JPH06301217A - Developer for photosensitive polyimide precursor - Google Patents

Abstract

PURPOSE:To control the developing rate during development and to obtain a positive fine polyimide pattern with likelihood by preparing an alkali soln. containing amino alcohols and other alkali. CONSTITUTION:This developer is an alkali soln. containing 0.5-30wt.% aminoalcohols and other alkali except for aminoalcohols. The aminoalcohols in the developer are pereferably, monoethanolamine, diethanolamine, and isopropanolamine. The alkali except for aminoalchols is preferably tetramethylammonium hydroxide soln. tetraethylammonium hydroxide soln., choline soln., and these alkalis are used in a single or mixed form. Further, a potassium chloride soln., lithium chloride soln. etc., may be used as a controlling agent. This developer may contain an additive component as far as the effect is not decreased.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a developer for a photosensitive polyimide precursor composition useful as an electronic material. More specifically, it relates to a developer for a positive photosensitive polyimide precursor composition.

[0002]

2. Description of the Related Art Conventionally, as a developing solution for a photosensitive polyimide precursor, a dipolar aprotic solvent such as N-methylpyrrolidone added with a lower alcohol such as methanol or water as a poor solvent (see, for example, Japanese Unexamined Patent Publication 58-66940
JP, JP-A-58-223149, JP-A-62.
No. 127,738) or a dipolar aprotic solvent such as N-methylpyrrolidone to which an aromatic hydrocarbon such as xylene is added (for example, JP-A-2-
255898).

However, these developing solutions are
All were developers for a negative photosensitive polyimide precursor in which the exposed portion remained after development. As the negative photosensitive polyimide precursor used in these developers, a methacrylic group or the like is added to the varnish of the polyimide precursor generally produced in a dipolar aprotic solvent by combining tetracarboxylic acid and diamine. A mixture of amino compounds having a photosensitive group (for example, Japanese Patent Publication No. 59-52).
822), in which a group dimerizable or polymerizable by light is introduced by an ester bond (for example, US Pat.
No. 12), a mixture of a polyimide precursor varnish with an N-methylol amide compound (for example, Proceedings of the Polymer Society of Japan p807, 1990), or a mixture of an acrylic monomer with a polyimide precursor varnish ( For example, Japanese Patent Application Laid-Open No. 2-50161) can be cited.

In recent years, when a polyimide film is used as a protective film of a semiconductor element or an interlayer insulating film of a multi-layer wiring for high-density packaging, yield and reliability are lowered, and dust is used as a mask used during exposure. The positive type photosensitive polyimide precursor has been developed because, when such a substance is attached, that portion becomes a defect and a pinhole is formed in the polyimide film. Further, as a positive photosensitive polyimide precursor, a method of introducing a photodegradable photosensitive group into a polyamic acid with an ester group, and forming a positive pattern by exposure and development (for example, JP-A-1-61747). Gazette),
A method in which a naphthoquinonediazide compound having a specific structure is added to a polyamic acid having a specific structure, and heat treatment is performed after exposure in a specific temperature range to form a positive pattern (for example, Proceedings of the Polymer Society of Japan, Vol. 40, No. 3). , 821 (199
1)), a method of exposing the film of the actinic radiation-sensitive polyimide precursor, performing a treatment after exposure to make the unexposed portion have a higher degree of curing than the exposed portion, and removing the exposed portion to form a positive pattern However, even if a developing solution containing the dipolar aprotic solvent as a main component is used for developing these positive photosensitive polyimide precursors, the development is impossible.

Therefore, an alkaline aqueous solution (for example, NMD-3 manufactured by Tokyo Ohka Kogyo Co., Ltd.) as used for a positive type photoresist is used for these developments. There is a drawback that the dissolution of the exposed area to be dissolved becomes extremely slow. Further, depending on the type of the positive photosensitive polyimide precursor, the film thickness, the drying conditions, and the exposure conditions, there is a problem that the development time changes greatly and the process becomes unstable.

[0006]

The present invention was devised in view of the drawbacks of the prior art, and its purpose is to stabilize the development process of a positive photosensitive polyimide precursor and to obtain a good positive It is to provide a developer for a positive photosensitive polyimide precursor that forms a pattern of a mold.

[0007]

The object of the present invention is as follows.
This is achieved by a developing solution for a photosensitive polyimide precursor, which is an alkaline aqueous solution containing 0.5 to 30% by weight of amino alcohols and an alkali other than amino alcohols.

