JP2001154358A - Method for processing positive type photosensitive resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for processing a positive type photosensitive resin composition by which a high sensitivity pattern is obtained at a high rate of a residual film even in thick film processing. SOLUTION: When a two-layer organic film of positive type photosensitive resin compositions different from each other in the reduction of the film thickness of the unexposed part is processed, a positive type photosensitive resin composition is applied and dried on a substrate, a positive type photosensitive resin composition which exhibits a smaller reduction of the film thickness of the unexposed part than the positive type photosensitive resin composition for the 1st layer is further applied and fried 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.

Embedded image

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 prebaking is larger than the desired film thickness by the amount of film reduction in the unexposed portion during development.
At the time of exposure, light hardly reaches the bottom of the film, which causes problems such as a decrease in sensitivity.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a high-sensitivity method which has a small film loss 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.

[0007]

According to the present invention, a positive photosensitive resin composition is coated on a support, dried at 60.degree. C. to 130.degree. C., and further coated thereon with a first layer of positive photosensitive resin. Is a processing method in which a positive photosensitive resin composition having a smaller film loss amount in an unexposed portion than the conductive resin composition is applied, dried at 60 ° C. to 130 ° C., and then subjected to pattern processing. This is a method for processing a positive photosensitive resin composition in which the 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.

Embedded image

The thickness of the first layer of the positive photosensitive resin composition after coating and drying is 10 to 100 μm, and the second layer of the positive photosensitive resin composition is coated and dried. A method for processing a positive-type photosensitive resin composition having a thickness of 1 to 10 μm afterwards, and preferably, a film reduction amount of an unexposed portion of the positive-type photosensitive resin composition of the second layer is 0.1%. -10 nm / se
This is a method for processing the positive-type photosensitive resin composition that is c.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, in order to obtain a high-sensitivity pattern with a small film loss of an unexposed portion even in a thick film, a positive-type photosensitive resin composition is coated on a support and dried.
Furthermore, it has been found that it is sufficient to apply a positive photosensitive resin composition having a smaller film loss amount in an unexposed portion than the first layer of the positive photosensitive resin composition, and then perform pattern processing after drying. is there.

The positive photosensitive resin composition used in the present invention preferably 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. X in the general formula (1) is, for example,

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

Among them, particularly preferred are:

Embedded image It is more chosen.

Further, Y in the formula (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 a structure of Y with a diamine having a 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, for example, a compound having a 1,2-naphthoquinonediazide structure, and is disclosed in US Pat. No. 2,772,972.
No. 2,797,213 and 3,669,658.

For example, the following may be mentioned.

Embedded image

Embedded image

Among these, the following are particularly preferred.

Embedded image

The amount of the diazonaphthoquinone compound in the polyamide is 1 to 50 parts by weight based on 100 parts by weight of the polyamide.
If the amount is less than 1 part by weight, the patterning property of the resin is poor, and if it exceeds 50 parts by weight, 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, to enhance the 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.

In the present invention, the amount of film reduction in the unexposed portion of the positive photosensitive resin composition of the second layer is smaller than that of the positive photosensitive resin composition of the first layer, preferably the positive photosensitive resin composition of the second layer. Film loss amount of the unexposed part of the photosensitive resin composition is 0.1 to 10
nm / sec. If the amount of film reduction exceeds 10 nm / sec, it becomes difficult to form a thick film. In general, the larger the molecular weight, the smaller the amount of film reduction in the unexposed portion of the positive photosensitive resin composition depending on the reaction molar ratio of the positive photosensitive resin composition.

