JP2003295430A - Photosensitive resin composition and positive pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high sensitivity photosensitive resin composition comprising a polyimide precursor, developable with an aqueous alkali solution and having positive pattern forming ability and to provide a new positive pattern forming method. <P>SOLUTION: The photosensitive resin composition comprises (A) an aromatic polyimide precursor having a repeating unit of formula (1), wherein R<SP>3</SP>and R<SP>4</SP>are each the residue of an acetal- or ester-linked vinyloxy-containing compound, (B) a polyfunctional vinyloxy-containing compound represented by the formula R<SP>5</SP>-[(CH<SB>2</SB>)<SB>i</SB>-O-CH=CH<SB>2</SB>]<SB>n</SB>, (C) a photoacid generating photosensitive agent such as triethylene glycol divinyl ether, (D) a sensitizer such as 1,8- naphthalimidyl triflate and (E) a solvent. <P>COPYRIGHT: (C)2004,JPO

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 / electronic insulating material in the production of semiconductor devices and the like. More specifically, this photosensitive resin composition is an IC It is applied to the formation of an insulating protective film, which is formed on a semiconductor element such as an LSI or an LSI and requires the processing of a fine pattern.

[0002]

2. Description of the Related Art In recent years, polyimide resins have been developed into electric and electronic fields including semiconductors due to their high heat resistance, chemical resistance, electric insulation, low dielectric constant, etc. , As a surface protection film for IC, LSI and VLSI chips. However, in the conventional pattern forming method, after coating and drying the polyimide precursor on the wafer, pattern etching must be performed using a photoresist, and at that time, a hydrazine solution which is a harmful substance is used. It had to be used as a polyimide etchant.

For this reason, material manufacturers have made attempts to introduce a photosensitive group into a polyimide precursor to enable pattern formation of the polyimide itself, and it has reached a practical stage in some product fields. However, the photosensitive polyimides currently in practical use can be roughly classified into those in which a photosensitive group is introduced into a polyimide precursor by an ionic bond and those in which a photosensitive group is introduced via an ester bond. 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 producing the polyimide precursor, and a polymer having a sufficiently high molecular weight that can be practically used cannot be obtained. Further, these resins employ a negative type pattern forming system and must be developed with an organic solvent at the time of pattern formation, which is a serious problem from the viewpoint of environmental protection.

Recently, as a positive type photosensitive resin composition, a composition prepared by adding a diazonaphthoquinone compound to polybenzoxazole has been proposed. However, this resin composition is inferior in heat resistance and chemical resistance to the polyimide resin, and can be applied only to limited semiconductor products. Further, this resin composition is compared with a positive resist that is widely used at the time of semiconductor circuit formation, for example, a resin composition obtained by mixing diazonaphthoquinone with a novolac resin,
Low sensitivity to ultraviolet rays 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.
Due to these problems, there is a strong demand for a positive photosensitive polyimide precursor that can utilize an alkaline aqueous solution for pattern formation, and is non-swelling with respect to this developer and capable of achieving high resolution and high sensitivity.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a polyimide precursor which has a positive pattern forming ability and can be developed in an alkaline aqueous solution, and which has high sensitivity. A positive photosensitive resin composition and a positive pattern forming method are provided.

[0006]

Means for Solving the Problems As a result of intensive research aimed at achieving the above-mentioned object, the present inventor has found that a positive-type photosensitive resin composition having a composition described later and a positive-type pattern formation of the resin composition. The present invention has been completed by finding that the method can achieve the above object.

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

[Chemical 3] (In the formula, R ¹ is a tetravalent aromatic group, a tetravalent organic group in which a plurality of aromatic rings are single-bonded, or a plurality of aromatic rings are —O—, —CO—, —SO. ₂ -, - CH ₂ - or -
A tetravalent organic group bonded 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 plurality of aromatic rings are —O—, —CO
_{-, - SO 2 -, -} CH 2 - or -C (CF _{3) 2}
It is a divalent organic group bonded by-. In addition, R ³ , R ⁴
Is a residue of a vinyloxy group-containing compound having a hydrogen atom or an acetal bond or an ester bond. ) (B) A polyfunctional vinyloxy group-containing compound represented by the following general formula,

