JPH0973176A - Method for patterning photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate scum in a patterning process and to ensure high resolution by applying a positive type photosensitive resin compsn. consisting of specified polyamide and a diazoquinone compd. to a substrate, etc., and forming a pattern by dissolution and removal with an alkaline aq. soln. after exposure. SOLUTION: A positive type photosensitive resin compsn. consisting of polyamide represented by the formula and a diazoquinone compd. is applied to a substrate, etc., prebaked and irradiated with light, and the exposed part is dissolved and removed with an alkaline aq. soln. contg. an anionic surfactant to form a pattern. In the formula, X is a tetravalent arom. group, Y is a divalent arom. group, (a) is 60.0-100mol%, (b) is 0-40.0mol%, a+b=100mol% and (n) is 2-500. The photosensitive resin compsn. can be patterned with very high resolution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern processing method of a photosensitive resin composition for obtaining a high resolution pattern without development residue.

[0002]

2. Description of the Related Art In recent years, in the semiconductor industry, IC and LS
A photosensitive resin such as a photoresist or a photosensitive polyimide is often used for an insulating film or a protective film in a package that requires the formation or processing of an ultrafine circuit such as I. A feature of the photosensitive resin is that a highly accurate resin pattern can be obtained with a relatively simple device. In particular, a positive-type photoresist based on a phenol novolak resin using diazoquinone or the like as a photosensitive agent does not swell during development, and can form a pattern with excellent resolution. Further, since the developing solution is an alkaline aqueous solution and has many features such as being excellent in safety, it is widely used in the manufacture of the above-mentioned semiconductor fine circuit and the like. On the other hand, even in a photosensitive heat-resistant resin such as photosensitive polyimide used for an insulating film and a protective film of a semiconductor, a positive photosensitive heat-resistant resin having characteristics such as high resolution and non-pollution of a developer is used as a photo-sensitive resin. Developed in the same manner as the resist (for example, see JP-A-64-60
No. 630, Japanese Patent Publication No. 1-46862, etc.), and are attracting attention as highly integrated semiconductor insulating films and resins for protective films.

Most positive-working photosensitive resin compositions consist of combining an alkali-soluble polymer with a diazoquinone compound as described above as a photosensitizer. In the unexposed area, these diazoquinone compounds are insoluble in an alkaline aqueous solution, but undergo a chemical change upon exposure to become soluble in an alkaline aqueous solution. Therefore, by utilizing the difference in solubility between the exposed and unexposed areas and removing the exposed areas with an alkaline aqueous solution, it is possible to form a coating film pattern only on the unexposed areas. The alkaline aqueous solution used as the developer is generally an aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH). When developing a photoresist based on a normal phenol novolak resin, the aqueous solution of TMAH can be favorably developed. For example, a polybenzoxazole precursor as disclosed in Japanese Patent Publication No. 1-46862 is used. In the case of the photosensitive resin composition described above, there is a drawback that undeveloped portions (scum) are generated in an exposed portion, which should be completely dissolved and removed, thereby deteriorating the resolution.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for patterning a photosensitive resin composition which eliminates scum in the pattern processing step and can obtain high resolution.

[0005]

Means for Solving the Problems The present invention provides the following formula (1)
Polyamide, indicated by

[0006]

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A positive type photosensitive resin composition comprising a diazoquinone compound is applied to a substrate or the like, prebaked and irradiated with light, and then the exposed portion is dissolved and removed with an alkaline aqueous solution containing an anionic surfactant, A method for patterning a photosensitive resin composition, which comprises obtaining a pattern.

