JP2024154447A - Positive photosensitive composition and cured film - Google Patents

Abstract

[Problem] An object of the present invention is to provide a positive-type photosensitive composition having excellent patterning properties, transparency, high transparency, and low dielectric constant characteristics, and a cured film thereof. [Solution] By using a positive-type photosensitive composition containing as essential components (A) a cyclic polysiloxane compound having a cationically polymerizable group and an alkali-soluble group, (B) a quinone diazide compound, and (C) an acid generator, it is possible to obtain an insulating film having excellent patterning properties, transparency, and low dielectric constant characteristics. The insulating film is useful as an insulating film used in LSIs, TFTs, touch panels, etc. [Selected Figures] None

Description

The present invention relates to a photosensitive composition that can produce a positive pattern by alkaline development and a cured film thereof.

Positive photosensitive compositions are widely used in display manufacturing and semiconductor manufacturing, and positive resists mainly composed of acrylic resin and phenolic resin have been proposed and commercialized. On the other hand, when using positive photosensitive compositions as permanent resists that remain on devices as functional films after patterning, positive photosensitive materials based on materials such as polyimide-based polymers (Patent Document 1) and silicon-based polymers (Patent Document 2), which are more durable resins, have been proposed, but none of these have satisfactory physical properties yet, as they have a high dielectric constant when used as insulating films between wiring, and signal delays due to parasitic capacitance become an issue.

JP 2011-033772 A JP 2011-022173 A

In view of the above, the object of the present invention is to provide a positive-type photosensitive composition that has excellent patterning properties and produces a cured film that exhibits high transparency and low dielectric constant characteristics.

In view of the above circumstances, the inventors conducted extensive research and discovered that the above problems could be solved by using a resin composition having the following characteristics, leading to the completion of the present invention. That is, the present invention has the following configuration.

1) A positive-type photosensitive composition containing, as essential components, (A) a cyclic polysiloxane compound having a cationically polymerizable group and an alkali-soluble group, (B) a quinone diazide compound, and (C) an acid generator.

2) The positive photosensitive composition according to 1), in which the cationic polymerizable group is at least one of an epoxy group and an oxetane group.

3) The positive photosensitive composition according to 1) or 2), characterized in that the alkali-soluble group is a structure selected from the structures represented by the following formulas (X1) to (X2).

4) A cured film obtained by curing the positive photosensitive composition according to any one of 1) to 3).

5) A thin-film transistor planarization film made from the cured film of 4).

6) An organic electroluminescence display device including the thin-film transistor planarization film of 5).

The positive-type photosensitive composition obtained by the present invention has excellent patterning properties, and when cured by heating, it can give a thin film with excellent transparency and low dielectric constant properties.

The details of the invention will now be described.
The photosensitive composition of the present invention can be formed into a positive pattern by photolithography, and can give a thin film having excellent transparency and low dielectric constant properties by curing it by heating.
The photosensitive composition of the present invention is characterized by containing (A) a cyclic polysiloxane compound having a cationic polymerizable group and an alkali-soluble group, (B) a quinone diazide compound, and (C) an acid generator as essential components. The cyclic polysiloxane compound has a structure that exhibits alkali solubility, and by combining with the naphthoquinone azide compound, positive patterning by alkaline development is possible, and since it has a cationic polymerizable group, a crosslinking reaction proceeds by heating after patterning, and a thin film exhibiting excellent transparency and low dielectric properties can be obtained. Details are described below.

<(A) Cyclic polysiloxane compound>
The photosensitive composition contains a cyclic polysiloxane compound having a cationic polymerizable group and an alkali-soluble group as component (A). Hereinafter, the cyclic polysiloxane compound having a cationic polymerizable group and an alkali-soluble group may be referred to as "compound (A)". Compound (A) has a cyclic polysiloxane structure, a cationic polymerizable group, and an alkali-soluble group.

In this specification, the term "cyclic polysiloxane structure" refers to a cyclic molecular structure skeleton having a siloxane unit (Si-O-Si) as a ring component. A compound containing a cyclic polysiloxane structure tends to have excellent film-forming properties and heat resistance of the resulting cured product compared to a compound containing only a linear polysiloxane structure. The compound (A) may contain a cyclic polysiloxane structure in the main chain or in the side chain. When the compound (A) contains a cyclic polysiloxane structure in the main chain, the cured product tends to have excellent heat resistance. The cyclic polysiloxane structure may be a monocyclic structure or a polycyclic structure. The polycyclic structure may be a polyhedral structure. The higher the content of T units (XSiO _3/2 ) or Q units (SiO _4/2 ) among the siloxane units constituting the ring, the higher the hardness and heat resistance of the resulting cured product tends to be. As the content of M units (X ₃ SiO _1/2 ) or D units (X ₂ SiO _2/2 ) increases, the resulting cured product tends to be more flexible and have lower stress.

