JP2001154354A - Processing method for positive type photosensitive resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing method for a positive type photosensitive resin composition in which the film thickness of the unexposed part is not reduced even in thick film processing and a high sensitivity pattern is obtained. SOLUTION: When a two-layer organic film of a positive type photosensitive resin composition and a positive type photoresist is processed, the positive type photosensitive resin composition is applied and dried on a substrate, the positive type photoresist is further applied and dried and the resulting two-layer organic film is exposed and developed to form a pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a heat-resistant protective film on a surface of a support for protecting the semiconductor support and reducing stress applied to the semiconductor support. The present invention relates to a method for processing a resin composition into a thick film.

[0002]

2. Description of the Related Art Polyimide resin has excellent heat resistance to withstand the semiconductor process temperature, and is used as a passivation film in the semiconductor industry for reasons such as flattening steps, relaxing stress, and preventing memory cell soft errors. It is used as a line shield layer and an interlayer insulating film. As a semiconductor device using this polyimide resin as a passivation film or an interlayer insulating film, a semiconductor device having a LOC structure (Japanese Patent Publication No. Sho 61-218)
No. 139) and a Cu-polyimide multilayer wiring structure (“Nikkei Electronics”, pp. 145-158, August 27, 1984). In a semiconductor device having an LOC structure, a semiconductor chip is thermocompression-bonded to a lead frame from the buffer coat side, but it is necessary to reduce the stress at this time.

Further, a Cu-polyimide multilayer wiring structure is
The current flowing through the wiring is large, and it is necessary to ensure insulation of the wiring. For this reason, thickening of the polyimide film is often required. On the other hand, a technique for imparting photosensitivity to the polyimide resin itself has recently attracted attention. For example, the following formula (2) is given as a photosensitive polyimide resin.

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When this is used, a part of the pattern forming process can be simplified, which has the effect of shortening the process.
Since a solvent such as methyl-2-pyrrolidone is required, there is a problem in safety and handling. Therefore, recently, a positive photosensitive resin that can be developed with an alkaline aqueous solution has been developed. For example, Japanese Patent Publication No. 1-46862 discloses a positive photosensitive resin composition composed of a polybenzoxazole precursor and a diazoquinone compound. It has high heat resistance, excellent electrical properties and fine workability, and has the potential not only as a wafer coat but also as an interlayer insulating resin. The mechanism of development of this positive photosensitive resin is such that the unexposed portion of the diazoquinone compound is insoluble in the alkaline aqueous solution, and the exposure causes the diazoquinone compound to undergo a chemical change and become soluble in the alkaline aqueous solution. By utilizing the difference in solubility between the exposed part and the unexposed part, a coating film pattern can be formed only in the unexposed part. However, in order to form a thick film using this positive photosensitive resin composition, the film thickness after pre-baking is larger than the desired film thickness by the amount of film reduction in the unexposed portion during development, so This makes it difficult for light to reach the bottom, causing problems such as a decrease in sensitivity.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a high-sensitivity method that does not reduce the film thickness of an unexposed portion even in a thick film processing. An object of the present invention is to provide a method for processing a positive photosensitive resin composition capable of obtaining a pattern.

[0006]

According to the present invention, a positive type photosensitive resin composition is coated on a support, dried at 60 ° C. to 130 ° C., and further patterned by using a positive type photoresist thereon. This is a method of processing a positive photosensitive resin composition by processing, and more preferably, the positive photosensitive resin composition is 100 parts by weight of a polyamide represented by the general formula (1) and 1 to 50 parts by weight of a diazonaphthoquinone compound. And a method for processing a positive photosensitive resin composition comprising

Embedded image Further, the positive photosensitive resin composition has a thickness of 10 to 100 μm after coating and drying, and the positive photoresist has a coating thickness of 0.1 to 5 μm after coating and drying. This is a method for processing a resin composition.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a positive photosensitive resin composition is coated on a support and dried to obtain a high-sensitivity pattern without reducing the thickness of unexposed portions even in a thick film. Further, a positive type photoresist is used thereon.

The positive photosensitive resin composition which can be used in the present invention contains polyamide as a main component and is preferably a polyamide represented by the general formula (1), and comprises 100 parts by weight of this polyamide and 1 to 50 parts by weight of diazonaphthoquinone. Is preferred.

X in the general formula (1) is, for example,

Embedded image Etc., but are not limited to these.

[0010] Of these, particularly preferred are:

Embedded image It is more chosen.

