JPH0646302B2 - Heat-resistant photosensitive polymer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-resistant photosensitive polymer composition used in semiconductor devices, multilayer wiring boards, microelectronic devices, etc. Type photosensitive material.

[Conventional technology]

Conventionally, as a heat-resistant photosensitive material that becomes a heat-resistant polymer, (a)
In Japanese Examined Patent Publication No. 59-52822, a wholly aromatic polyamic acid,
A compound comprising a compound containing a carbon-carbon double bond dimerizable or polymerizable by actinic radiation and an amino group, and a sensitizer added if necessary, (b) in JP-A-56-110728.
A photosensitive polymer in which a photosensitive group is introduced into an aromatic diamine component is known, which is a polyamic acid synthesized from aromatic tetracarboxylic dianhydride and aromatic diamine.

However, the materials (a) and (b) have low resolution when formed into a thick film, so that the final cured film thickness may be about 2 to 5 μm. Although it can be applied to a protective film, it could not be applied to applications such as an α-ray shield film of a memory device and an interlayer insulating film of a thin film multilayer substrate which require a film thickness of 10 to 20 μm or more.

[Problems to be solved by the invention]

When the material of (a) above is used as a thick film, the resolution is reduced because the photocurable group is not directly bonded to the polymer main chain, so that the curability of the exposed area is low, while the unexposed area is low. It is considered that the solubility is poor. For this reason, if the developing temperature is raised to completely dissolve the unexposed portion, or if the developing time is lengthened, the exposed portion is also dissolved, and in the case of patterns having different diameters, the deviation width with respect to the mask size may be significantly different.

In the case of the above-mentioned material (n), the curability of the exposed portion is sufficient, but the solubility of the unexposed portion is low, so the resolution of the fine pattern becomes poor.

It is considered that a factor related to the developing solution is the main cause of the lowered resolution. That is, as a developer for oceanizing the unexposed portion of the materials (a) and (b), N-methyl-2-
An aprotic polar solvent such as pyrrolidone or N, N-dithymeracetamide must be used as a main component, but all of them have a relatively high liquid viscosity, so that dissolution and diffusion of unexposed portions are suppressed. Since the material has a strong dissolving power, a material having an insufficient photo-curing degree has a problem that the exposed portion is also dissolved. For this reason,
It is considered that the resolution is lowered.

An object of the present invention is to provide a heat-sensitive photosensitive material capable of forming a pattern even when a weak polar solvent having a low liquid viscosity and a low dissolving power is used as a developing solution in order to improve resolution when formed into a thick film. To provide a volatile polymer composition.

[Means for solving problems]

The present invention is based on the basic idea that the above object can be achieved by making the structure of the main component polymer as follows. That is, the reason why the materials (a) and (b) cannot be dissolved in a solvent containing an aprotic polar solvent such as N-methyl-2-pyrrolidone as a main component is that polyamic acid has a highly polar carboxyl group. It is believed to be because they are linked. Therefore, it is basically possible to convert this into a less polar carboxylic acid ester.

Therefore, as a result of intensive study by the present inventors based on the above idea, (a) general formula (1) (However, in the formula, R ¹ is 4 including at least 4 or more carbons.
Valent organic group, R ² is a trivalent or tetravalent organic group containing an aromatic ring, R ³ and R ⁴ are each an organic group having 10 or less carbon atoms,
Y is a photosensitive group, X is an organic group connecting R ² and a photosensitive group, or -0
-Or And (n is 1 or 2) 100 parts by weight of a polymer having a repeating unit represented by the formula (b) as a main component and (b) a photopolymerization initiator and a photocrosslinking agent as a sensitizer in an amount of 0.1 to 30 parts by weight. It has been found that the volatile polymer composition is effective. That is, these heat-resistant photosensitive polymer composition,
It is possible to use a solvent such as γ-butyrolactone or dimethoxyethane, which cannot be used in the heat-resistant photosensitive material described above, as the main component of the developing solution, and further, it has good resolution when formed into a thick film. I found it.

Hereinafter, the present invention will be described in detail.

Examples of preferable R ¹ of the polymer represented by the repeating unit of the general formula (1) are: However, the present invention is not limited to these.

