JP4753237B2 - Photosensitive resin composition - Google Patents

Description

  The present invention relates to a photosensitive resin composition, more specifically, a photosensitive resin suitable for the production of semiconductor devices, flat panel displays (FPD), etc., particularly for the formation of interlayer insulating films or planarization films such as semiconductor devices and FPDs. The present invention relates to a composition, an FPD and a semiconductor device formed using the photosensitive resin composition, and a method for forming a heat-resistant thin film using the photosensitive resin composition.

  Conventionally, photolithography technology has been used to form or process microelements in a wide range of fields such as semiconductor integrated circuits such as LSIs, FPD display surfaces, thermal heads and other circuit boards. It's being used. In the photolithography technique, a positive or negative photosensitive resin composition is used to form a resist pattern. In recent years, as a new application of these photosensitive resin compositions, attention has been paid to a technique for forming an interlayer insulating film or a planarizing film such as a semiconductor integrated circuit or FPD. In particular, there is a strong market demand for higher definition of FPD display surfaces. In order to achieve this higher definition, interlayer insulation films and planarization films that are highly transparent and excellent in insulation are said to be indispensable materials. Yes. Many studies have been made on photosensitive resin compositions used for such applications, and patents have been filed and published (see, for example, Patent Documents 1 and 2). However, the photosensitive resin compositions conventionally proposed as being suitable for applications such as interlayer insulating films require a cross-linking (curing) agent to increase heat resistance, so that they are not stable over time and are finely processed. Compared with a general positive resist used in the above, special attention is required for the storage environment of the composition. Further, in the photolithography in the manufacturing process of the FPD display surface, a recycled developer that repeatedly uses the developer is used. In this recycled developer, when a positive resist for TFT (thin film transistor) production and a photosensitive resin composition containing the cross-linking agent are mixed, the cross-linking agent in the composition containing the positive resist and the cross-linking agent reacts. As a result, there is a problem that a large amount of precipitates insoluble in the developer is generated.

  In addition, a technique for preventing the flattened film after the heat treatment from becoming clouded by incorporating a monomer having an epoxy group in the polymer main chain is also known (for example, see Patent Documents 1 and 2). The stability of the polymer is poor, and the storage stability of the photosensitive resin composition becomes very short. Furthermore, when the polymer and the epoxy resin are mixed and used without being a copolymer, the storage stability is very excellent, but there is a problem that the surface of the planarized film after the heat treatment becomes cloudy.

In order to solve such problems, a method has been proposed in which carboxylic acid is added to the composition to suppress clouding of the film surface (Patent Document 3). However, as a result of investigations by the present inventors, it was found that although the problem of cloudiness on the film surface can be solved by this method, the remaining film ratio at the time of development processing may decrease as a new problem. For this reason, a composition that can achieve both suppression of cloudiness on the surface of the film and suppression of decrease in the remaining film ratio has been desired.
JP-A-7-248629 JP-A-8-262709 International Patent Publication No. 2005/008337 Pamphlet JP-A-5-297582 J. Appl. Polym. Sci., 77, pp3077 (2000) Orpanic preparation and procedures international (1985), 17 (2), pp121

In view of the situation as described above, the present invention maintains the flatness of the film surface even after high temperature baking in a photosensitive resin composition containing an alkali-soluble resin, a sensitizer containing a quinonediazide group, and a curing agent, An object of the present invention is to provide a photosensitive resin composition in which a thin film having good light transmittance and a low dielectric constant is obtained, has good temporal stability, and can achieve a high residual film ratio during development. is there.
The present invention also provides an FPD or a semiconductor device having a planarizing film or an interlayer insulating film formed from the photosensitive resin composition.
Furthermore, the present invention provides a method for forming a heat-resistant thin film by patterning using the photosensitive resin composition, performing overall exposure, and then post-baking.

  As a result of diligent research and investigations, the inventors of the present invention have found that a specific substance as an alkali-soluble resin and a curing agent in an alkali-soluble resin, a photosensitive agent containing a quinonediazide group, and a curing agent. And the photosensitive resin composition contains a polycarboxylic acid ester compound having a melting point of 20 ° C. or less and a part of a plurality of carboxyl groups esterified with a higher alcohol. That is, for example, the film surface flatness is maintained even after heat treatment at 220 ° C. for 1 hour, a thin film having good light transmittance and low dielectric constant is obtained, and long-term stability is achieved. It was found that an excellent photosensitive resin composition can be obtained, and the present invention has been achieved.

  The photosensitive resin composition according to the present invention is a photosensitive resin composition comprising an alkali-soluble acrylic resin, a photosensitive agent having a quinonediazide group and a curing agent having an epoxy group, and has a melting point of 20 ° C. or lower. The photosensitive resin composition further comprises a polycarboxylic acid ester compound in which some of a plurality of carboxyl groups are esterified with a higher alcohol.