Further, Y in the equation (1) is, for example,

Embedded image Etc., but are not limited to these.

Among these, particularly preferred are:

Embedded image It is more chosen.

In the formula (1), E is obtained by reacting a dicarboxylic acid derivative having the structure of Y with a diamine having the structure of X to synthesize a polyamide, and then converting the terminal amino group to at least one alkenyl group or alkynyl group. The reaction is carried out by reacting a carboxylic acid derivative having two or more carboxylic acid derivatives. Examples of the carboxylic acid derivative include 5-norbornene-2, 3-dicarboxylic acid, and maleic anhydride. -Dicarboxylic acids are preferred.

Further, Z in the formula (1) is, for example,

Embedded image And the like, but are not limited to these.

Z in the formula (1) is used in the case of a substrate that requires even higher adhesion, but its use ratio b can be up to 40 mol%. 40 mol%
If the ratio exceeds, the solubility of the resin is extremely reduced and scum is generated, so that pattern processing cannot be performed. Note that these X,
When using Y, E, and Z, one type or a mixture of two or more types may be used.

The diazonaphthoquinone compound used in the present invention is a compound having a 1,2-naphthoquinonediazide structure, and is disclosed in US Pat. Nos. 2,772,972, 2,797,213, 3,669, No. 658.

For example, the following are mentioned.

Embedded image

Embedded image

Among these, the following are particularly preferred.

Embedded image

The compounding amount of the diazonaphthoquinone compound to the polyamide is 1 to 5 parts by weight with respect to 100 parts by weight of the polyamide. If the compounding amount is less than 1 part by weight, the patterning property of the resin is poor. If it exceeds the part, the tensile elongation of the film is significantly reduced.

A dihydropyridine derivative can be added to the positive photosensitive resin composition of the present invention, if necessary, in order to enhance photosensitive characteristics. Examples of the dihydropyridine derivative include, for example, 2,6-dimethyl-3,5-diacetyl-4- (2′-nitrophenyl) -1,4-dihydropyridine, 4- (2′-nitrophenyl) -2,6-dimethyl -3,5-dicarbethoxy-1,4-dihydropyridine, 4- (2 ', 4'-dinitrophenyl) -2,
6-dimethyl-3,5-carbomethoxy-1,4-dihydropyridine and the like can be mentioned.

If necessary, additives such as a leveling agent and a silane coupling agent can be added to the positive photosensitive resin composition of the present invention.

In the present invention, these components are dissolved in a solvent and used in the form of a varnish. Examples of the solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, Propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-
1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate, methyl-3-methoxypropionate and the like may be used alone or in combination.

The positive photoresist used in the present invention is a commercially available alkali-developing positive photoresist used in ordinary semiconductor processing, and the amount of film reduction in the developing solution from the positive photosensitive resin composition is reduced. The product is manufactured by Far East Co., Ltd. “Microposit S1400-
13 "and" AZ-1350 "manufactured by Hoechst Japan KK, but are not limited thereto.

In the method for processing a positive photosensitive resin composition of the present invention, the composition is first applied to a suitable support, for example, a silicon wafer, ceramic, aluminum substrate or the like. Examples of the coating method include spin coating using a spinner, spray coating using a spray coater, dipping, printing, and roll coating. Next, the coating film is dried by pre-baking at 60 to 130 ° C. After application, it is necessary to dry at 60-130 ° C. When dried at less than 60 ° C., there is a problem that the drying is insufficient and the material is melted during development, and when dried at more than 130 ° C., there is a problem that the photosensitive agent is decomposed. Thereafter, an alkali developing type photoresist is further applied thereon. After prebaking and drying the coating film, a desired pattern shape is irradiated with actinic radiation. As the actinic radiation, X-rays, electron beams, ultraviolet rays, visible rays and the like can be used.
Those having a wavelength of 00 nm are preferred. Next, a relief pattern is obtained by dissolving and removing the irradiated portion with a developer. As a developer, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, inorganic alkalis such as aqueous ammonia, ethylamine,
primary amines such as n-propylamine; secondary amines such as diethylamine and di-n-propylamine; tertiary amines such as triethylamine and methyldiethylamine;
Aqueous solutions of alcohol amines such as dimethylethanolamine and triethanolamine, and quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, and aqueous solutions of alcohols such as methanol and ethanol An aqueous solution to which a suitable amount of a neutral organic solvent or a surfactant is added can be suitably used. As a developing method, a system such as spray, paddle, immersion, and ultrasonic wave can be used. Next, the relief pattern formed by development is rinsed. Distilled water is used as the rinsing liquid. Next, heat treatment is performed to form an oxazole ring, and a final pattern having high heat resistance is obtained.