As a more preferable example, Etc.

Examples of preferred R ² are (However, Z is -0-,-S-,-SO ₂ -,-CO-, CH _2- , Which represents a group selected from among
It is not limited to these.

As a more preferable example, Etc.

Preferable examples of R ³ and R ⁴ include an alkyl group having 5 or less carbon atoms, an alkoxymethyl group, an alkoxyethyl group, an alkoxypropyl group, an alkylcarboxyethyl group, a phenylcarboxyethyl group, and the like. Not limited.

More preferable examples include a methyl group, an ethyl group, an isopropyl group, a butyl group, a methoxyethyl group, an ethoxyethyl group, an acetoxyethyl group, and a phenylcarboxyethyl group.

R ³ and R ⁴ may be the same or different.

Preferred examples of X are -0-, Examples thereof include, but are not limited to, -R ⁵ -0- (wherein R ⁵ represents lower alkylene) and the like.

More preferable examples -CH ₂ 0-, and the like.

As a preferable example of the photosensitive group Y, (However, R ⁶ is a group selected from hydrogen, a cyano group, and lower alkyl, R ₇ is a group selected from hydrogen, a lower alkyl group, and an alkoxy group, R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² Represents a group selected from hydrogen, a lower alkyl group, a vinyl group, a phenyl group) and the like, but is not limited thereto.

As a more preferable example, Etc.

The polymer represented by the repeating unit of the general formula (1) is an addition polymerization reaction of a tetracarboxylic acid dichloride diester and an aromatic diamine compound having a photosensitive group, or a dehydration condensation polymerization of a tetracarboxylic acid diester and an aromatic diamine compound having a photosensitive group. It is synthesized by the reaction.

The heat-resistant photosensitive polymer composition according to the present invention requires the addition of a photopolymerization initiator and / or a photocrosslinking agent and / or a sensitizer in order to achieve a photosensitivity that can be put to practical use. Preferred examples of these are Michler's ketone, bis-4,4'-diethylaminobenzophenone, benzophenone, benzoin ether, benzoin isopropyl ether, anthrone, 1,9-benzanthrone, acridine, nitropyrene, 1,8-dinitropyrene, 5 -Nitroacenaphthene, 2-nitrofluorene, pyrene-1,6
-Quinone, 9-fluorene, 1,2-benzanthraquinone, anthanthrone, 2-chloro-1,2-benzanthraquinone, 2-bromobenzanthraquinone, 2-chloro-1,8-phthaloylnaphthalene, 3,5- Diethylthioxanthone, 3,5-dimethylthioxanthone, 3,5-diisopropylthioxanthone, benzyl, 2,6-di (4 '
-Azidobenzal) cyclohexanone, 2,6-di (4 '
-Azidobenzal) -4-methylcyclohexanone, 2,
6-di (4'-azidobenzal) -4-carboxycyclohexanone, 2,6-di (4'-azidobenzal) -4
-Hydroxycyclohexanone, 2,6-di (4'-azidocinnamylidene) cyclohexanone, 2,6-di (4 '
-Azidocinnamylidene) -4-methylcyclohexanone, 2,6-di (4'-azidocinnamylidene) -4-carboxycyclohexanone, 2,6-di (4'-azidocinnamylidene) -4-hydroxy Cyclohexanone, 1
-Phenyl-5-mercapto-1H-tetrazole, 1
-Phenyl-5-merticus, 3-acetylphenanthrene, 1-indanone, 7-H-benz [de] anthracene-7-one, 1-naphtholaldehyde, thioxanthen-9-one, 10-thioxanthenone, 3- Examples include, but are not limited to, acetoindole.

More preferred examples of these include Michler's ketone, bis-4,4'-diethylaminobenzophenone,
1-phenyl-5-mercapto-1H-tetrazole,
Examples thereof include benzyl, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone and 2,4-dimethylthioxanthone. These may be used alone or as a mixture of several kinds.

A suitable blending ratio of the photopolymerization initiator, the photocrosslinking agent and / or the sensitizer used in the present invention is 0.1 to 30 with respect to 100 parts by weight of the polymer represented by the repeating unit of the general formula (1).
Parts by weight are preferred and even more preferred, in the range 0.5 to 20 parts by weight. If it deviates from this range, the developability will be adversely affected.