[Chemical 4] (However, in the formula, R^FiveIs a divalent or trivalent aliphatic group
Or an aromatic group or multiple aliphatic or aromatic rings
Single bond, -O-, -CO-, -SO₂-, -CH ₂-,
-NH- or -C (CF₃)₂Bivalent combined with-
Alternatively, it is a trivalent organic group. I is an integer of 1 to 3,
n is an integer of 2-3. ) (C) Decomposes to actinic rays such as ultraviolet rays to generate acid
A photosensitizer, (D) a sensitizer that accelerates the decomposition of the photosensitizer, and
(E) It is characterized by comprising a solvent.

In the positive pattern forming method of the present invention, the positive photosensitive resin composition according to claim 1 is coated on a substrate and dried at 70 to 150 ° C. to form an insolubilized coating film in an alkaline aqueous solution. The insolubilized coating film forming step, which is performed, and the exposed insolubilized coating film are exposed to active ultraviolet rays through a positive mask pattern, and then exposed at 70 to 150 ° C. to decompose only the exposed portion of the insolubilized coating film. A film decomposition step, a positive pattern development step of dissolving only the exposed and decomposed portion of the exposed coating film using an alkaline aqueous solution to develop a positive pattern, and a heat treatment of the developed positive pattern to form a polyimide positive pattern. And an imidation heat treatment step of forming.

The present invention will be described in detail below.

Examples of the acid component serving as the R ¹ skeleton of the (A) polyimide precursor used in the present invention include 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'-diphenylsulfone tetracarboxylic 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,
3,4-butanetetracarboxylic acid, 1,2,4,5-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3,3 ', 4,4'-bicyclohexyltetracarboxylic acid Acid, 2,3,5-tricarboxycyclopentyl acetic acid, 3,4-dicarboxy-
Examples include 1,2,3,4-tetrahydronaphthalene-1-succinic acid and anhydrides thereof, and these may be used alone or in combination.

Examples of the (A) diamine component serving as the R ² skeleton of the polyimide precursor used in the present invention include m-phenylenediamine, p-phenylenediamine, o-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-diaminobenzoic 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'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 4,
4'-diaminodiphenyl sulfone, 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-diaminopyridine, 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-toluidine sulfone, 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-amino) Phenyl) 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, bisanilinefluorene and the like can be mentioned, and these can be used alone or in combination of two or more.

(A) of the polyimide precursor used in the present invention
R¹, R²Carbonyl group having a skeleton containing
Introducing an acetal bond or an ester bond into R³or
Is R ^FourExamples of compounds having a skeleton are as follows:
Is mentioned.

[0013]

[Chemical 5]

[Chemical 6]

[Chemical 7]

[Chemical 8] These vinyloxy group-containing compounds or cyclic vinyloxy group-containing compounds react with a carbonyl group to form an acetal bond or an ester bond. These compounds are
More preferred in the present invention, the compound (A) is not limited to the above structure as long as it is a compound that forms an acetal bond or an ester bond in the carbonyl group of the polymer having a skeleton containing R ¹ and R ² of the polyimide precursor. Not something. Moreover, these can be used individually or in mixture of 2 or more types. When an acetal bond or an ester bond is formed on the carbonyl group, the unbonded carboxyl group may remain.

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 (A) polyimide precursor used in the present invention, for example, N-methylpyrrolidone, N, N'- An aprotic polar solvent such as dimethylacetamide, N, N′-dimethylformamide, cyclohexanone, cyclopentanone, γ-butyrolactone, tetrahydrofuran or the like is used, and these can be used alone or in combination of two or more. . Further, in order to improve the film properties of the resin, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, etc. are used alone or in combination in the above solvent. can do.

The (B) polyfunctional 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, the compounds shown in the following chemical formulas 9 to 13 may be mentioned, and these may be used alone or in admixture of two or more kinds. The addition amount is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the photosensitive resin composition. If the addition amount is less than 1 part by weight, the effect is not exerted, and if it exceeds 10 parts by weight, the characteristics of the coating film obtained are deteriorated.