The amino alcohols contained in the developer of the present invention include monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, dimethylaminoethanol, triisopropanolamine, 2-hydroxymethylaminoethanol, N-.
Examples thereof include isobutyldiethanolamine and 2-aminocyclohexanol 2-aminomethylcycloalkanol, but the present invention is not limited thereto. Preferred are monoethanolamine, diethanolamine, and isopropanolamine.

The content of the amino alcohol is 0.5 to 30% by weight in the developer. Preferably 1.5-2
It is 0% by weight. When the content is less than 0.5% by weight, the development time is greatly changed depending on the type of positive photosensitive polyimide precursor, drying conditions and exposure conditions, and the process becomes unstable. In particular, when the film thickness of the photosensitive polyimide precursor film becomes thick, it is difficult to proceed with the development, and there is a problem that the development time becomes extremely long. On the other hand, if it exceeds 30% by weight, there is a disadvantage that the developing time becomes too fast, which makes it difficult to control the developing time.

Examples of alkalis other than amino alcohols include tetramethylammonium hydroxide aqueous solution, tetraethylammonium hydroxide aqueous solution, choline aqueous solution, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, barium hydroxide aqueous solution, lithium hydroxide aqueous solution, sodium carbonate. Aqueous solution, potassium carbonate solution, barium carbonate solution, lithium carbonate solution, potassium chloride solution,
Examples thereof include aqueous lithium chloride solution. Preferred are tetramethylammonium hydroxide aqueous solution, tetraethylammonium hydroxide aqueous solution, and choline aqueous solution. These alkalis are used alone or in combination of two or more.

The concentration of alkali other than amino alcohols in the developer is preferably 0.5 to 15% by weight. More preferably, it is 1.5 to 10% by weight. The concentration is 0.5
When it is less than 15% by weight, the development of the photosensitive polyimide precursor hardly progresses, and when it exceeds 15% by weight, the development becomes faster and it becomes difficult to control the development time. In addition, even the unexposed areas that should originally remain are dissolved, making it difficult to form a good positive pattern.

The developer according to the present invention may contain additional components as long as the effects of the present invention are not impaired.

As a positive photosensitive polyimide precursor that can be developed with the developer of the present invention, a photodegradable photosensitive group is introduced into a polyamic acid by an ester group, and a positive pattern is formed by exposure and development. (For example, Japanese Patent Laid-Open No. 1-6
1747), a naphthoquinonediazide compound having a specific structure is added to a polyamic acid having a specific structure, and heat-treated at a specific temperature range after exposure to form a positive pattern (for example, Proceedings of the Polymer Society of Japan, Volume 40, Issue 3, 8
21 (1991)), the film of the actinic radiation-sensitive polyimide precursor is exposed to light, and after exposure, the unexposed portion is treated to have a higher degree of curing than the exposed portion, and the exposed portion is removed to form a positive pattern. Things are included.

The positive type pattern is formed, for example, as follows. First, a varnish of a photosensitive polyimide precursor is applied onto a substrate such as a silicon wafer by a method such as spin coating, the solvent is scattered in a hot plate or an oven, and a predetermined amount of the varnish is applied through a photomask made of chromium. Expose. After that, heat treatment such as dehydration baking is performed in a hot plate or an oven, followed by development.

As a developing method, a substrate such as a silicon wafer is fixed on a spinner, and 100 rpm to 30 rpm
A spray method in which the developing solution is sprayed while rotating about 00 rotations, a substrate such as a silicon wafer is fixed on a spinner, the developing solution is placed on the substrate, and the paddle development is performed by allowing the developing solution to stand still. Examples of the method include immersion development in which a substrate is immersed in a bath of a developing solution, ultrasonic application immersion development in which ultrasonic waves are applied in immersion development, and the development can be performed by any method.

After the development, it is usually washed with a rinse liquid to remove the developer. As the rinse liquid, water, methyl alcohol, ethyl alcohol, isopropyl alcohol,
Toluene, xylene, acetone, methyl ethyl ketone,
Examples thereof include methyl cellosolve and ethyl cellosolve. Then, on a hot plate or oven, 100-4
A final product is obtained by performing heat treatment at about 50 ° C. and converting to polyimide.

[0017]

EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited thereto.