  Moreover, the flat panel display or semiconductor device according to the present invention is characterized by having a planarizing film or an interlayer insulating film formed of the photosensitive resin composition.

  In addition, the method for forming a heat-resistant thin film according to the present invention is characterized in that after patterning using the photosensitive resin composition, the entire surface is exposed and then post-baked.

  The photosensitive resin composition according to the present invention is excellent in stability over time and coating properties, and the photosensitive resin composition of the present invention has high heat resistance, for example, even after heat treatment at a high temperature of 220 ° C. for 1 hour. It is possible to form a thin film that does not deteriorate and maintains flatness, has good light transmittance, low dielectric constant, and also has solvent resistance. And in the development process at the time of thin film formation, a high residual film ratio is maintained, and the formed thin film maintains a sufficient thickness. For this reason, the photosensitive resin composition of the present invention can be suitably used for planarizing films such as semiconductor devices, interlayer insulating films, etc., and by using the photosensitive resin composition of the present invention, excellent characteristics can be obtained. FPDs and semiconductor devices can be obtained.

Hereinafter, the present invention will be described in detail.
In the photosensitive resin composition of the present invention, an alkali-soluble acrylic resin is used. The alkali-soluble acrylic resin used in the present invention may be any acrylic resin as long as it is conventionally used as an alkali-soluble resin of a photosensitive resin, and an azo group having a cyano group as a polymerization initiator. Alkali-soluble acrylic resin synthesized using a polymerization initiator, alkali-soluble acrylic resin synthesized using an azo polymerization initiator having no cyano group, or an azo system having no cyano group Any one such as an alkali-soluble acrylic resin synthesized by using a polymerization initiator in combination with an azo polymerization initiator having a cyano group can be preferably used.

  The azo polymerization initiator having no cyano group or the azo polymerization initiator having a cyano group, which is used in the synthesis of the alkali-soluble acrylic resin, may be selected from those generally used. it can. Examples of such compounds are described in Patent Document 3, for example.

  Among such polymerization initiators, preferred azo polymerization initiators having no cyano group include 1,1′-azobis (1-acetoxy-1-phenylethane), 1,1′-azobis (1- Propionoxy-1-phenylethane), 1,1′-azobis (1-isobutyroxy-1-phenylethane), 1,1′-azobis (1-pivaloxy-1-phenylethane), 1,1′-azobis (1 -Acetoxy-1-phenylpropane), 1,1′-azobis [1-acetoxy-1- (p-methylphenyl) ethane], 1,1′-azobis [1-acetoxy-1- (p-chlorophenyl) ethane 1,1′-azobis (1-acetoxy-1-phenylbutane), dimethyl-2,2′-azobis (2-methylpropionate), and preferred silanes. Examples of the azo polymerization initiator having an ano group include 2,2'-azobisisobutyronitrile.

  When synthesizing an acrylic resin using an azo polymerization initiator having no cyano group as a polymerization initiator in the synthesis of the acrylic resin, and using this resin as the acrylic resin of the photosensitive resin composition of the present invention Therefore, it is possible to form a film having extremely good light transmittance and good heat resistance and solvent resistance. On the other hand, when an acrylic resin synthesized using an azo polymerization initiator having a cyano group is used as a polymerization initiator, a photosensitive resin composition excellent in heat resistance and solvent resistance can be obtained. Furthermore, when an acrylic resin synthesized using an azo polymerization initiator having no cyano group and an azo polymerization initiator having a cyano group is used as a polymerization initiator, light transmittance, solvent resistance, heat resistance It is possible to obtain a photosensitive resin composition excellent in various properties such as properties in a well-balanced manner. In any case, the temporal stability of the photosensitive resin composition of the present invention is extremely excellent. When an azo polymerization initiator having no cyano group and an azo polymerization initiator having a cyano group are used in combination as a polymerization initiator, these are usually in a molar ratio of 20:80 to 80:20, preferably It is used in the range of 30:70 to 70:30.

  Examples of the alkali-soluble acrylic resin used in the photosensitive resin composition of the present invention include (a) alkali-soluble polyacrylic acid ester, (b) alkali-soluble polymethacrylic acid ester, and (c) at least one acrylic. Mention may be made of alkali-soluble poly (acrylic acid esters / methacrylic acid esters) containing acid esters and at least one methacrylic acid ester as constituent units. These acrylic resins may be used alone or in combination of two or more. In addition, these acrylic resins preferably contain an organic acid monomer as a copolymerization component in order to make the resin alkali-soluble, but the copolymer unit that imparts alkali solubility to the resin is limited to the organic acid monomer. It is not something that can be done.

