JP2002122993A - Photosensitive resin composition and positive type pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition containing a polyimide precursor, developable with an aqueous alkali solution and having positive type pattern forming ability and to provide a new positive type pattern forming method. SOLUTION: The positive type photosensitive resin composition comprises (A) a polyimide precursor having a phenolic hydroxyl group in its ester structure part, (B) a vinyloxy-containing compound such as triethylene glycol divinyl ether, (C) a photosensitive agent which is degraded under active light such as UV to generate an acid, (D) a sensitizer which accelerates the degradation of the photo-acid generating agent, e.g. pyrene and (E) a solvent. In the positive type pattern forming method, a coating film insolubilized in an aqueous alkali solution is formed by the components (A) and (B), exposed with active UV and heated, only the part exposed and decomposed by the acid generated from the component (C) is dissolved in the aqueous alkali solution to form a positive type pattern by development and this positive type pattern is subjected to imidation heat treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide-based photosensitive resin composition used as an electrical or electronic insulating material in the manufacture of semiconductor devices and the like. It is formed on a semiconductor element such as a semiconductor device or an LSI, and is applied to the formation of an insulating protective film that requires fine pattern processing.

[0002]

2. Description of the Related Art In recent years, polyimide resins have been developed in the fields of electricity and electronics, including semiconductors, due to their high heat resistance, chemical resistance, electrical insulation, low dielectric constant, and the like. , IC, LSI and VLSI chips are used as interlayer insulating films and surface protective films. However, in the conventional pattern forming method, after a polyimide precursor is applied on a wafer and dried to form a polyimide resinized film, pattern etching using a photoresist must be performed. In addition, a harmful hydrazine solution had to be used as a polyimide etching solution.

[0003] For this reason, attempts to introduce a photosensitive group into a polyimide precursor to enable pattern formation of the polyimide itself have been made by various material manufacturers, and are in the practical stage in some product fields. However, photosensitive polyimides currently in practical use can be broadly classified into those in which photosensitive groups are introduced into the polyimide precursor through ionic bonds and those in which photosensitive groups are introduced through ester bonds. The sensitivity is low (the solubility difference is low) with respect to the exposure apparatus used in the process, and the process margin is low because the solubility of the resin decreases in the process. Also,
In the latter case, a complicated process is required for the production of the polyimide precursor, and a high-molecular-weight product having a practically usable high molecular weight cannot be obtained. Further, these resins employ a negative pattern forming method, and must be developed with an organic solvent when forming a pattern, which is a serious problem from the viewpoint of environmental conservation.

Recently, as a positive photosensitive resin composition, a composition in which a diazonaphthoquinone compound is added to polybenzoxazole has been proposed. However, this resin composition is inferior to polyimide resin in heat resistance and chemical resistance, and can be applied only to limited semiconductor products. In addition, this resin composition is compared with a positive resist widely used at the time of forming a semiconductor circuit, for example, a resin composition obtained by mixing diazonaphthoquinone with a novolak resin.
Low sensitivity to ultraviolet light and poor pattern forming ability. For this reason, defects such as a thin film remaining during pattern development and an excessively large pattern size have occurred.
From these problems, there is a strong demand for a positive photosensitive polyimide precursor that can use an aqueous alkaline solution at the time of pattern formation, and that does not swell with the developer and can increase the resolution.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional disadvantages and to provide a positive photosensitive resin composition containing a polyimide precursor having a positive pattern forming ability which can be developed with an alkaline aqueous solution. And a method for forming a positive pattern.

[0006]

Means for Solving the Problems As a result of diligent research aimed at achieving the above object, the present inventor has adopted a novel positive photosensitive resin composition having a composition described later and a method for forming a positive pattern thereof. By doing so, the inventors have found that the above object can be achieved, and have completed the present invention.

