JP4168443B2 - Radiation-sensitive resin composition, interlayer insulating film and microlens, and production method thereof - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition, an interlayer insulating film and a microlens, and methods for producing them.

  In an electronic component such as a thin film transistor (hereinafter referred to as “TFT”) type liquid crystal display element, magnetic head element, integrated circuit element, solid-state imaging element, etc., an interlayer insulation is generally used to insulate between wirings arranged in layers. A membrane is provided. As a material for forming the interlayer insulating film, a material having a small number of steps for obtaining a required pattern shape and sufficient flatness is preferable, and therefore, a radiation sensitive resin composition is widely used (for example, , See Patent Document 1 and Patent Document 2.)

  Among the electronic components, for example, a TFT type liquid crystal display element is manufactured through a process of forming a transparent electrode film on the interlayer insulating film and further forming a liquid crystal alignment film on the interlayer insulating film. Since the film is exposed to a high temperature condition in the transparent electrode film forming process or exposed to a resist stripping solution used for forming an electrode pattern, sufficient resistance to these is required.

  In recent years, TFT-type liquid crystal display elements have been in the trend of larger screens, higher brightness, higher definition, faster response, thinner thickness, etc., and the composition for forming an interlayer insulating film used therefor has high sensitivity. In addition, the formed interlayer insulating film is required to have high heat resistance, high transmittance, and the like.

  On the other hand, a microlens having a lens diameter of about 3 to 100 μm or an optical system material for an on-chip color filter such as a facsimile, an electronic copying machine, a solid-state image sensor, or the like is defined as an optical system material. An array of microlenses is used.

  To form a microlens or microlens array, a resist pattern corresponding to the lens is formed and then melt-flowed by heat treatment and used as it is as a lens, or by using the melt-flowed lens pattern as a mask and drying. A method of transferring a lens shape to a base by etching is known. For the formation of the lens pattern, a radiation sensitive resin composition is widely used (see, for example, Patent Document 3 and Patent Document 4).

  By the way, the element in which the microlens or the microlens array as described above is formed is then applied with a planarizing film and an etching resist film in order to remove various insulating films on the bonding pad which is a wiring forming portion. Exposure and development are performed using a desired mask to remove the etching resist in the bonding pad portion, and then the step is performed to remove the planarizing film and various insulating films by etching to expose the bonding pad portion. Therefore, the microlens or the microlens array requires solvent resistance and heat resistance in the flattening film and etching resist coating film forming process and the etching process.

  The radiation-sensitive resin composition used to form such a microlens has high sensitivity, and the microlens formed therefrom has a desired radius of curvature, and has high heat resistance and high transmittance. It is required to be a rate.

  In addition, the interlayer insulating film and the microlens thus obtained can penetrate between the pattern and the substrate if the development time is slightly longer than the optimum time in the development process when forming them. Therefore, it is necessary to strictly control the development time, and there is a problem in terms of product yield.

As described above, in forming the interlayer insulating film and the microlens from the radiation-sensitive resin composition, the composition is required to have high sensitivity, and the developing time in the developing process during the forming process is longer than a predetermined time. Even when it is excessive, the pattern does not peel off and shows good adhesion, and the interlayer insulating film formed therefrom is required to have high heat resistance, high solvent resistance, high transmittance, etc. When forming a lens, a good melt shape (desired radius of curvature), high heat resistance, high solvent resistance, and high transmittance are required as a microlens. However, a radiation-sensitive resin composition that can satisfy such requirements has not been known.
JP 2001-354822 A JP 2001-343743 A JP-A-6-18702 JP-A-6-136239

  The present invention has been made based on the above situation. Therefore, an object of the present invention is to provide a pattern shape having high radiation sensitivity, having a development margin capable of forming a good pattern shape even in the development process exceeding the optimum development time, and having excellent adhesion. An object of the present invention is to provide a radiation sensitive composition capable of easily forming a thin film.

  Another object of the present invention is to form an interlayer insulating film having high heat resistance and high transmittance when used for forming an interlayer insulating film, and high transmittance when used for forming a microlens. Another object of the present invention is to provide a radiation sensitive resin composition capable of forming a microlens having a good melt shape.

  Still another object of the present invention is to provide a method for forming an interlayer insulating film and a microlens using the radiation sensitive resin composition.

  Still another object of the present invention is to provide an interlayer insulating film and a microlens formed by the method of the present invention.

  Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are firstly
[A] (a1) unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride (hereinafter sometimes referred to as “compound (a1)”),
(A2) The following formula

An unsaturated compound having an alicyclic epoxy skeleton represented by the following (hereinafter sometimes referred to as “compound (a2)”), and (a3) cyclohexylmaleimide, 2-hydroxyethyl methacrylate, tricyclo [5.2.1 0.0 ^2,6 ] decan-8-yl methacrylate, p-vinylbenzyl glycidyl ether, glycidyl methacrylate and n-lauryl methacrylate and an unsaturated compound (hereinafter referred to as “compound (a3 ) "(Hereinafter sometimes referred to as" copolymer [A] "), and [B] 1,2-naphthoquinonediazide sulfonic acid ester (hereinafter referred to as" [B] "). It is achieved by a radiation-sensitive resin composition characterized by containing “component”. It is.

Secondly, the objects and advantages of the present invention are:
This is achieved by a method for forming an interlayer insulating film or a microlens, which includes the following steps in the following order.

(1) The process of forming the coating film of said radiation sensitive composition on a board | substrate,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) Development step, and (4) Heating step.

Third, the objects and advantages of the present invention are
This is achieved by the interlayer insulating film or microlens formed by the above method.

  The radiation-sensitive resin composition of the present invention has high radiation sensitivity, has a development margin that can form a good pattern shape even when the optimum development time is exceeded in the development process, and has excellent adhesion. A patterned thin film can be easily formed.

  The interlayer insulating film of the present invention formed from the above composition has good adhesion to the substrate, excellent solvent resistance and heat resistance, high transmittance, low dielectric constant, and interlayer between electronic components. It can be suitably used as an insulating film.

  In addition, the microlens of the present invention formed from the above composition has good adhesion to a substrate, excellent solvent resistance and heat resistance, has high transmittance and good melt shape, and is solid-state imaging It can be suitably used as a microlens for the element.

  Hereinafter, the radiation sensitive resin composition of this invention is explained in full detail.

Copolymer [A]
Copolymer [A] can be produced by radical polymerization of compound (a1), compound (a2) and compound (a3) in the presence of a polymerization initiator in a solvent. The copolymer [A] used in the present invention is preferably a structural unit derived from the compound (a1) based on the total of repeating units derived from the compounds (a1), (a2) and (a3). 5 to 40% by weight, particularly preferably 10 to 30% by weight. When a copolymer having a constitutional unit of less than 5% by weight is used, it is difficult to dissolve in an alkaline aqueous solution during the development process, while a copolymer exceeding 40% by weight tends to be too soluble in an alkaline aqueous solution. .

