JP2003026919A - Alkaline development type photosensitive resin composition and method for forming pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alkaline development type photosensitive resin composition that enables the formation of a pattern with good resolution upon development with an aqueous alkaline solution without adding a dissolution inhibitor and a method for forming a pattern using the alkaline development type photosensitive resin composition. SOLUTION: The alkaline development type photosensitive resin composition comprises an aqueous alkaline solution-soluble polyimide precursor having an acidic functional group in its molecular chain, a compound having a basic functional group and a protected acidic functional group and a photosensitive agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an alkali-developable photosensitive resin composition suitable for a surface protective film of a semiconductor element such as an α-ray shielding film and a buffer coat film, an interlayer insulating film of a multilayer wiring board, and the like. The present invention relates to a pattern forming method using.

[0002]

2. Description of the Related Art In recent years, in the semiconductor industry, an organic material excellent in heat resistance such as polyimide resin is used as an interlayer insulating material which has been conventionally used by using an inorganic material by utilizing its characteristics. It is supposed to be done. Above all,
In the process of forming a circuit pattern on a semiconductor integrated circuit or a printed circuit board, a resist material is formed on the surface of the base material, exposure is performed at a predetermined location, unnecessary portions are removed by etching, etc. Since the pattern formation is carried out through all the steps, it is desired to develop a heat-resistant photosensitive material which can be used as an insulating material while leaving the resist of a necessary portion as it is after the pattern formation by exposure and development.

At the initial development stage, as these materials,
For example, a heat-resistant photosensitive material using a photosensitive polyimide, a cyclized polybutadiene, or the like as a base polymer has been proposed. Particularly, the photosensitive polyimide has excellent heat resistance and is easy to remove impurities. Has received particular attention from. As such a photosensitive polyimide, a system comprising a polyimide precursor and dichromate (Japanese Patent Publication No.
-17374) was first proposed, but this material has advantages such as practical photosensitivity and high film-forming ability, but on the other hand, it lacks in storage stability and chromium ions remain in the polyimide. However, there were drawbacks such as the fact that it was not practically used.

Next developed were organic solvent developing type (Japanese Patent Laid-Open No. 54-109828) obtained by adding or mixing a compound having a photosensitive group to a polyimide precursor, and alkaline aqueous solution developing type. Examples include photosensitive polyimide. The former compound having a photosensitive group in the polyimide precursor produces a contrast by a photo-crosslinking reaction, and the material is designed basically for organic solvent development. Therefore, a good pattern cannot be formed at the time of development using an alkaline aqueous solution such as a tetramethylammonium hydroxide aqueous solution, and it is difficult to deal with environmental problems such as waste liquid treatment. Therefore, recently, attention has been focused on the latter alkali-developable photosensitive polyimide. The alkali-developable photosensitive polyimide basically contains a water-soluble group as a material. Well-known positive type compounds include, for example, NQD (o-naphthoquinonediazide) and other dissolution inhibitors having a function of acting on water-soluble groups, added to a phenol group-containing polyimide or polybenzoxazole. A method of making a difference in dissolution between an exposed portion and an unexposed portion is known.

[0005]

However, since the kinds of compounds to which NQD can be applied are limited, it is difficult to apply them depending on the kind of polyimide. Further, since there is no dissolution inhibiting effect on the carboxylic acid site, there is a problem that it cannot be used for ordinary polyimide precursors such as polyamic acid. The present invention provides an alkali-developable photosensitive resin composition and a pattern forming method using the same, which is different from the alkali-developable photosensitive resin to which a dissolution inhibitor is added. The above-mentioned problems are solved by using a compound containing.

[0006]

The present invention is directed to an aqueous alkaline solution-soluble polyimide precursor having an acid functional group in its molecular chain,
A compound having a basic functional group and a protected acid functional group,
And an alkali-developable photosensitive resin composition containing a photosensitizer. The present invention also irradiates an actinic ray through a mask on which a desired pattern is drawn on a coating film using the above-mentioned alkali-developable photosensitive resin composition, then develops it with an alkali developing solution, and unirradiates it. The present invention relates to a pattern forming method for removing a portion.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The photosensitive polyimide precursor according to the present invention has an acid functional group which is an alkali aqueous solution-soluble group, and also has a photosensitive group which is dimerized or polymerized by light. It is a so-called negative photosensitive composition in which the exposed portion is not dissolved or becomes difficult to dissolve in an alkali developing solution due to quantification or polymerization.