  Examples of the monomer component constituting these alkali-soluble polyacrylic resins include acrylic acid esters, methacrylic acid esters, organic acid monomers, and other copolymerizable monomers. As the monomer component constituting these polymers, the following exemplified acrylic acid ester, methacrylic acid ester, and organic acid monomer are preferable.

Acrylic acid ester:
Methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, n-hexyl acrylate, isopropyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, methyl-α-chloro acrylate , Phenyl-α-acrylate, etc.

Methacrylic acid ester:
Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, n-hexyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, 1-phenylethyl methacrylate, 2-phenyl Ethyl methacrylate, furfuryl methacrylate, diphenylmethyl methacrylate, pentachlorophenyl methacrylate, naphthyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, etc.

Organic acid monomer:
Monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, dicarboxylic acids such as itaconic acid, maleic acid, fumaric acid, citraconic acid and mesaconic acid and anhydrides of these dicarboxylic acids, 2-acryloyl hydrogen phthalate, 2-acryloyl Oxypropyl hydrogen phthalate, etc.

  In addition, as other copolymerizable monomers constituting the acrylic resin used in the present invention, maleic acid diester, fumaric acid diester, styrene and styrene derivatives, acrylonitrile, (meth) acrylamide, vinyl acetate, vinyl chloride, And vinylidene chloride. The copolymer containing these other copolymerizable monomers may be used as necessary, and the amount thereof is also used within the range in which the acrylic resin can achieve the object of the present invention.

  What is preferable as an acrylic resin in the present invention is a copolymer containing a structural unit derived from alkyl (meth) acrylate and a structural unit derived from (meth) acrylic acid, and more preferably 5 to 30 (meth) acrylic acid. Contains mol%. The molecular weight of the alkali-soluble acrylic resin used in the present invention is preferably a polystyrene-converted weight average molecular weight of 5,000 to 30,000. When the molecular weight of the acrylic resin is less than 5,000, there may be a problem that the solvent resistance and heat resistance are poor, and when it exceeds 30,000, a development residue may be generated. is there.

The photosensitizer having a quinonediazide group used in the photosensitive resin composition of the present invention is preferably a reaction product of a phenolic compound represented by the following general formula (I) or (II) and a naphthoquinonediazide compound. As mentioned.

Wherein R ¹ , R ² , R ³ and R ⁴ each independently represent H or a C ₁ -C ₂ alkyl group, and R ⁵ and R ⁶ each independently represent C ₁ -C ₂ Represents an alkyl group of

を表し、ｍおよびｎはそれぞれ独立して０〜２の整数であり、ａ、ｂ、ｃ、ｄ、ｅ、ｆ、ｇおよびｈは、ａ＋ｂ≦５、ｃ＋ｄ≦５、ｅ＋ｆ≦５、ｇ＋ｈ≦５を満たす０〜５の整数であり、ｉは０〜２の整数である。） (Wherein R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are each independently H, a C ₁ -C ₄ alkyl group or

M and n are each independently an integer of 0 to 2, and a, b, c, d, e, f, g and h are a + b ≦ 5, c + d ≦ 5, e + f ≦ 5, g + h ≦ 5 is an integer of 0 to 5 satisfying 5, and i is an integer of 0 to 2. )

  Examples of the phenolic compound represented by the general formula (I) include the following compounds. The synthesis of these compounds can be appropriately performed by a conventionally known method such as the method described in Patent Document 4.