In the present invention, the sensitization aid added as necessary is used as a polymerization accelerator when the photopolymerization initiator is used. Preferred examples include 4-diethylaminoethylbenzoate, 4-diethylaminoisopropylbenzoate, 4-dimethylaminoethylbenzoate, 4-dimethylaminoisopropylbenzoate, 4
-Dimethylaminoisoamylbenzoate, ethylene glycol dithioglycolate, ethylene glycol di (3-mercaptopropionate), trimethylolpropane thioglycolate, trimethylolpropane tri (3-mercaptopropiolate), pentaerythritol terilathioglycolate , Pentaerythritol tetra (3-mercaptopropionate), trimethylolethane trithioglycolate, trimethylolethane tri (3-mercaptopropionate, dipentaerythritol hexa (3-mercaptopropionate), dipentaerythritol hexa (3-mercaptopropionate), thioglycolic acid, α-mercaptopropionic acid, etc. However, the present invention is not limited thereto.

Among these, more preferable examples include 4-dimethylaminoethylbenzoate, 4-dimethylaminoisoamylbenzoate, pentaerythritol tetrathioglycolate, pentaerythritol tetra (3-mercaptopropionate), and trimethylolpropane thioglycolate. Etc. These may be used alone or as a mixture of several kinds.

When the sensitization aid is used in the present invention, the mixing ratio is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 100 parts by weight of the polymer represented by the repeating unit of the general formula (1).
-20 parts by weight. If the amount is less than this range, the effect of promoting polymerization due to use cannot be obtained.

The heat-resistant photosensitive polymer composition according to the present invention is used in a solution state in which the above-mentioned constituents are dissolved in an appropriate organic solvent. As the solvent used in this case, an aprotic polar solvent is desired from the viewpoint of solubility, and N-methyl-2-
Pyrrolidone, N-acetyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphortriamide, N -Acetyl-ε-caprolactam, dimethylimidazolidinone, 1,2-dimethoxyethane, 1-
Preferable examples include acetoxy-2-methoxyethane, γ-butyrolactone, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether and the like. These may be used alone or as a mixed system. Further, in order to improve the coating property, an aromatic solvent such as toluene, xylene or methoxybenzene may be mixed within a range that does not adversely affect the dissolution of the polymer.

In order to improve the adhesiveness between the coating film of the heat-resistant photosensitive polymer composition according to the present invention or the polyimide coating after heat curing and the supporting substrate, the supporting substrate may be treated with an adhesion aid as appropriate.

The heat-resistant photosensitive polymer composition of the present invention can be patterned by an ordinary fine processing technique. For application of the present composition to the supporting substrate, spin coating using a spinner, dipping, spray printing and the like can be used and can be appropriately selected. The coating film thickness can be adjusted by the coating means, the solid content concentration of the composition, and the like.

The composition according to the present invention, which has been formed into a coating film on a supporting substrate through a drying step, is irradiated with ultraviolet rays through a photomask, and then the unexposed portion is dissolved and removed with a developing solution to give a desired relief pattern. obtain.

The main components of the developer are γ-butyrolactone, 1,2-
A polar solvent such as dimethoxyethane, 1-acetoxy-2-methoxyethane or diethylene glycol dimethyl ether can be used. However, depending on the purpose, an aprotic polar solvent such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide, or dimethylimidazolidinone, which is more polar and has a higher solubility, or toluene having a lower polarity. It is also possible to use a mixed system with an aromatic solvent such as xylene or the like, an alcohol which is a non-solvent of the polymer represented by the repeating unit of the general formula (1), and water. Further, depending on the intended use, development is also carried out with a mixed system of a polar solvent having high solubility, alcohol and water.

The relay pattern formed by the development is then washed with a rinse liquid to remove the development solvent.

As the rinse liquid, a non-solvent of the polymer having good miscibility with the developer and represented by the repeating unit of the general formula (1) is used. Preferable examples include methanol, ethanol, isopropyl alcohol, benzene, toluene, xylene, water and the like.