  Examples of the compound (a1) include monocarboxylic acids, dicarboxylic acids, dicarboxylic acid anhydrides, mono [(meth) acryloyloxyalkyl] esters of polyvalent carboxylic acids, and polymers having a carboxyl group and a hydroxyl group at both ends. Examples thereof include mono (meth) acrylates, polycyclic compounds having a carboxyl group, and anhydrides thereof.

Specific examples thereof include, for example, acrylic acid, methacrylic acid, crotonic acid and the like as monocarboxylic acid;
Maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid etc. as dicarboxylic acid;
As anhydrides of dicarboxylic acids, anhydrides of the compounds exemplified as the above dicarboxylic acids, etc .;
Mono [(meth) acryloyloxyalkyl] esters of polycarboxylic acids such as succinic acid mono [2- (meth) acryloyloxyethyl], phthalic acid mono [2- (meth) acryloyloxyethyl], etc .;
As a mono (meth) acrylate of a polymer having a carboxyl group and a hydroxyl group at both ends, ω-carboxypolycaprolactone mono (meth) acrylate and the like;
5-carboxybicyclo [2.2.1] hept-2-ene, 5,6-dicarboxybicyclo [2.2.1] hept-2-ene as a polycyclic compound having a carboxyl group and its anhydride, 5-carboxy-5-methylbicyclo [2.2.1] hept-2-ene, 5-carboxy-5-ethylbicyclo [2.2.1] hept-2-ene, 5-carboxy-6-methylbicyclo [2.2.1] Hept-2-ene, 5-carboxy-6-ethylbicyclo [2.2.1] hept-2-ene, 5,6-dicarboxybicyclo [2.2.1] hept- 2-ene anhydride etc. are mentioned, respectively.

  Of these, monocarboxylic acid and dicarboxylic acid anhydrides are preferably used, and acrylic acid, methacrylic acid, and maleic anhydride are particularly preferably used from the viewpoints of copolymerization reactivity, solubility in alkaline aqueous solution, and availability. It is done. These may be used alone or in combination.

  The copolymer [A] used in the present invention is preferably a structural unit derived from the compound (a2) based on the total of repeating units derived from the compounds (a1), (a2) and (a3). 10 to 70% by weight, particularly preferably 20 to 60% by weight. When this structural unit is less than 10% by weight, the heat resistance and surface hardness of the resulting interlayer insulating film and microlens tend to be reduced. On the other hand, when the amount of this structural unit exceeds 70% by weight, a radiation sensitive resin is used. The storage stability of the composition tends to decrease.

  The compound (a2) having an alicyclic epoxy skeleton has the following formula:

It has the alicyclic epoxy frame | skeleton represented by these. As the compound (a2), for example, methacrylic acid esters, acrylic acid esters, styrenes, and vinyl ethers having the alicyclic epoxy skeleton are preferable, and methacrylic acid esters are particularly preferable. As the compound (a2) having an alicyclic epoxy skeleton, the following formula

(Wherein R ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₂ is a divalent hydrocarbon group having 1 or more carbon atoms)
The compound represented by these can be mentioned as a preferable example.

Examples of the unsaturated compound of compound (a3) include cyclohexylmaleimide, 2-hydroxyethyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, p-vinylbenzyl glycidyl ether, glycidyl methacrylate, and A combination of at least one selected from the group consisting of n-lauryl methacrylate and styrene is used.

These sac Chi, scan Chile down is preferred in view of solubility in copolymerization reactivity and an aqueous alkaline solution.

Also, main methacrylic acid glycidyl (glycidyl methacrylate), p - vinyl benzyl glycidyl ether, the heat resistance of the interlayer insulating film or microlens obtained and copolymerization reactivity, are preferably used from the viewpoint of enhancing the surface hardness. These may be used alone or in combination.

Preferable specific examples of the copolymer [A] used in the present invention include, for example, methacrylic acid / styrene / tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate / 3,4-epoxy. Cyclohexylmethyl methacrylate copolymer, methacrylic acid / styrene / tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate / 3,4-epoxycyclohexylmethyl methacrylate / cyclohexyl maleimide Polymer, methacrylic acid / styrene / tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate / 3,4-epoxycyclohexylmethyl methacrylate / 2-hydroxyethyl methacrylate copolymer, methacrylic acid / styrene / tricyclo [5.2.1.0 ^2,6] decan-8-yl methacrylate / 3,4 Pokishishikuro hexyl methyl methacrylate / n-lauryl methacrylate copolymers to.

The copolymer [A] used in the present invention has a polystyrene-equivalent weight average molecular weight (hereinafter referred to as “Mw”), preferably 2 × 10 ³ to 1 × 10 ⁵ , more preferably 5 × 10 ^{3 to} 5. It is desirable that it is × 10 ⁴ . If the Mw is less than 2 × 10 ³ , the development margin may not be sufficient, and the remaining film ratio of the resulting film may decrease, or the pattern shape of the resulting interlayer insulating film or microlens, heat resistance, etc. May be inferior. On the other hand, if it exceeds 1 × 10 ⁵ , the sensitivity may decrease or the pattern shape may be inferior. The molecular weight distribution (hereinafter referred to as “Mw / Mn”) is preferably 5.0 or less, more preferably 3.0 or less. When Mw / Mn exceeds 5.0, the pattern shape of the obtained interlayer insulating film or microlens may be inferior. The radiation-sensitive resin composition containing the copolymer [A] can easily form a predetermined pattern shape without causing a development residue during development.

  Examples of the solvent used for the production of the copolymer [A] include alcohol, ether, glycol ether, ethylene glycol alkyl ether acetate, diethylene glycol, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, propylene glycol alkyl ether propio Nates, aromatic hydrocarbons, ketones, esters and the like.

  Specific examples thereof include alcohols such as methanol and ethanol;

Examples of ethers include tetrahydrofuran and the like;
Examples of glycol ethers include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether;

  Examples of the ethylene glycol alkyl ether acetate include methyl cellosolve acetate and ethyl cellosolve acetate;

Examples of diethylene glycol include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol ethyl methyl ether;
Examples of the propylene glycol monoalkyl ether include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether;

  Examples of the propylene glycol alkyl ether acetate include propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, and propylene glycol butyl ether acetate;

  Examples of the propylene glycol alkyl ether propionate include propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate, propylene glycol butyl ether propionate and the like;

  Examples of the aromatic hydrocarbon include toluene and xylene;

  Examples of the ketone include methyl ethyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone;

  Examples of the ester include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, Ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, 2- Methyl hydroxy-3-methylbutanoate, methyl methoxyacetate, ethyl methoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, butyl ethoxyacetate, propo Methyl cyanoacetate, ethyl propoxyacetate, propylpropoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propyl butoxyacetate, butylbutoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, 2-methoxypropionate Propyl acid, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, 2-butoxypropionic acid Ethyl, propyl 2-butoxypropionate, butyl 2-butoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, 3-methoxy Butyl lopionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl 3-propoxypropionate, 3-propoxypropion Examples thereof include propyl acid, butyl 3-propoxypropionate, methyl 3-butoxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate, and butyl 3-butoxypropionate.