That is, the positive photosensitive resin composition of the present invention comprises: (A) a polyimide precursor represented by the following general formula:

Embedded image (Wherein, R ¹ is a tetravalent aromatic group, a tetravalent organic group in which a plurality of aromatic rings are single-bonded, or a group in which a plurality of aromatic rings are -O-, -CO-, -SO ₂ -, - CH ₂ - or -
A tetravalent organic group linked by C (CF ₃ ) ₂ —,
² is a divalent aromatic group, a divalent organic group in which a plurality of aromatic rings are single-bonded, or a group in which a plurality of aromatic rings are -O-, -CO
_{-, - SO 2 -, -} CH 2 - or -C (CF _{3) 2}
And R ³ and R ⁴ are each an aromatic group substituted with one or more phenolic hydroxyl groups. K and l are integers of 1 to 3 and m is an integer of 1 or more.) (B) A vinyloxy group-containing compound represented by the following general formula:

Embedded image (Where R ⁵ is a divalent or trivalent aliphatic group or aromatic group, or a plurality of aromatic rings having a single bond, —O—,
_{-CO -, - SO 2 -,} - CH 2 -, - NH- or -C (CF _{3) 2} - is a divalent or trivalent organic radical which is bonded in. I and n are integers of 1 to 3) (C) a photosensitizer which decomposes to actinic rays such as ultraviolet rays to generate an acid, and (D) a sensitizer which promotes decomposition of the photosensitizer of (C). And (E) a solvent.

The method of forming a positive pattern according to the present invention is also directed to a method of forming a positive-type photosensitive resin composition on a substrate, followed by drying at 70 to 150 ° C. to form a coating film insolubilized with an aqueous alkaline solution. A film forming step, and an exposed insolubilized coating film that is exposed to active ultraviolet rays through a positive mask pattern and then heated at 70 to 150 ° C. to decompose only the exposed portion of the insolubilized coating film. And a positive pattern developing step of dissolving only the exposed and decomposed portions of the exposed coating film using an alkaline aqueous solution to develop a positive pattern, and heat treating the developed positive pattern to form a polyimide positive pattern. And an imidization heat treatment step.

Hereinafter, the present invention will be described in detail.

The acid component serving as the R ¹ skeleton of the polyimide precursor (A) used in the present invention includes, for example, pyromellitic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ', 4'-biphenyltetracarboxylic acid, 3,3', 4,4'-benzophenonetetracarboxylic acid, 4,4'-oxydiphthalic acid, 3,3 ', 4
4'-diphenylsulfonetetracarboxylic acid, 2,2-
Bis (3,4-dicarboxyphenyl) hexafluoropropane, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid,
1,4,5,8-naphthalenetetracarboxylic acid, 1,
2,3,4-cyclobutanetetracarboxylic acid, 1,2,2
3,4-butanetetracarboxylic acid, 1,2,4,5-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3,3 ', 4,4'-bicyclohexyltetracarboxylic Acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-
Examples thereof include 1,2,3,4-tetrahydronaphthalene-1-succinic acid and anhydrides thereof, and these can be used alone or in combination.

As the diamine component serving as the R ² skeleton of the polyimide precursor (A) used in the present invention, for example, m-phenylenediamine, p-phenylenediamine, 2,4-
Diaminotoluene, 2,5-diaminotoluene, 2,6
-Diaminotoluene, 3,5-diaminotoluene, 1-
Methoxy-2,4-diaminobenzene, 1,4-diamino-2-methoxy-5-methylbenzene, 1,3-diamino-4,6-dimethylbenzene, 3,5-diaminobenzoic acid, 2,5-diamino Benzoic acid, 1,2-diaminonaphthalene, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,
7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,3-diaminonaphthalene, 2,6-diaminonaphthalene, 1,4-diamino-2-methylnaphthalene,
1,5-diamino-2-methylnaphthalene, 1,3-diamino-2-phenylnaphthalene, 2,2-bis (4-
Aminophenyl) propane, 1,1-bis (4-aminophenyl) ethane, 4,4′-diaminodiphenylmethane, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, 3,3 ′, 5,5 ′ -Tetramethyl-4,
4'-diaminodiphenylmethane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetraethyl-4,4'
-Diaminodiphenylmethane, 4,4'-methylenebis (cyclohexylamine), 4,4'-methylenebis (3,3-dimethyl-cyclohexylamine), 2,
4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 4,4'-diaminobenzanilide, 3,3'-
Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, bis (4-aminophenyl) diethylsilane, bis (4-aminophenyl) diphenylsilane, bis (4-
(Aminophenyl) -N-methylamine, bis (4-aminophenyl) -N-phenylamine, 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,6-diaminopyridine, 3,5-diamino Pyridine, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3, 3'-dihydroxy-4,4 '
-Diaminobiphenyl, o-toluidinesulfone,
4,4'-bis (4-aminophenoxy) biphenyl,
2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 1,4-bis (4-
Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 9,10-bis (4-aminophenyl) anthracene, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis ( 4-aminophenyl) hexafluoropropane, 2,2-bis (3-aminophenyl) hexafluoropropane, 1,1-bis (4-aminophenyl) -1-phenyl-2,2,2-
Trifluoroethane, 2,2-bis (3-amino-4-
Hydroxyphenyl) hexafluoropropane, 2,2
-Bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, etc., and these may be used alone or in combination of two or more. Can be used.