The leaf pattern polymer obtained by the above treatment is a precursor of polyimide, and a polymer pattern having heat resistance can be obtained by treating at a heating temperature selected from the range of 150 ° C to 450 ° C. To be

[Action]

As described above, according to the present invention, the liquid viscosity is relatively low, and even when a weakly polar solvent having a low dissolving power is used as a developer, it is possible to ensure sufficient solubility of an unexposed portion, The dissolution and diffusion of the unexposed portion can be made favorable, while the dissolution of the exposed portion can be sufficiently suppressed. Therefore, excellent resolution can be obtained even in the case of a thick film.

〔Example〕

 Examples of the present invention will be described below.

Example 1 3,3'-di (chlorocarbonyl) -4,4'-di (methoxycarbonyl) biphenyl, 3,3'-di (methoxycarbonyl) -4,4'-di (chlorocarbonyl) biphenyl,
7.9 g of a mixture of three isomers of 3,4'-di (chlorocarbonyl) -4,3'-di (methoxycarbonyl) biphenyl
(0.02 mol) was dissolved in 50 g of anhydrous N, N-dimethylacetamide under a nitrogen stream to give pyridine (1.58 g, 0.02 mol).
Was added to prepare an acid chloride solution.

To this solution, 2.28 g (0.02 mol) of 3,5-diamino (2'-methacryloyloxyethyl) benzoate was added as 2 parts.
A solution dissolved in 8.4 g of anhydrous N, N-dimethylacetamide was added dropwise with stirring in an ice bath. After dropping, the mixture was further reacted at room temperature for 3 hours (formula 1). The reaction mixture was slowly poured into vigorously stirred 700 ml of methanol. Polymer (Ia) began to precipitate as soon as the reaction mixture was mixed with methanol.

The precipitated polymer was collected by suction filtration and washed with 200 ml of methanol three times. Further, it was dried under reduced pressure to finally obtain 8.3 g (yield 70%) of polymer Ia.

2.5 g of the polymer Ia obtained above, 0.075 g of 2,4-diethylthioxanthone and 0.15 g of 4-dimethylaminoethylbenzoate were dissolved in 7.5 g of N, N-dimethylacetamide, and then pressure was applied using a filter having a pore size of 1 μm. A photosensitive varnish was obtained by filtration.

The above varnish was spin-coated on a silicon wafer using a spinner and then dried at 85 ° C. for 30 minutes to obtain a 28 μm coating film. This coating film was adhered and covered with a photomask having a rectangular pattern with different diameters of 10 μm steps, and was irradiated with ultraviolet rays for 1 minute using a 500 W high pressure mercury lamp. The ultraviolet intensity on the light receiving surface was 5 mW / cm ² at a wavelength of 365 nm. After exposure, it was developed with a developing solution containing 7 volumes of γ-butyrolactone and 3 volumes of N, N-dimethylacetamide at 25 ° C. for 10 minutes, and then rinsed with isopropyl alcohol to a minimum of 30 μm.
A relief pattern was obtained in which the holes were resolved. Then, this was heated to 200 ° C. for 30 minutes and 350 ° C. for 30 minutes to obtain a heat resistant polyimide pattern having a thickness of 16 μm.
At this time, the pattern was not blurred.

Example 2 3,3'-dicarboxy-4,4 '-(methoxycarbonyl)
Biphenyl, 3,3'-di (methoxycarbonyl) -4,4 '
-Dicarboxybiphenyl, 3,4'-dicarboxy-4,
A mixture of three isomers of 3'-di (methoxycarbonyl) biphenyl 8.95 g (0.025 mol), 3,5-diamino (2 '
-Methacryloyloxyethyl) benzoate 5.28 g
350 ml of (0.02 mol) under a nitrogen stream, 350 ml of anhydrous γ
-Dissolved in butyrolactone, an additional 4.55 g of pyridine was added. To this solution, 10.3 g (0.05 mol) of dicyclohexylcarbodiimide was added with stirring in an ice bath.
After the addition was completed, the reaction was allowed to proceed for another 2 hours, and then 10 ml of methanol was added. When the reaction mixture was slowly poured into vigorously stirred methanol, polymer (Ib) was precipitated (formula 2).