In the method for processing a positive photosensitive resin composition of the present invention, first, the positive photosensitive resin composition is treated with a suitable support,
For example, it is applied to 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. Then 60-130 ° C
And pre-baked to dry the coating. When the drying temperature is lower than 60 ° C., there is a disadvantage that the drying is insufficient and the resin is melted during development, and when it exceeds 130 ° C., the photosensitive agent is decomposed. Thereafter, a positive photosensitive resin composition having a smaller film loss amount in the unexposed portion than the first layer is further applied thereon. Then, after pre-baking at 60 to 130 ° C. to dry the coating film, the 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, but those having a wavelength of 200 to 500 nm are preferable. Next, a relief pattern is obtained by dissolving and removing the irradiated portion with a developer. Examples of the developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, and di-n. Secondary amines such as propylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, and quaternary ammoniums such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. An aqueous solution of an alkali such as a salt or an aqueous solution obtained by adding a suitable amount of a water-soluble organic solvent such as an alcohol such as methanol or ethanol or a surfactant thereto 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, 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.

In the method of processing a positive photosensitive resin composition according to the present invention, pattern processing can be performed with a high residual film ratio, and since the basic resin skeleton is the same, there is no need to peel off the second layer. Since a thick film can be easily obtained, application to an insulating film of a device such as a transistor having a large current flowing through a wiring or a wafer level package can be expected. 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.

[0027]

EXAMPLES <Example 1> * Synthesis of Polyamide (1) Diphenyl ether was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a raw material charging port 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) obtained by reacting 1 mol of 1-hydroxybenzotriazole at both ends of diphenyl ether-4,4′-dicarboxylic acid. Next, 137.9 g (0.28 mol) of this dicarboxylic acid derivative (A) and 120.9 g (0.33 mol) of hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane
Was dissolved in 1000 g of N-methyl-2-pyrrolidone.
Thereafter, the reaction system was heated to 75 ° C. and reacted for 12 hours. Next, 5 dissolved in 50.0 g of N-methyl-2-pyrrolidone
-Norbornene-2,3-dicarboxylic anhydride 11.5
g (0.07 mol) was added, 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.

* Synthesis of polyamide (2) Also, 147.7 g of this dicarboxylic acid derivative (A)
(0.3 mol) and hexafluoro-2,2-bis (3-
Amino-4-hydroxyphenyl) propane 120.9
g (0.33 mol) in N-methyl-2-pyrrolidone 10
00g. Thereafter, the reaction system was brought to 75 ° C.
Reacted for hours. Next, N-methyl-2-pyrrolidone 5
11.5 g (0.07 mol) of 5-norbornene-2,3-dicarboxylic anhydride dissolved in 0.0 g was added, and the mixture was further reacted for 12 hours. Water / methanol = 3
/ 1, the precipitate was collected, washed sufficiently with pure water, and dried under vacuum to obtain a polybenzoxazole precursor (P-2) as a polyamide.

Preparation of Positive Photosensitive Resin Composition (1) The synthesized polybenzoxazole precursor (P-1)
100 g, 25 parts by weight of diazonaphthoquinone (Q-1) having a structure of the following formula, and 200 parts by weight of γ-butyl lactone were dissolved into a solution having a viscosity of about 4000 cP.
The mixture was filtered through a 0.2 μm Teflon filter to obtain a photosensitive resin composition (1). The film loss of this film was 67 nm with a 2.38% aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH) in a developing solution (24 ° C.).
/ Sec.

Embedded image

Preparation of Positive Photosensitive Resin Composition (2) The synthesized polybenzoxazole precursor (P-2)
100 g, 25 parts by weight of diazonaphthoquinone (Q-1) having the structure of the above formula, and 200 parts by weight of γ-butyl lactone were dissolved to form a solution having a viscosity of about 4000 cP.
The solution was filtered through a 0.2 μm Teflon filter to obtain a positive photosensitive resin composition (2). The film loss of this is TMA
The H developer (24 ° C.) was 7 nm / sec.