In the present invention, examples of the compound having an R ³ or R ⁴ skeleton to be introduced into an acid anhydride having an R ¹ skeleton via an ester bond include the following.

Embedded image These compounds are more preferable in the present invention, but are not limited to the above structure as long as they are alcohol compounds having a phenolic hydroxyl group at a terminal.
These can be used alone or in combination of two or more.

As the solvent for the polycondensation reaction of the acid component having the R ¹ skeleton and the diamine component having the R ² skeleton of the polyimide precursor (A) used in the present invention, for example, N-methylpyrrolidone, N, N′- An aprotic polar solvent such as dimethylacetamide and N, N'-dimethylformamide, cyclohexanone, cyclopentanone, γ-butyrolactone and the like are used, and these can be used alone or as a mixture of two or more.

The (B) vinyloxy group-containing compound having an R ⁵ skeleton used in the present invention has a vinyloxy group (vinyl ether group) at the terminal of the compound as a reactive group. For example, compounds represented by the following formulas 6 to 10 are exemplified,
These can be used alone or in combination of two or more. The addition amount is preferably 1 to 10 parts by weight based on 100 parts by weight of the photosensitive resin composition. If the amount is less than 1 part by weight, the effect is not obtained. If the amount exceeds 10 parts by weight, the properties of the obtained coating film are deteriorated.

[0015]

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Embedded image Examples of the photosensitizer (C) which decomposes to actinic rays such as ultraviolet rays and generates an acid used in the present invention include,
The compound shown in Chemical formula 20 is exemplified. These compounds are more preferable in the present invention, but are not limited to the above structure as long as they can be decomposed by irradiation with active ultraviolet rays to efficiently generate an acid. These can be used alone or in combination, and the amount of addition is 0.1 to 100 parts by weight of the photosensitive resin composition.
20 parts by weight are preferred. When the amount is less than 0.1 part by weight, the sensitivity to ultraviolet rays is low, and when the amount exceeds 20 parts by weight, the properties of the obtained coating film deteriorate.

[0016]

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Embedded image The sensitizer (D) used in the present invention promotes the decomposition of the component (C) against actinic rays such as ultraviolet rays, and examples thereof include compounds represented by the following formula (21). These compounds are more preferred in the present invention,
The structure is not limited to the above structure as long as it promotes the decomposition of the compound (C). These can be used alone or as a mixture, and the addition amount thereof is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the photosensitive resin composition. When the amount is less than 0.1 part by weight, the sensitivity to ultraviolet rays is low, and when the amount exceeds 20 parts by weight, the properties of the obtained coating film deteriorate.

[0017]

Embedded image Further, the photosensitive resin composition obtained by the present invention,
(E) It is used in the state of being dissolved in a solvent. Examples of the solvent (E) include N-methylpyrrolidone, N, N '
Aprotic polar solvents such as -dimethylacetamide, N, N'-dimethylformamide, cyclohexanone,
Cyclopentanone, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, γ-butyrolactone, etc., and these can be used alone or in combination of two or more. .

Next, a positive pattern forming method using the photosensitive resin composition obtained by the present invention will be described.