[0016]

[Chemical 9]

[Chemical 10]

[Chemical 11]

[Chemical 12]

[Chemical 13] Examples of the photosensitizer (C) used in the present invention that decomposes to actinic rays such as ultraviolet rays to generate an acid include the following compounds
The compound shown in Chemical formula 23 is mentioned. These compounds are more preferable in the present invention, but are not limited to the above structure as long as they are decomposed by irradiation with active ultraviolet rays and efficiently generate an acid. Moreover, these can be used individually or in a mixture, and the addition amount thereof is 0.1 to 100 parts by weight of the photosensitive resin composition.
20 parts by weight is preferred. If it is less than 0.1 parts by weight, the sensitivity to ultraviolet rays is low, and if it exceeds 20 parts by weight, the properties of the coating film obtained are deteriorated, so this range is preferable.

[0017]

[Chemical 14]

[Chemical 15]

[Chemical 16]

[Chemical 17]

[Chemical 18]

[Chemical 19]

[Chemical 20]

[Chemical 21]

[Chemical formula 22]

[Chemical formula 23] The sensitizer (D) used in the present invention accelerates the decomposition of the above component (C) to actinic rays such as ultraviolet rays, and examples thereof include compounds represented by the following chemical formula 24. Although these compounds are more preferable in the present invention,
The compound is not limited to the above structure as long as it promotes the decomposition of the compound (C). These may be used alone or in combination, and the addition amount thereof is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the photosensitive resin composition. If it is less than 0.1 parts by weight, the sensitivity to ultraviolet rays is low, and if it exceeds 20 parts by weight, the properties of the coating film obtained are deteriorated, so this range is preferable.

[0018]

[Chemical formula 24] Further, the photosensitive resin composition obtained by the present invention,
(E) Used in a state of being dissolved in a solvent, examples of the (E) solvent include N-methylpyrrolidone, N, N '.
-Aprotic polar solvent such as dimethylacetamide, N, N'-dimethylformamide, cyclohexanone,
Examples thereof include cyclopentanone, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, γ-butyrolactone, and the like, which may be used alone or in combination of two or more. Can be used.

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

Considering application to a semiconductor device, first, this resin composition is coated on a target wafer by using a spin coater, and then the coating film is dried at 70 to 150 ° C. A mask having a pattern drawn on the obtained coating film is transmitted to irradiate active ultraviolet rays of 365 nm and 436 nm. Next, the coating film is heated again at 70 to 150 ° C., and subsequently the coating film is treated with an alkaline aqueous solution such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, an aqueous solution of an inorganic alkali such as ammonia, ethylamine, n-propyl. Primary amines such as amines,
Secondary amines such as diethylamine and di-n-propylamine, tertiary amines such as triethylamine and ethyldimethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like. Only the portion irradiated with actinic light is dissolved and developed using an aqueous solution of a primary amine, and rinsed with pure water. As a developing method, a method such as spraying, paddle, dipping, and ultrasonic wave can be considered. As a result, a desired positive pattern can be obtained on the target wafer. further,
By heat-treating this coating film at 150 ° C. for 1 hour, at 250 ° C. for 1 hour, and at 350 ° C. for 1 hour, the resin composition is imidized to form a polyimide film having excellent film characteristics.

[0021]

In other words, the greatest feature of the present invention is that the present inventor
As a result of earnest research, the positive type putter described below
It was in the discovery of the mechanism of protein formation. This resin composition
In the positive pattern formation method described above,
In the insolubilizing coating film drying step of drying after pin coating, R
¹, R²R of the general formula polymer having a skeleton³, R ^FourSkeleton
Is a carboxyl group moiety having R^FiveBureaucracy with skeleton
It undergoes a chemical substitution reaction with a compound containing a carboxyl group,
Insoluble in aqueous solution of Lucari. Then this insolubilization coating
By irradiating the film with actinic rays such as ultraviolet rays
The photo-acid generating photosensitizer in the line-exposed area is decomposed to generate acid. Change
Acid generated during the exposure coating decomposition process
R decomposes the above chemical bond and R¹, R²Have a skeleton
It returns to the polymer and regenerates the carboxyl groups. This poly
The carboxyl group of mer is high in alkaline aqueous solution.
It has a high solubility, and as a result, actinic rays such as ultraviolet rays
Highly soluble only in the alkaline solution
As shown, the unirradiated part is insoluble and does not melt at all. This
Due to the high contrast of
The fat composition is a positive type putter with high resolution and good dimensional controllability.
It has become possible to form Moreover, the above photoacid
Since we found a sensitizer that accelerates the decomposition of the generated photosensitizer,
By irradiating active rays such as ultraviolet rays,
Decomposition of the photo-acid generating photosensitizer in the irradiated area is promoted more and more
Generates acid, unirradiated area is not affected, alkaline water
Since it remains insoluble in the liquid, it has a higher contrast than ever.
It is possible to form a highly sensitive positive pattern with a strike.
became.

