JP2000250209A - Photosensitive resin composition and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the photosensitive resins composition composed of a polyimide developable in an aqueous alkaline solution and capable of forming a positive pattern and its manufacturing method. SOLUTION: This resin composition contains (A) the photosensitive polyimide having repeating units represented by the formula in which R1 is a tetravalent organic group, such as a 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride group; R2 is a trivalent organic group, such as a 3,5-diamino-benzoic acid anhydride group; and R3 is a univalent organic group having a diazonaphthoquinone or phenolic yydroxylgroup on the terminal; (B) diphenyl(2,3- dihydro-2-thioxo-3-benzo-oxazole)phosphate or the like dehydrating condensing agent to be used for synthesizing the above photosensitive polyimide; (C) a photosensitive agent such as diazonaphthoqinone; (D) solvent.

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 insulating material in the production of semiconductor devices and the like, and a method for producing the same. The insulating / protective film formed on the element is a positive photosensitive film that is suitable for processing a fine pattern and is soluble in an alkaline aqueous solution.

[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 method of forming a film pattern, after applying and drying a polyimide precursor on a wafer, it is necessary to form a pattern of a photoresist on the film of this polyimide precursor and perform etching, and At that time, a hydrazine solution, which is a harmful substance, had to be used as an etchant for the polyimide precursor.

[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 sufficient high molecular weight cannot be obtained. Furthermore, all of these resins adopt a negative pattern forming method, and must be developed with an organic solvent at the time of pattern formation, which is a serious problem from the viewpoint of environmental conservation. . From these problems, there is a strong demand for a positive photosensitive polyimide that can use an aqueous alkaline solution as a developing solution when forming a pattern and that does not swell with the developing solution and can increase the resolution.

On the other hand, production of a photosensitive resin composition using a soluble polyimide has been attempted. Advantages of using a soluble polyimide include a small change in pattern dimension before and after curing, and no by-product of water on the wafer. In fact, there have been several reports of positive photosensitive resin compositions using soluble polyimides, but in each case, hydroxyl groups remain in the cured base polymer, and thus moisture absorption is regarded as a problem.

[0005]

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

[0006]

Means for Solving the Problems As a result of diligent research aimed at achieving the above object, the present inventor has adopted a photosensitive resin composition described below and a method for producing the same.
The inventors have found that the above object can be achieved, and have completed the present invention.

That is, the photosensitive resin composition of the present invention comprises:
(A) a photosensitive polyimide containing a repeating unit 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 - or -CH ₂ - is a tetravalent organic group bonded by, R ² is a trivalent aromatic group, a trivalent or tetravalent aromatic group more aromatic rings is a single bond, Or a plurality of aromatic rings are -O-, -CO-, -SO
₂ - or -CH ₂ - is a trivalent or tetravalent aromatic group that is bonded, R ³ is, -O-SO ₂ late group - or -NH-SO ₂ - is linked via a diazo A monovalent organic group having a naphthoquinone ring or a monovalent organic group having a phenolic OH at the end, and n represents an integer of 1 or 2. (B) Synthesizing the above (A) photosensitive polyimide The method for producing a photosensitive resin composition according to the present invention comprises: a dehydrating condensing agent used in the step (A), a photosensitive agent (C) for improving the sensitivity to actinic rays, and a solvent (D). 1) a polycondensation reaction step between an acid dianhydride having an R ¹ skeleton and a diamine compound having an R ² skeleton and a carboxyl group represented by the following repeating unit 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 - or -CH ₂ - is a tetravalent organic group bonded by, R ² is a trivalent aromatic group, a trivalent or tetravalent aromatic group more aromatic rings is a single bond, Or a plurality of aromatic rings are -O-, -CO-, -SO
₂ - or -CH ₂ - is a trivalent or tetravalent aromatic group that is bonded, R ³ is, -O-SO ₂ late group - or -NH-SO ₂ - is linked via a diazo A monovalent organic group having a naphthoquinone ring or a monovalent organic group having a phenolic OH at the end of the group, and n represents an integer of 1 or 2) (2) an imidization reaction step of the above polycondensation reaction product; (3) an esterification reaction step between the above imidation reaction product and an alcoholic compound having an R ³ skeleton in the chemical formula 2, (4) a purification step of the above esterification reaction product, and (5) a resin solution containing a photosensitizer. Characterized in that it comprises a preparation step of

Hereinafter, the present invention will be described in detail.