Reference Example 1 Synthesis of Photosensitive Polyimide Precursor Composition (A) 3,3 ', 4,4'-benzophenenonone tetracarboxylic acid dianhydride 80.55 g, pyromellitic dianhydride 5
4.53 g was reacted with 2.3 g of ethanol and 549 g of N-methyl-2-pyrrolidone at 70 ° C. for 3 hours. Then, it was cooled to 20 ° C., and 95.1 g of 4,4′-diaminodiphenyl ether and bis (3-aminopropyl)
Add 6.2 g of tetramethyldisiloxane and add another 60
The reaction was carried out at 0 ° C for 3 hours to obtain a polymer solution having a viscosity of 122 poise (25 ° C). 157.3 g of dimethylaminoethyl methacrylate (equivalent to the carboxyl group in the polymer), 3-phenyl-5-isoxazolone 42.27 were added to this solution.
g, 3,3'-carbonylbis (diethylaminocoumaroline) 2.36 g and N-methyl-2-pyrrolidone 1
90 g was added to obtain a photosensitive polyimide precursor composition (A).

Reference Example 2 Synthesis of Photosensitive Polyimide Precursor Composition (B) 161.1 g of 3,3 ', 4,4'-benzophenenonone tetracarboxylic dianhydride was added to 2.3 g of ethanol and N-
The reaction was carried out at 70 ° C. for 3 hours together with 549 g of methyl-2-pyrrolidone. Then, the mixture was cooled to 20 ° C., 95.1 g of 4,4′-diaminodiphenyl ether and 6.2 g of bis (3-aminopropyl) tetramethyldisiloxane were added, and the mixture was further reacted at 60 ° C. for 3 hours to give a viscosity of 100 poise ( A polymer solution at 25 ° C.) was obtained. To this solution were added 157.3 g of dimethylaminoethyl methacrylate (equivalent to the carboxyl group in the polymer), 42.27 g of 3-phenyl-5-isoxazolone, 2.62 g of 3,3'-carbonylbis (diethylaminocoumaroline) and N. -Methyl-2
-Pyrrolidone (190 g) was added to obtain a photosensitive polyimide precursor composition (B).

Reference Example 3 Synthesis of Photosensitive Polyimide Precursor Composition (C) 147.1 g of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride was added to 4.6 g of ethanol and N-methyl-
The reaction was carried out with 599 g of 2-pyrrolidone at 70 ° C. for 3 hours. Then, the mixture was cooled to 20 ° C., 54.05 g of paraphenylenediamine was added, and the mixture was further reacted at 60 ° C. for 3 hours,
A polymer solution having a viscosity of 500 poise (25 ° C.) was obtained. 185.3 g of dimethylaminoethyl methacrylate in this solution
(Equivalent to carboxyl group in polymer), 3-phenyl-
30.17 g of 5-isoxazolone, 2.62 g of 3,3′-carbonylbis (diethylaminocoumaroline) and 250 g of N-methyl-2-pyrrolidone were added to obtain a photosensitive polyimide precursor composition (C).

Example 1 The concentration of tetramethylammonium hydroxide was 2.5.
1% of monoethanolamine was added to the aqueous solution, which was wt%.
A developer for a photosensitive polyimide precursor containing 5% by weight was prepared.

Next, on a 4-inch silicon wafer,
The photosensitive polyimide precursor composition (A) obtained in Reference Example 1 was spin-coated and dried in an oven at 60 ° C. for 30 minutes. The film thickness at this time was 6.4 μm. Then, using a contact aligner PLA-501F manufactured by Canon Inc., light exposure of 200 mJ / cm ² was performed at a wavelength of 365 nm through a photomask made of chromium. After the exposure, heat treatment was performed on a hot plate at 140 ° C. for 3 minutes. This sample was immersed in the developer, rinsed with water, then blown with nitrogen and dried.

When the result of development for 3 minutes was observed with an optical microscope, a 10 μm through-hole portion was completely resolved, and uniform resolution was achieved from the central portion to the peripheral portion of the wafer. Further, the film thickness after development was 5.6 μm, and the film thickness retention rate was 87.5%, which was good with respect to the film thickness before development.

Example 2 Exactly the same conditions as in Example 1 except that a developing solution for a photosensitive polyimide precursor containing 15% by weight of monoethanolamine was used in the aqueous solution having a choline concentration of 5% by weight. Pattern processing was performed.

When the result of development for 3 minutes was observed with an optical microscope, a 10 μm through-hole portion was completely resolved, and uniform resolution was achieved from the central portion to the peripheral portion of the wafer. Further, the film thickness after development was 5.9 μm, and the film thickness retention ratio was as good as 92% with respect to the film thickness before development.

Example 3 Pattern processing was carried out under exactly the same conditions as in Example 1 except that the thickness of the photosensitive polyimide precursor composition (A) obtained in Reference Example 1 after coating and drying was 12.3 μm. I went.