  Examples of the phenolic compound represented by the general formula (II) include o-cresol, m-cresol, p-cresol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, and bisphenol A. , B, C, E, F and G, 4,4 ′, 4 ″ -methylidynetrisphenol, 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol, 4, 4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol, 4,4 ′-[1- [4- [2- (4-hydroxyphenyl)] -2-propyl] phenyl] ethylidene] bisphenol, 4,4 ′, 4 ″ -ethylidinetrisphenol, 4- [bis (4-hydroxyphenyl) methyl] -2-ethoxy Enol, 4,4 ′-[(2-hydroxyphenyl) methylene] bis [2,3-dimethylphenol], 4,4 ′-[(3-hydroxyphenyl) methylene] bis [2,6-dimethylphenol], 4,4 ′-[(4-hydroxyphenyl) methylene] bis [2,6-dimethylphenol], 2,2 ′-[(2-hydroxyphenyl) methylene] bis [3,5-dimethylphenol], 2, 2 ′-[(4-hydroxyphenyl) methylene] bis [3,5-dimethylphenol], 4,4 ′-[(3,4-dihydroxyphenyl) methylene] bis [2,3,6-trimethylphenol], 4- [bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) methyl] -1,2-benzenediol, 4,6-bis [(3,5-dimethyl-4 -Hydroxyphenyl) methyl] -1,2,3-benzenetriol, 4,4 '-[(2-hydroxyphenyl) methylene] bis [3-methylphenol], 4,4', 4 "-(3-methyl -1-propanyl-3-ylidine) trisphenol, 4,4 ′, 4 ″, 4 ′ ″-(1,4-phenylenedimethylidyne) tetrakisphenol, 2,4,6-tris “(3,5- Dimethyl-4-hydroxyphenyl) methyl] -1,3-benzenediol, 2,4,6-tris [(3,5-dimethyl-2-hydroxyphenyl) methyl] -1,3-benzenediol, 4,4 '-[1- [4- [1- [4-Hydroxy-3,5-bis [(hydroxy-3-methylphenyl) methyl] phenyl] -1-methylethyl] phenyl] ethylidene] bis [2, -, and the like bis (hydroxy-3-methylphenyl) methyl] phenol. Preferred compounds include 4,4 ′, 4 ″ -methylidyne trisphenol, 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol, 4,4 ′-[1- [4- [1- (4-Hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol, 4,4 ′-[1- [4- [2- (4-hydroxyphenyl) -2-propyl] phenyl ] Ethylidene] bisphenol, 4,4 ', 4 "-ethylidene trisphenol and the like.

  Among these phenolic compounds represented by the general formula (II), compounds represented by the following formula (III) or the following formula (IV) are particularly preferable.

  On the other hand, the naphthoquinone diazide compound reacted with the phenolic compound represented by the general formula (I) or (II) reacts with the phenolic compound represented by the general formula (I) or (II) to form an esterified product. Any compound containing a quinonediazide group can be used. Examples of such quinonediazide compounds include naphthoquinonediazidesulfonic acid chloride and benzoquinonediazidesulfonic acid chloride represented by 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2-naphthoquinonediazide-4-sulfonylchloride, and the like. A quinonediazide sulfonic acid halide is mentioned. The esterification reaction is performed by, for example, converting a phenolic compound represented by the general formula (I) or (II) and a quinonediazide sulfonic acid halide into a basic catalyst such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, triethylamine, etc. Is usually carried out by reacting at a temperature of about -20 to 60 ° C. The esterification may be part of the hydroxyl groups of the phenolic compound represented by the general formula (I) or (II), or may be all hydroxyl groups. The esterification rate can be appropriately adjusted by adjusting the amount of the phenolic compound represented by the general formula (I) or (II) and the amount of the compound having a quinonediazide group. In this esterification reaction, mixtures with different esterification numbers and esterification positions are obtained. Accordingly, the esterification rate is expressed as an average value of these mixtures. Moreover, these reaction products may be used individually by 1 type, and 2 or more types may be used together. In the present invention, by using a reaction product of the phenolic compound represented by the above general formula (I) or (II) and a naphthoquinonediazide compound, it has excellent long-term storage stability, light transmittance, and solvent resistance. A film having excellent properties, heat resistance, and insulation can be formed. In this invention, the said reaction product is normally used in the quantity of 1-30 weight part with respect to 100 weight part of alkali-soluble resin components in the photosensitive resin composition. As the photosensitizer, other photosensitizers may be used together with the reaction product as long as the object of the present invention is not impaired.

  Moreover, the photosensitive resin composition by this invention comprises the hardening | curing agent which has an epoxy group as a hardening | curing agent. Examples of the curing agent having an epoxy group include a bisphenol type epoxy resin, a cresol novolac type epoxy resin, a cyclic aliphatic epoxy resin, a glycidyl ether type epoxy resin, a glycidyl amine type epoxy resin, and a heterocyclic epoxy resin. it can. However, the curing agent that can be used in the present invention is not limited to these high molecular weight epoxy resins, and may be a low molecular weight epoxy compound such as glycidyl ether of bisphenol A or bisphenol F. These curing agents having an epoxy group are preferably used in an amount of 2 to 60 parts by weight, more preferably 10 to 40 parts by weight with respect to 100 parts by weight of the alkali-soluble resin.

  The photosensitive resin composition according to the present invention further comprises a polycarboxylic acid ester compound having a melting point of 20 ° C. or less and in which some of the plurality of carboxyl groups are esterified with a higher alcohol. When a polyester compound having a melting point exceeding 20 ° C. is used, bumping may occur when the composition is applied and then dried under reduced pressure, but the melting point is 20 ° C., that is, a polycarboxylic acid ester that is liquid at room temperature. Such problems are avoided by using compounds. For these reasons, the lower limit of the melting point of the polycarboxylic acid ester compound is not particularly limited, but is generally −100 to 20 ° C., preferably −80 to 0 ° C.