In this specification, the term "cationically polymerizable group" refers to a functional group that undergoes cationic polymerization and forms a crosslinked structure when exposed to heat or active energy rays. Examples of the cationic polymerizable group include an epoxy group, a vinyl ether group, an oxetane group, and an alkoxysilyl group. From the viewpoint of stability, it is preferable that the compound (A) has an epoxy group as a crosslinkable group. Among the epoxy groups, from the viewpoint of stability, an alicyclic epoxy group or a glycidyl group is preferable. In particular, an alicyclic epoxy group is preferable because of its excellent polymerizability.

Compound (A) may have multiple cationic polymerizable groups in one molecule. When compound (A) has multiple cationic polymerizable groups in one molecule, a cured product with high crosslink density is obtained, and heat resistance tends to be improved. The multiple cationic polymerizable groups may be the same or may be two or more different functional groups.

In this specification, an alkali-soluble group means a functional group that imparts alkali solubility to a compound. Compound (A) exhibits solubility in an alkaline aqueous solution due to the presence of an alkali-soluble functional group. A photosensitive composition containing compound (A) and a quinone diazide compound can be used as a pattern-forming material (positive photosensitive composition) that can be patterned by alkaline development.

Examples of the alkali-soluble group include an isocyanuric acid derivative structure represented by the following X1 or X2, a phenolic hydroxyl group, and a carboxyl group. From the viewpoint of the heat resistance of the resulting cured product, it is preferable that compound (A) has a structure represented by the above formula X1 or X2 as the alkali-soluble group.

The method for introducing the cationically polymerizable group and the alkali-soluble group into the polysiloxane compound is not particularly limited. A method using a hydrosilylation reaction is preferred because the crosslinkable group and the alkali-soluble group can be introduced into the polysiloxane compound via a chemically stable silicon-carbon bond (Si-C bond). In other words, the compound (A) is preferably a cyclic polysiloxane compound that has been organically modified by a hydrosilylation reaction and has the cationically polymerizable group and the alkali-soluble group introduced via the silicon-carbon bond.

A cyclic polysiloxane compound having a cationically polymerizable group and an alkali-soluble group introduced therein can be obtained, for example, by a hydrosilylation reaction using the following compound as a starting material:
(α) a compound having, in one molecule, a carbon-carbon double bond reactive with a SiH group (hydrosilyl group) and an alkali-soluble functional group;
(β) a cyclic polysiloxane compound having at least two SiH groups in one molecule; and (γ) a compound having a carbon-carbon double bond reactive with a SiH group and a cationically polymerizable functional group in one molecule.

(Compound (α))
Compound (α) is not particularly limited as long as it is an organic compound having a carbon-carbon double bond reactive with a SiH group and an alkali-soluble functional group in one molecule. By using compound (α), the alkali-soluble functional group is introduced into compound (A).

Examples of groups containing a carbon-carbon double bond that are reactive with SiH groups (hereinafter, sometimes simply referred to as "alkenyl groups") include vinyl groups, allyl groups, methallyl groups, acrylic groups, methacrylic groups, 2-hydroxy-3-(allyloxy)propyl groups, 2-allylphenyl groups, 3-allylphenyl groups, 4-allylphenyl groups, 2-(allyloxy)phenyl groups, 3-(allyloxy)phenyl groups, 4-(allyloxy)phenyl groups, 2-(allyloxy)ethyl groups, 2,2-bis(allyloxymethyl)butyl groups, 3-allyloxy-2,2-bis(allyloxymethyl)propyl groups, and vinyl ether groups. From the viewpoint of reactivity with SiH groups, it is preferable that compound (α) contains a vinyl group or an allyl group as the alkenyl group.

Compound (α) may have two or more alkenyl groups in one molecule. When compound (α) contains multiple alkenyl groups in one molecule, multiple compounds (β) can be crosslinked by a hydrosilylation reaction, so the crosslink density of the resulting cured product tends to be high and the heat resistance is improved.

From the viewpoint of availability, compound (α) is preferably diallyl isocyanuric acid, monoallyl isocyanuric acid, vinylphenol, allylphenol, a compound represented by the following general formula (IIa) or (IIb), butenoic acid, pentenoic acid, hexenoic acid, heptenoic acid or undecylenic acid. In general formulas (IIa) and (IIb), R is a divalent group selected from the group consisting of -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, and -SO ₂ -.