  Among these, ethylene glycol alkyl ether acetate, diethylene glycol, propylene glycol monoalkyl ether, and propylene glycol alkyl ether acetate are preferable, and diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol methyl ether, and propylene glycol methyl ether acetate are particularly preferable.

  As the polymerization initiator used in the production of the copolymer [A], those generally known as radical polymerization initiators can be used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-2,4-dimethylvaleronitrile) Azo compounds such as benzoyl peroxide, lauroyl peroxide, t-butyl peroxypivalate, organic peroxides such as 1,1′-bis- (t-butylperoxy) cyclohexane, and hydrogen peroxide. When a peroxide is used as the radical polymerization initiator, it may be a redox initiator using the peroxide together with a reducing agent.

  In the production of the copolymer [A], a molecular weight modifier can be used to adjust the molecular weight. Specific examples thereof include halogenated hydrocarbons such as chloroform and carbon tetrabromide; mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan and thioglycolic acid; dimethylxanthogen sulfide And xanthogens such as diisopropylxanthogen disulfide; terpinolene, α-methylstyrene dimer and the like.

[B] Component As the 1,2-naphthoquinone diazide sulfonic acid ester of the [B] component used in the present invention, for example, a condensate of a phenolic compound or an alcoholic compound and 1,2-naphthoquinone diazide sulfonic acid halide is preferable. It is mentioned as a thing. As the 1,2-naphthoquinone diazide sulfonic acid halide, 1,2-naphthoquinone diazide sulfonic acid chloride is preferable.

  Examples of the phenolic compound or alcoholic compound include trihydroxybenzophenone, tetrahydroxybenzophenone, pentahydroxybenzophenone, hexahydroxybenzophenone, and (polyhydroxyphenyl) alkane.

  Specific examples thereof include trihydroxybenzophenone such as 2,3,4-trihydroxybenzophenone and 2,4,6-trihydroxybenzophenone;

  Examples of tetrahydroxybenzophenone include 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,3,4,3′-tetrahydroxybenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, 2,3 , 4,2′-tetrahydroxy-4′-methylbenzophenone, 2,3,4,4′-tetrahydroxy-3′-methoxybenzophenone, etc .;

Examples of pentahydroxybenzophenone include 2,3,4,2 ′, 6′-pentahydroxybenzophenone;
Examples of hexahydroxybenzophenone include 2,4,6,3 ′, 4 ′, 5′-hexahydroxybenzophenone, 3,4,5,3 ′, 4 ′, 5′-hexahydroxybenzophenone and the like;

  Examples of (polyhydroxyphenyl) alkane include 2-methyl-2- (2,4-dihydroxyphenyl) -4- (4-hydroxyphenyl) -7-hydroxychroman and 2- [bis {(5-isopropyl-4 -Hydroxy-2-methyl) phenyl} methyl] phenol, 1- [1- (3- {1- (4-hydroxyphenyl) -1-methylethyl} -4,6-dihydroxyphenyl) -1-methylethyl] -3- (1- (3- {1- (4-hydroxyphenyl) -1-methylethyl} -4,6-dihydroxyphenyl) -1-methylethyl) benzene, and 4,6-bis {1- ( 4-hydroxyphenyl) -1-methylethyl} -1,3-dihydroxybenzenebis (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, 1,1,3-tris (2,5-dimethyl-4-hydroxyphenyl) -3-phenylpropane, 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, 2,2,4-trimethyl-7,2 ′, 4′-trihydroxyflavan, etc. It can be mentioned are.

  In the condensation reaction, 1,2-naphthoquinonediazide sulfonic acid halide corresponding to 30 to 85 mol%, more preferably 50 to 70 mol% is used with respect to the number of OH groups in the phenolic compound or alcoholic compound. be able to.

  Examples of the solvent that can be used at this time include ketones and cyclic ethers. Specific examples of these include ketones such as acetone, methyl ethyl ketone, methyl isoamyl ketone, and methyl isobutyl ketone. Examples of cyclic ethers include 1,4-dioxane and 1,3,5-trioxane. it can. When a solvent is used, the amount used is preferably 100 to 500 parts by weight with respect to 100 parts by weight in total of the specific phenol compound and 1,2-naphthoquinonediazide sulfonic acid halide.

  A basic compound can be used as the catalyst. Preferred examples include triethylamine, tetramethylammonium chloride, tetramethylammonium bromide, pyridine and the like. The amount of the catalyst used is preferably 1 mol or more, more preferably 1.05 to 1.2 mol, per 1 mol of 1,2-naphthoquinonediazidesulfonic acid halide.

  The catalyst dropping temperature and the reaction temperature are preferably 0 to 50 ° C, more preferably 0 to 40 ° C, and particularly preferably 10 to 35 ° C.

  The reaction time is preferably 0.5 to 10 hours, more preferably 1 to 5 hours, and particularly preferably 1 to 3 hours.

  After the condensation reaction, the precipitate is filtered, and then the filtrate is put into a large amount of 0.1 to 3.0 wt% dilute hydrochloric acid aqueous solution to precipitate the reaction product. Thereafter, the precipitate is filtered, washed with water until the filtrate becomes neutral, and then dried to obtain the component [B].

  These [B] components can be used alone or in combination of two or more.

  [B] The usage-amount of a component becomes like this. Preferably it is 5-100 weight part with respect to 100 weight part of copolymers [A], More preferably, it is 10-50 weight part. When this ratio is less than 5 parts by weight, the difference in solubility between the irradiated portion and the unirradiated portion in the alkaline aqueous solution serving as the developer is small, and patterning becomes difficult, and the obtained interlayer insulating film or micro-layer The heat resistance and solvent resistance of the lens may be insufficient. On the other hand, when this ratio exceeds 100 parts by weight, the solubility in the alkaline aqueous solution may be insufficient in the radiation irradiated portion, and development may be difficult.

Other Components The radiation-sensitive resin composition of the present invention contains the above-mentioned copolymer [A] and [B] components as essential components, but [C] a thermosensitive acid-generating compound, [ D] A polymerizable compound having at least one ethylenically unsaturated double bond, an epoxy resin other than [E] copolymer [A], [F] an adhesion assistant, or [G] a surfactant. be able to.

  [C] The heat-sensitive acid generating compound can be used to improve heat resistance and hardness. Specific examples thereof include onium salts such as sulfonium salts, benzothiazonium salts, ammonium salts, and phosphonium salts.

  Specific examples of the sulfonium salt include alkylsulfonium salts, benzylsulfonium salts, dibenzylsulfonium salts, substituted benzylsulfonium salts and the like.