When application to a semiconductor device is considered, first, this resin composition is coated on a target wafer using a spin coater, and then the coating film is dried at 70 to 150 ° C. An active ultraviolet ray having a wavelength of 365 nm or 436 nm is irradiated through a mask having a pattern drawn on the obtained coating film. Next, the coating film is heated again at 70 to 150 ° C., and the coating film is successively applied with an aqueous alkali solution, for example, an aqueous solution of an inorganic alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia, ethylamine, or n-propyl. Primary amines such as amines,
Secondary amines such as diethylamine and di-n-propylamine; tertiary amines such as triethylamine and methyldimethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; and tetraamines such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. Only the actinic ray irradiated portion is dissolved and developed using an aqueous solution of a graded amine, and rinsed with pure water. As a developing system, a system such as spray, paddle, immersion, and ultrasonic wave can be considered. Thereby, a desired positive pattern can be obtained on the target wafer. further,
By subjecting this coating film to a heat treatment at, for example, 150 ° C. for 1 hour, 250 ° C. for 1 hour, and 350 ° C. for 1 hour, the resin composition is imidized and a polyimide film having excellent film properties can be formed.

[0020]

The greatest feature of the present invention is that the inventor of the present invention has conducted intensive studies and, as a result, has discovered a positive pattern formation mechanism described below. In the above positive pattern forming method, the resin composition is subjected to R
^1, R Formula polyimide precursor of R ³ with ² skeleton,
The phenolic hydroxyl group moiety having the R ⁴ skeleton chemically reacts with the compound having the R ⁵ skeleton and becomes insoluble in an aqueous alkali solution. Next, by irradiating the insolubilized coating film with actinic rays such as ultraviolet rays, the photoacid generator in the actinic ray-exposed area is decomposed to generate acid. Further, in the exposed coating film decomposition step of heating, the generated acid decomposes the chemical bond, returns to the polymer of the polyimide precursor having R ¹ and R ² skeleton again, and regenerates the phenolic hydroxyl group. The phenolic hydroxyl group of this polymer has high solubility in an aqueous alkali solution, and as a result, only the portion irradiated with active light such as ultraviolet light shows high solubility in the aqueous alkali solution, and the unirradiated portion is insolubilized. Does not melt at all. Due to this high contrast, the photosensitive resin composition of the present invention can form a positive pattern with high resolution and good dimensional control. In addition, since a compound that promotes the decomposition of the photoacid generating photosensitizer described above was found, the decomposition of the photoacid generating photosensitizer in the active light irradiation portion was further promoted by irradiating actinic rays such as ultraviolet rays, and many acids were exposed. Since the unirradiated portion is not affected and remains insoluble in an aqueous alkaline solution, a positive pattern having higher contrast and higher sensitivity than before can be formed.

Furthermore, in the resin compositions containing a diazonaphthoquinone compound proposed so far, low sensitivity to actinic rays has been a problem. The main cause is derived from diazonaphthoquinone compounds. That is, the addition of a large amount of the diazonaphthoquinone compound lowers the transmittance of actinic rays, thereby lowering the sensitivity. In the photosensitive resin composition of the present invention, in order to form a positive pattern without using a diazonaphthoquinone compound, not only has a good active light transmittance, but also repeatedly uses an acid generated from a photoacid generator. Therefore, sufficient pattern forming ability can be exhibited even with a low amount of active light. Since this reaction mechanism can cause a chemical reaction in an amplifying manner, it has become possible to provide a highly sensitive photosensitive resin composition in the present invention.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on embodiments.

Example 1 First, 1 mol of benzophenonetetracarboxylic dianhydride and 2.1 mol of 2 L of N-methyl-2-pyrrolidone and P-hydroxybenzyl alcohol were added to a reaction flask equipped with a nitrogen inlet tube and stirred. And then 2.1mo
1 of triethylamine is added dropwise over 30 minutes. After standing for 3 hours in this state, 1.0 mol of 4,4 '
Add diaminodiphenyl ether and stir for 30 minutes to dissolve. Next, 2.1 mol of diphenyl (2,3
-Dihydro-2-thioxo-3-benzoxazole)
The phosphonate is added in five portions, and a condensation reaction is performed for 5 hours in that state. The obtained slurry mixture is poured into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. Dried solid resin 2
0 g and 10 g of triethylene glycol divinyl ether
And 1.0 g of 1,8-naphthalimidyl triflate and 0.5 g of pyrene were dissolved in 30 g of N-methyl-2-pyrrolidone, and the obtained slurry was filtered at 1 μm to give Sample 1.