The alkali aqueous solution-soluble polyimide precursor having an acid functional group in its molecular chain is, for example, a repeating unit represented by the general formula (I) obtained by forming an amide bond between tetracarboxylic acid or its derivative and diamine. And the like.

[Chemical 1] (In the formula, X represents a tetravalent organic group, and Y represents a divalent organic group.) In the general formula (I), if Y contains a siloxane bond, higher substrate adhesiveness should be imparted. Is more preferable because it can be obtained. In that case, it is better from the viewpoint of compatibility that the content ratio of the bifunctional amine is 20 mol% or less based on the total content of the bifunctional amine forming the photosensitive polyimide precursor. As X and Y, one aromatic ring, 2 to
10 aromatic rings are single bonds, ether groups, thioether groups,
Alkylene group, fluorinated alkylene group, carbonyl group,
Examples thereof include those bonded via a sulfonyl group, a sulfoxyl group or the like. Further, these may have a substituent such as a hydrocarbon group, a halogenated hydrocarbon group or a halogen atom on the aromatic ring.

The tetracarboxylic acid dianhydrides include pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4.
4'-biphenyltetracarboxylic dianhydride, 1,2,
5,6-naphthalenetetracarboxylic dianhydride, 2,
3,6,7-naphthalenetetracarboxylic dianhydride,
2,3,5,6-pyridinetetracarboxylic dianhydride,
1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 4,4'-sulfonyldiphthalic dianhydride, m-
Terphenyl-3,3 ", 4,4" -tetracarboxylic dianhydride, p-terphenyl-3,3 ", 4,4" -tetracarboxylic dianhydride, 4,4'-oxydiphthalic acid dianhydride Anhydrous, 1,1,1,3,3,3-hexafluoro-2,
2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) Propane dianhydride, 1,1,1,3
3,3-hexafluoro-2,2'-bis [4- (2,
3-dicarboxyphenoxy) phenyl] propane dianhydride, 1,1,1,3,3,3-hexafluoro-2,
2'-bis [4- (3,4-dicarboxyphenoxy)
Phenyl] propane dianhydride and the like.

As the diamine, p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 1,5-diaminonaphthalene, benzidine, 3,3'-dimethylbenzidine,
3,3'-dimethoxybenzidine, 4,4 '(or 3,
4'-, 3,3'-, 2,4 '-)-diaminodiphenylmethane, 4,4' (or 3,4'-, 3,3'-, 2,
4 '-)-diaminodiphenyl ether, 4,4' (or 3,4'-, 3,3'-, 2,4 '-)-diaminodiphenyl sulfone, 4,4' (or 3,4'-, 3 ，
3'-, 2,4 '-)-diaminodiphenyl sulfide,
4,4'-benzophenone diamine, 3,3'-benzophenone diamine, 4,4'-di (4-aminophenoxy) phenyl sulfone, 4,4'-bis (4-aminophenoxy) biphenyl, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,1,1,3,3,3-hexafluoro-2,2-bis (4-aminophenyl) propane,
2,2-bis [4- (4-aminophenoxy) phenyl] propane, 3,3-dimethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetramethyl-
4,4'-diaminodiphenylmethane, 4,4'-di (3
-Aminophenoxy) phenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,2'-bis (4-aminophenyl) propane, 2-methyl-4,4'-diaminobiphenyl, 3-methyl-4,4 '. -Diaminobiphenyl, 2,2'-dimethyl-3,3'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2 ', 6,6'-tetramethyl-3,3 '-Diaminobiphenyl, 2,2', 6,6'-tetramethyl-
Aromatic diamines such as 4,4′-diaminobiphenyl;
2,6-diaminopyridine, 2,4-diaminopyrimidine, 2,4-diamino-s-triazine, 2,7-diaminobenzofuran, 2,7-diaminocarbazole,
3,7-diaminophenothiazine, 2,5-diamino-
1,3,4-thiadiazole, 2,4-diamino-6-
Heterocyclic diamines such as phenyl-s-triazine; trimethylenediamine, tetramethylenediamine, hexamethylenediamine, 2,2-dimethylpropylenediamine, diaminopolysiloxane represented by the general formula (II).