Among these, from the viewpoint of the heat resistance of the cured product, the compound (α1) is preferably diallyl isocyanuric acid, monoallyl isocyanuric acid, diallyl bisphenol A, diallyl bisphenol S, vinylphenol or allylphenol. Furthermore, from the viewpoint of the electrical properties of the cured product, the compound (α) is particularly preferably diallyl isocyanuric acid or monoallyl isocyanuric acid.

(Compound (β))
Compound (β) is a cyclic polysiloxane compound having at least two SiH groups in one molecule, and for example, compounds described in International Publication No. 96/15194 having at least two SiH groups in one molecule can be used. Compound (β) preferably contains three or more SiH groups in one 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.

Compound (β) is, for example, a cyclic polysiloxane represented by the following general formula (III):

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 elements 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, aryl groups and the like. Among them, chain alkyl groups such as methyl groups, ethyl groups, propyl groups, hexyl groups, octyl groups, decyl groups and dodecyl groups, cyclic alkyl groups such as cyclohexyl groups and norbornyl groups, or phenyl groups are preferred. From the viewpoint of availability of compound (β), R ⁴ , R ⁵ and R ⁶ are preferably methyl groups, propyl groups, hexyl groups or phenyl groups. ^{R 4} and R ⁵ are more preferably chain alkyl groups having 1 to 6 carbon atoms, and particularly preferably methyl groups.

Examples of the cyclic polysiloxane compound represented by the general formula (III) 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, from the viewpoints of availability and reactivity of the SiH group, 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane (a compound in which, in general formula (III), m=4, n=0, and ^R4 is a methyl group) is preferred.

Compound (β) may be a polycyclic polysiloxane. The polycyclic ring may have a polyhedral structure. The polysiloxane having a polyhedral skeleton preferably has 6 to 24 Si atoms constituting the polyhedral skeleton, and more preferably has 6 to 10 Si atoms. A specific example of a polysiloxane having a polyhedral skeleton is silsesquioxane (number of Si atoms = 8) represented by the following general formula (IV).

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

The cyclic polysiloxane may be a silylated silicic acid having a polyhedral skeleton. A specific example of a silylated silicic acid having a polyhedral skeleton is a compound represented by the following general formula (V) (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 (IV), and at least two of R ¹⁸ to R ⁴¹ are hydrogen atoms.

In silylated silica with a polyhedral skeleton, the Si atoms that make up the polyhedral skeleton and the SiH groups (reactive groups in the hydrosilylation reaction) are bonded via siloxane bonds, which imparts flexibility to the cured product.

Cyclic polysiloxanes can be obtained by known synthesis methods. For example, cyclic polysiloxanes represented by general formula (III) can be synthesized by methods described in International Publication No. 96/15194 and the like. Polysiloxanes having a polyhedral skeleton, such as silsesquioxanes, and silylated silicas having a polyhedral skeleton can be synthesized by methods described in, for example, JP-A-2004-359933, JP-A-2004-143449, JP-A-2006-269402, and the like. A commercially available cyclic polysiloxane compound may be used as compound (β).

(Compound (γ))
Compound (γ) is not particularly limited as long as it is a compound having an alkenyl group and a cationic polymerizable group in one molecule. By using compound (γ), a cationic polymerizable group is introduced into compound (A). Therefore, the cationic polymerizable group in compound (γ) is the same as the cationic polymerizable group in compound (A) described above, and the preferred embodiments are also the same. The alkenyl group in compound (γ) is preferably the same as the alkenyl group in compound (α) described above.

Specific examples of the compound (γ) having an epoxy group as a cationically polymerizable functional group include vinylcyclohexene oxide, allyl glycidyl ether, diallyl monoglycidyl isocyanurate, and monoallyl diglycidyl isocyanurate. From the viewpoint of reactivity, a compound having an alicyclic epoxy group is preferred, and vinylcyclohexene oxide is particularly preferred.

The cationic polymerizable functional group of the compound (γ) may be a vinyl ether group, an oxetane group, an alkoxysilyl group, or the like. Specific examples of the compound (γ) having an alkoxysilyl group as the cationic polymerizable functional group include alkoxysilanes such as trimethoxyvinylsilane, triethoxyvinylsilane, methyldiethoxyvinylsilane, methyldimethoxyvinylsilane, and phenyldimethoxyvinylsilane. Examples of the compound (γ) having a vinyl ether group as the cationic polymerizable functional group include propenyl ethenyl ether. Examples of the compound (γ) having an oxetane group as the cationic polymerizable functional group include 2-vinyloxetane, 3-allyloxyoxetane, and (3-ethyloxetane-3-yl)methyl acrylate.