This sample 1 was coated on a 6-inch silicon wafer using a spin coater, and was dried by heating at 110 ° C. for 4 minutes on a baking plate.
A μm coating was obtained. The coating film was irradiated with an ultraviolet light using a filter that transmits only 365 nm to a thickness of 100 nm.
irradiating a test pattern with energy of mj / cm ² ,
Subsequently, the mixture was heated at 100 ° C. for 1 minute. Then the 2.38% T
Paddle development was performed for 60 seconds using an aqueous solution of MAH (tetramethylammonium hydride), followed by washing with pure water. By this operation, a positive relief pattern in which only the ultraviolet irradiation part of the coating film was dissolved was obtained.
Observation of the obtained pattern with an optical microscope confirmed that a pattern up to 3.0 μm was formed sharply. At this time, the change in film thickness during development was 0.3 μm, which was almost unchanged, and it was observed that the film was insoluble.

Further, the pattern was applied at 150 ° C. for 1 hour and 2 hours.
Heat treatment at 50 ° C for 1 hour and 350 ° C for 1 hour,
The imidization of the coating film was completed. This imide pattern is
A sharp profile was maintained without collapse even in the heat treatment.

Example 2 First, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic dianhydride and 2 L of N-methyl-2-pyrrolidone and P-hydroxybenzyl alcohol were placed in a reaction flask equipped with a nitrogen inlet tube. Is added and stirred, followed by dropwise addition of 2.1 mol of triethylamine over 30 minutes. In this state, the mixture is left for 3 hours, and after completion of the reaction, 1.0 mol of 4,4'-diaminodiphenyl ether is added, and the mixture is stirred and dissolved for 30 minutes. Next, 2.1mo
l of diphenyl (2,3-dihydro-2-thioxo-3
-Benzoxazole) phosphonate is added in five portions, and a condensation reaction is performed for 5 hours in that state. The obtained slurry mixture is poured into a large amount of methanol for washing,
The obtained solid resin is dried by a vacuum dryer for 12 hours. 20 g of the dried solid resin, 10 g of triethylene glycol divinyl ether, 1.0 g of 1,8-naphthalimidyl triflate and 0.5 g of pyrene are dissolved in 30 g of N-methyl-2-pyrrolidone to obtain a slurry. Was filtered by 1 μm to obtain Sample 2.

This sample 2 was coated on a 6-inch silicon wafer using a spin coater, and dried by heating at 110 ° C. for 4 minutes on a baking plate to form a film having a film thickness of 10%.
A μm coating was obtained. The coating film was irradiated with an ultraviolet light using a filter that transmits only 365 nm to a thickness of 100 nm.
irradiating a test pattern with energy of mj / cm ² ,
Subsequently, the mixture was heated at 100 ° C. for 1 minute. Then the 2.38% T
Paddle development was performed for 60 seconds using an aqueous solution of MAH (tetramethylammonium hydride), followed by washing with pure water. By this operation, a positive relief pattern in which only the ultraviolet irradiation part of the coating film was dissolved was obtained.
Observation of the obtained pattern with an optical microscope confirmed that a pattern up to 3.0 μm was formed sharply. At this time, the change in film thickness during development was 0.3 μm, which was almost unchanged, and it was observed that the film was insoluble.

Further, this pattern was applied at 150 ° C. for 1 hour and 2 hours.
Heat treatment at 50 ° C for 1 hour and 350 ° C for 1 hour,
The imidization of the coating film was completed. This imide pattern is
A sharp profile was maintained without collapse even in the heat treatment.