  This polycarboxylic acid ester compound has both an ester group and a carboxyl group because only a part of the plurality of carboxyl groups of the polycarboxylic acid is esterified with a higher alcohol.

Such a compound can be represented by the following general formula (A): (R ^b OCO) _p -R ^a- (COOH) _q (A)
Here, R ^a is a hydrocarbon group that may be substituted with a hydroxyl group, a halogen, an amino group, or a sulfonic acid group, R ^b is a hydrocarbon group, and p and q are each an integer of 1 or more. .
R ^a is preferably ^a saturated hydrocarbon, an unsaturated hydrocarbon, or an aromatic hydrocarbon, and particularly preferably an unsaturated hydrocarbon. The number of carbon atoms in R ^b is not particularly limited, but is preferably 3 to 16, and more preferably 5 to 12. Furthermore, Rb may be a linear alkyl group or a branched alkyl group. Further, p is preferably 1 to 2, and q is preferably 1 to 3. However, when p is 2 or more, each R ^b may be the same or different.

  Such a compound can generally be obtained by reacting a polycarboxylic acid with a higher alcohol.

  Here, examples of the polycarboxylic acid include dicarboxylic acid and tricarboxylic acid. Specifically, as the dicarboxylic acid, (1) aliphatic saturated dicarboxylic acid, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sepacic acid, (2) Aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, (3) aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and the like. . Further, tricarboxylic acid, tetracarboxylic acid and the like having a larger number of carboxyl groups can also be used.

  Examples of the higher alcohol include alcohols having 3 to 16 carbon atoms, preferably 5 to 12 carbon atoms, having a linear or branched chain, an alkyl group, an alkylene group, and an alkenyl group. These may be any of primary alcohol, secondary alcohol, and tertiary alcohol. Specifically (i) linear primary alcohols such as n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-decanol, and n-dodecanol, (Ii) linear secondary alcohols such as isopentanol, isohexanol, isooctanol and isodecanol, (iii) primary alcohols having a branched chain such as 2-methyl-1-hexanol, (iv) 2-methyl Secondary alcohols having a branched chain such as -3-hexanol, (v) tertiary alcohols such as tert-butanol, 2-methyl-2-pentanol, 3-ethyl-3-pentanol, (vi) 3-hexene Examples thereof include unsaturated alcohols such as -1-ol and 4-octen-2-ol.

  From these polycarboxylic acids and higher alcohols, the polycarboxylic acid ester compounds used in the present invention can be formed by a usual esterification reaction. At this time, it is common to add a higher alcohol in such an amount that a part of the carboxyl groups of the polycarboxylic acid is not esterified. For example, maleic acid monoester can be formed by blending maleic anhydride and higher alcohol so as to be equimolar and reacting by heating and stirring (Non-patent Documents 1 and 2).

  As the polycarboxylic acid ester compound used in the present invention, any combination of these polycarboxylic acids and higher alcohols can be used as long as the melting point is 20 ° C. or lower. In general, the higher the carbon number of the higher alcohol, the greater the effect of the present invention, but the lower the melting point. On the other hand, when the polycarboxylic acid contains a double bond, the melting point of the ester tends to increase. For this reason, it is preferable that the polycarboxylic acid is an unsaturated carboxylic acid because the number of carbon atoms of the higher fatty alcohol can be increased.

  Particularly preferred polycarboxylic acid ester compounds are those in which one carboxyl group of an aliphatic unsaturated dicarboxylic acid is substituted with an alkyl group. Specific examples include monoesters of (i) maleic acid or fumaric acid and (ii) the above-mentioned higher alcohols. Among these, maleic acid monooctyl ester is particularly preferred.

  Also, here, a polycarboxylic acid ester compound formed by the reaction of a polycarboxylic acid and a higher alcohol is shown, but even if it is produced by other methods, some of the plurality of carboxyl groups are higher alcohol. Any of the polycarboxylic acid ester compounds esterified with, particularly the compounds represented by the above general formula (I) and having a melting point of 20 ° C. or less can be used in the photosensitive resin composition according to the present invention.

  These polycarboxylic acid ester compounds can also be used in combination. Moreover, content in the photosensitive resin composition by this invention is generally 0.01-10 weight part with respect to 100 weight part of alkali-soluble resin, Preferably it is 0.5-5 weight part. If the content of the polycarboxylic acid ester compound is small, the film surface alteration in the post-baking process, that is, the effect of suppressing white turbidity tends to be reduced, and if too much, the heat resistance of the formed film tends to deteriorate. Because there is, attention is necessary.