Specific examples thereof include alkylsulfonium salts such as 4-acetophenyldimethylsulfonium hexafluoroantimonate, 4-acetoxyphenyldimethylsulfonium hexafluoroarsenate, dimethyl-4- (benzyloxycarbonyloxy) phenylsulfonium hexafluoro. Antimonate, dimethyl-4- (benzoyloxy) phenylsulfonium hexafluoroantimonate, dimethyl-4- (benzoyloxy) phenylsulfonium hexafluoroarsenate, dimethyl-3-chloro-4-acetoxyphenylsulfonium hexafluoroantimonate, etc .;
Examples of the benzylsulfonium salt include benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, benzyl-4-methoxyphenyl. Methylsulfonium hexafluoroantimonate, benzyl-2-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-3-chloro-4-hydroxyphenylmethylsulfonium hexafluoroarsenate, 4-methoxybenzyl-4-hydroxyphenyl Methylsulfonium hexafluorophosphate, etc .;
Examples of the dibenzylsulfonium salt include dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluorophosphate, 4-acetoxyphenyldibenzylsulfonium hexafluoroantimonate, and dibenzyl-4-methoxyphenylsulfonium. Hexafluoroantimonate, dibenzyl-3-chloro-4-hydroxyphenylsulfonium hexafluoroarsenate, dibenzyl-3-methyl-4-hydroxy-5-tert-butylphenylsulfonium hexafluoroantimonate, benzyl-4-methoxybenzyl- 4-hydroxyphenylsulfonium hexafluorophosphate and the like;
Examples of substituted benzylsulfonium salts include p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, and p-chlorobenzyl-4-hydroxyphenylmethyl. Sulfonium hexafluorophosphate, p-nitrobenzyl-3-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 3,5-dichlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, o-chlorobenzyl-3- And chloro-4-hydroxyphenylmethylsulfonium hexafluoroantimonate.

  Specific examples of the benzothiazonium salt include 3-benzylbenzothiazonium hexafluoroantimonate, 3-benzylbenzothiazonium hexafluorophosphate, 3-benzylbenzothiazonium tetrafluoroborate, 3- (p- Benzylbenzothiazonium such as methoxybenzyl) benzothiazonium hexafluoroantimonate, 3-benzyl-2-methylthiobenzothiazonium hexafluoroantimonate, 3-benzyl-5-chlorobenzothiazonium hexafluoroantimonate Salt.

  Of these, sulfonium salts and benzothiazonium salts are preferably used, among which 4-acetoxyphenyldimethylsulfonium hexafluoroarsenate, benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylmethyl Sulfonium hexafluoroantimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylsulfonium hexafluoroantimonate, and 3-benzylbenzothiazolium hexafluoroantimonate are particularly preferably used.

  Examples of these commercially available products include Sun-Aid SI-L85, SI-L110, SI-L145, SI-L150, SI-L160 (manufactured by Sanshin Chemical Industry Co., Ltd.).

  The proportion of component [C] used is preferably 20 parts by weight or less, more preferably 5 parts by weight or less with respect to 100 parts by weight of copolymer [A]. When the amount used exceeds 20 parts by weight, precipitates may be deposited in the coating film forming step, which may hinder the coating film formation.

  Examples of the polymerizable compound having at least one ethylenically unsaturated double bond as component [D] (hereinafter sometimes referred to as “component D”) include monofunctional (meth) acrylate, bifunctional ( Preferable examples include (meth) acrylate or tri- or higher functional (meth) acrylate.

  Examples of the monofunctional (meth) acrylate include 2-hydroxyethyl (meth) acrylate, carbitol (meth) acrylate, isobornyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, and 2- (meth) acryloyloxyethyl. And 2-hydroxypropyl phthalate. As these commercial products, for example, Aronix M-101, M-111, M-114 (above, manufactured by Toagosei Co., Ltd.), KAYARAD TC-110S, TC-120S (above, Nippon Kayaku Co., Ltd.) ) Co., Ltd.), Biscoat 158, 2311 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

  Examples of the bifunctional (meth) acrylate include ethylene glycol (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, Examples include tetraethylene glycol di (meth) acrylate, bisphenoxyethanol full orange acrylate, and bisphenoxyethanol full orange acrylate. As these commercial products, for example, Aronix M-210, M-240, M-6200 (above, manufactured by Toagosei Co., Ltd.), KAYARAD HDDA, HX-220, R-604 (above, Nippon Kayaku) Medicine Co., Ltd.), Viscoat 260, 312 and 335HP (above, Osaka Organic Chemical Industries, Ltd.).

  Examples of the trifunctional or higher functional (meth) acrylate include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tri ((meth) acryloyloxyethyl) phosphate, and pentaerythritol tetra (meth) acrylate. , Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like, and as commercially available products thereof, for example, Aronix M-309, M-400, M-405, M-450, M-7100, M-8030, M-8060 (above, manufactured by Toagosei Co., Ltd.), KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120 (Nippon Kayaku Co., Ltd.), screw Over DOO 295, the 300, the 360, the GPT, said 3PA, the 400 (manufactured by Osaka Organic Chemical Industry Ltd.) and the like.

  Of these, a tri- or higher functional (meth) acrylate is preferably used, and among them, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol hexa (meth) acrylate are particularly preferable.

  These monofunctional, bifunctional, or trifunctional or higher (meth) acrylates are used alone or in combination. The proportion of the component [D] used is preferably 50 parts by weight or less, more preferably 30 parts by weight or less with respect to 100 parts by weight of the copolymer [A].

  By including the component [D] at such a ratio, the heat resistance, surface hardness, etc. of the interlayer insulating film or microlens obtained from the radiation-sensitive resin composition of the present invention can be improved. When the amount used exceeds 50 parts by weight, film roughening may occur in the step of forming a coating film of the radiation sensitive resin composition on the substrate.

  The epoxy resin other than the copolymer [A] which is the above [E] component (hereinafter sometimes referred to as “E component”) is not limited as long as the compatibility is not affected, but preferably (Co) polymerization of bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, cycloaliphatic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, heterocyclic epoxy resin, glycidyl methacrylate And the like. Of these, bisphenol A type epoxy resins, cresol novolac type epoxy resins, glycidyl ester type epoxy resins and the like are particularly preferable.

  [E] The usage-amount of a component becomes like this. Preferably it is 30 weight part or less with respect to 100 weight part of copolymers [A]. By containing the component [E] at such a ratio, the heat resistance and surface hardness of the protective film or insulating film obtained from the radiation-sensitive resin composition of the present invention can be further improved. When this ratio exceeds 30 parts by weight, the film thickness uniformity of the coating film may be insufficient when a coating film of the radiation sensitive resin composition is formed on the substrate.

  The copolymer [A] can also be referred to as an “epoxy resin”, but differs from the component [E] in that it has alkali solubility.

  In the radiation sensitive resin composition of the present invention, a surfactant which is the above-mentioned [F] component can be used to further improve the coating property. As the surfactant, for example, a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant can be preferably mentioned.