The precipitated polymer was collected by suction filtration and further 200 ml x 3
Wash with methanol once. Further, it was dried under reduced pressure to finally obtain 11 g (yield 77%) of the polymer (Ib).

2.5 g of polymer Ib obtained above, 0.075 Michlerketone
g, pentaerythritol thioglycolate 0.2 g 8
g, dissolved in N, N-dimethylacetamide, then 1 μm
A photosensitive varnish was obtained using a filter having m holes.

The above varnish was spin coated on a silicon wafer using a spinner and then dried at 85 ° C. for 30 minutes to obtain a coating film of 31 μm. This coating film was adhered and covered with a photomask having a rectangular pattern having different diameters of 10 μm pitch, and was irradiated with ultraviolet rays for 1 minute using a 500 W high pressure mercury lamp. The ultraviolet intensity on the light receiving surface was 5 mW / cm ² at 365 nm. It was developed with γ-butyrolactone for 10 minutes at 25 ° C. and then rinsed with methanol to obtain a relief pattern having a minimum of 30 μm pores resolved.

Examples 3 to 26 With the compositions shown in Table 1, Examples 3 to 18 performed the same operation as Example 1, and Examples 19 to 26 performed the same operation as Example 2. The results obtained are shown in the same table.

Comparative Example 11 g of diaminodiphenyl ether was added to N-methyl-2-
An amine solution was prepared by dissolving in pyrrolidone 51.8. 12 g of pyromellitic dianhydride was added to the amine solution and reacted at 50 ° C. for 3 hours to obtain a polyamic acid solution.

A solution prepared by dissolving 1.15 g of mihiraketone in 30 g of dimethylacetamide and a solution prepared by dissolving 10.2 g of diethylaminomethacrylate in 10 g of dimethylacetamide were mixed with 50 g of the above polyamic acid solution, and the mixture was filtered under pressure using a filter having a pore size of 1 μm.

The obtained solution was applied with a spinner and dried at 100 ° C. for 5 minutes to obtain a 27 μm coating film. Exposure was carried out for 1 minute using the same exposure apparatus and photomask as in Example 1, and a mixture of 5 volumes of dimethylformamide and 2 volumes of methanol was used at 25 ° C.
After development for 0 minutes, the unexposed area was not completely dissolved and the pattern was not resolved. Therefore, the developing temperature was raised to 35 ° C. In this case, the entire pattern including the exposed portion was not melted and a pattern could not be obtained. Next, the exposure time is set to 5 minutes and 35
Develop for 15 minutes at ° C. At this time, the minimum size of the resolved pattern was 150 μm. 200 ° C, 20 minutes,
The final film thickness obtained by heating at 350 ° C for 30 minutes is 8 μm.
Met.

〔The invention's effect〕

As described above in detail, according to the present invention, the development characteristics of the heat-resistant photosensitive polymer composition can be significantly improved, and thick film pattern formation is possible. As a result, it can be used as an α-ray shield film for LSI memories and as an interlayer insulating film material for thin film multilayer substrates.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication location H05K 3/06 6921-4E (72) Inventor Jun Tanaka 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Inside the Hitachi, Ltd. Production Technology Research Laboratory (72) Inventor Tetsuya Yamazaki 292 Yoshida-cho, Totsuka-ku, Yokohama City, Kanagawa Prefecture Inside the Hitachi Production Engineering Research Center (72) Inventor Mitsumasa Kojima 4-chome, Higashi-cho, Ibaraki Prefecture 13 No. 1 in the Yamazaki Plant of Hitachi Chemical Co., Ltd. (56) Reference JP 54-70820 (JP, A) JP 54-89623 (JP, A) JP 54-91218 (JP, A) JP-A-55-9510 (JP, A) JP-A-55-9538 (JP, A) JP-A-58-120636 (JP, A)

Claims (8)