[Chemical 2] (M and n are each independently an integer of 1 to 10, and s is 1 to
At least one selected from aliphatic diamines such as (which is an integer of 10). If necessary, a functional group containing a phenolic hydroxyl group or a carboxylic acid group can be used.

The above tetracarboxylic dianhydride and diamine compound are used alone or in combination of two or more.

The above polyimide precursor preferably has a weight average molecular weight in the range of 5,000 to 80,000.

The compound having a basic functional group and a protected acid functional group has the general formula (III)

Embedded image NRmR′n (III) (m + n = 3, R and R ′ each represent a substituent on the nitrogen atom, and at least one of them represents a carboxylic acid and / or a phenolic hydroxyl group protected by a protecting group. It is possible to use at least one kind selected from those shown in Table 1. Examples of the substituent represented by R include
Hydrogen groups, aliphatic substituents such as methyl, ethyl and butyl groups, ether substituents such as dimethyl ether and diethyl ether groups, ester substituents such as dimethyl ester and diethyl ester groups, amide groups, thioether groups and aromatic groups Those containing a group can be used. The substituent represented by R ′ has a carboxylic acid protected by a protecting group and / or a phenolic hydroxyl group, and a carboxylic acid protected by a protecting group at the terminal or side chain and / or
Or if it has a phenolic hydroxyl group, the above-mentioned methyl, ethyl, aliphatic substituents such as butyl group, dimethyl ether, ether substituents such as diethyl ether group, dimethyl ester, other ester substituents such as diethyl ester group, Those containing an amide group, a thioether group, or an aromatic group can be used.

The readily available starting materials include
For example, glycine, alanine, valine, norvaline, isoleucine, leucine, aminobutyric acid, diiminodiacetic acid, sarcosine, N, N-dimethylglycine, 2- (methylamino) isobutyric acid, proline, pipecolic acid,
Nipecotic acid, aspartic acid, glutamic acid, tyrosine, aminoadipic acid, methionine, ethionine, 4-
(Methylamino) benzoic acid, phenylglycine, hydroxyphenylglycine, phenylalanine, methyldiiminodiacetic acid, nitrilotriacetic acid, N- (2-hydroxyethyl) diiminodiacetic acid, 3-dimethylaminophenol,
3-diethylaminophenol, 4-hydroxypyridine, isonicotinic acid, 4-dimethylaminobenzoic acid, 4
-Diethylaminobenzoic acid, hydroxypicolinic acid, pyridine dicarboxylic acid, etc., and these acid functional groups are
For example, methylthiomenthyl ester group, t-butyl ester group, tetrahydropyranyl group, p-methoxybenzyl ester group, 4-sulfobenzyl ester group, trimethylsilyl ester group, triethylsilyl ester group, t-butyldimethylsilyl ester group, methoxy Ethoxymethyl ether group, cyclohexyl ether group,
Examples thereof include those protected with t-butyl ether group, benzyl ether group, 4-methoxybenzyl ether group, trimethylsilyl ether group, triethylsilyl ether group, t-butyldimethylsilyl ether group and the like.
In that case, it is more preferable that the basic functional group is a tertiary amine group. As an easily available starting material, for example, methyldiiminodiacetic acid, nitrilotriacetic acid,
N- (2-hydroxyethyl) diiminodiacetic acid, 3-dimethylaminophenol, 3-diethylaminophenol, 4-hydroxypyridine, isonicotinic acid, 4-dimethylaminobenzoic acid, 4-diethylaminobenzoic acid,
Hydroxypicolinic acid, pyridinedicarboxylic acid, etc. are often used, and these acid functional group moieties are methylthiomenthyl ester group, t-butyl ester group, tetrahydropyranyl group, p
-Methoxybenzyl ester group, 4-sulfobenzyl ester group, trimethylsilyl ester group, triethylsilyl ester group, t-butyldimethylsilyl ester group, methoxyethoxymethyl ether group, cyclohexyl ether group, t-butyl ether group, benzyl ether group, 4 Examples include those protected with a methoxybenzyl ether group, a trimethylsilyl ether group, a triethylsilyl ether group, a t-butyldimethylsilyl ether group, and the like.

