JPS60135457A - Photopolymer composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which can be thick-patterned and has excellent workability, consisting of a specified polyamic acid, a bisazide photo- crosslinking agent, an amine compd. contg. C=C bonds and a compd. contg. an OH group. CONSTITUTION:2-10pts.wt. bisazide photo-crosslinking agent of formula II(wherein X is OH, carboxyl, hydroxyalkyl, alkoxy, alkyl, amino; the N3 group is attached to the meta- or para-position of the benzene nucleus), 1-40pts.wt. amine compd. contg. C=C bonds and having formula III (wherein R<3>-R<5>, R<8> are each H, lower alkyl, phenylvinyl; R<7> is alkylene), 1-50pts.wt. compd. contg. at least one OH group per molecule such as triethylene glycol and 100-10,000 pts.wt. aprotic polar solvent such as N-methyl-2-pyrrolidone are blended with 100pts.wt. polyamic acid having a repeating unit of formula I (wherein R<1> is a bivalent org. group contg. an arom. ring).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a photosensitive polymer composition used in semiconductor devices, microelectronic devices, etc.

[Background of the invention]

Conventionally, glabella insulating films and surface protective films for semiconductor devices, microelectronic devices, etc.
21 film has excellent flattening ability, (3) high heat resistance,
(4) Polyimide is used because it has excellent electrical and mechanical properties.

Recently, (1) a photosensitive polymer in which a photosensitive group is introduced into polyamic acid, which is a polyimide precursor, and (2) a photosensitive polymer composition comprising a polyamic acid and a photosensitizer, are being used to form a photoresist and an insulating film. A number of materials have been studied to date, since they can serve both functions and greatly streamline the patterning process for polyimide films.

To give a specific example, (a) a polymer whose main component is polyamic acid (polyimide precursor) and a compound containing a carbon-carbon double bond and an amino group that can be dimerized or polymerized by actinic radiation; (3) A composition comprising a polyamic acid and an amine compound containing an aromatic azide group or a nulfonyl azide group. etc. are known.

As the development of these photosensitive polyimide precursors or precursor compositions progresses, surface protective films for ICs, transistors, etc. and hybrid ICs are being developed to improve workability or ensure device characteristics.

When used as an insulating film for thin film devices such as thermal recording heads for facsimile, the pattern formation process with one coating makes it relatively thick as 5 μm as an insulating film for thin film devices.
It has been desired to pattern a polyimide film with a thickness of m or more.

However, in the case of the above-mentioned photosensitive polyimide precursor or precursor composition, the mark (b) indicates low sensitivity, and the photocured portion gradually dissolves during development, resulting in poor workability and poor reproducibility of film thickness. There were problems in terms of. In addition, in the case of (c), the UV absorption of the membrane is large and the UV transmittance is low, so 5
It has been difficult to handle patterning of thick films of μm or more.

[Purpose of the invention]

The purpose of the present invention is to overcome the problems of the prior art described above, and
The object of the present invention is to provide a photosensitive polymer composition that can be patterned into a thick film of μm or more and has excellent workability.

[Summary of the invention]

In order to achieve the above objective, the UV transmittance of the photosensitive film after coating and drying (wavelength range 350 to 450 nm).

Emission peak of high pressure mercury lamp 365, 405, 436 nm
As a result of intensive study, we considered that it was necessary to increase the formation speed and efficiency of photocrosslinked chains generated by UV irradiation (corresponding to A photosensitive polymer composition comprising a compound containing one or more hydroxyl groups in the molecule and having a boiling point of 150° C. or higher at normal pressure, wherein the polyamic acid structure is represented by repeating units of the general formula CI). (However, R1 represents a divalent aromatic ring-containing organic group or a silicon-containing organic group.) A bisazide photocrosslinking agent represented by the general formula (It) is used, and the blending ratio thereof is General formula (1
) 2 to 100 parts by weight of polyamic acid represented by
It has been found that a photosensitive polymer composition characterized in that it is blended in an amount of 10 parts by weight has excellent workability and can be patterned into thick films.