Moreover, the carboxylic acid described in patent document 3 can also be used for the photosensitive resin composition by this invention in combination. Such a carboxylic acid may be a saturated carboxylic acid or an unsaturated carboxylic acid. Preferable saturated carboxylic acid includes C ₁₂ -C ₁₈ fatty acid represented by the general formula: C _n H _{2n + 1} COOH (n represents an integer of 11 to 17). The aliphatic group of the saturated fatty acid represented by the general formula may be linear or branched, but a linear aliphatic group is preferred. As these saturated fatty acids, for example, stearic acid and palmitic acid are preferable. Also preferred examples of the unsaturated carboxylic acids include unsaturated fatty acids C ₁₂ -C ₂₄ having 1-3 unsaturated double bonds in the molecule. Examples of unsaturated fatty acids having one double bond include nervonic acid, erucic acid, oleic acid, and palmitoleic acid. Examples of unsaturated fatty acids having two double bonds include 11,14-eicosadienoic acid, Examples of the unsaturated fatty acid in which linoleic acid and the like further have three double bonds include cis-8,11,14-eicosatrienoic acid and linolenic acid. In these unsaturated fatty acids, when the length of the alkyl chain is shortened, the clouding prevention effect tends to be small. On the other hand, when the alkyl chain is long, the clouding prevention effect is good, but a development residue may be generated. In addition, when the alkyl chain becomes longer, the melting point becomes room temperature or higher, and bumping may occur during drying under reduced pressure. Therefore, it is preferable to select an unsaturated fatty acid that does not have these problems. As the unsaturated fatty acid, oleic acid is one of the particularly preferred ones.

  By adding such a carboxylic acid, the heat resistance temperature of the thin film to be formed is improved, and the development residue generated during development tends to be reduced.

  The photosensitive resin composition according to the present invention includes the alkali-soluble acrylic resin, the reaction product of the phenolic compound represented by the general formula (I) or (II) and the naphthoquinonediazide compound, and an epoxy group. In addition to the curing agent, it is preferable to comprise a phenolic compound represented by the general formula (I) or (II). In the photosensitive resin composition according to the present invention, the phenolic compound represented by the general formula (I) or (II) is usually used to adjust the dissolution rate as a dissolution inhibitor or the photosensitive resin composition. It is used to improve the remaining film rate or adjust sensitivity. As the phenolic compound represented by the general formula (II), the phenolic compound represented by the formula (III) or (IV) is preferable. These phenolic compounds are used in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of the alkali-soluble resin.

  The photosensitive resin composition according to the present invention includes a solvent that dissolves an alkali-soluble resin, a photosensitive agent, a curing agent, a polycarboxylic acid ester compound, and other additives to form a photosensitive resin composition solution. it can. Specific examples of such solvents include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate. Diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether and diethylene glycol methyl ethyl ether, propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol mono Propylene glycol monoalkyl ether acetates such as tilether acetate, lactic acid esters such as methyl lactate and ethyl lactate, aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone, 2-heptanone and cyclohexanone, N, N -Amides such as dimethylacetamide and N-methylpyrrolidone, and lactones such as γ-butyrolactone. These solvents can be used alone or in admixture of two or more.

  If necessary, the photosensitive resin composition according to the present invention may further contain an adhesion assistant and a surfactant. Examples of adhesion assistants include alkyl imidazoline, butyric acid, alkyl acid, polyhydroxystyrene, polyvinyl methyl ether, t-butyl novolac, epoxy silane, epoxy polymer, silane, etc. Non-ionic surfactants are examples of surfactants. Surfactants such as polyglycols and their derivatives, ie, polypropylene glycol or polyoxyethylene lauryl ether, fluorine-containing surfactants such as Fluorard (trade name, manufactured by Sumitomo 3M Co., Ltd.), Megafuck (trade name, Dainippon) Ink Chemical Industry Co., Ltd.), Sulflon (trade name, manufactured by Asahi Glass Co., Ltd.), or organosiloxane surfactants such as KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.).

  The photosensitive resin composition according to the present invention is prepared by dissolving each component in a predetermined amount of a solvent. At this time, each component may be prepared by dissolving each component separately in advance in a solvent and mixing each component at a predetermined ratio immediately before use. Usually, the solution of the photosensitive resin composition is subjected to use after being filtered using a 0.2 μm filter or the like.