* Characteristic evaluation After coating the positive photosensitive resin composition (1) on a silicon wafer using a spin coater, the coating was dried at 120 ° C. for 4 minutes on a hot plate to obtain a coating having a thickness of about 40 μm. A membrane was obtained. Thereafter, the positive photosensitive resin composition (2) is further applied on this coating film by using a spin coater, and then dried on a hot plate at 120 ° C. for 4 minutes to obtain a total film thickness of about 43.
A μm coating was obtained. A g-line stepper exposure line N
2500 mJ / cm ² through SR-1505G3A (manufactured by Nikon Corporation) through a mask having a test pattern.
Increase from each 50mJ / cm ² 4950mJ / cm ²
Exposure was carried out. Next, the exposed portion was dissolved and removed by immersion in a TMAH developer for 200 seconds, and then rinsed with pure water for 30 seconds. As a result, 4000 mJ / cm ²
It was confirmed that a pattern was formed from the portion irradiated with (a sensitivity of 4000 mJ / cm ² ). At this time, the film thickness of the unexposed portion was 40 μm. Next, this coating film was placed in an oven under a nitrogen atmosphere at 150 ° C. for 30 minutes at 320 ° C.
By heating and curing in the order of 30 minutes.
A coating of 0 μm was obtained.

Example 2 * Characteristics Evaluation A positive photosensitive resin composition (1) 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. Drying at 4 ° C. for 4 minutes gave a coating film having a thickness of about 35 μm. Thereafter, the positive photosensitive resin composition (2) was further applied on this coating film by using a spin coater, and then applied at 110 ° C. on a hot plate.
After drying for a minute, a coating film having a total film thickness of about 40 μm was obtained. It was exposed to 4950mJ / cm ² increased from 2,500 mJ / cm ² through a mask having a test pattern by 50 mJ / cm ² by g-line stepper exposure line NSR-1505G3A the coated film (manufactured by Nikon Corporation). next,
The exposed portion was dissolved and removed by immersion in a TMAH developer for 200 seconds, and then rinsed with pure water for 30 seconds. As a result, it was confirmed that a pattern was formed from the portion irradiated at 3300 mJ / cm ² (the sensitivity was 3300 mJ / cm ^2).
mJ / cm ² ). At this time, the film thickness of the unexposed portion was 37 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 27 μm.

Comparative Example 1 A positive photosensitive resin composition (1) prepared in the same manner as in Example 1 was applied on a silicon wafer by using a spin coater, and then heated at 120 ° C. on a hot plate. After drying for a minute, a coating film having a thickness of about 50 μm was obtained. A g-line stepper exposure line NSR-150 is applied to this coating film.
5G3A (manufactured by Nikon Corporation) through a mask having a test pattern from 2500 mJ / cm ² to 50 mJ.
/ Cm ^2, and exposure was performed up to 4950 mJ / cm ² . Next, the exposed portion was dissolved and removed by immersion in a TMAH developing solution for 240 seconds, followed by rinsing with pure water for 30 seconds to make the film thickness of the unexposed portion the same as the film thickness of the unexposed portion in Example 1. The thickness (40 μm) was set. As a result, the exposed portion was not completely melted and no pattern was formed.

[0034]

According to the present invention, the coating film of the positive-type photosensitive resin composition does not need to be peeled off even if the second layer remains, and a highly sensitive pattern with a high residual film ratio can be obtained. Can be.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA01 AA08 AA10 AB16 AB17 AC01 AD03 BE01 BJ01 CB24 DA13

Claims (6)

[Claims] 1. A positive photosensitive resin composition is coated on a support, dried at 60.degree. C. to 130.degree. C., and further reduced on the unexposed portion with respect to the developer (hereinafter referred to as "film reduction"). amount"
The positive photosensitive resin composition less than the positive photosensitive resin composition of the first layer is applied, and 60 ° C. to 130 ° C.
A patterning process after drying with a photosensitive resin composition. 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 film thickness of the first layer after application and drying of the positive photosensitive resin composition is 10 to 100 μm.
Or the processing method of the positive photosensitive resin composition according to 2. 4. The film thickness of the second layer after application and drying of the positive photosensitive resin composition is 1 to 10 μm.
Or the processing method of the positive photosensitive resin composition of 3. 5. The positive-type photosensitive composition according to claim 1, wherein the positive photosensitive resin composition of the second layer has an unexposed portion having a thickness reduction of 0.1 to 10 nm / sec. Processing method of the conductive resin composition. 6. A semiconductor device manufactured by using the method for processing a positive photosensitive resin composition according to claim 1.