Example 3 First, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic dianhydride and 2 L of N-methyl-2-pyrrolidone and P-hydroxybenzyl alcohol were placed in a reaction flask equipped with a nitrogen inlet tube. Is added and stirred, followed by dropwise addition of 2.1 mol of triethylamine over 30 minutes. In this state, the mixture is left for 3 hours, and after completion of the reaction, 1.0 mol of 4,4'-diaminodiphenyl ether is added, and the mixture is stirred and dissolved for 30 minutes. Next, 2.1mo
l of diphenyl (2,3-dihydro-2-thioxo-3
-Benzoxazole) phosphonate is added in five portions, and a condensation reaction is performed for 5 hours in that state. The obtained slurry mixture is poured into a large amount of methanol for washing,
The obtained solid resin is dried by a vacuum dryer for 12 hours. 20 g of the dried solid resin and 2,2-bis (4- (2
-Vinyloxyethoxy) phenyl) propane (10 g), 1,8-naphthalimidyl triflate (1.0 g) and pyrene (0.5 g) are dissolved in N-methyl-2-pyrrolidone (30 g), and the resulting slurry is filtered by 1 μm. As a result, Sample 3 was obtained.

The sample 3 was coated on a 6-inch silicon wafer using a spin coater, and dried by heating at 110 ° C. for 4 minutes on a baking plate.
A μm coating was obtained. This coating film was exposed to an ultraviolet light using a filter that transmits only 365 nm to a thickness of 150 nm.
irradiating a test pattern with energy of mj / cm ² ,
Subsequently, the mixture was heated at 100 ° C. for 1 minute. Then the 2.38% T
Paddle development was performed for 60 seconds using an aqueous solution of MAH (tetramethylammonium hydride), followed by washing with pure water. By this operation, a positive relief pattern in which only the ultraviolet irradiation part of the coating film was dissolved was obtained.
Observation of the obtained pattern with an optical microscope confirmed that a pattern up to 3.0 μm was formed sharply. At this time, the change in film thickness during development was 0.3 μm, which was almost unchanged, and it was observed that the film was insoluble.

Further, the pattern was applied at 150 ° C. for 1 hour and 2 hours.
Heat treatment at 50 ° C for 1 hour and 350 ° C for 1 hour,
The imidization of the coating film was completed. This imide pattern is
A sharp profile was maintained without collapse even in the heat treatment.

Example 4 First, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic dianhydride and 2 L of N-methyl-2-pyrrolidone and O-hydroxybenzyl alcohol were placed in a reaction flask equipped with a nitrogen inlet tube. Is added and stirred, followed by dropwise addition of 2.1 mol of triethylamine over 30 minutes. In this state, the mixture is left for 3 hours, and after completion of the reaction, 1.0 mol of 4,4'-diaminodiphenyl ether is added, and the mixture is stirred and dissolved for 30 minutes. Next, 2.1mo
l of diphenyl (2,3-dihydro-2-thioxo-3
-Benzoxazole) phosphonate is added in five portions, and a condensation reaction is performed for 5 hours in that state. The obtained slurry mixture is poured into a large amount of methanol for washing,
The obtained solid resin is dried by a vacuum dryer for 12 hours. 20 g of the dried solid resin and 2,2-bis (4- (2
-Vinyloxyethoxy) phenyl) propane (10 g), 1,8-naphthalimidyl triflate (1.0 g) and pyrene (0.5 g) are dissolved in N-methyl-2-pyrrolidone (30 g), and the resulting slurry is filtered by 1 μm. Thus, Sample 4 was obtained.

This sample 4 was coated on a 6-inch silicon wafer using a spin coater, and dried by heating at 110 ° C. for 4 minutes on a bake plate.
A μm coating was obtained. This coating film was exposed to an ultraviolet light using a filter that transmits only 365 nm to a thickness of 200 nm.
irradiating a test pattern with energy of mj / cm ² ,
Subsequently, the mixture was heated at 100 ° C. for 1 minute. Then the 2.38% T
Paddle development was performed for 60 seconds using an aqueous solution of MAH (tetramethylammonium hydride), followed by washing with pure water. By this operation, a positive relief pattern in which only the ultraviolet irradiation part of the coating film was dissolved was obtained.
Observation of the obtained pattern with an optical microscope confirmed that a pattern up to 3.0 μm was formed sharply. Further, at this time, the change in film thickness during development was almost unchanged at 0.2 μm, and it was observed that the film was insoluble.