The photosensitive resin composition according to the present invention is formed into a thin film by the following method and is suitably used as a flat film or an interlayer insulating film. That is, first, a solution of the photosensitive resin composition according to the present invention is applied on a substrate and pre-baked to form a coating film (photoresist film) of the photosensitive resin composition. At this time, the substrate to which the photosensitive resin composition is applied may be any known substrate such as a conventional FPD substrate or a semiconductor device forming substrate such as glass or silicon. The substrate may be a bare substrate, may be formed with an oxide film, a nitride film, a metal film, or the like, or may be a substrate on which a circuit pattern or a semiconductor device is formed. Next, after pattern exposure is performed on the photoresist film through a predetermined mask, development processing is performed using an alkali developer, and rinsing processing is performed as necessary to form a thin film positive pattern of the photosensitive resin composition. . When the photosensitive resin composition according to the present invention is used, the remaining film ratio during the development processing is excellent. The thin film positive pattern thus formed is exposed to the entire surface and then post-baked, whereby a thin film having a high heat resistance temperature is formed. The exposure amount during the entire surface exposure is usually 600 mJ / cm ² or more. The post-bake temperature is usually 150 to 250 ° C., preferably 180 to 230 ° C., and the post-bake time is usually 30 to 90 minutes.

  The thin film positive pattern formed using the photosensitive resin composition according to the present invention has high insulation, high transparency, high heat resistance, and solvent resistance, such as semiconductor devices, liquid crystal display devices, plasma displays, etc. It is used as a flattening film or interlayer insulating film of FPD. When a heat-resistant and solvent-resistant thin film is formed on the entire surface, pattern exposure, development, etc. need not be performed. Here, the planarizing film and the interlayer insulating film in the present invention are not completely independent, and the thin film formed by the photosensitive resin composition according to the present invention or the heat-resistant thin film forming method is used as a planarizing film. It can also be used as an interlayer insulating film. In a semiconductor device or the like, such a thin film functions as both an interlayer insulating film and a planarizing film.

  In the formation of the thin film, as a method for applying the photosensitive resin composition solution, any method such as a spin coating method, a roll coating method, a land coating method, a spray method, a casting coating method, or a dip coating method may be used. Examples of the radiation used for exposure include ultraviolet rays such as g-line and i-line, far ultraviolet rays such as KrF excimer laser or ArF excimer laser light, X-rays and electron beams.

  Further, as a developing method, a method conventionally used for developing a photoresist, such as a paddle developing method, an immersion developing method, or a swing immersion developing method may be used. Developers include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate and sodium silicate, organic amines such as ammonia, ethylamine, propylamine, diethylamine, diethylaminoethanol and triethylamine, and tetramethylammonium hydroxide. A quaternary amine etc. are mentioned.

  Examples The present invention will be described more specifically with reference to examples. However, the embodiments of the present invention are not limited to these examples.

Synthesis Example 1 (Synthesis of acrylic copolymer 1)
In a 2000 ml four-necked flask equipped with a stirrer, condenser, thermometer and nitrogen inlet tube, 700 g of propylene glycol monomethyl ether acetate, 171 g of methyl methacrylate, 90 g of 2-hydroxypropyl methacrylate, 39 g of methacrylic acid, dimethyl-2,2 '-Azobis (2-methylpropionate) 8.0g was charged and stirred, heated while blowing nitrogen, and polymerized at 85 ° C for 8 hours to obtain an acrylic copolymer 1 having a weight average molecular weight of 21,000. It was.

Example 1
100 parts by weight of the acrylic copolymer 1 obtained in Synthesis Example 1, 25 parts by weight of an esterified product (esterification rate 50%) represented by the following formula (V), and further represented by the above formula (III) 5 parts by weight of a phenolic compound, 17 parts by weight of techmore VG3101L (manufactured by Mitsui Chemicals) as an epoxy group-containing curing agent and 0.5 parts by weight of maleic acid monooctyl ester were mixed with propylene glycol monomethyl ether acetate / diethylene glycol dimethyl ether (80 / 20) In order to prevent radial wrinkles formed on the photoresist film upon spin coating, so-called striations, a fluorosurfactant, Megafac R-08 (Dainippon Ink Chemical Co., Ltd.) ))) Was added and stirred, and then filtered through a 0.2 μm filter. A light-sensitive resin composition 1 was prepared.

<Formation of thin film pattern>
The photosensitive resin composition 1 obtained above was spin-coated on a 4-inch silicon wafer and baked on a hot plate at 100 ° C. for 90 seconds to obtain a 3.0 μm thick photoresist film. The resist film was exposed to various line widths and contact hole test patterns having a line and space width of 1: 1 with a g + h + i line mask aligner (PLA-501F) manufactured by Canon Inc. at an optimum exposure amount. A pattern and contact holes with a line and space width of 1: 1 were formed by developing with a 4 wt% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds.

<Evaluation of film surface characteristics>
The pattern-formed substrate obtained above was exposed to the entire surface (600 mJ / cm ² ) using a g + h + i-line mask aligner (PLA-501F) manufactured by Canon Inc., and then heated at 120 ° C. for 15 minutes on a hot plate. After that, heat treatment was performed at 220 ° C. for 60 minutes in a circulating clean oven. Thereafter, the surface state of the film was observed with an optical microscope, and evaluated as ◯ if no white turbidity was observed, Δ when slightly turbidity was observed, and × when white turbidity was observed. The results are shown in Table 1.