[0008]

The polyamide of the formula (1) comprises a bisaminophenol having a structure of X and a dicarboxylic acid having a structure of Y, and when the polyamide is heated at about 300 to 400 ° C., the ring is closed to give a heat resistance of polybenzoxazole. Change to resin. Generally, a positive photosensitive resin composition is developed with an aqueous alkali solution. For example, photoresist is
Development is possible because the base phenol novolac resin has a phenolic hydroxyl group. Similarly, the positive photosensitive resin based on the polyamide represented by the formula (1) can be developed by the phenolic hydroxyl group of bisaminophenol having the structure of X, but the photoresist based on the phenol novolak resin can be developed. As a result, the developability is inferior, and scum is generated in the exposed portion, resulting in poor resolution. It is considered that this is because in the polyamide represented by the formula (1), the hydroxyl group is the only amine component in the phenol novolac resin containing one hydroxyl group per one benzene ring. A part of bisaminophenol having a structure of X is used for improving adhesion.
Polyamide or the like, which is replaced with silicone diamine having the Z structure of the formula (1), has a lower resin solubility, so that more scum occurs and the resolution becomes extremely poor. However, this scum does not occur at all when processed with an alkaline aqueous solution containing the anionic surfactant of the present invention.
Although the cause is not clear, it is considered that the affinity between the resin and the developer is improved by the anionic surfactant.

X of the polyamide (1) of the present invention is, for example,

[0010]

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However, the present invention is not limited to these. Further, Y in the expression (1) is, for example,

[0012]

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However, the present invention is not limited to these. Further, Z in the formula (1) is, for example,

[0014]

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However, the present invention is not limited to these. Z in the formula (1) is used when adhesion is required to a substrate such as a silicon wafer, for example, and the usage ratio b can be used up to 40.0 mol%. When it exceeds 40.0 mol%, the solubility of the resin is extremely lowered, and scum occurs even when the pattern processing method of the present invention is used, and pattern processing cannot be performed. In using these X, Y, and Z, one type or a mixture of two or more types may be used. A typical example of the anionic surfactant used in the present invention is alkylbenzene sulfonic acid. Specific examples include, but are not limited to, dodecylbenzenesulfonic acid, sodium dodecylbenzenesulfonic acid, and the like. The content of the anionic surfactant in the alkaline aqueous solution which is the developer of the present invention is preferably 0.1 to 10% by weight in the total alkaline aqueous solution. If it is less than 0.1% by weight, scum tends to be generated, and if it exceeds 10% by weight, the film loss in the unexposed portion becomes large and a good pattern cannot be obtained.

The alkaline aqueous solution of the present invention dissolves and removes the alkali-soluble polymer, and it is essential that it is an aqueous solution in which an alkaline compound is dissolved. Examples of the alkali compound include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, 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. And the like.

The photosensitive resin composition used in the present invention contains a solvent other than polyamide and a quinonediazide compound as a main component, but a polyamic acid may be added if necessary. Since the polyamic acid has a carboxyl group, the solubility is increased and the development time can be shortened.

The diazoquinone used in the present invention is 1,2-
It is a compound having a benzoquinonediazide or 1,2-naphthoquinonediazide structure, and is a substance known from U.S. Patent Nos. 2,772,972, 2,797,213, and 3,669,658. For example,

[0019]

[Chemical 6]

[0020]

[Chemical 7]

And the like. In the method for producing a pattern, the composition is first applied to a suitable support, for example, a silicon wafer, ceramic, an aluminum substrate, or the like. The coating method is performed by spin coating using a spinner, spray coating using a spray coater, dipping, printing, roll coating, or the like. Next, the coating film is dried at a temperature of about 60 to 180 ° C. Examples of the drying method include an oven, an infrared furnace, a hot plate and the like, but a hot plate is preferable because of efficiency and easy temperature control. When drying with this hot plate, it is preferable to dry at 80 to 130 ° C. When the temperature is lower than 80 ° C., drying is insufficient, which is not preferable. On the other hand, when the temperature exceeds 130 ° C., drying becomes excessive, which is not preferable. More preferred is 2 to 4 minutes at 100 to 120 ° C. Next, a desired pattern shape is irradiated with light using 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 m are preferred. In order to obtain a higher-resolution pattern, it is more preferable to use an i-line stepper using a wavelength of 365 nm or a g-line stepper using a wavelength of 436 nm.