Next, a ketone or ester organic solvent,
For example, the positive photoresist is removed by wet etching using acetone, n-butyl acetate, or the like, or dry etching using oxygen plasma or the like. Next, a heat treatment is performed at a temperature necessary for ring closure to form an oxazole ring, and a final pattern having high heat resistance is obtained. The method of processing a positive photosensitive resin composition according to the present invention can perform pattern processing without concern for film reduction in an unexposed portion, and a thick film can be easily obtained. It can be expected to be applied to insulating films of devices such as large transistors and wafer level packages. A semiconductor device manufactured by using the method for processing a positive photosensitive resin composition according to the present invention has high product productivity and high reliability. A known method can be used for a method of manufacturing a semiconductor device other than the method of the present invention.

[0026]

EXAMPLES <Example 1> * Synthesis of polyamide Diphenyl ether was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a raw material inlet, and a nitrogen gas inlet.
258.2 g (1 mol) of 4,4'-dicarboxylic acid and 1-
270.3 g (2 mol) of hydroxybenzotriazole
Was dissolved in 1500 g of N-methyl-2-pyrrolidone, and then 412.7 g (2 mol) of dicyclohexylcarbodiimide dissolved in 500 g of N-methyl-2-pyrrolidone.
Is added dropwise while cooling the temperature of the reaction system to 0 to 5 ° C. After the addition, the temperature of the reaction system was returned to room temperature, and the mixture was stirred for 12 hours. After completion of the reaction, the precipitated dicyclohexylcarbodiurea is removed by filtration, and then 2,000 g of pure water is added dropwise to the filtrate. The precipitate is collected by filtration,
After sufficiently washing with isopropyl alcohol, vacuum drying was performed to obtain an active ester (A) in which 1 mol of 1-hydroxybenzotriazole was reacted at both ends of diphenyl ether-4,4'-dicarboxylic acid. Next, 147.7 g (0.3 mol) of this dicarboxylic acid derivative (A) and 120.9 g (0.33 mol) of hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane were added to N -Methyl-2-pyrrolidone dissolved in 1000 g. Thereafter, the reaction system was heated to 75 ° C. and reacted for 12 hours. Next, the 5-mer dissolved in 50.0 g of N-methyl-2-pyrrolidone
Norbornene-2,3-dicarboxylic anhydride 11.5 g
(0.07 mol), and the mixture was further reacted for 12 hours. The reaction mixture was poured into a solution of water / methanol = 3/1, the precipitate was collected, washed sufficiently with pure water, dried under vacuum, and dried under vacuum to obtain a polybenzoxazole precursor (P-polyamide).
1) was obtained.

Preparation of Positive Photosensitive Resin Composition This synthesized polybenzoxazole precursor (P-1)
100 g of a diazoquinone (Q-
1) After dissolving in 25 parts by weight and 200 parts by weight of γ-butyl lactone to obtain a solution having a viscosity of about 4000 cP, 0.2
Filtration through a μm Teflon filter gave a photosensitive resin composition.

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* Characteristic evaluation After coating this positive photosensitive resin composition on a silicon wafer by using a spin coater, 1
After drying at 20 ° C. for 7 minutes, a coating film having a thickness of about 40 μm was obtained.
Thereafter, an alkali-developable positive photoresist OFPR-5000 (manufactured by Tokyo Ohka Co., Ltd.) is further coated on the coating film using a spin coater, and then dried at 110 ° C. for 1 minute on a hot plate to obtain a whole. Of about 41 μm was obtained. A g-line stepper exposure line NSR-15 is applied to this coating film.
05G3A (manufactured by Nikon Corporation) through a mask having a test pattern from 2500 mJ / cm ² to 50 m
Exposure was performed in increments of J / cm ² up to 4950 mJ / cm ² . Next, the exposed part was dissolved and removed by immersion in a developer of a 2.38% aqueous solution of tetramethylammonium hydroxide for 200 seconds, and then rinsed with pure water for 30 seconds. As a result, it was confirmed that the pattern is formed from the portion irradiated with 3950mJ / cm ² (sensitivity 3950mJ / cm ^2). After that, the oxygen gas flow rate was 200 sc in the plasma apparatus OPM-EM1000.
The positive photoresist was removed by applying oxygen plasma at a pressure of 2.4 Torr and an output of 800 W for 10 minutes. At this time, the film thickness of the unexposed portion was 40 μm. Next, this coating film was heated and cured in an oven under an atmosphere of nitrogen at 150 ° C. for 30 minutes and then at 320 ° C. for 30 minutes to obtain a coating film having a thickness of about 30 μm.