<Evaluation of remaining film ratio>
In the formation of the thin film pattern, the film thickness after coating and baking was measured with Lambda Ace (VM-1210) manufactured by Dainippon Screen Co., Ltd. Further, the film thickness after development by the above method was measured by the same method. Using each obtained film thickness, the remaining film ratio was calculated according to the following formula.
(Residual film ratio) = (film thickness after development) / (film thickness after baking) × 100
The results are shown in Table 1.

Example 2
Photosensitive resin composition 2 was prepared in the same manner as in Example 1 except that the amount of maleic acid monooctyl ester was changed to 0.1 parts by weight. Using this photosensitive resin composition 2, a thin film pattern was formed in the same manner as in Example 1 to evaluate the evaluation of the film surface characteristics and the remaining film ratio. The evaluation results are shown in Table 1.

Example 3
Photosensitive resin composition 3 was prepared in the same manner as in Example 1 except that the amount of maleic acid monooctyl ester was changed to 5 parts by weight. Using this photosensitive resin composition 3, a thin film pattern was formed in the same manner as in Example 1 to evaluate the evaluation of the film surface characteristics and the remaining film ratio. The evaluation results are shown in Table 1.

Comparative Example 1
Photosensitive resin composition 4 was prepared in the same manner as in Example 1 except that 3.0 parts by weight of oleic acid was used instead of 0.5 parts by weight of maleic acid monooctyl ester. Using this photosensitive resin composition 4, a thin film pattern was formed in the same manner as in Example 1 to evaluate the evaluation of the film surface characteristics and the remaining film rate. The evaluation results are shown in Table 1.

Comparative Example 2
A photosensitive resin composition 5 was prepared in the same manner as in Example 1 except that 1.0 part by weight of oleic acid was used instead of 0.5 part by weight of maleic acid monooctyl ester. Using this photosensitive resin composition 5, a thin film pattern was formed in the same manner as in Example 1, and evaluation of the film surface characteristics and the remaining film rate was evaluated. The evaluation results are shown in Table 1.

Comparative Example 3
A photosensitive resin composition 6 was prepared in the same manner as in Example 1 except that 0.5 part by weight of maleic acid monooctyl ester was excluded. Using this photosensitive resin composition 6, a thin film pattern was formed in the same manner as in Example 1, and the evaluation of the film surface characteristics and the remaining film rate was evaluated. The evaluation results are shown in Table 1.

  From these results, it can be seen that the photosensitive resin composition according to the present invention is excellent in both the film surface characteristics and the remaining film ratio. In addition, the insulating properties, heat resistance, solvent resistance, flatness, and electrical characteristics of the resist film after the heat treatment were good in any of the examples.

Claims (6)

A photosensitive resin composition comprising an alkali-soluble acrylic resin, a photosensitive agent having a quinonediazide group, and a curing agent having an epoxy group, having a melting point of 20 ° C. or less , maleic acid or fumaric acid, and a carbon number of 3 A photosensitive resin composition, wherein the photosensitive resin composition further comprises a monoester with an alcohol having an alkyl group, an alkylene group, or an alkenyl group having a linear or branched chain of -16 . The photosensitive resin composition of Claim 1 whose said photosensitive agent is a reaction product of the phenolic compound represented by the following general formula (I) or (II), and a naphthoquinone diazide compound.

Wherein R ₁ , R ₂ , R ₃ and R ₄ each independently represent H or a C ₁ -C ₂ alkyl group, and R ₅ and R ₆ each independently represent C ₁ -C ₂ Represents an alkyl group of

(Wherein R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently H, a C ₁ -C ₄ alkyl group or

M and n are each independently an integer of 0 to 2, and a, b, c, d, e, f, g and h are a + b ≦ 5, c + d ≦ 5, e + f ≦ 5, g + h ≦ 5 is an integer of 0 to 5 satisfying 5, and i is an integer of 0 to 2. )   The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition further comprises a phenolic compound represented by the general formula (I) or (II). Flat panel display characterized by having a planarizing film or an interlayer insulating film formed by the photosensitive resin composition according to any one of claims 1-3. Semiconductor device characterized in that it comprises a flat film or an interlayer insulating film formed by the photosensitive resin composition according to any one of claims 1-3. A coating film is formed by pre-baking after the solution of the photosensitive resin composition according to any one of claims 1 to 3 is applied on a substrate,
Expose the resulting coating film,
The exposed coating film is developed with an alkaline developer to form a pattern,
Further exposure of the pattern obtained by development,
A method for forming a heat-resistant thin film comprising post-baking.