(Other Starting Materials)
In the synthesis of compound (A) by hydrosilylation reaction, in addition to the above compounds (α), (β), and (γ), other starting materials may be used. For example, compound (δ): a compound having two or more alkenyl groups in one molecule (excluding compounds (α) and (γ)) may be used as a starting material. If compound (δ) containing multiple alkenyl groups in one molecule is used as a starting material, multiple compounds (β) are crosslinked by hydrosilylation reaction, so that the molecular weight of compound (A) is increased, and film-forming property and heat resistance of cured film tend to be improved.

The compound (δ) 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 acid 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 (δ) 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, diaryl 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 Examples of such epoxy resins include 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 epoxy resins in which all of the glycidyl groups of conventionally known epoxy resins have been replaced with allyl groups.

From the viewpoint of heat resistance and light resistance, compound (δ) is preferably a compound represented by the following general formula (VI):

In the formula, ^R1 and ^R2 are alkenyl groups and may be the same or different, ^{and R3} represents a monovalent organic group having 1 to 50 carbon atoms.

R ¹ and R ² are preferably the same as the alkenyl group in the above-mentioned compound (α), and among them, vinyl group and allyl group are preferable, and allyl group is particularly preferable. From the viewpoint of improving the heat resistance of the cured product, the carbon number of R ³ is preferably 1 to 20, more preferably 1 to 10. Specific examples of R ³ are the same as the specific examples of R ¹⁰ to R ¹⁷ in the above-mentioned general formula (IV). R ³ may contain a carbon-carbon double bond having reactivity with a SiH group. Preferred examples of the compound (δ) include triallyl isocyanurate and diallyl monomethyl isocyanurate.

R ³ in the general formula (VI) may be a reactive group such as a glycidyl group. Since the glycidyl group, which is a type of epoxy group, has cationic polymerizability, the compound in which R ³ in the general formula (VI) is a glycidyl group is classified as the above-mentioned compound (γ). On the other hand, when a compound containing a functional group having higher cationic polymerizability than the glycidyl group (for example, a compound containing an alicyclic epoxy group such as vinylcyclohexene oxide) is used as the compound (γ), the alicyclic epoxy group mainly participates in the cationic polymerization, so that the contribution of the glycidyl group to the cationic polymerization is small. Therefore, the compound in which R ³ in the general formula (VI) is a glycidyl group can also be classified as a compound (δ). A specific example of such a compound (δ) is diallyl monoglycidyl isocyanurate.

Compound (ε): a compound having only one functional group participating in the hydrosilylation reaction in one molecule (excluding compounds (α) and (γ)) may be used as a starting material in the synthesis of compound (A) by hydrosilylation reaction. The functional group participating in the hydrosilylation reaction is a SiH group or an alkenyl group. By using a compound having only one functional group participating in the hydrosilylation reaction, a specific functional group can be introduced at the end of compound (A).

For example, by using a siloxane compound having one SiH group as the compound (ε), a siloxane structural portion can be introduced to the end of the compound (A). Specific examples of the siloxane compound having one SiH group include a cyclic polysiloxane compound in which m=1 in the above-mentioned general formula (III), a polyhedral polysiloxane compound in which one of R ¹⁰ to R ¹⁷ in the above-mentioned general formula (IV) is a hydrogen atom, and a silylated silicic acid compound in which one of R ¹⁸ to R ⁴¹ in the above-mentioned general formula (V) is a hydrogen atom. The siloxane compound having one SiH group may be a chain siloxane compound.

By using a compound having one group containing an alkenyl group as compound (ε), the desired functional group can be introduced to the end of compound (A).

In addition to the above, the starting materials may include compounds that participate in hydrosilylation reactions, such as linear polysiloxanes having two or more SiH groups.

In the above example, by using a compound (α) having an alkenyl group and an alkali-soluble functional group, and a compound having an alkenyl group and a crosslinkable group, an alkali-soluble group and a cationic polymerizable functional group are introduced into a cyclic polysiloxane compound (β) having multiple SiH groups. A compound containing an alkali-soluble functional group and a SiH group may be used instead of compound (α), and a compound containing a crosslinkable group and a SiH group may be used instead of compound (γ). In this case, by using a cyclic polysiloxane compound having an alkenyl group, a crosslinkable group and an alkali-soluble functional group can be introduced into the cyclic polysiloxane compound. A compound having multiple alkenyl groups may be used as the cyclic polysiloxane compound.

Examples of cyclic siloxane compounds containing alkenyl 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. From the viewpoint of heat resistance and light resistance, it is preferable that the organic group present on the Si atom of the cyclic polysiloxane compound having an alkenyl group is a vinyl group or a methyl group.