Further, this pattern was applied at 150 ° C. for 1 hour and 2 hours.
Heat treatment at 50 ° C for 1 hour and 350 ° C for 1 hour,
The imidization of the coating film was completed. This imide pattern is
A sharp profile was maintained without collapse even in the heat treatment.

Example 5 First, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic dianhydride and 2 L of N-methyl-2-pyrrolidone were added to a reaction flask equipped with a nitrogen introducing tube.
2.1 mol of dihydroxybenzyl alcohol are added and stirred, followed by dropwise addition of 2.1 mol of triethylamine in 30 minutes. In this state, the mixture is left for 3 hours, and after completion of the reaction, 1.0 mol of 4,4'-diaminodiphenyl ether is added, and the mixture is stirred and dissolved for 30 minutes. Next, 2.
1 mol of diphenyl (2,3-dihydro-2-thioxo-3-benzoxazole) phosphonate is added in five portions, and a condensation reaction is performed for 5 hours in that state. The obtained slurry mixture is poured into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. 20 g of the dried solid resin and 2,2-bis (4
-(2-vinyloxyethoxy) phenyl) propane 10
g, 1.0 g of 1,8-naphthalimidyl triflate and 0.5 g of pyrene were dissolved in 30 g of N-methyl-2-pyrrolidone, and the resulting slurry was filtered at 1 μm to give Sample 5.

This sample 5 was coated on a 6-inch silicon wafer using a spin coater, and was dried by heating at 110 ° C. for 4 minutes on a baking plate.
A μm coating was obtained. The coating film was irradiated with an ultraviolet light using a filter that transmits only 365 nm to a thickness of 100 nm.
irradiating a test pattern with energy of mj / cm ² ,
Subsequently, the mixture was heated at 100 ° C. for 1 minute. Then the 2.38% T
Paddle development was performed for 60 seconds using an aqueous solution of MAH (tetramethylammonium hydride), followed by washing with pure water. By this operation, a positive relief pattern in which only the ultraviolet irradiation part of the coating film was dissolved was obtained.
Observation of the obtained pattern with an optical microscope confirmed that a pattern up to 3.0 μm was formed sharply. At this time, the change in film thickness during development was 0.5 μm, which was almost unchanged, and was observed to be insoluble.

Further, this pattern was applied at 150 ° C. for 1 hour and 2 hours.
Heat treatment at 50 ° C for 1 hour and 350 ° C for 1 hour,
The imidization of the coating film was completed. This imide pattern is
A sharp profile was maintained without collapse even in the heat treatment.

COMPARATIVE EXAMPLE 1 mol of benzophenonetetracarboxylic dianhydride and 2.1 mol of 2 L of N-methyl-2-pyrrolidone and P-hydroxybenzyl alcohol were added, followed by stirring, followed by 2.1 mol of triethylamine for 30 minutes. And dripping. Leave for 3 hours in this state, and after completion of the reaction,
l, 4,4'-diaminodiphenyl ether
Stir for 0 minutes to dissolve. Next, 2.1 mol of diphenyl (2,3-dihydro-2-thioxo-3-benzoxazole) phosphonate is added in five portions, and a condensation reaction is performed for 5 hours in that state. The obtained slurry mixture is poured into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. 20 g of the dried solid resin and 5 g of a benzophenone-type disubstituted diazonaphthoquinone compound were dissolved in 30 g of N-methyl-2-pyrrolidone, and the obtained slurry was filtered at 1 μm to obtain Sample 6.

This sample 6 was coated on a 6-inch silicon wafer using a spin coater, and was dried by heating at 120 ° C. for 4 minutes on a baking plate.
A μm coating was obtained. This coating film was irradiated with an ultraviolet light using a filter that transmits only 365 nm to a thickness of 500 nm.
irradiating a test pattern with energy of mj / cm ² ,
Subsequently, paddle development was performed for 1 minute with a 2.38% aqueous solution of TMAH (tetramethylammonium hydride). By this operation, a positive relief pattern in which only the ultraviolet irradiation part of the coating film was dissolved was obtained. Observation of the obtained pattern with an optical microscope revealed that
It was confirmed that a pattern up to 5.0 μm was formed. However, this pattern was swollen and not a sharp shape.