[Claims] 1. A general formula (1) (However, in the formula, R ¹ is 4 including at least 4 or more carbons.
Valent organic group, R ² is a trivalent or tetravalent organic group containing an aromatic ring, R ³ and R ⁴ are each an organic group having 10 or less carbon atoms,
Y is a photosensitive group, X is an organic group connecting R ² and a photosensitive group, or -O
-Or In which n is 1 or 2) and 100 parts by weight of a polymer having a repeating unit represented by the formula (b) as a photopolymerization initiator, a photocrosslinking agent and / or a sensitizer.
A heat-resistant photosensitive polymer composition comprising 30 parts by weight. 2. The heat-resistant photosensitive polymer composition according to claim 1, further comprising 0.1 to 30 parts by weight of a sensitizing aid. 3. In the above general formula (1), R ¹ is The heat-resistant polymer composition according to claim 1, wherein 4. In the above general formula (1), R ² is (Representing a group selected from among the above), the heat-resistant photosensitive polymer composition according to claim 1. 5. In the above general formula (1), R ³ and R ⁴
Is a C5 or less alkyl group, an alkoxymethyl group, an alkoxyethyl group, an alkoxypropyl group, an alkylcarboxyethyl group or a phenylcarboxyethyl group, The heat-resistant photosensitive polymer composition according to claim 1. object. 6. In the general formula (1), the photosensitive group Y is (However, R ⁶ is a group selected from hydrogen, a cyano group and a lower alkyl group, R ⁷ is a group selected from hydrogen, a lower alkyl group and an alkoxy group, R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² represents a group selected from hydrogen, a lower alkyl group, a vinyl group and a phenyl group), The heat-resistant photosensitive polymer composition according to claim 1. 7. The photopolymerization initiator, photocrosslinking agent and / or sensitizer is Michler's ketone, bis-4,4'-diethylaminobenzophenone, benzophenone, benzoin ether, benzoin isopropyl ether, anthrone,
1,9-benzanthrone, acridine, nitropyrene,
1,8-dinitropyrene, 5-nitroacenaphthene, 2-
Nitrofluorene, pyrene-1,6-quinone, 9-fluorene, 1,2-benzanthraquinone, anthanthrone, 2-chloro-1,2-benzanthraquinone, 2-bromobenzanthraquinone, 2-chloro-1,8- Phthaloylnaphthalene, 3,5-diethylthioxanthone, 3,5-
Dimethylthioxanthone, 3,5-diisopropylthioxanthone, benzyl, 2,6-di (4'-azidobenzal) cyclohexanone, 2,6-di (4'-azidobenzal) -4-methylcyclohexanone, 2,6-di (4 ' −
Azidobenzal) -4-carboxycyclohexanone,
2,6-Di (4'-azidobenzal) -4-hydroxycyclohexanone, 2,6-di (4'-azidocinnamylidene) cyclohexanone, 2,6-di (4'-azidocinnamylidene) -4- Methylcyclohexanone, 2,6-di (4'-azidocinnamylidene) -4-carboxycyclohexanone, 2,6-di (4'-azidocinnamylidene) -4-hydroxycyclohexanone, 1-phenyl-5-mercapto -1H-tetrazole, 1-phenyl-5-merticus, 3-acetylphenanthrene, 1
-Indanone, 7-H-benz [de] anthracene-7
-One, 1-naphtholaldehyde, thioxanthene-9
The heat-resistant photosensitive polymer composition according to claim 1, which is -one, 10-thioxanthenone and / or 3-acetylindole. 8. The sensitizing aid is 4-diethylaminoethylbenzoate, 4-diethylaminoisopropylbenzoate, 4-dimethylaminoethylbenzoate, 4
-Dimethylaminoisopropylbenzoate, 4-dimethylaminoisoamylbenzoate, ethylene glycol dithioglycolate, ethylene glycol di (3-mercaptopropionate), trimethylolpropane thioglycolate, trimethylolpropane tri (3-mercaptopropiolate) , Pentaerythritol tetrathioglycolate, pentaerythritol tetra (3
-Mercaptopropionate), trimethylolethane trithioglycolate, trimethylolethane tri (3
-Mercaptopropionate, dipentaerythritol hexa (3-mercaptopropionate), dipentaerythritol hexa (3-mercaptopropionate), thioglycolic acid and / or α-mercaptopropionic acid. The heat-resistant photosensitive polymer composition according to item 1.