The amount of the compound having a basic functional group and the protected acid functional group used is 20 with respect to the amount of the aqueous alkali solution soluble polyimide precursor having an acid functional group in the molecular chain.
It is preferable to be set to ˜300 wt%. This usage is
If it is less than 20% by weight, the unexposed portion is eluted during development, and the film after development tends not to remain. If it exceeds 300% by weight, the film may be whitened during film formation.

The photosensitizer is preferably an acid generator which generates an acid by photoreaction. For example, an onium salt compound represented by the general formula (IV);

[Chemical 4] (Ar the aromatic substituent, Tf denotes the _-SO 2 CF ₃₎ halogen compound represented by the general formula (V);

[Chemical 5] (Ar represents an aromatic substituent and X represents a halogen group such as Cl, Br, F, etc.) The sulfonic acid ester compound represented by the general formula (VI);

[Chemical 6] (Ar represents an aromatic substituent and R represents various other aliphatic substituents) A sulfonyl compound represented by the general formula (VII);

[Chemical 7] (Ar represents an aromatic substituent) or the like can be used. Among these, as a combination with the composition of the present invention, a combination selected from an onium salt compound, a sulfonate compound and a sulfonyl compound is preferable from the viewpoint of photoreaction. These photosensitizers are used alone or in combination of two or more.

The amount of the photosensitizer used is based on the aqueous alkaline solution-soluble polyimide precursor having an acid functional group in the molecular chain.
Usually, it is preferably 0.01 to 15% by weight per type, and when combined, it is preferably 0.1 to 40% by weight in total.

The alkali-developable photosensitive resin composition contains other additives known to be used in the photosensitive resin composition,
For example, additives such as a polymerization inhibitor or a polymerization inhibitor, a plasticizer, and an adhesion promoter can be included.

As the organic solvent used for dissolving the alkali-developable photosensitive resin composition, a polar solvent capable of completely dissolving the polyimide to be produced is generally preferable, for example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide,
Examples thereof include dimethyl sulfoxide, tetramethylurea, hexamethylphosphoric triamide and γ-butyrolactone. Other than the above polar solvents, ketones, esters, lactones, ethers, halogenated hydrocarbons, hydrocarbons such as acetone, diethyl ketone,
Methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichloro Butane, trichloroethane, chlorobenzene, o-
Dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene and the like can also be used. These organic solvents can be used alone or in combination of two or more kinds.

The alkali-developable photosensitive resin composition is applied onto a substrate such as a silicon wafer, a metal substrate or a ceramic substrate by a dipping method, a spray method, a screen printing method, a spin coating method or the like, and a solvent is appropriately heated. A coating film having no tackiness can be obtained by drying. This coating film is irradiated with actinic rays or actinic rays through a mask on which a desired pattern is drawn. As the actinic ray or actinic ray to be irradiated, a contact / proximity exposure machine using an ultra-high pressure mercury lamp, a mirror projection exposure machine, an i-line stepper, a g-line stepper, other ultraviolet rays, a visible light source, X
Lines and electron beams can be used. After irradiation, the non-irradiated portion is dissolved and removed with a developing solution to obtain a desired negative pattern. As the developing solution, a basic solution such as an aqueous solution of tetramethylammonium hydroxide or an aqueous solution of triethanolamine is used. After development, rinsing is carried out with water or a poor solvent as needed. The pattern thus obtained is heated to obtain a stable and highly heat-resistant polyimide pattern from which the photosensitizer and the solvent have been completely removed. The heating temperature at this time is preferably 150 to 500 ° C., and 200 to
More preferably, the temperature is 400 ° C. This heating temperature is
If the temperature is lower than 150 ° C, the mechanical properties and thermal properties of the polyimide film tend to deteriorate, and if it exceeds 500 ° C, the mechanical properties and thermal properties of the polyimide film tend to deteriorate.
The heating time at this time is preferably 0.05 to 10 hours. If this heating time is less than 0.05 hours, the mechanical properties and thermal properties of the polyimide film will tend to deteriorate, and if it exceeds 10 hours, the mechanical properties and thermal properties of the polyimide film will tend to deteriorate. Thus, the alkali-developable photosensitive resin composition of the present invention can be used as a surface protective film for semiconductors, an interlayer insulating film of a multilayer wiring board, and the like. The surface protective film using the photosensitive resin composition of the present invention has excellent adhesiveness to SiN, a sealant, etc., and therefore, a semiconductor device using the surface protective film obtained from the photosensitive resin composition of the present invention Is extremely reliable.