First, the procedures (1) to (5) in the method for producing the photosensitive polymer composition of the present invention will be described.

[0010] As the acid component with R ¹ backbone of the reduction in equation 4 [polycondensation reaction of a diamine compound having an acid dianhydride and R ² backbone and a carboxyl group having the R ¹ skeleton in the formula of 4] 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, 1,2,3 , - butane tetra carboxylic 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,
Examples thereof include 4-dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic acid and anhydrides thereof, and these can be used alone or in combination.

Further, diamine compounds having an R ² skeleton and a carboxyl group include 3,5-diaminobenzoic acid,
Examples thereof include 3,4-diaminobenzoic acid and bis (4-amino-3-carboxyphenyl) methane, which can be used alone or in combination. Further, a diamine compound having no carboxyl group as a substituent by mixing with these compounds, for example, metaphenylenediamine, paraphenylenediamine, 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-methylbenzene, 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'-diphenylmethane, 3,3 ', 5,5'-tetraethyl-4,4'-diphenylmethane, 4'-methylenebis (cyclohexylamine), 4,4'-methylenebis (3,3'-dimethyl-cyclohexylamine), 2,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 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-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-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) hexa Fluoropropane, 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane,
2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane and the like can be used alone or in combination of two or more. All of these diamine compounds are preferably used in an equimolar amount with respect to the acid component having an R ¹ skeleton. Can be used with

The above R¹An acid component having a skeleton and the above R^TwoSkeleton
Of polycondensation of diamine compounds having carboxylic and carboxyl groups
The response is R as in the present invention.¹Acid dianhydride with skeleton
And R ^TwoDiamine compound having skeleton and carboxyl group
As a reaction solvent, a non-
Protic polar solvent (N-methyl-2-pyrrolidone, etc.)
It is preferably carried out at room temperature using

[Imidation reaction of the above polycondensation reaction product] By adding a basic catalyst (triethylamine, pyridine, triethanolamine, etc.) to the above polycondensation reaction solution and heating, the dehydration cyclization reaction proceeds and is generated. Water is removed by azeotropic distillation with toluene or xylene. The basic catalyst can be used in a range of 1.5 to 3 times mol, preferably 2.0 to 2.5 times mol based on the acid dianhydride used for the polycondensation reaction, and the heating temperature is It is carried out at 100 to 250 ° C, preferably 150 to 200 ° C.

[Esterification reaction of the above imidation reaction product with an alcoholic compound having an R ³ skeleton in the chemical formula 4] As the alcoholic compound having an R ³ skeleton introduced into the above imidation reaction product by an ester bond, And those of Group A (Formula 5) and Group B (Formula 6). A shown in Chemical Formula 5
The group of alcoholic compounds has —O—SO ₂ — at its terminal.
Or -NH-SO ₂ - is an alcohol having a combined diazonaphthoquinone ring through.

[0015]

Embedded image Further, the alcoholic compounds belonging to Group B represented by Chemical Formula 6 are alcohols having phenolic OH at the terminal thereof.

[0016]

Embedded image The introduction ratio of Group A and Group B is 10: 9 in ester bond ratio.
0 to 30: 70 parts by weight is preferred. If the ratio of group A is high,
The solubility of the resin composition in an aqueous alkali solution is reduced,
If the ratio of the group B is high, the sensitivity to ultraviolet rays decreases. A
The compounds in group B and group B can be used alone or in combination of two or more.

Next, the dehydrating condensing agent for the above imidization reaction product and the alcoholic compound having an R ³ skeleton in the formula (4) used in the present invention will be described.