  Specific examples of the fluorosurfactant include 1,1,2,2-tetrafluorooctyl (1,1,2,2-tetrafluoropropyl) ether, 1,1,2,2-tetrafluorooctylhexyl ether. , Octaethylene glycol di (1,1,2,2-tetrafluorobutyl) ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoropentyl) ether, octapropylene glycol di (1,1 , 2,2-tetrafluorobutyl) ether, hexapropylene glycol di (1,1,2,2,3,3-hexafluoropentyl) ether, sodium perfluorododecyl sulfonate, 1,1,2,2,8 , 8,9,9,10,10-decafluorododecane, 1,1,2,2,3,3-hexafluorodecane, etc. Sodium sulfonates; fluoroalkyloxyethylene ethers; fluoroalkylammonium iodides, fluoroalkylpolyoxyethylene ethers, perfluoroalkylpolyoxyethanols; perfluoroalkylalkoxylates; fluorinated alkyl esters be able to. These commercial products include BM-1000, BM-1100 (manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183, F178, F191, F191 (and above, Dainippon Ink). Chemical Industries, Ltd.), Fluorad FC-170C, FC-171, FC-430, FC-431 (above, manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S-141, S-145, S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (manufactured by Asahi Glass Co., Ltd.) ), F-top EF301, 303, and 352 (manufactured by Shin-Akita Kasei Co., Ltd.).

  Examples of the silicone surfactant include DC3PA, DC7PA, FS-1265, SF-8428, SH11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH-190, SH-193, SZ-6032 (above, Toray Dow Corning) -Silicone Co., Ltd.), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4442 (above, GE Toshiba Silicone Co., Ltd.) are commercially available. You can list what you have.

  Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether Polyoxyethylene aryl ethers such as polyoxyethylene dilaurate, polyoxyethylene dialkyl esters such as polyoxyethylene distearate, and the like; (meth) acrylic acid copolymer polyflow no. 57, 95 (manufactured by Kyoeisha Chemical Co., Ltd.) or the like can be used.

  These surfactants can be used alone or in combination of two or more.

  These [F] surfactants are preferably used in an amount of 5 parts by weight or less, more preferably 2 parts by weight or less based on 100 parts by weight of the copolymer [A]. [F] When the amount of the surfactant used exceeds 5 parts by weight, the coating film may be easily formed when the coating film is formed on the substrate.

  In the radiation-sensitive resin composition of the present invention, an adhesion assistant as the [G] component can also be used in order to improve the adhesion to the substrate. As such [G] adhesion assistant, a functional silane coupling agent is preferably used. For example, the silane coupling agent which has reactive substituents, such as a carboxyl group, a methacryloyl group, an isocyanate group, an epoxy group, is mentioned. Specifically, trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like. Such [G] adhesion assistant is preferably used in an amount of 20 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the copolymer [A]. In the case where the amount of the adhesion assistant exceeds 20 parts by weight, there may be a case where a development residue is likely to occur in the development process.

Radiation-sensitive resin composition The radiation-sensitive resin composition of the present invention is prepared by uniformly mixing the above-mentioned copolymer [A] and [B] components and other components optionally added as described above. Is done. The radiation-sensitive resin composition of the present invention is preferably used in a solution state after being dissolved in an appropriate solvent. For example, the radiation sensitive resin composition in a solution state can be prepared by mixing the copolymer [A] and [B] components and other optionally added components in a predetermined ratio.

  As a solvent used for the preparation of the radiation sensitive resin composition of the present invention, each component of the copolymer [A] and [B] components and other components optionally blended is uniformly dissolved, and each component Those that do not react with.

  As such a solvent, the thing similar to what was illustrated as a solvent which can be used in order to manufacture copolymer [A] mentioned above can be mentioned.

  Of these solvents, glycol ether, ethylene glycol alkyl ether acetate, ester and diethylene glycol are preferably used from the viewpoints of solubility of each component, reactivity with each component, ease of film formation, and the like. Of these, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl methoxypropionate, and ethyl ethoxypropionate can be particularly preferably used.

  Furthermore, in order to improve the in-plane uniformity of the film thickness together with the solvent, a high boiling point solvent can be used in combination. Examples of the high-boiling solvent that can be used in combination include N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and benzylethyl ether. , Dihexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, carbonic acid Examples include propylene and phenyl cellosolve acetate. Of these, N-methylpyrrolidone, γ-butyrolactone, and N, N-dimethylacetamide are preferable.

  When a high boiling point solvent is used in combination as the solvent of the radiation sensitive resin composition of the present invention, the amount used is 50% by weight or less, preferably 40% by weight or less, more preferably 30% by weight or less, based on the total amount of the solvent. can do. When the amount of the high-boiling solvent used exceeds this amount, the coating film thickness uniformity, sensitivity, and residual film rate may be reduced.

  When the radiation-sensitive resin composition of the present invention is prepared in a solution state, components other than the solvent in the solution (that is, the total of the copolymer [A] and [B] components and other components optionally added) The ratio of (amount) can be arbitrarily set according to the purpose of use, the value of the desired film thickness, and the like. Preferably it is 5-50 weight%, More preferably, it is 10-40 weight%, More preferably, it is 15-35 weight%.

  The composition solution thus prepared can be used after being filtered using a Millipore filter having a pore size of about 0.2 μm.

Formation of Interlayer Insulating Film and Microlens Next, a method for forming the interlayer insulating film and microlens of the present invention using the radiation sensitive resin composition of the present invention will be described. The method for forming an interlayer insulating film or microlens of the present invention can include the following steps in the order described below.

(1) The process of forming the coating film of the radiation sensitive resin composition of this invention on a board | substrate,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) Development step, and (4) Heating step.

(1) The process of forming the coating film of the radiation sensitive resin composition of this invention on a board | substrate In the process of said (1), apply | coating the solution of the resin composition of this invention on the board | substrate surface, and prebaking. To remove the solvent to form a coating film of the radiation-sensitive resin composition.

  Examples of the types of substrates that can be used include glass substrates, silicon wafers, and substrates on which various metals are formed.

  The method for applying the composition solution is not particularly limited, and for example, an appropriate method such as a spray method, a roll coating method, a spin coating method, or a bar coating method can be employed. The pre-baking conditions vary depending on the type of each component, the use ratio, and the like. For example, it can be set at about 60 to 110 ° C. for about 30 seconds to 15 minutes.

  The film thickness of the coating film to be formed is, for example, 3 to 6 μm when forming an interlayer insulating film as a value after pre-baking, and 0.5 to 3 μm, for example, when forming a microlens. Is preferred.

(2) Step of irradiating at least a part of the coating film In the step of (2) above, after irradiating the formed coating film with radiation through a mask having a predetermined pattern, a developer is applied. The patterning is performed by removing the irradiated portion using the development process. Examples of the radiation used at this time include ultraviolet rays, far ultraviolet rays, X-rays, and charged particle beams.

