereto. After completion of the reaction, the solvent was distilled off under reduced pressure.

<Examples 6 to 11>
A polymer was prepared in the same manner as in Example 5, except that the amounts of Compound 1, D4H, and DAMMIC were changed as shown in Table 1.

Example 12
A polymer was prepared in the same manner as in Example 1, except that Compound 2 was used in place of Compound 1 and the amounts charged were changed as shown in Table 1.

Example 13
A flask was charged with 3.72 g of D4H and an equal amount of toluene to that of D4H, and the gas phase was replaced with nitrogen. The internal temperature was then heated to 105°C and the mixture was stirred. A solution of 4.35 g of compound 1 and 4.2 mg of a platinum catalyst solution dissolved in dioxane in an amount four times the amount of compound 1 was added dropwise. After completion of the reaction, a solution of 1.93 g of allyl glycidyl ether (AGE) dissolved in toluene in an amount twice the amount of AGE was added dropwise. After completion of the reaction, the solvent was distilled off under reduced pressure.

Example 14
A polymer was prepared in the same manner as in Example 13, except that AGE was replaced with 3-[(allyloxy)methyl]-3-ethyloxetane (AL-EOX) and the amounts charged were changed as shown in Table 1.

Example 15
A flask was charged with 3.73 g of D4H and an equal amount of toluene to that of D4H. The gas phase was replaced with nitrogen, and the internal temperature was heated to 105°C with stirring. A solution of 3.15 g of DAMMIC and 3.7 mg of a platinum catalyst solution dissolved in dioxane in an amount four times the amount of DAMMIC was added dropwise. After completion of the reaction, a solution of 3.12 g of compound 3 dissolved in toluene in an amount twice the amount of compound 3 was added dropwise. After completion of the reaction, the solvent was distilled off under reduced pressure.

<Comparative Example 1>
A flask was charged with 4.65 g of D4H and the same amount of toluene as D4H, and the gas phase was replaced with nitrogen. The mixture was then heated to an internal temperature of 105° C. and stirred. A solution prepared by dissolving 3.85 g of compound 4, 1.50 g of 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (D4Vi), and 2.2 mg of a platinum catalyst solution in 38.5 g of toluene was added dropwise thereto, and after the reaction was completed, the solvent was distilled off under reduced pressure.

[evaluation]
<Preparation of Composition>
A positive photosensitive composition was prepared by mixing 100 parts by weight of the polymer obtained in Examples 1 to 15 and Comparative Example 1, 1 part by weight of a photoacid generator (ADEKA "ADEKA ARCLES SP-606" manufactured by ADEKA), 1 part by weight of a photosensitizer (9,10-dibutoxyanthracene), and 400 parts by weight of propylene glycol monomethyl ether acetate as a solvent. In Example 16, a positive photosensitive composition was prepared by mixing the polymer obtained in Example 1, the photoacid generator, the photosensitizer, and the solvent, as well as 3 parts by weight of triallyl isocyanurate (TAIC) as a crosslinker and a platinum catalyst solution containing 0.05 parts by weight of platinum.

<Exposure sensitivity>
The positive photosensitive composition was spin-coated onto a glass substrate (50 mm × 50 mm) so that the dried film thickness would be 3 μm, and then heated on a hot plate heated to 100°C for 2 minutes. Next, the substrate was exposed to light through a photomask with a 10 μm hole pattern at an integrated light dose of 10 to 120 mJ/ ^cm2 using a parallel light irradiation device equipped with a high-pressure mercury lamp ("UV-K160HC" manufactured by Minaga Electric Mfg. Co., Ltd.), heated at 60°C for 1 minute, and then developed by immersion in an alkaline developer (aqueous solution of 2.38% TMAH) for 1 minute to prepare a sample for evaluating patterning properties.

For samples with each exposure dose, the pattern shape was observed, and samples with hole diameters within the range of 10.0±0.2 μm were deemed OK. For each example and comparative example, the exposure dose required for a patterning evaluation of OK was used as an index of exposure sensitivity. The smaller the exposure dose required for patterning, the better the exposure sensitivity.

<Light transmittance>
An insulating film was prepared on a glass substrate in the same manner as above, except that no exposure was performed. The sample was heated in an oven at 220°C for 30 minutes. After further heating at 240°C for 1 hour, the transmission spectrum was measured using a visible-ultraviolet spectrometer to determine the light transmittance at a wavelength of 400 nm.