Further, this pattern was applied at 150 ° C. for 1 hour and 2 hours.
Heat treatment at 50 ° C for 1 hour and 350 ° C for 1 hour,
The imidization of the coating film was completed. This imide pattern is
It was firmly adhered on the silicon wafer, and no resin crack or peeling was observed in the pattern.

[0041]

The present invention is a photosensitive polyimide precursor having a positive pattern forming ability, and an alkaline aqueous solution can be used for pattern formation. Furthermore, since the photosensitive resin composition of the present invention reacts chemically with ultraviolet light, it has a high contrast, a high sensitivity, and a very sharp positive pattern with good dimensional control can be obtained. . In addition, the sensitivity can be further increased by adding a compound that promotes acid decomposition.
Further, the polyimide coating finally obtained is excellent in heat resistance and chemical resistance, so that it can be used in the same manner as a commonly used semiconductor device protective film. These are based on a completely new idea, and it can be easily understood that they are unique and excellent inventions.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/38 511 G03F 7/38 511 7/40 501 7/40 501 H01L 21/027 H01L 21/30 502R F-term (reference) 2H025 AA01 AA02 AA04 AA20 AB16 AB17 AC01 AD03 BE00 BE10 BG00 CB25 CB41 CC03 CC17 CC20 EA01 FA12 FA17 FA29 2H096 AA25 AA27 BA09 DA01 EA02 FA01 GA08 HA01 4J011 PA97 PC02 QA21 QA11 SAA SA86 SA87 UA01 UA06 VA01 WA01 4J026 AB34 BA15 BA16 BA17 BB01 DA02 DA08 DB02 DB09 DB11 DB15 DB36 FA05 GA06 GA07 GA08

Claims (2)

[Claims] (A) a polyimide precursor represented by the following general formula: (Wherein, R ¹ is a tetravalent aromatic group, a tetravalent organic group in which a plurality of aromatic rings are single-bonded, or a group in which a plurality of aromatic rings are -O-, -CO-, -SO ₂ -, - CH ₂ - or -
A tetravalent organic group linked by C (CF ₃ ) ₂ —,
² is a divalent aromatic group, a divalent organic group in which a plurality of aromatic rings are single-bonded, or a group in which a plurality of aromatic rings are -O-, -CO
_{-, - SO 2 -, -} CH 2 - or -C (CF _{3) 2}
And R ³ and R ⁴ are each an aromatic group substituted with one or more phenolic hydroxyl groups. K and l are integers of 1 to 3 and m is an integer of 1 or more.) (B) A vinyloxy group-containing compound represented by the following general formula: (Where R ⁵ is a divalent or trivalent aliphatic group or aromatic group, or a plurality of aromatic rings having a single bond, —O—,
_{-CO -, - SO 2 -,} - CH 2 -, - NH- or -C (CF _{3) 2} - is a divalent or trivalent organic radical which is bonded in. I and n are integers of 1 to 3) (C) a photosensitizer which decomposes to actinic rays such as ultraviolet rays to generate an acid, and (D) a sensitizer which promotes decomposition of the photosensitizer of (C). A positive photosensitive resin composition comprising an agent and (E) a solvent. 2. An insolubilized coating film forming step of coating the positive photosensitive resin composition according to claim 1 on a substrate and drying at 70 to 150 ° C. to form an insolubilized coating film for an alkaline aqueous solution. After exposing the insolubilized coating film to active ultraviolet light through a positive mask pattern, 70-150
Exposure coating decomposition process to decompose only the exposed portion of the insolubilized coating by heating at ℃, and positive pattern development to dissolve only the exposed decomposition portion of the exposed coating using an alkaline aqueous solution and develop it into a positive pattern A positive pattern forming method, comprising: a step of heat treating the developed positive pattern to form a polyimide positive pattern by heat treatment.