Hereinafter, the present invention will be described specifically with reference to examples. Example 1 Synthesis of polyamide 33.6 parts by weight of hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane (0.100 parts)
Mol) was dissolved in 150 parts by weight of N, N-dimethylacetamide and 33.2 (0.420 mol) of pyridine. Next, 21.3 parts by weight (0.105 mol) of terephthalic acid chloride dissolved in 100 parts by weight of cyclohexanone was added dropwise at -10 to -15 ° C over 30 minutes, and then stirred at room temperature for 4 hours to complete the reaction. After filtering the reaction mixture, the solution was poured into water to precipitate the desired polymer (A). The precipitate is collected by filtration and washed thoroughly with water, then under vacuum 80
It was dried at ℃ for 24 hours.

[0023]

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Preparation of Photosensitive Resin Composition 100 parts by weight of synthesized polyamide (A) and 25 parts by weight of diazoquinone (D) having the following structure were added to N-methyl-2-
After dissolving in 200 parts by weight of pyrrolidone (hereinafter referred to as NMP), it was filtered through a 0.2 μm Teflon filter to obtain a photosensitive resin composition.

[0025]

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Photosensitivity Evaluation This photosensitive resin composition was spin-coated on a silicon wafer and heated on a hot plate at 120 ° C. for 3 minutes to evaporate the solvent to form a coating film having a thickness of 5 μm.
200 mJ / cm ² of ultraviolet rays from a high-pressure mercury lamp was irradiated on this coating film through a mask manufactured by Toppan Printing Co., Ltd. (test chart No. 1; a residual pattern and a blank pattern having a width of 50 to 0.88 μm are drawn). . 1.20 parts by weight of the obtained coating film tetramethylammonium hydroxide,
Pure water 98.30 parts by weight, dodecylbenzene sulfonic acid,
Development was carried out by a paddle method for 30 seconds using a developing solution consisting of 0.50 parts by weight, the coating film in the exposed area was dissolved and removed, and then the developing solution was washed off with water for 10 seconds. As a result, a scum-free pattern having a resolution of 2.5 μm was obtained. Film loss rate during development (thickness reduction due to development / thickness before development x 100
(%); The smaller this value is, the better) at 10%.

Example 2 Synthesis of Polyamide 33.0 parts by weight of hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane (0.090
Mol) and 1,3-bis (3-aminopropyl) -1,
2.5 parts by weight (0.010 mol) of 1,3,3-tetramethyldisiloxane and N, N-dimethylacetamide 1
Dissolved in 50 parts by weight. Next, 21.3 parts by weight (0.105 mol) of terephthalic acid chloride dissolved in 100 parts by weight of cyclohexanone was added dropwise at -10 to -15 ° C over 30 minutes, and then stirred at room temperature for 4 hours to complete the reaction. After filtering the reaction mixture, the solution was poured into water to precipitate the desired polymer (B). The precipitate was collected by filtration, washed thoroughly with water, and dried under vacuum at 80 ° C. for 24 hours.

[0028]

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Preparation of Photosensitive Resin Composition 100 parts by weight of the synthesized polyamide (B) and 25 parts by weight of diazoquinone (D) having the following structure were dissolved in 200 parts by weight of NMP, and then filtered with a 0.2 μm Teflon filter to be exposed. A resin composition was obtained. Photosensitivity evaluation Under the same conditions as in Example 1, after spin coating and pre-baking exposure, 1.20 parts by weight of tetramethylammonium hydroxide, 93.80 parts by weight of pure water, 5.00 parts by weight of dodecylbenzenesulfonic acid. Was developed by a paddle method for 60 seconds, the coating film in the exposed area was dissolved and removed, and then the developer was washed off with water for 10 seconds.
As a result, a scum-free pattern having a resolution of 5 μm was obtained. At this time, the film reduction rate was 8%, which was good. Example 3 Synthesis of Polyamic Acid 1,3-Bis (γ-aminopropyl) -1,1,3,3
-43.6 parts by weight of tetramethyldisiloxane (0.17
5 mol) and benzophenonetetracarboxylic dianhydride 5
7.5 parts by weight (0.178 mol) was dissolved in 400 parts by weight of NMP and stirred at room temperature for 7 hours. The reaction solution was poured into water to obtain a precipitate, which was then dried under vacuum at 80 ° C. to obtain a polyamic acid (C) having the following structure.