<Chemical resistance>
An insulating film was prepared in the same manner as above, except that the heating at 240°C for 1 hour was not performed. The insulating film was immersed for 5 minutes in a mixed solution of dimethyl sulfoxide/2-aminoethanol (30/70 by weight) heated to 60°C, and then heated at 220°C for 10 minutes to remove the remaining solvent in the film. Then, from the film thicknesses of the insulating film before and after immersion, the film thickness retention rate (%) = 100 × (film thickness after immersion/film thickness before immersion) was calculated.

Table 1 shows the amounts of raw materials (monomers) used to prepare the polymers of the above examples and comparative examples, the amount of NH groups generated in the presence of acid (theoretical value), and the evaluation results.

As shown in Table 1, the polymers of Examples 1 to 15, which used isocyanuric acid derivatives Compounds 1 to 3 as monomers, were superior in transparency (transmittance) and chemical resistance (film thickness retention) to the polymer of Comparative Example 1, which had a phenol structure, and were also found to have sufficient exposure sensitivity as positive-type photosensitive compositions.

Comparing Examples 1 to 4 and Examples 5 to 9, it can be seen that the greater the amount of Structure X introduced by the isocyanuric acid derivative, the higher the exposure sensitivity of the photosensitive composition tends to be. Furthermore, comparing Examples 3 and 12, it can be seen that the presence of a Boc protecting group tends to increase exposure sensitivity.

Examples 13 and 14, in which crosslinkable functional groups were introduced into the polymer, showed improved chemical resistance compared to the other Examples. Also, Example 16, in which TAIC was added as a crosslinking agent, showed improved chemical resistance compared to Example 1. In these Examples, it is believed that the formation of crosslinks between polymers by post-baking contributed to the improved chemical resistance.

Claims (16)

A positive-working photosensitive composition containing a polymer and a photoacid generator,
The polymer has one or more structures selected from the group consisting of a structure represented by the following general formula (X1) and a structure represented by the following general formula (X2),
^R1 is a tert-butyl group or a tert-butoxycarbonyl group ;
Positive photosensitive composition. 2. The positive-acting photosensitive composition of claim 1 , wherein the polymer comprises a polysiloxane backbone. 3. The positive photosensitive composition according to claim 1, wherein the amount of NH groups generated by elimination of ^R1 in general formula (X1) and general formula (X2) in the presence of an acid is 0.1 mmol/g or more. 4. The positive photosensitive composition according to claim 1 , wherein the polymer has a weight average molecular weight of 1,000 to 200,000. 5. The positive photosensitive composition according to claim 1 , wherein the polymer contains a crosslinkable functional group capable of forming a crosslinked structure by heating. 6. The positive photosensitive composition according to claim 5 , wherein the crosslinkable functional group is at least one selected from the group consisting of an epoxy group and an oxetane group. 7. The positive photosensitive composition according to claim 5 , further comprising a compound containing, in one molecule, two or more functional groups capable of reacting with the crosslinkable functional group of the polymer. The positive photosensitive composition according to any one of claims 1 to 7 , further comprising a thermosetting resin. A method for producing a patterned insulating film, comprising applying the positive photosensitive composition according to any one of claims 1 to 8 onto a substrate, and then patterning the composition by exposure and alkaline development. A polymer used as a base polymer for a positive-working photosensitive composition,
A polymer having one or more structures selected from the group consisting of a structure represented by the following general formula (X1) and a structure represented by the following general formula (X2):
^R1 is a tert-butyl group or a tert-butoxycarbonyl group. The polymer of claim 10 comprising a polysiloxane backbone. 12. The polymer according to claim 10 , wherein the amount of NH groups generated by elimination of R ¹ in general formula (X1) and general formula (X2) in the presence of an acid is 0.1 mmol/g or more. The polymer according to any one of claims 10 to 12 , having a weight average molecular weight of 1,000 to 200,000. The polymer according to any one of claims 10 to 13 , which contains a crosslinkable functional group capable of forming a crosslinked structure by heating. 15. The alkali-soluble polymer according to claim 14 , wherein the crosslinkable functional group is at least one selected from the group consisting of an epoxy group and an oxetane group. An insulating film comprising the polymer according to any one of claims 10 to 15 .