When the above-mentioned imidization reaction composition and the alcoholic compound having an R ³ skeleton are subjected to an esterification reaction, the esterification reaction is usually carried out using an acid chloride. Since chlorine ions cause poor product reliability, when esterification is performed by the acid chloride method, it is necessary to sufficiently wash with pure water after the esterification reaction. In addition, carbodiimide derivatives such as DCC (dicyclohexylcarbodiimide) used as a dehydration condensing agent in other esterification reactions can be used. However, DCC has problems such as simultaneous side reactions, gelation of polyimide, and toxicity. In addition, it is difficult to completely remove urea generated as a by-product. Therefore, it is necessary to cool the reaction system, add the dehydration condensing agent in several portions, or break the molar balance of the compound to be subjected to the esterification reaction before use. As another method, diphenyl (2,3-dihydro-2-thioxo-3-benzoxazole) phosphonate and its derivative, diphenyl (2,3) have recently been proposed as dehydration condensing agents by the present inventors. -Dihydro-
An esterification reaction with 2-thioxo-3-benzothiazole) phosphonate and a derivative thereof can be mentioned. In this method, stable production can be performed under mild conditions, so that a polyimide having high resolution and high film properties can be obtained. Obtainable. These can be used alone or in combination of two or more. These addition amounts are in the range of 1 to 3 moles, preferably in the range of 2 to
It can be used in a range of 2.5 moles.

As the solvent used in the present invention, for example, N
Aprotic polar solvents such as -methylpyrrolidone, N, N'-dimethylacetamide, N, N'-dimethylformamide, cyclohexanone, cyclopentanone and the like are used, and these may be used alone or as a mixture of two or more. be able to.

[Purification of the above esterification reaction product] Further, the obtained slurry esterification reaction product is stirred and washed in a poor solvent such as methanol, ethanol, isopropyl alcohol, and water, and the precipitate is dried under reduced pressure. Then, a purified polyimide having a resin skeleton represented by Chemical Formula 4 is obtained.

[Preparation of Resin Solution Containing Photosensitive Agent] For the purpose of improving the sensitivity to actinic rays of an exposure machine used in the manufacture of semiconductor devices, for example, Added.

[0022]

Embedded image The photosensitive agent used in the present invention is not limited to the above structure. In use, these photosensitizers can be used alone or in combination of two or more. The addition amount thereof is preferably 1 to 10 parts by weight based on 100 parts by weight of the composition. If the amount exceeds 10 parts by weight, the properties of the resulting coating film will be reduced.

The photosensitive resin composition of the present invention is used in the form dissolved in a solvent. Examples of the solvent used for dissolution include N-methylpyrrolidone and 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, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate; Butyl lactate or the like is used, and these can be used alone or in combination.

Next, the method of using the 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 90 to 100 ° 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, this coating film is applied to an alkaline aqueous solution, for example, sodium hydroxide, potassium hydroxide,
Inorganic alkaline aqueous solutions such as sodium carbonate, potassium carbonate and ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-propylamine; tertiary amines such as triethylamine and methyldimethylamine; dimethyl Only the active light-irradiated portion is dissolved and developed using an alcoholamine such as ethanolamine and triethanolamine, and a quaternary amine such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, and rinsed with pure water. As a developing system, a system such as spray, paddle, immersion, and ultrasonic wave can be considered. Thus, a desired positive pattern can be obtained on the target wafer. Further, by heat-treating the coating film, the resin composition is imidized, and a polyimide film having excellent film properties can be formed.