(However, in the formula, X represents a hydroxyl group, a carboxyl group, a hydroxyalkyl group, an alkoxy group, an alkylgostyl group, or an amine group, and N and the group are located at the meta or rose position in the benzene nucleus.) UV of the photosensitive coating In order to increase the transmittance, it is necessary to increase the UV transmittance of the base polymer, polyamic acid. One of the factors that reduces the UV transmittance of polyamic acid is that in polyamic acid represented by the repeating unit of general formula (III), the entire lyamic acid is incorporated into the conjugated system, which causes the UV absorption region to have a longer wavelength. This can be mentioned.

This conjugate cleavage is thought to prevent the UV absorption region from becoming longer wavelength (where ru represents 0 or an integer), but if ru is 1 or more, it may contain methylene at the benzyl position, which is active against oxidation reactions. It was thought that the heat resistance and environmental resistance would be insufficient when made of polyimide.

On the other hand, Lou 0. In other words, it has been found that when the biphenyl skeleton is present, the UV absorption region is suppressed from becoming longer in wavelength and the UV transmittance is improved, and the heat resistance when made into polyimide can also be made sufficient (450-520
heat resistance above ℃ was ensured).

In order to increase the rate and efficiency of photocrosslinking chain formation by UV irradiation, it is necessary to use a photocrosslinking agent with high photoreactivity. Examples of photocrosslinking agents provided for this purpose include bisazide photocrosslinking agents represented by formula [■] or formula [■], which are used in negative photoresists using cyclized polyyprene as a base polymer. . However, these have poor compatibility with polyamic acids and are photosensitive CH.

It cannot be used because it separates and precipitates from the film. On the other hand, the bisazide photocrosslinking agent represented by the general formula (II), which has a polar substituent introduced at the 4-position of the cyclohexanone ring, has excellent compatibility with highly polar polyamic acid, so it can be used for photocrosslinking for the above purpose. It can be used as an agent.

The blending ratio of the bisazide photocrosslinking agent represented by the general formula (n) is adjusted to achieve the above-mentioned purpose.
It is blended in a ratio of 2 to 10 parts by weight to 3,100 parts by weight. Since the bisazide photocrosslinking agent (n) itself also absorbs UV, if the amount exceeds this range, it will be difficult to pattern a thick film.In addition, if the amount exceeds this range and the amount is reduced, crosslinking will occur. This results in a decrease in density, resulting in disadvantages such as a decrease in sensitivity and insufficient stability in reproducing the thickness of the photocured portion during development.

The present invention will be explained in detail below.

C’H3 shao　−＠＠−o　−◎− CE, CM.

Examples include.

The polyamic acid represented by the repeating unit of general formula [13] may be used as a copolymer using two or more different RIs among the specific examples of RI shown above.

As the bisazide photocrosslinking agent represented by the general formula [■], O.C.E.

CE, OR 0OE 0 C’UOCH.

H Gin B CR 112OH 0OH coocB.

Nli.

etc. are given as suitable examples.

Suitable examples of the amine compound having a carbon-carbon double bond to be incorporated as a crosslinking aid include compounds represented by the general formula [■].

(However, R1, R4, R8, R11 are hydrogen, a group selected from a lower alkyl group, a phenyl group, a vinyl group, R
7 represents alkylene. ) Specifically, 2-()I,N-dimethylamino)ethyl acrylate, 2-(N,N-dimethylamino)ethyl methacrylate), 3-(N,N-dimethylamino)propyl acrylate, 6 -(N,N-dimethylamino)zorobyl methacrylate, 4-(N,N-dimethylamino)butyl acrylate, 4-(N,N-dimethylamino)butyl methacrylate, 5-(N,N-dimethylamino)pentyl acrylate, 5-(N,N-dimethylamino)pentyl methacrylate, 6-(N,N-dimethylamino)hexyl acrylate, 6-(N,N-dimethylamino)hexyl methacrylate, 2-(N, N~
dimethylamino)ethylcinnamate, 6-(N,N
Preferred examples include -dimethylamino)propyl cinnamate.