  Examples of the ultraviolet rays include g-line (wavelength 436 nm), i-line (wavelength 365 nm), and the like. Examples of the far ultraviolet rays include KrF excimer laser. Examples of X-rays include synchrotron radiation. Examples of the charged particle beam include an electron beam.

  Among these, ultraviolet rays are preferable, and radiation including g-line and / or i-line is particularly preferable.

The exposure amount, 50~1,500J / m ² In the case of forming an interlayer insulating film, in the case of forming a micro-lens is preferably set to 50~2,000J / m ^2.

(3) Development process Examples of the developer used in the development process include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, diethylaminoethanol, di-acid. N-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene An aqueous solution of an alkali (basic compound) such as 1,5-diazabicyclo [4,3,0] -5-nonane can be used. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the above aqueous alkali solution, or various organic solvents that dissolve the composition of the present invention can be used as a developing solution. Furthermore, as a developing method, an appropriate method such as a liquid piling method, a dipping method, a rocking dipping method, a shower method, or the like can be used. The development time at this time varies depending on the composition of the composition. For example, it can be 30 to 120 seconds.

  In addition, the conventionally known radiation-sensitive resin composition has been required to strictly control the development time because the formed pattern peels when the development time exceeds about 20 to 25 seconds from the optimum value. In the case of the radiation-sensitive resin composition of the invention, good pattern formation is possible even when the excess time from the optimum development time is 30 seconds or more, and there is an advantage in product yield.

(4) Heating step (3) Performed as described above (3) After the development step, the patterned thin film is preferably rinsed, for example, by washing with running water, and more preferably irradiated with radiation from a high-pressure mercury lamp or the like. (After post-exposure), the 1,2-quinonediadito compound remaining in the thin film is decomposed, and then the thin film is heated (post-baked) with a heating device such as a hot plate or an oven. Thus, the thin film can be cured. Exposure at the later exposure step is preferably 2,000~5,000J / m ² approximately. Moreover, the baking temperature in this hardening process is 120-250 degreeC, for example. Although heating time changes with kinds of heating apparatus, for example, when performing heat processing on a hotplate, it can be set to 30 to 90 minutes when performing heat processing in oven, for example. At this time, a step baking method or the like in which a heating process is performed twice or more can also be used.

  In this way, a patterned thin film corresponding to the target interlayer insulating film or microlens can be formed on the surface of the substrate.

  The interlayer insulating film and the microlens formed as described above are excellent in adhesion, heat resistance, solvent resistance, transparency, and the like, as will be apparent from the examples described later.

Interlayer Insulating Film The interlayer insulating film of the present invention formed as described above has good adhesion to the substrate, excellent solvent resistance and heat resistance, high transmittance, and interlayer insulation of electronic components. It can be suitably used as a membrane.

The microlens of the present invention formed as described above has good adhesion to the substrate, excellent solvent resistance and heat resistance, and has high transmittance and a good melt shape. It can be suitably used as a microlens for a solid-state imaging device.

  The shape of the microlens of the present invention is a semi-convex lens shape as shown in FIG.

  The present invention will be described more specifically with reference to synthesis examples and examples. However, the present invention is not limited to the following examples.

Synthesis example of copolymer [A] Synthesis example 1
A flask equipped with a condenser and a stirrer was charged with 10 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 250 parts by weight of diethylene glycol ethyl methyl ether. Subsequently, 22 parts by weight of methacrylic acid, 5 parts by weight of styrene, 28 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 45 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate and α -After 5 parts by weight of methylstyrene dimer was charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 4 hours to obtain a polymer solution containing the copolymer [A-1].

  The copolymer [A-1] had a polystyrene equivalent weight average molecular weight (Mw) of 8,000 and a molecular weight distribution (Mw / Mn) of 2.3. The solid content concentration of the polymer solution obtained here was 29.8% by weight.

Synthesis example 2
A flask equipped with a condenser and a stirrer was charged with 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of diethylene glycol ethyl methyl ether. Subsequently, 18 parts by weight of methacrylic acid, 5 parts by weight of styrene, 17 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 40 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate, cyclohexyl After 20 parts by weight of maleimide and 3 parts by weight of α-methylstyrene dimer were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer [A-2].

  The copolymer [A-2] had a polystyrene equivalent weight average molecular weight (Mw) of 11,000 and a molecular weight distribution (Mw / Mn) of 2.1. The solid content concentration of the polymer solution obtained here was 31.5% by weight.

Synthesis example 3
A flask equipped with a condenser and a stirrer was charged with 6 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of diethylene glycol ethyl methyl ether. Subsequently, 15 parts by weight of methacrylic acid, 5 parts by weight of styrene, 20 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 40 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate, 2 After 20 parts by weight of hydroxyethyl methacrylate and 3 parts by weight of α-methylstyrene dimer were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 4.5 hours to obtain a polymer solution containing the copolymer [A-3].

  The copolymer [A-3] had a polystyrene equivalent weight average molecular weight (Mw) of 13,000 and a molecular weight distribution (Mw / Mn) of 2.2. Moreover, the solid content concentration of the polymer solution obtained here was 32.7% by weight.

Synthesis example 4
A flask equipped with a condenser and a stirrer was charged with 8.5 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 220 parts by weight of diethylene glycol ethyl methyl ether. Subsequently, 15 parts by weight of methacrylic acid, 5 parts by weight of styrene, 30 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 40 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate, n -After 10 parts by weight of lauryl methacrylate and 3 parts by weight of α-methylstyrene dimer were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 4.5 hours to obtain a polymer solution containing the copolymer [A-4].

  The copolymer [A-4] had a weight average molecular weight (Mw) in terms of polystyrene of 8,000 and a molecular weight distribution (Mw / Mn) of 1.8. Further, the solid content concentration of the polymer solution obtained here was 31.5% by weight.

Synthesis example 5
A flask equipped with a condenser and a stirrer was charged with 8.5 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 220 parts by weight of diethylene glycol ethyl methyl ether. Subsequently, 15 parts by weight of methacrylic acid, 5 parts by weight of styrene, 30 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 20 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate, p -20 parts by weight of vinylbenzyl glycidyl ether, 10 parts by weight of n-lauryl methacrylate and 3 parts by weight of α-methylstyrene dimer were charged and purged with nitrogen, and then gently stirred. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 4.5 hours to obtain a polymer solution containing the copolymer [A-5].

  The copolymer [A-5] had a polystyrene equivalent weight average molecular weight (Mw) of 8,500 and a molecular weight distribution (Mw / Mn) of 2.2. The polymer solution obtained here had a solid content concentration of 31.7% by weight.

Synthesis Example 6
A flask equipped with a condenser and a stirrer was charged with 8.5 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 220 parts by weight of diethylene glycol ethyl methyl ether. Subsequently, 15 parts by weight of methacrylic acid, 5 parts by weight of styrene, 30 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 20 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate, glycidyl. After 20 parts by weight of methacrylate, 10 parts by weight of n-lauryl methacrylate and 3 parts by weight of α-methylstyrene dimer were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 4.5 hours to obtain a polymer solution containing the copolymer [A-6].