(Hydrosilylation reaction)
The order and method of the hydrosilylation reaction are not particularly limited. For example, compound (A) can be obtained by a hydrosilylation reaction according to the method described in International Publication No. 2009/075233. From the viewpoint of simplifying the synthesis process, it is preferable to carry out the hydrosilylation reaction by charging all starting materials into one pot, and finally remove the unreacted compounds. On the other hand, from the viewpoint of suppressing the generation of low molecular weight substances, it is preferable to carry out the introduction of an alkali-soluble functional group and the introduction of a cationic polymerizable functional group into a cyclic polysiloxane compound in a stepwise manner. For example, it is preferable to carry out the hydrosilylation reaction of a compound containing multiple alkenyl groups (e.g., compound (α) and/or compound (δ)) and a compound containing multiple SiH groups (e.g., compound (β)) with one of them being in excess, and after removing the unreacted compounds, to add a compound having only one functional group involved in the hydrosilylation reaction in one molecule (e.g., compound (γ) and/or compound (ε) to carry out the hydrosilylation reaction.

The ratio of each compound in the hydrosilylation reaction is not particularly limited, but it is preferable that the total amount of alkenyl groups in the starting materials, A, and the total amount of SiH groups, B, satisfy 1≦B/A≦30, and it is more preferable that 1≦B/A≦10. If B/A is 1 or more, unreacted alkenyl groups are unlikely to remain, and if B/A is 30 or less, unreacted SiH groups are unlikely to remain, which improves the properties of the cured film.

For the hydrosilylation reaction, a hydrosilylation catalyst such as chloroplatinic acid, a platinum-olefin complex, or a platinum-vinylsiloxane complex may be used. 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 amount (number of moles) of alkenyl groups contained in the starting material.

The reaction temperature for hydrosilylation may be set appropriately, and is preferably 30 to 200°C, and more preferably 50 to 150°C. The volume concentration of oxygen in the gas phase during the hydrosilylation reaction is preferably 3% or less. From the viewpoint of promoting the hydrosilylation reaction by adding oxygen, the gas phase may contain approximately 0.1 to 3% by volume of oxygen.

A solvent may be used in the hydrosilylation reaction. Examples of the solvent 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 and methyl ethyl ketone; and halogen solvents such as chloroform, methylene chloride, and 1,2-dichloroethane. Toluene, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, and chloroform are preferred because they are easy to remove by distillation after the reaction. A gelation inhibitor may be used in the hydrosilylation reaction, if necessary.

(Preferred embodiment of compound (A))
The compound (A) preferably has an alicyclic epoxy group as a cationically polymerizable group. The alicyclic epoxy group is preferably introduced into the compound (A) using a compound (γ) having a vinyl group and an alicyclic epoxy group in one molecule as a starting material.

Compound (A) has an alkali-soluble group. Among the alkali-soluble groups, the above-mentioned structure X1 or structure X2 is preferred. As described above, structures X1 and X2 can be introduced into compound (A) using diallyl isocyanuric acid and monoallyl isocyanuric acid, respectively, as starting materials (compound (α)).

The cyclic structure of the cyclic polysiloxane is preferably introduced into compound (A) using a cyclic polysiloxane having two or more SiH groups as a starting material (compound (β)). Of these, it is preferable to use 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane as compound (β).

((B) Quinone diazide compounds)
The photosensitive composition of the present invention contains a quinone diazide compound as an essential component, and by combining it with a compound containing a structure that exhibits alkali solubility, it exhibits positive patterning properties. There is no particular limitation on the quinone diazide compound, and any known quinone diazide compound that is used as a photosensitizer in the resist field can be used. Two or more quinone diazide compounds may be used in combination. Examples of the quinone diazide compound include esters of a phenol compound and 1,2-benzoquinone diazide-4-sulfonic acid or 1,2-benzoquinone diazide-5-sulfonic acid, and esters of a phenol compound and 1,2-naphthoquinone diazide-4-sulfonic acid or 1,2-naphthoquinone diazide-5-sulfonic acid.

Examples of the phenol compounds include 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,3,3',4-tetrahydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, bis(2,4-dihydroxyphenyl)methane, bis(p-hydroxyphenyl)methane, tri(p-hydroxyphenyl)methane, 1,1,1-tri(p-hydroxyphenyl)ethane, bis(2,3,4-trihydroxyphenyl)methane, 2,2-bis(2,3,4-trihydroxyphenyl)propane, 1, These include 1,3-tris(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropane, 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α,α-dimethylbenzyl}phenol, 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol, bis(2,5-dimethyl-4-hydroxyphenyl)-2-hydroxyphenylmethane, 3,3,3',3'-tetramethyl-1,1'-spirobiindene-5,6,7,5',6',7'-hexanol, and 2,2,4-trimethyl-7,2',4'-trihydroxyflavan.