In the resin compositions containing the diazonaphthoquinone compound proposed so far, low sensitivity to actinic rays has been a problem. The main cause of the low sensitivity is derived from the diazonaphthoquinone compound itself. That is, the diazonaphthoquinone compound lowers the sensitivity because it decreases the transmittance of actinic rays when added in a large amount. In the photosensitive resin composition of the present invention, since a bodi-shaped pattern is formed without using a diazonaphthoquinone compound, not only has a good actinic ray transmittance but also an acid generated from a photo-acid generating photosensitizer is repeatedly used. Since it can be sensitized and can be sensitized, sufficient pattern forming ability can be exhibited even with a small amount of actinic rays. As mentioned above,
Since this reaction mechanism is capable of causing a chemical reaction in an amplified manner, it has become possible to provide a highly sensitive photosensitive resin composition in the present invention.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below based on Examples.

Example 1 First, 1 mol of 4,4'-diaminodiphenyl ether, 1 L of N-methyl-2-pyrrolidone and 1 L of tetrahydrofuran were added to a reaction flask equipped with a nitrogen introducing tube and stirred and dissolved for 1 hour. . Next, 1 mol of benzophenone tetracarboxylic acid dianhydride was added in 3 batches, and a polymerization reaction was performed for 6 hours in that state. Then 0.0
5 mol of p-toluenesulfonic acid is added and stirred for 30 minutes, 2 mol of 3,4-dihydro-2H-pyran is further added, and the reaction is performed for 3 hours in this state. The obtained slurry-like mixture is put into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. 10 g of dried solid resin, 10 g of triethylene glycol divinyl ether, 1.0 g of 1,8-naphthalimidyl triflate and 0.5 g of pyrene in 30 g of N-
It was dissolved in methyl-2-pyrrolidone, and the obtained slurry was filtered by 1 μm to obtain Sample 1.

A 6-inch silicon wafer was coated with this sample 1 using a spin coater, and dried on a bake plate at 100 ° C. for 4 minutes to give a film thickness of 10
A coating film of μm was obtained. This coating film is exposed to 100 nm by an ultraviolet exposure machine using a filter that transmits only 365 nm.
Irradiate the test pattern with energy of mJ / cm ² ,
Then, it heated at 120 degreeC for 1 minute. Next, T of 2.38%
Paddle development was performed for 60 seconds with an MAH (tetramethylammonium hydride) aqueous solution, followed by washing with pure water. By this operation, it was possible to obtain a positive relief pattern in which only the ultraviolet irradiation portion of the coating film was dissolved.
When the obtained pattern was observed with an optical microscope, it was confirmed that a pattern of 3.0 μm or less was sharply formed. 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 insolubilized.

Further, this pattern is applied at 150 ° C. for 1 hour, 2
Heat treatment was sequentially performed at 50 ° C. for 1 hour and 350 ° C. for 1 hour to complete imidization of the coating film. This imide pattern did not collapse even in the above heat treatment and maintained a sharp profile.