Example 2 * Characteristics Evaluation A positive photosensitive resin composition prepared in the same manner as in Example 1 was applied on a silicon wafer using a spin coater, and then heated on a hot plate at 120 ° C. for 7 hours. After drying for a minute, a coating film having a thickness of about 35 μm was obtained. Thereafter, an alkali-developable positive photoresist OFPR-50 is further applied on the coating film.
00 (manufactured by Tokyo Ohka Co., Ltd.) was applied using a spin coater, and then dried on a hot plate at 110 ° C. for 1 minute to obtain a coating having a total thickness of about 37 μm. A g-line stepper exposure line NSR-1505G3A (Nikon Corporation)
25) through a mask having a test pattern.
Increase from 00mJ / cm ² by 50mJ / cm ² 49
Exposure was performed up to 50 mJ / cm ² . Next, 2.38%
The exposed portion was dissolved and removed by immersion in a developing solution of an aqueous solution of tetramethylammonium hydroxide for 200 seconds, followed by rinsing with pure water for 30 seconds. As a result, 3
It was confirmed that a pattern was formed from the portion irradiated at 100 mJ / cm ² (the sensitivity was 3100 mJ / c).
m ² ). Thereafter, the positive photoresist was removed by immersing the coating film in a propylene glycol monomethyl ether acetate resist stripper for 90 seconds.
At this time, the film thickness of the unexposed portion was 35 μm. Next, this coating film was placed in an oven under a nitrogen atmosphere at 150 ° C. for 30 minutes.
Then, by heating and curing at 320 ° C. for 30 minutes, a coating film having a thickness of about 25 μm was obtained.

Comparative Example 1 A positive photosensitive resin composition prepared in the same manner as in Example 1 was applied on a silicon wafer using a spin coater, and then applied on a hot plate.
After drying at 20 ° C. for 8 minutes, a coating film having a thickness of about 50 μm was obtained.
A g-line stepper exposure line NSR-1505G3
A 50 mJ from 2,500 mJ / cm ² through a mask having a test pattern by (Nikon Co., Ltd.) / cm ²
Exposure was performed up to 4950 mJ / cm ^{2 in} increments.
Next, the exposed portion was dissolved and removed by immersion in a developer of a 2.38% aqueous solution of tetramethylammonium hydroxide for 240 seconds, followed by rinsing with pure water for 30 seconds to adjust the film thickness of the unexposed portion in Example 1. The film thickness (40 μm) was the same as the film thickness of the unexposed part. As a result, the exposed portion was not completely melted and no pattern was formed.

[0031]

According to the present invention, the coating film of the positive photosensitive resin composition has an unexposed portion which is not reduced in film thickness during development.
A highly sensitive pattern can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/26 511 G03F 7/26 511 F term (Reference) 2H025 AA08 AB16 AB17 AC01 AD03 BE02 CB24 CB26 DA13 FA29 2H096 AA25 AA27 BA10 EA02 HA01 KA02 KA03 KA06 4J002 CL061 CN011 CN031 CP171 EQ016 FD146 GP03 GQ05

Claims (5)

[Claims] 1. A positive photosensitive resin composition is coated on a support, dried at 60.degree. C. to 130.degree. C., and further patterned by using a positive photoresist. Of a positive photosensitive resin composition to be processed. 2. The positive photosensitive resin composition according to claim 1, wherein the positive photosensitive resin composition comprises 100 parts by weight of a polyamide represented by the general formula (1) and 1 to 50 parts by weight of a diazonaphthoquinone compound. Processing method. Embedded image 3. The method for processing a positive photosensitive resin composition according to claim 1, wherein the thickness of the positive photosensitive resin composition after coating and drying is 10 to 100 μm. 4. The method for processing a positive photosensitive resin composition according to claim 1, wherein the thickness of the positive photoresist after coating and drying is 0.1 to 5 μm. 5. A semiconductor device manufactured by using the method for processing a positive photosensitive resin composition according to claim 1.