Specific examples of quinone diazide compounds that can be suitably used include esters of 2,3,4-trihydroxybenzophenone and 1,2-naphthoquinone diazide-4-sulfonic acid, esters of 2,3,4-trihydroxybenzophenone and 1,2-naphthoquinone diazide-5-sulfonic acid, esters of 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α,α-dimethylbenzyl}phenol and 1,2-naphthoquinone diazide-4-sulfonic acid, and esters of 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α,α-dimethylbenzyl}phenol and 1,2-naphthoquinone diazide-5-sulfonic acid.

In the photosensitive composition of the present invention, the content of the quinone diazide compound is preferably 1 to 30 parts by weight, more preferably 3 to 20 parts by weight, and even more preferably 5 to 15 parts by weight, per 100 parts by weight of the components excluding the solvent.

((C) Acid Generator)
The photosensitive composition of the present invention can promote the crosslinking reaction by cationic polymerization groups by containing an acid generator that is activated by heat or light. The acid generator used is not particularly limited, and known photoacid generators and thermal acid generators can be used. The acid generator is not particularly limited as long as it generates a Lewis acid by heat or exposure to light. Examples of the photoacid generator include ionic photoacid generators such as sulfonium salts, iodonium salts, ammonium salts, and other onium salts; and nonionic photoacid generators such as imide sulfonates, oxime sulfonates, and sulfonyl diazomethanes. Examples of commercially available photoacid generators include FX-512 (3M), UVR-6990 and UVR-6974 (Union Carbide), UVE-1014 and UVE-1016 (General Electric), KI-85 (Degussa), SP-150, SP-172, SP-606 (ADEKA), and San-Aid SI-60L, SI-80L, and SI-100L (Sanshin Chemical Industry Co., Ltd.), WPI113 and WPI116 (Wako Pure Chemical Industries, Ltd.), CPI-210S, CPI310FG, Ik-1 (San-Apro), RHODORSIL PI2074 (Rhodia), BBI-102, BBI-103, and BBI-105 (Midori Chemical).

<Other ingredients>
The photosensitive composition of the present invention may contain resin components and additives other than the above (A) to (C).

(Storage stabilizer)
In order to ensure storage stability, the photosensitive composition of the present invention may contain a hydrosilylation reaction inhibitor.Specific examples of the inhibitor include compounds containing an aliphatic unsaturated bond, organic phosphorus compounds, organic sulfur compounds, nitrogen-containing compounds, tin compounds, organic peroxides, etc., which may be used in combination.

Examples of compounds containing aliphatic unsaturated bonds include propargyl alcohols such as 3-hydroxy-3-methyl-1-butyne, 3-hydroxy-3-phenyl-1-butyne, and 1-ethynyl-1-cyclohexanol, ene-yne compounds, and maleic acid esters such as dimethyl maleate. Examples of organic phosphorus compounds include triorganophosphines, diorganophosphines, organophosphones, and triorganophosphites. Examples of organic sulfur compounds include organomercaptans, diorganosulfides, hydrogen sulfide, benzothiazole, thiazole, and benzothiazole disulfide. Examples of tin compounds include stannous halide dihydrate and stannous carboxylate. Examples of organic peroxides include di-t-butyl peroxide, dicumyl peroxide, benzoyl peroxide, and t-butyl perbenzoate.

Of these gelation inhibitors, benzothiazole, thiazole, dimethyl malate, 3-hydroxy-3-methyl-1-butyne, 1-ethynyl-1-cyclohexanol, and triphenylphosphine are preferred from the viewpoints of good retardation activity and good availability of raw materials.

(solvent)
In order to apply the curable composition of the present invention uniformly, it is preferable to use a solvent. The solvent that can be used is not particularly limited, and specific examples thereof include hydrocarbon solvents such as ethylcyclohexane and trimethylpentane, ether solvents such as 1,4-dioxane and 1,3-dioxolane, ketone solvents such as methyl isobutyl ketone and cyclohexanone, ester solvents such as isobutyl isobutyrate and isobutyl butyrate, glycol solvents such as propylene glycol-1-monomethyl ether-2-acetate (PGMEA), ethylene glycol dimethyl ether and ethylene glycol diethyl ether, and halogen solvents such as trifluorotoluene.