  The copolymer [A-6] had a weight average molecular weight (Mw) in terms of polystyrene of 9,000 and a molecular weight distribution (Mw / Mn) of 2.5. Moreover, the solid content concentration of the polymer solution obtained here was 31.9% by weight.

Synthesis example of component [B] Synthesis example 7
In a flask equipped with a stirrer, a dropping funnel and a thermometer under light shielding, 36.41 g of 2-methyl-2- (2,4-dihydroxyphenyl) -4- (4-hydroxyphenyl) -7-hydroxychroman ( 100 mmol), 85.49 g (300 mmol) of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 735 mL of acetone were charged and dissolved uniformly. Next, 33.37 g (330 mmol) of triethylamine was added dropwise over 30 minutes while maintaining the temperature of the solution at 20 to 30 ° C., and the mixture was reacted at the same temperature for 2 hours.

  The precipitate is removed by filtration, the filtrate is poured into a large excess of 1% by weight aqueous hydrochloric acid solution to precipitate the product, filtered, washed with water until the filtrate is neutral, and then at 40 ° C. in a vacuum dryer. [B-1] (2-methyl-2- (2,4-dihydroxyphenyl) -4- (4-hydroxyphenyl) -7-hydroxychroman (1.0 mol) and 1,2- Naphthoquinonediazide-5-sulfonic acid chloride (3.0 mol) condensate) was obtained.

Synthesis Examples 8-12
The same procedure as in Synthesis Example 7 was conducted except that the type and amount of the specific phenol compound and the amount of 1,2-naphthoquinonediazide-5-sulfonic acid chloride were changed as shown in Table 1 in Synthesis Example 7. [B-2] to [B-6] were obtained.

Example 1
[Preparation of radiation-sensitive resin composition]
The solution containing the polymer [A-1] as the [A] component synthesized in Synthesis Example 1 above, the amount corresponding to 100 parts by weight (solid content) of the polymer [A-1], and the [B] component After dissolving 20 parts by weight of [B-1] synthesized in Synthesis Example 7 in diethylene glycol ethyl methyl ether so that the solid content concentration is 30% by weight, it is filtered through a membrane filter having a diameter of 0.2 μm, A solution (S-1) of a radiation sensitive resin composition was prepared.

Examples 2-16
[Preparation of radiation-sensitive resin composition]
In Example 1, it carried out like Example 1 except having used the kind and quantity as shown in Table 2 as [A] component and [B] component, and carried out the solution of the radiation sensitive resin composition. (S-2) to (S-16) were prepared.

C-1: Cymel 300 (Mitsui Cyanamid Co., Ltd.)
C-2: Cymel 272 (Mitsui Cyanamid Co., Ltd.)
C-3: Nikarak Ns-11 (Sanwa Chemical Co., Ltd.)

D-1: Epicoat 828 (Oilized Shell Epoxy Co., Ltd.)
D-2: Epolite 100MF (manufactured by Kyoeisha Chemical Co., Ltd.)

Examples 1 to 16, Comparative Examples 1 and 2
<Performance evaluation as interlayer insulation film>
Using the radiation-sensitive resin composition prepared as described above, various characteristics as an interlayer insulating film were evaluated as follows. The compositions used in Comparative Examples 1 and 2 are both commercial products of a composition of m / p-cresol novolak and 1,2-naphthoquinonediazide-5-sulfonic acid ester (manufactured by Tokyo Ohka Kogyo Co., Ltd.). It is.

[Evaluation of sensitivity]
The composition shown in Table 2 was applied onto a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. The resulting coating film was exposed to light by changing the exposure time with a PLA-501F exposure machine (extra-high pressure mercury lamp) manufactured by Canon Inc. through a pattern mask having a predetermined pattern. Development was carried out by a puddle method at 25 ° C. for 90 seconds with a concentration of tetramethylammonium hydroxide aqueous solution (developer). The substrate was washed with ultrapure water for 1 minute and dried to form a pattern on the wafer. The amount of exposure required to completely dissolve the 3.0 μm line-and-space (10 to 1) space pattern was measured. This value is shown in Table 3 as sensitivity. It can be said that the sensitivity is good when this value is 1000 J / m ² or less.

[Evaluation of development margin]
The composition shown in Table 2 was applied onto a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. Using a PLA-501F exposure machine (extra-high pressure mercury lamp) manufactured by Canon Inc. through a mask having a 3.0 μm line and space (10 to 1) pattern on the obtained coating film, Exposure was performed at an exposure amount corresponding to the sensitivity value measured in [Evaluation of Sensitivity], and development was carried out with a tetramethylammonium hydroxide aqueous solution having a concentration shown in Table 3 at 25 ° C. for 90 seconds by a puddle method. Subsequently, the substrate was washed with ultrapure water for 1 minute and dried to form a pattern on the wafer. At this time, the development time necessary for the line width to be 3 μm is shown in Table 3 as the optimum development time. Further, when the development was further continued from the optimum development time, the time until the 3.0 μm line pattern was peeled off was measured and shown in Table 3 as a development margin. When this value is 30 seconds or more, it can be said that the development margin is good.

[Evaluation of solvent resistance]
The composition shown in Table 2 was applied onto a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. The obtained coating film was exposed to a cumulative irradiation amount of 3,000 J / m ² with a PLA-501F exposure machine (extra-high pressure mercury lamp) manufactured by Canon Inc., and this silicon substrate was exposed to 220 in a clean oven. A cured film was obtained by heating at 0 ° C. for 1 hour. The film thickness (T1) of the obtained cured film was measured. And after immersing the silicon substrate in which this cured film was formed in dimethyl sulfoxide temperature-controlled at 70 degreeC for 20 minutes, the film thickness (t1) of the said cured film was measured, and the film thickness change rate by immersion { | T1-T1 | / T1} × 100 [%] was calculated. The results are shown in Table 3. When this value is 5% or less, the solvent resistance is good.

  In the evaluation of solvent resistance, since the patterning of the film to be formed is unnecessary, the radiation irradiation process and the development process were omitted, and only the coating film forming process, the post-baking process, and the heating process were performed for evaluation.

[Evaluation of heat resistance]
A cured film was formed in the same manner as in the evaluation of the solvent resistance, and the film thickness (T2) of the obtained cured film was measured. Next, this cured film substrate was additionally baked in a clean oven at 240 ° C. for 1 hour, and then the film thickness (t2) of the cured film was measured, and the film thickness change rate {| t2-T2 | / T2 due to the additional baking. } × 100 [%] was calculated. The results are shown in Table 3. When this value is 5% or less, the heat resistance is good.