[0030]

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Preparation of Photosensitive Resin Composition 30 parts by weight of quinonediazide (D) was added to 80 parts by weight of the polyamide (A) and 20 parts by weight of the polyamic acid (C) obtained in Example 1 and 0.2 μm after dissolution. To obtain a photosensitive resin composition. Photosensitivity evaluation Under the same conditions as in Example 1, spin coating, pre-baking,
After the exposure, a developing solution consisting of 1.20 parts by weight of tetramethylammonium hydroxide, 98.50 parts by weight of pure water, and 0.30 parts by weight of dodecylbenzenesulfonic acid was used to develop for 20 seconds by the paddle method, and then exposed. After the coating film of a part was removed by dissolution, the developing solution was washed off with water for 10 seconds. As a result, a scum-free pattern having a resolution of 2 μm was obtained. At this time, the film reduction rate was 13%, which was good. Example 4 The quinonediazide (E) having the following structure was used in place of the quinonediazide (D) of Example 1, and the same evaluation as in Example 1 was carried out. A scum-free pattern resolved up to 3 μm was obtained. It was At this time, the film reduction rate was 9%, which was good.

[0032]

[Chemical 12]

Comparative Example 1 The same evaluation was carried out by changing the developing solution in Example 1 to a solution containing 1.20 parts by weight of tetramethylammonium hydroxide and 98.80 parts by weight of pure water and not containing dodecylbenzenesulfonic acid. I went. Comparative Example 2 The same evaluation was carried out by changing the developing solution in Example 2 to one containing 2.00 parts by weight of tetramethylammonium hydroxide and 98.00 parts by weight and not containing dodecylbenzenesulfonic acid. Comparative Example 3 1.20 parts by weight of tetramethylammonium hydroxide, 86.80 parts by weight of pure water,
The same evaluation was performed by changing the developing solution to 12.00 parts by weight of dodecylbenzenesulfonic acid. Comparative Example 4 The same evaluation as in Example 1 was performed except that the developing solution was changed to a developing solution comprising 1.20 parts by weight of tetramethylammonium hydroxide, 98.75 parts by weight of pure water, and 0.05 part by weight of dodecylbenzenesulfonic acid. went. The results of Examples and Comparative Examples are shown in Table 1.

[0034]

[Table 1]

[0035]

According to the present invention, when development is performed with an alkaline aqueous solution containing an anionic surfactant, residual development (scum) does not occur. Therefore, the photosensitive resin composition comprising a polyamide and a quinonediazide compound enables very high resolution pattern processing.

Claims (3)

[Claims] 1. A polyamide represented by the following formula (1): A positive photosensitive resin composition composed of a diazoquinone compound is applied to a substrate or the like, prebaked, irradiated with light, and then the exposed portion is dissolved and removed with an alkaline aqueous solution containing an anionic surfactant to obtain a pattern. A method for patterning a photosensitive resin composition, comprising: 2. The pattern processing method for a photosensitive resin composition according to claim 1, wherein the anionic surfactant is alkylbenzene sulfonic acid. 3. The pattern processing method of the photosensitive resin composition according to claim 1, wherein the content of the anionic surfactant in the total alkaline aqueous solution is 0.1 to 10% by weight.