In particular, from the viewpoint of the ease of forming a uniform film, 1,4-dioxane, isobutyl isobutyrate, propylene glycol-1-monomethyl ether-2-acetate, methyl isobutyl ketone, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, etc. are preferred.

The amount of solvent used can be set appropriately, but the preferred lower limit of the amount used per gram of positive photosensitive composition is 0.1 g or even 0.3 g, and the preferred upper limit of the amount used is 0.95 g or even 0.85 g. If the amount used is small, it is difficult to obtain the effects of using the solvent, such as low viscosity, and if the amount used is large, the solvent will remain in the material and may cause problems such as thermal cracking. These solvents may be used alone or as a mixed solvent of two or more types.

(Additives)
In addition to the above, the positive photosensitive composition of the present invention may contain an adhesion improver, a coupling agent (such as a silane coupling agent), a deterioration inhibitor, a radical inhibitor, a release agent, a flame retardant, a flame retardant auxiliary, a surfactant, an antifoaming agent, an emulsifier, a leveling agent, an anti-repellent agent, an ion trapping agent (such as antimony-bismuth), a thixotropy imparting agent, a tackifier, a storage stability improving agent, an ozone deterioration inhibitor, a light stabilizer, a thickener, a plasticizer, a reactive diluent, an antioxidant, a heat stabilizer, an electrical conductivity imparting agent, an antistatic agent, a radiation shielding agent, a nucleating agent, a phosphorus-based peroxide decomposer, a lubricant, a pigment, a metal deactivator, a thermal conductivity imparting agent, a physical property adjusting agent, and the like, within the scope of not impairing the objects and effects of the present invention.

(About post-baking)
The photosensitive composition of the present invention can finally obtain a thin film excellent in low dielectric constant characteristics by heating, whereby a crosslinking reaction by the crosslinkable groups proceeds. The heating temperature is preferably 280° C. or less, and more preferably 250° C. or less from the viewpoint of minimizing thermal damage to surrounding members.

(About photolithography)
The method for preparing the photosensitive composition of the present invention is not particularly limited, and it can be prepared by various methods. Various components may be mixed and prepared just before curing, or all components may be mixed and prepared in advance in a one-liquid state and stored at low temperature.

The method for coating the photosensitive composition of the present invention onto various substrates is not particularly limited as long as it is a method that allows uniform application, and can be applied by commonly used methods such as spin coating and slit coating.

As the light source for sensitizing, a light source that emits light with an absorption wavelength of the naphthoquinone diazide compound used may be used, and light sources having a wavelength in the range of 300 to 450 nm, such as high pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, high power metal halide lamps, xenon lamps, carbon arc lamps, light emitting diodes, etc. The exposure dose is not particularly limited, but the preferred range is 1 to 1000 mJ/ ^cm2 , more preferably 1 to 500 mJ/ ^cm2 .

In order to remove the solvent, a pre-baking or vacuum devolatilization process can be performed before exposure. However, because of problems such as a decrease in developability due to the application of heat, the pre-baking temperature is preferably 130°C or less, and more preferably 120°C or less. Vacuum devolatilization and heating can also be performed simultaneously.

There is no particular limitation on the method for forming a pattern by development, and the exposed area can be dissolved and removed to form the desired pattern by commonly used development methods such as immersion and spraying. Any commonly used developer can be used without particular limitation, and specific examples include organic alkaline aqueous solutions such as tetramethylammonium hydroxide aqueous solution and choline aqueous solution, 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, and aqueous solutions to which alcohol or surfactants have been added to adjust the dissolution rate, and various organic solvents.

In order to obtain a cured film having excellent transparency, a bleaching treatment can be performed. The light source used in bleaching can be any of those listed above, without any particular limitation. The exposure dose during bleaching is not particularly limited, but the preferred range is 10 to 5000 mJ/cm ² , and more preferably 50 to 2000 mJ/cm ² .

(Regarding dielectric constant)
The photosensitive composition of the present invention functions as an excellent insulating film when cured. In particular, when applied as an insulating film used for a planarizing film of a thin film transistor, the lower the dielectric constant, the smaller the parasitic capacitance between wirings, and the smaller the error such as transmission delay. At a frequency of 100 kHz, the value is preferably 3.1 or less, more preferably 3.0 or less, and even more preferably 2.9 or less.

(Light transmittance)
The photosensitive composition of the present invention has excellent transparency when cured into a thin film. In particular, when the composition is used as an insulating film for planarizing a thin film transistor of a display, the higher the light transmittance, the more advantageous it is for improving the image quality of the display. At a light wavelength of 400 nm, the value is preferably 93% or more, more preferably 95% or more, and even more preferably 96% or more.

The following are examples and comparative examples of the present invention, but the present invention is not limited to them.