[0021]

EXAMPLES The present invention will be described below with reference to examples. [Synthesis Example 1] 25.2 g (0.3 mol) of dihydropyran was added to 7.4 g (0.05 mol) of methyliminodiacetic acid in 100 ml of dry methylene chloride under dry nitrogen under ice melting.
19 g (0.1 mol) of p-toluenesulfonic acid monohydrate was added, and the mixture was stirred for 1 hour and then at room temperature for 1 hour. The obtained reaction solution was poured into diethyl ether / sodium bicarbonate aqueous solution for neutralization, and then the organic layer was washed with saturated saline and further with ion-exchanged water. Magnesium sulfate was added to the obtained solution, and the filtered solution was dried under reduced pressure to obtain 15.8 g (0.05 mol) of methyliminodiacetic acid ditetrahydropyran protected compound. Then under dry nitrogen 10.9 g in 80 ml of dry N-methylpyrrolidone
To a stirred solution of (0.05 mol) pyromellitic dianhydride, 4.3 g (0.04 mol) of metaphenylenediamine was added, and the mixture was stirred at room temperature overnight. For the polyimide precursor solution obtained thereafter, 15.8 g obtained earlier
(0.05 mol) of methyliminodiacetic acid ditetrahydropyran protected compound, and 3.0 g (0.005 mol) of 9,10-dimethoxyanthracene-2-sulfonic acid diphenyliodonium were added and dissolved with stirring at room temperature overnight. A photosensitive resin composition solution was obtained by filtering with a filter.

Synthesis Example 2 14.7 g (0.05 mol) in 100 ml of dry N-methylpyrrolidone under dry nitrogen.
In a stirred solution of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride of 8.01 g (0.04 mol) of 4,
4-Oxydianiline was added and stirred at room temperature overnight.
Synthesis Example 1 was applied to the polyimide precursor solution obtained thereafter.
15.8 g (0.05 mol) of methyliminodiacetic acid ditetrahydropyran protected compound obtained in 1., and 3.0 g
(0.005 mol) of 9,10-dimethoxyanthracene-2-sulfonate diphenyliodonium was added, and the mixture was stirred and dissolved at room temperature for one day and then filtered to obtain a photosensitive resin composition solution.

[Synthesis Example 3] 100 m under dry nitrogen under ice melting
To 9.6 g (0.05 mol) of nitrilotriacetic acid in 1 of dry methylene chloride was added 42 g (0.5 mol) of dihydropyran, 19 g (0.1 mol) of p-toluenesulfonic acid monohydrate. The mixture was stirred for 1 hour and then at room temperature for 1 hour. The obtained reaction solution was poured into diethyl ether / sodium bicarbonate aqueous solution for neutralization, and then the organic layer was washed with saturated saline and further with ion-exchanged water. Magnesium sulfate was added to the obtained solution, and the filtered solution was dried under reduced pressure to obtain 22.2 g (0.05 mol) of nitrilotriacetate tritetrahydropyran protected body. Then under dry nitrogen 10.9 g in 80 ml of dry N-methylpyrrolidone
To a stirred solution of (0.05 mol) pyromellitic dianhydride, 8.01 g (0.04 mol) of 4,4-oxydianiline was added and stirred overnight at room temperature. Then, 22.2 g of the polyimide precursor solution obtained above was obtained.
(0.05 mol) nitrilotriacetic acid tritetrahydropyran protected body, and 3.0 g (0.005 mol) of 9,1
Diphenyliodonium 0-dimethoxyanthracene-2-sulfonate was added, and the mixture was stirred at room temperature for one day and dissolved,
A photosensitive resin composition solution was obtained by filtering with a filter.