[0026]

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

Example 1 First, 3 was added to a reaction flask having a nitrogen introduction tube and a reflux tube.
1 mol of 5-diaminobenzoic acid and 2000 ml of N-
Add methyl-2-pyrrolidone and stir, then add 2,2
1 mol of 2'-bis (3,4-dicarboxyphenyl) hexafluoropropane is added over 30 minutes. In this state, the mixture is left for 3 hours, and after the reaction is completed, 500 ml of xylene is added and the mixture is heated at 200 ° C. for 2 hours. Continue heating,
After distilling off xylene, the mixture is cooled, 0.6 mol of 1,2-diazonaphthoquinone-4-sulfonic acid p-hydroxybenzyl alcohol ester and 1.5 mol of 4-hydroxybenzyl alcohol are 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. Furthermore, the dried solid resin 3
0 g was dissolved in 70 g of N-methyl-2-pyrrolidone, and the obtained slurry was filtered at 1 μm to obtain sample 1
And

Sample 1 was coated on a 6-inch silicon wafer using a spin coater, and dried by heating at 100 ° C. for 3 minutes on a bake plate to obtain a 10 μm-thick coating film. This coating film was irradiated with an ultraviolet light exposing machine using a filter transmitting only 365 nm.
The test pattern was irradiated with an energy of 00 mJ / cm ² , and then paddle development was performed with a 2.38% aqueous solution of TMAH (tetramethylammonium hydride) for 1 minute. 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 1.0 μm was formed sharply.

Further, this pattern was applied at 150 ° C. for 1 hour.
Heat treatment was performed at 250 ° C. for 1 hour and at 350 ° C. for 1 hour to complete the 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.

[0030]

As is apparent from the above description, the present invention is a photosensitive polyimide resin composition having a positive pattern forming ability, and an alkaline aqueous solution can be used for forming a pattern. . For this reason, the swelling of the obtained pattern with respect to the developing solution is small, and not only can an extremely sharp high-resolution pattern be obtained,
Industrial wastes of organic solvents that have been generated in large quantities can be completely eliminated. 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.

The present invention relates to a polyimide resin skeleton itself used in a photosensitive resin composition and a method for producing the same, but these are based on a completely new idea, and are extremely unique. It can be easily understood that this is an excellent invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/027 H01L 21/30 502R F-term (Reference) 2H025 AA01 AA02 AA06 AA10 AA20 AB16 AD03 BE01 BE02 BJ10 CB25 CB41 CB45 CC03 CC20 FA17 4J002 CM041 EQ017 EV217 EV227 EW126 FD206 FD207 GP03 GQ01 GQ05 HA05

Claims (2)

[Claims] (A) A photosensitive polyimide containing a repeating unit 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 - or -CH ₂ - is a tetravalent organic group bonded by, R ² is a trivalent aromatic group, a trivalent or tetravalent aromatic group more aromatic rings is a single bond, Or a plurality of aromatic rings are -O-, -CO-, -SO
₂ - or -CH ₂ - is a trivalent or tetravalent aromatic group that is bonded, R ³ is, -O-SO ₂ late group - or -NH-SO ₂ - is linked via a diazo A monovalent organic group having a naphthoquinone ring or a monovalent organic group having a phenolic OH at the end, and n represents an integer of 1 or 2. (B) Synthesizing the above (A) photosensitive polyimide A photosensitive resin composition comprising: a dehydration-condensing agent used in (1), (C) a photosensitive agent for improving sensitivity to actinic rays, and (D) a solvent. 2. (1) a polycondensation reaction step between an acid dianhydride having an R ¹ skeleton and a diamine compound having an R ² skeleton and a carboxyl group 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 - or -CH ₂ - is a tetravalent organic group bonded by, R ² is a trivalent aromatic group, a trivalent or tetravalent aromatic group more aromatic rings is a single bond, Or a plurality of aromatic rings are -O-, -CO-, -SO
₂ - or -CH ₂ - is a trivalent or tetravalent aromatic group that is bonded, R ³ is, -O-SO ₂ late group - or -NH-SO ₂ - is linked via a diazo A monovalent organic group having a naphthoquinone ring or a monovalent organic group having a phenolic OH at the end of the group, and n represents an integer of 1 or 2) (2) an imidization reaction step of the above polycondensation reaction product; (3) an esterification reaction step between the above imidation reaction product and an alcoholic compound having an R ³ skeleton in the chemical formula 2, (4) a purification step of the above esterification reaction product, and (5) a resin solution containing a photosensitizer. A method for producing a photosensitive resin composition, comprising a step of preparing a photosensitive resin composition.