Example 2 First, 1 mol of 4,4'-diaminodiphenyl ether, 1 L of N-methyl-2-pyrrolidone and 1 L of tetrahydrofuran were added to a reaction flask equipped with a nitrogen introducing tube and stirred and dissolved for 1 hour. . Next, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic acid dianhydride was added in 3 batches, and the polymerization reaction was continued for 6 hours in this state. Then add 0.05 mol phosphoric acid to 30
Stir for 2 minutes and then add 2 mol of 3,4-dihydro-2H-
Pyran is added and the reaction is performed for 3 hours in this state. The obtained slurry-like mixture is put into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. A slurry obtained by dissolving 10 g of dried solid resin, 10 g of triethylene glycol divinyl ether, 1.0 g of 1,8-naphthalimidyl triflate and 0.5 g of pyrene in 30 g of N-methyl-2-pyrrolidone. Was filtered through 1 μm to obtain Sample 2.

A 6-inch silicon wafer was coated with this sample 2 by using a spin coater, and heated and dried at 100 ° C. for 4 minutes on a bake plate to obtain a film thickness of 10
A coating film of μm was obtained. This coating film is exposed to 100 nm by an ultraviolet exposure machine using a filter that transmits only 365 nm.
Irradiate the test pattern with energy of mJ / cm ² ,
Then, it heated at 120 degreeC for 1 minute. Next, T of 2.38%
Paddle development was performed for 60 seconds with an MAH (tetramethylammonium hydride) aqueous solution, followed by washing with pure water. By this operation, it was possible to obtain a positive relief pattern in which only the ultraviolet irradiation portion of the coating film was dissolved.
When the obtained pattern was observed with an optical microscope, it was confirmed that a pattern of 3.0 μm or less was sharply formed. 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 insolubilized.

Further, this pattern is applied at 150 ° C. for 1 hour, 2
Heat treatment was sequentially performed at 50 ° C. for 1 hour and 350 ° C. for 1 hour to complete imidization of the coating film. This imide pattern did not collapse even in the above heat treatment and maintained a sharp profile.

Example 3 First, 1 mol of 4,4'-diaminodiphenyl ether, 1 L of N-methyl-2-pyrrolidone and 1 L of tetrahydrofuran were added to a reaction flask equipped with a nitrogen introducing tube and stirred and dissolved for 1 hour. . Next, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic acid dianhydride was added in 3 batches, and the polymerization reaction was continued for 6 hours in this state. Then add 0.05 mol phosphoric acid to 30
The mixture is stirred for 1 minute, 2 mol of isobutyl vinyl ether is further added, and the reaction is performed for 3 hours in this state. The obtained slurry-like mixture is put into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. 10 g of dried solid resin, 10 g of triethylene glycol divinyl ether, 1.0 g of 1,8-naphthalimidyl triflate and 0.5 g of pyrene in 30 g of N-
It was dissolved in methyl-2-pyrrolidone, and the obtained slurry was filtered by 1 μm to obtain Sample 3.

A 6-inch silicon wafer was coated with this sample 3 using a spin coater, and dried on a baking plate at 100 ° C. for 4 minutes to obtain a film thickness of 10
A coating film of μm was obtained. This coating film is exposed to 100 nm by an ultraviolet exposure machine using a filter that transmits only 365 nm.
Irradiate the test pattern with energy of mJ / cm ² ,
Then, it heated at 120 degreeC for 1 minute. Next, T of 2.38%
Paddle development was performed for 60 seconds with an MAH (tetramethylammonium hydride) aqueous solution, followed by washing with pure water. By this operation, it was possible to obtain a positive relief pattern in which only the ultraviolet irradiation portion of the coating film was dissolved.
When the obtained pattern was observed with an optical microscope, it was confirmed that a pattern of 3.0 μm or less was sharply formed. 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 insolubilized.

Further, this pattern is applied at 150 ° C. for 1 hour, 2
Heat treatment was sequentially performed at 50 ° C. for 1 hour and 350 ° C. for 1 hour to complete imidization of the coating film. This imide pattern did not collapse even in the above heat treatment and maintained a sharp profile.