Synthesis Example 4 14.7 (0.05 mol) in 100 ml of dry N-methylpyrrolidone under dry nitrogen.
8.5 g (0.04 mol) of 3,3'-dimethyl-4,4'-diaminobiphenyl was added to a stirred solution of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and the mixture was stirred at room temperature overnight. It was stirred. 22.2 g (0.05 mol) of nitrilotriacetate tritetrahydropyran protected compound obtained in Synthesis Example 3 and 3.0 g (0.005 mol) of 9,10- were obtained with respect to the resulting polyimide precursor solution. Dimethoxyanthracene-2-sulfonate diphenyliodonium was added, and the mixture was stirred and dissolved at room temperature for one day and then filtered to obtain a photosensitive resin composition solution.

Example 1 The photosensitive resin composition solution obtained in Synthesis Example 1 was spin-coated on a 5-inch silicon wafer and then dried.
After forming a coating film of 0 ± 1.0 μm 1, the film was exposed through a photomask at an exposure dose of 500 mJ / cm 2. After leaving it in a light-tight box for 1 hour, further heating it at 120 ° C. for 60 seconds on a hot plate, and then using a 2.38% tetramethylammonium hydroxide aqueous solution, development required for removing the exposed portion When paddle development was performed for 1.1 times the time and rinsed with water, the minimum via hole diameter reached 20 μm, and a relief pattern with a very good shape was obtained.

Example 2 The photosensitive resin composition solution obtained in Synthesis Example 2 was used, and otherwise the same treatment as in Example 1 was carried out. The minimum via hole diameter reached 20 μm, and a good relief pattern was obtained. was gotten.

Example 3 The photosensitive resin composition solution obtained in Synthetic Example 3 was used, and otherwise the same treatment as in Example 1 was carried out. The minimum via hole diameter reached 20 μm, and a good relief pattern was obtained. was gotten.

Example 4 The photosensitive resin composition solution obtained in Synthesis Example 4 was used, and otherwise the same treatment as in Example 1 was carried out. The minimum via hole diameter reached 20 μm, and a good relief pattern was obtained. was gotten.

Comparative Example 1 The photosensitive polyimide precursor resin obtained in Synthesis Example 1 was prepared in the same manner as in Example 1 except that the methyliminodiacetic acid ditetrahydropyran protector was not added. When processed in the same manner, there was almost no difference in dissolution rate between the unexposed portion and the exposed portion, and a good pattern as in the example was not formed.

Comparative Example 2 The photosensitive polyimide precursor resin obtained in Synthesis Example 2 was prepared in the same manner as in Example 1 except that the protected methyliminodiacetic acid ditetrahydropyran was not added. When processed in the same manner, there was almost no difference in dissolution rate between the unexposed portion and the exposed portion, and a good pattern as in the example was not formed.

Comparative Example 3 The photosensitive polyimide precursor resin obtained in Synthetic Example 3 was prepared in the same manner as in Example 1 except that the protected nitrilotriacetate / tritetrahydropyran was not added. When processed in the same manner, there was almost no difference in dissolution rate between the unexposed portion and the exposed portion, and a good pattern as in the example was not formed.

Comparative Example 4 The photosensitive polyimide precursor resin obtained in Synthesis Example 4 was prepared in the same manner as in Example 1 except that nitrilotriacetate tritetrahydropyran protector was not added. When processed in the same manner, there was almost no difference in dissolution rate between the unexposed portion and the exposed portion, and a good pattern as in the example was not formed.

[0033]

Industrial Applicability The alkali-developable photosensitive resin composition of the present invention can be developed with an aqueous alkali solution without adding a dissolution inhibitor, has a high exposure sensitivity, and has a good resolution pattern. Can be formed.

Claims (4)

[Claims] 1. An alkali-developable photosensitive resin composition comprising an alkali aqueous solution-soluble polyimide precursor having an acid functional group in its molecular chain, a compound having a basic functional group and a protected acid functional group, and a photosensitizer. 2. The protecting group of the protected acid functional group can be deprotected in an acidic atmosphere, and the photosensitizer is an acid generator.
1. The alkali-developable photosensitive resin composition as described in 1. 3. The basic functional group is a tertiary amine group.
1. The alkali-developable photosensitive resin composition as described in 1. 4. Alkali development after irradiating with actinic rays through a mask in which a desired pattern is drawn on a coating film using the alkali development type photosensitive resin composition according to any one of claims 1 to 3. A pattern forming method in which a non-irradiated portion is removed by developing using a liquid.