[Evaluation of transparency]
In the evaluation of the solvent resistance, a cured film was formed on the glass substrate in the same manner except that a glass substrate “Corning 7059 (manufactured by Corning)” was used instead of the silicon substrate. The light transmittance of the glass substrate having this cured film was measured at a wavelength in the range of 400 to 800 nm using a spectrophotometer “150-20 type double beam (manufactured by Hitachi, Ltd.)”. Table 3 shows the values of the minimum light transmittance at that time. When this value is 90% or more, it can be said that the transparency is good.

Examples 17 to 32, Comparative Examples 3 and 4
<Performance evaluation as a micro lens>
Using the radiation-sensitive resin composition prepared as described above, various characteristics as a microlens were evaluated as follows. For the evaluation of heat resistance and evaluation of transparency, refer to the results of performance evaluation as the interlayer insulating film.

  In addition, the compositions used in Comparative Examples 3 and 4 are all commercially available products (manufactured by Tokyo Ohka Kogyo Co., Ltd.) of m / p-cresol novolak and 1,2-naphthoquinonediazide-5-sulfonic acid ester. It is.

[Evaluation of sensitivity]
The composition shown in Table 4 was applied onto a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. The obtained coating film was exposed with a NSR1755i7A reduction projection exposure machine (NA = 0.50, λ = 365 nm) manufactured by Nikon Corporation through a pattern mask having a predetermined pattern, and exposure was performed in Table 5. Development was carried out by a puddle method at 25 ° C. for 1 minute in an aqueous tetramethylammonium hydroxide solution having the concentration described. It was rinsed with water and dried to form a pattern on the wafer. The exposure time required for the space line width of the 0.8 μm line and space pattern (1 to 1) to be 0.8 μm was measured. This value is shown in Table 5 as sensitivity. It can be said that the sensitivity is good when this value is 2,500 J / m ² or less.

[Evaluation of development margin]
The composition shown in Table 4 was applied onto a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. The obtained coating film was measured with the above “[Evaluation of sensitivity]” with a NSR1755i7A reduction projection exposure machine (NA = 0.50, λ = 365 nm) manufactured by Nikon Corporation through a pattern mask having a predetermined pattern. Exposure was carried out at an exposure amount corresponding to the sensitivity value, and development was carried out with a tetramethylammonium hydroxide aqueous solution having the concentration shown in Table 5 at 25 ° C. for 1 minute (development method described). It was rinsed with water and dried to form a pattern on the wafer. Table 5 shows the development time required for the 0.8 μm line and space pattern (one to one) space line width to be 0.8 μm as the optimum development time. Further, the time (development margin) until the pattern having a width of 0.8 μm was peeled off when the development was further continued from the optimum development time was shown in Table 5 as the development margin. When this value is 30 seconds or more, it can be said that the development margin is good.

[Evaluation of solvent resistance]
The composition shown in Table 4 was applied onto a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. The obtained coating film was exposed to a cumulative irradiation amount of 3,000 J / m ² with a PLA-501F exposure machine (extra-high pressure mercury lamp) manufactured by Canon Inc., and this silicon substrate was exposed to 220 in a clean oven. A cured film was obtained by heating at 0 ° C. for 1 hour. The film thickness (T3) of the obtained cured film was measured. And after immersing the silicon substrate in which this cured film was formed in isopropyl alcohol temperature-controlled at 50 degreeC for 10 minutes, the film thickness (t3) of the said cured film was measured, and the film thickness change rate by immersion { | T3-T3 | / T3} × 100 [%] was calculated. The results are shown in Table 5. When this value is 5% or less, the solvent resistance is good.

  In the evaluation of solvent resistance, since the patterning of the film to be formed is unnecessary, the radiation irradiation process and the development process were omitted, and only the coating film forming process, the post-baking process, and the heating process were performed for evaluation.

[Formation of microlenses]
The composition shown in Table 4 was applied onto a silicon substrate using a spinner, and then prebaked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. The obtained coating film was passed through a pattern mask having 4.0 [mu] m dots and 2.0 [mu] m space pattern with a NSR1755i7A reduction projection exposure machine (NA = 0.50, [lambda] = 365 nm) manufactured by Nikon Corporation. Exposure is performed at an exposure amount corresponding to the sensitivity value measured in [Evaluation of Sensitivity], and 25 ° C. is applied in an aqueous tetramethylammonium hydroxide solution having a concentration described as the developer concentration in the sensitivity evaluation in Table 5. Development was performed by a liquid pouring method for a minute (development method described). It was rinsed with water and dried to form a pattern on the wafer. Then, it exposed so that an integrated irradiation amount might be set to 3,000 J / m < ² > with the PLA-501F exposure machine (extra-high pressure mercury lamp) by Canon. Thereafter, the pattern was melt-flowed by heating at 160 ° C. for 10 minutes on a hot plate and further at 230 ° C. for 10 minutes to form a microlens.

  Table 5 shows the size (diameter) and cross-sectional shape of the bottom (surface contacting the substrate) of the formed microlens. It can be said that the microlens bottom portion is good when it is larger than 4.0 μm and smaller than 5.0 μm. In addition, when this dimension is 5.0 μm or more, the adjacent lenses are in contact with each other, which is not preferable. Further, the cross-sectional shape is good when it is a semi-convex lens shape as shown in (a) in the schematic diagram shown in FIG. 1, and it is bad when it is on a substantially trapezoidal shape as shown in (b).

C-1: Cymel 300 (Mitsui Cyanamid Co., Ltd.)
C-2: Cymel 272 (Mitsui Cyanamid Co., Ltd.)
C-3: Nikarak Ns-11 (Sanwa Chemical Co., Ltd.)

D-1: Epicoat 828 (Oilized Shell Epoxy Co., Ltd.)
D-2: Epolite 100MF (manufactured by Kyoeisha Chemical Co., Ltd.)

It is a schematic diagram of the cross-sectional shape of a micro lens.

Claims (7)

[A] (a1) unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, (a2)

An unsaturated compound having an alicyclic epoxy skeleton represented by the formula: (a3) cyclohexylmaleimide, 2-hydroxyethyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, p- A copolymer of at least one selected from the group consisting of vinylbenzyl glycidyl ether, glycidyl methacrylate and n-lauryl methacrylate and an unsaturated compound consisting of styrene , and [B] 1,2-naphthoquinonediazide sulfonic acid ester,
A radiation-sensitive resin composition comprising: The radiation-sensitive resin composition according to claim 1, which is used for forming an interlayer insulating film. A method for forming an interlayer insulating film, comprising the following steps in the order described below.
(1) The process of forming the coating film of the radiation sensitive resin composition of Claim 1 on a board | substrate,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) Development step, and (4) Heating step. An interlayer insulating film formed by the method according to claim 3 . The radiation sensitive resin composition according to claim 1, which is used for forming a microlens. A method for forming a microlens comprising the following steps in the order described below.
(1) The process of forming the coating film of the radiation sensitive resin composition of Claim 1 on a board | substrate,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) Development step, and (4) Heating step. A microlens formed by the method of claim 6 .

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