Example 4 First, 1 mol of p-phenylenediamine, 1 L of N-methyl-2-pyrrolidone and 1 L of tetrahydrofuran were added to a reaction flask equipped with a nitrogen introducing tube, and dissolved by stirring for 1 hour. Next, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic acid dianhydride was added in 3 batches, and the polymerization reaction was continued for 6 hours in this state. Then add 0.05 mol phosphoric acid and stir for 30 minutes,
Further, 2 mol of n-butyl vinyl ether is added, and the reaction is performed for 3 hours in this state. The obtained slurry-like mixture is put into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. 3 g of 10 g of dried solid resin, 10 g of 2,2-bis (4- (2-vinyloxyethoxy) phenyl) propane, 1.0 g of 1,8-naphthalimidyl triflate and 0.5 g of pyrene.
It was dissolved in 0 g of γ-butyrolactone, and the obtained slurry was filtered by 1 μm to obtain Sample 4.

A 6-inch silicon wafer was coated with this sample 4 by using a spin coater, and dried on a bake plate at 100 ° C. for 4 minutes to obtain a film thickness of 10
A coating film of μm was obtained. This coating film is exposed to 100 nm by an ultraviolet exposure machine using a filter that transmits only 365 nm.
Irradiate the test pattern with energy of mJ / cm ² ,
Then, it heated at 120 degreeC for 1 minute. Next, T of 2.38%
Paddle development was performed for 60 seconds with an MAH (tetramethylammonium hydride) aqueous solution, followed by washing with pure water. By this operation, it was possible to obtain a positive relief pattern in which only the ultraviolet irradiation portion of the coating film was dissolved.
When the obtained pattern was observed with an optical microscope, it was confirmed that a pattern of 3.0 μm or less was sharply formed. 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 insolubilized.

Further, this pattern is applied at 150 ° C. for 1 hour, 2
Heat treatment was sequentially performed at 50 ° C. for 1 hour and 350 ° C. for 1 hour to complete imidization of the coating film. This imide pattern did not collapse even in the above heat treatment and maintained a sharp profile.

Example 5 First, 1 mol of bisanilinefluorene, 1 L of N-methyl-2-pyrrolidone and 1 L of tetrahydrofuran were added to a reaction flask equipped with a nitrogen introducing tube, and dissolved by stirring for 1 hour. Next, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic acid dianhydride was added in 3 batches, and the polymerization reaction was continued for 6 hours in this state. Then add 0.05 mol phosphoric acid and stir for 30 minutes,
Further, 2 mol of ethyl vinyl ether is added, and the reaction is performed for 3 hours in this state. The obtained slurry-like mixture is put into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. 30 g of dried solid resin 10 g, 2,2-bis (4- (2-vinyloxyethoxy) phenyl) propane 10 g, 1,8-naphthalimidyl triflate 1.0 g and pyrene 0.5 g
Was dissolved in γ-butyrolactone of Example 1 and the obtained slurry was filtered by 1 μm to obtain Sample 5.

A 6-inch silicon wafer was coated with this sample 5 using a spin coater, and dried on a bake plate at 100 ° C. for 4 minutes to obtain a film thickness of 10
A coating film of μm was obtained. This coating film is exposed to 100 nm by an ultraviolet exposure machine using a filter that transmits only 365 nm.
Irradiate the test pattern with energy of mJ / cm ² ,
Then, it heated at 120 degreeC for 1 minute. Next, T of 2.38%
Paddle development was performed for 60 seconds with an MAH (tetramethylammonium hydride) aqueous solution, followed by washing with pure water. By this operation, it was possible to obtain a positive relief pattern in which only the ultraviolet irradiation portion of the coating film was dissolved.
When the obtained pattern was observed with an optical microscope, it was confirmed that a pattern of 3.0 μm or less was sharply formed. 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 insolubilized.

Further, this pattern is applied at 150 ° C. for 1 hour, 2
Heat treatment was sequentially performed at 50 ° C. for 1 hour and 350 ° C. for 1 hour to complete imidization of the coating film. This imide pattern did not collapse even in the above heat treatment and maintained a sharp profile.