Thin films formed from the photosensitive composition of the present invention can be patterned in a positive tone and function as insulating films that exhibit superior properties compared to the compositions of the comparative examples.

(Thin film formation and photolithography evaluation method: patterning ability)
The photosensitive compositions obtained in Examples 1 and 2 and Comparative Example 1 were spin-coated on a glass substrate or a 50×50 mm glass substrate with a 2000 Å molybdenum thin film to form a 2 μm thick film, dried on a hot plate at 100° C. for 2 minutes, exposed to 120 mJ/cm ² through a hole pattern photomask using a mask aligner (MA-10, manufactured by Mikasa), and developed with an alkaline developer (aqueous solution of TMAH 2.38%, manufactured by Tama Chemical Industries). The entire surface of the substrate was exposed to 500 mJ/cm ² for bleaching, and then post-baked at 230° C. for 30 minutes to form a thin film. The pattern shape was observed under a microscope, and those in which 5×5 μm holes were formed were marked with ◯, and those in which holes were not formed were marked with ×.

(Dielectric constant evaluation)
An aluminum electrode (3 mm in diameter) was formed by a vacuum deposition machine on the thin film of photosensitive composition formed on the glass substrate with the molybdenum thin film by the above method, to prepare a capacitor.
The capacitance (F) was measured using a semiconductor parameter analyzer (Keithley 4200) when 1 kHz and 10 V were applied, and the dielectric constant was calculated from the following formula.

ε=C×t/ε ₀ ×A
C: Capacitance (F)
ε ₀ : Dielectric constant of a vacuum (8.85×10 ⁻¹² )
t: film thickness (m)
A: Area ( ^m2 )
The relative dielectric constant (ε) was calculated from the above formula.
(Light transmittance)
The cured film of the photosensitive composition formed on the glass substrate by the above method was measured for light transmittance at 400 nm in air using a UV-visible spectrophotometer (JASCO JSV 560, manufactured by JASCO Corporation).

Synthesis Example 1
20 g of toluene and 3 g of 1,3,5,7-tetramethylcyclotetrasiloxane were placed in a 100 mL four-neck flask, and the gas phase was replaced with nitrogen, followed by heating and stirring at an internal temperature of 100°C. A mixture of 2 g of diallyl isocyanuric acid, 3 g of diallyl monomethyl isocyanurate, 0.7 mg of a xylene solution of platinum vinylsiloxane complex (containing 3 wt% platinum), and 5 g of toluene was added. After the addition, the disappearance of the peak derived from the vinyl group was confirmed by ¹ H-NMR, and then the internal temperature was raised to 80°C and 1 g of vinylcyclohexene oxide was added. After the addition, the disappearance of the peak derived from the vinyl group was confirmed by ¹ H-NMR, followed by distilling off the toluene under reduced pressure to obtain a colorless, transparent liquid "Reactant A."

(Comparative Synthesis Example 1)
In a 100 mL four-neck flask, 100 g of diethylene glycol ethyl methyl ether, 5 g of tetraethoxysilane, 10 g of dimethyldiethoxysilane, and 30 g of phenyltriethoxysilane were placed, and a mixed solution of 10.3 g of formic acid and 16.0 g of water was added dropwise. The mixture was then heated at 80° C. for 1 hour, and low molecular weight components were distilled off to obtain “Reactant B”.

(Examples 1 to 2, Comparative Example 1)
The reaction products A and B obtained in Synthesis Examples 1 to 3 and Comparative Synthesis Example 1, a quinone diazide compound (an ester of 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α,α-dimethylbenzyl}phenol and 1,2-naphthoquinone diazide-5-sulfonic acid (esterification rate 2.0)), an acid generator (SP-210S), and a solvent (propylene glycol-1-monomethyl ether-2-acetate) were mixed in the ratios shown in Table 1 to prepare photosensitive compositions. The results are shown in Table 2.

Claims (6)

A positive-type photosensitive composition comprising, as essential components, (A) a cyclic polysiloxane compound having a cationically polymerizable group and an alkali-soluble group, (B) a quinone diazide compound, and (C) an acid generator.
2. The positive photosensitive composition according to claim 1, wherein the cationically polymerizable group is at least one of an epoxy group and an oxetane group.
2. The positive photosensitive composition according to claim 1, wherein the alkali-soluble group has a structure selected from the structures represented by the following formulas (X1) and (X2):
A cured film obtained by curing the positive photosensitive composition according to any one of claims 1 to 3.
A thin film transistor planarization film comprising the cured film of claim 4.
An organic EL display device comprising the thin-film transistor planarization film of claim 5.