When the result of development for 4 minutes was observed with an optical microscope, a 20 μm through hole portion was completely resolved, and uniform resolution was achieved from the central portion to the peripheral portion of the wafer. Further, the film thickness after development was 11.5 μm, and the film thickness retention ratio was 94%, which was good with respect to the film thickness before development.

Example 4 Pattern processing was carried out under exactly the same conditions as in Example 1 except that the photosensitive polyimide precursor composition (B) obtained in Reference Example 2 was used.

When the result of development for 3 minutes was observed with an optical microscope, a 10 μm through-hole portion was completely resolved, and uniform resolution was achieved from the central portion to the peripheral portion of the wafer. The film thickness after development was 5.5 μm, and the film thickness retention ratio was 86%, which was good with respect to the film thickness before development.

Example 5 Pattern processing was carried out under exactly the same conditions as in Example 1 except that the photosensitive polyimide precursor composition (C) obtained in Reference Example 3 was used.

When the result of development for 2 minutes was observed with an optical microscope, a 10 μm through hole portion was completely resolved, and uniform resolution was achieved from the central portion to the peripheral portion of the wafer. The film thickness after development was 5.5 μm, and the film thickness retention ratio was 86%, which was good with respect to the film thickness before development.

Comparative Example 1 Exactly the same conditions as in Example 1 except that an alkaline aqueous solution (NMD-3 manufactured by Tokyo Ohka Co., Ltd.) used for a positive photoresist was used as a developing solution for a photosensitive polyimide precursor. When the pattern processing was performed with, the development did not proceed even when immersed in the developing solution for 15 minutes, and the pattern of the photosensitive polyimide precursor could not be obtained.

Comparative Example 2 The concentration of tetramethylammonium hydroxide was 2.5.
The patterning was performed under exactly the same conditions as in Example 1 except that the aqueous solution (wt%) was used as the developing solution for the photosensitive polyimide precursor, and the development proceeded even when immersed in the developing solution for 15 minutes. No pattern of the photosensitive polyimide precursor was obtained.

Comparative Example 3 A pattern was processed under exactly the same conditions as in Example 1 except that the aqueous solution containing tetramethylammonium hydroxide at a concentration of 17% by weight was used as a developing solution for a photosensitive polyimide precursor. After being immersed in the developing solution, both the exposed and unexposed areas were dissolved within a few seconds, and the pattern of the photosensitive polyimide precursor could not be obtained.

Comparative Example 4 The concentration of tetramethylammonium hydroxide was 2.
Monoethanolamine 3 was added to the 5% by weight aqueous solution.
Pattern processing was performed under exactly the same conditions as in Example 1 except that a developing solution for a photosensitive polyimide precursor mixed with 5% by weight was used.

When the result of development for 2 minutes was observed with an optical microscope, the pattern of the through-holes spread and it was over-development. The film thickness after development was 2.5 μm, and the film thickness retention ratio was 40% with respect to the film thickness before development.

[0037]

By using the developer of the present invention,
In the processing of a positive photosensitive polyimide, the development speed at the time of development can be controlled, and a positive fine polyimide pattern can be obtained with a margin.

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[Procedure amendment]

[Submission date] March 2, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

Examples of alkalis other than amino alcohols include tetramethylammonium hydroxide aqueous solution, tetraethylammonium hydroxide aqueous solution, choline aqueous solution, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, barium hydroxide aqueous solution, lithium hydroxide aqueous solution, sodium carbonate. aqueous, aqueous potassium carbonate, etc. lithium carbonated aqueous solution and the like. Preferred are tetramethylammonium hydroxide aqueous solution, tetraethylammonium hydroxide aqueous solution, and choline aqueous solution. These alkalis are used alone or in combination of two or more. Also, do not use potassium chloride solution or lithium chloride solution.
Any may be used as a regulator.

Claims (3)

[Claims] 1. A developing solution for a photosensitive polyimide precursor, which is an aqueous alkaline solution containing 0.5 to 30% by weight of amino alcohols and an alkali other than amino alcohols. 2. The photosensitive material according to claim 1, which contains at least one selected from the group consisting of an aqueous solution of tetramethylammonium hydroxide, an aqueous solution of tetraethylammonium hydroxide and an aqueous solution of choline, as an alkali other than amino alcohols. Developer for polyimide precursor. 3. The concentration of alkali other than amino alcohols is 0.5 to 15% by weight.
Alternatively, the developing solution for the photosensitive polyimide precursor described in 2.