Comparative Example First, 1 mol of bisanilinefluorene, 1 L of N-methyl-2-pyrrolidone and 1 L of tetrahydrofuran were added to a reaction flask equipped with a nitrogen introducing tube, and the mixture was stirred and dissolved for 1 hour. Next, 1 mol of hexafluoroisopropylidene-2,2'-bisphthalic acid dianhydride was added in 3 batches, and the polymerization reaction was continued for 6 hours in this state. Then add 0.05 mol phosphoric acid and stir for 30 minutes,
Further, 2 mol of ethyl vinyl ether is added, and the reaction is performed for 3 hours in this state. The obtained slurry-like mixture is put into a large amount of methanol for washing, and the obtained solid resin is dried by a vacuum dryer for 12 hours. 10 g of the dried solid resin and 5 g of the benzophenone-type disubstituted diazonaphthoquinone compound were dissolved in 30 g of N-methyl-2-pyrrolidone, and the obtained slurry was filtered to 1 μm to obtain Sample 6.

A 6-inch silicon wafer was coated with this sample 6 using a spin coater, and dried on a bake plate at 120 ° C. for 4 minutes to give a film thickness of 10
A coating film of μm was obtained. This coating film is exposed to 500 nm by an ultraviolet exposure machine using a filter that transmits only 365 nm.
Irradiate the test pattern with energy of mJ / cm ² ,
Subsequently, paddle development was performed for 1 minute with a 2.38% TMAH (tetramethylammonium hydride) aqueous solution. By this operation, it was possible to obtain a positive relief pattern in which only the ultraviolet irradiation portion of the coating film was dissolved. When the obtained pattern was observed with an optical microscope, it was 1
It was confirmed that a pattern of up to 5.0 μm was formed. However, this pattern was swollen and not a sharp shape.

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

[0042]

INDUSTRIAL APPLICABILITY The present invention is a photosensitive polyimide precursor having a positive type pattern forming ability, and an alkaline aqueous solution can be used for pattern formation. Furthermore, the photosensitive resin composition of the present invention can provide a positive pattern having high sensitivity and good dimensional controllability due to high contrast. In addition, the sensitivity can be further increased by adding a compound that accelerates the decomposition of acid. Since the finally obtained polyimide coating film is excellent in heat resistance and chemical resistance, it can be used in the same manner as a commonly used semiconductor device protective film. It can be easily understood that these are based on a completely new idea and are very excellent inventions that cannot be found anywhere else.

Claims (2)

[Claims] 1. A repeating unit represented by the following general formula:
A polyimide precursor, [Chemical 1] (However, in the formula, R¹Is a tetravalent aromatic group, a plurality of aromatic groups
A tetravalent organic group in which a ring is single-bonded, or a plurality of aromatic rings
-O-, -CO-, -SO₂-, -CH₂-Or-
C (CF₃)₂A tetravalent organic group bonded by-, R
²Is a divalent aromatic group, multiple aromatic rings are single-bonded
A divalent organic group or a plurality of aromatic rings is -O- or -CO.
-, -SO₂-, -CH₂-Or-C (CF₃)₂
It is a divalent organic group bonded by-. Also, R³, R^Four
Is a hydrogen atom or an acetal bond or an ester bond
It is a residue of a compound containing a vinyloxy group. ) (B) Containing a polyfunctional vinyloxy group represented by the following general formula
Compound, [Chemical 2] (However, in the formula, R^FiveIs a divalent or trivalent aliphatic group
Or an aromatic group or multiple aliphatic or aromatic rings
Single bond, -O-, -CO-, -SO₂-, -CH ₂-,
-NH- or -C (CF₃)₂Bivalent combined with-
Alternatively, it is a trivalent organic group. I is an integer of 1 to 3,
n is an integer of 2-3. ) (C) Decomposes to actinic rays such as ultraviolet rays to generate acid
A photosensitizer, (D) a sensitizer that accelerates the decomposition of the photosensitizer, and
(E) Positive type photosensitive resin characterized by comprising a solvent
Composition. 2. A step of forming an insolubilized coating film, which comprises 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 in an alkaline aqueous solution. After exposing the insolubilized coating film through a positive mask pattern with active ultraviolet rays, 70 to 15
An exposure coating film decomposition step of heating only at 0 ° C. to decompose only the exposed portion of the insolubilized coating film, and a positive pattern development for dissolving only the exposed decomposition portion of the exposed coating film using an alkaline aqueous solution to develop a positive pattern A positive type pattern forming method, comprising: a step of performing heat treatment on the developed positive type pattern to form a polyimide positive type pattern.