The blending ratio of the amine compound (VIU is 1 part by weight or more and 400 parts by weight or less per 100 parts by weight of the polymer whose main component is a repeating unit represented by the general formula [1],
Preferably, it is used in an amount of 10 parts by weight or more and 4001 parts by weight or less. If it is outside the above range, it will have an adverse effect on the developability and the quality of the polyimide film of the final product.

Compounds containing one or more hydroxyl groups in the molecule and having a boiling point of 150°C or higher at normal pressure that are added for the purpose of preventing cracks that occur during development include ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene. Glycol, polyethylene glycol, propylene glycol, dipropylene glycol.

Examples include tripropylene glycol, glycerin, triethylene glycol monomethyl ether, and triethylene glycol monoethyl ether. Preferred are triethylene glycol, tetraethylene glycol, and glycerin.

The blending ratio of the above compound is preferably 1 part by weight or more and 50 parts by weight or less, and preferably 10 parts by weight or more and 40 parts by weight or less, based on the weight part of the polyamic acid ioo of the repeating unit represented by the general formula CI). preferable.

If it deviates from this range, the developability will be adversely affected.The photosensitive polymer composition according to the present invention is used in the form of a solution in which the above components are dissolved in a suitable organic solvent. From the viewpoint of solubility, the solvent is preferably an aprotic polar solvent, such as N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N-benzyl-2-pyroIJ door, #1N-dimethylformamide, NlN -dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-acetyl-ε-cagzoloctam,
Examples include dimethylimidazolidinone.

These may be used alone or in combination. The amount of the solvent used is desirably 100 parts by weight or more and 1'0.000 parts by weight or less, more preferably 100 parts by weight or less, based on 100 parts by weight of the polyamic acid represented by the repeating unit of general formula (1). More preferably, it is used in an amount of 200 parts by weight or more and 5000 parts by weight or more, and if it deviates from this range, film forming properties will be affected.

A sensitizer may be appropriately added to the above composition for the purpose of improving sensitivity, but the amount of addition is limited to polyamic acid represented by the repeating unit of general formula [I] and bisazide represented by general formula (n). When the total amount of photocrosslinking agent is 100 parts by weight, 0.1 part by weight or more and 10 parts by weight or less of the photocrosslinking agent is used at °C.
It is desirable that the amount is within this range, and if it is outside this range, it will have an adverse effect on the developability and the heat resistance of the final polyimide.

Compounds effective for sensitizing aromatic bisazide compounds are Tsunoda,
Mountains [Photo, Sci, End,, 17.390
(1973) et al.

Among them, anthrone, 1,9-benzaanthrone, acridine, cyanoacridine, nitropyrene, 1,8-dinitropyrene, mihiraketone, 5-nitroacenaphthene, 2-nitropyrene.

Pyrene-1,6-quinone, 9-fluorenone, 1,2-
Preferred are benzanthraquinone, anthantrone, 2-chloro-1,2-benzanthraquinone, 2-bromobenzanthraquinone, 2-chloro-1,8-phthaloylnaphthalene, and the like.

In order to improve the adhesion between the coating film of the photosensitive polymer composition according to the present invention or the polyimide film after heat curing and the supporting substrate, the supporting substrate may be appropriately treated with an adhesion promoter.

Support substrates include metal, glass, and semiconductors.

Metal oxide insulators (e.g. ij Tie, , Ta, 0
5. Sin.

), silicon nitride, etc.

The photosensitive polymer composition according to the present invention can be patterned using conventional microfabrication techniques. The present polymer composition can be applied to the support by means such as spin coating using a spinner, dipping, and spray printing, which can be selected as appropriate. The coating film thickness can be adjusted by the coating means, the solid concentration of phene in the polymer composition, the viscosity, etc.

A relief pattern is obtained by irradiating the photosensitive polymer composition of the present invention, which has become a coating film on a display substrate, with ultraviolet rays, and then dissolving and removing the unexposed areas with a developer. The light source is not limited to ultraviolet light, but may also be visible light or radiation.

As a developer, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphorotriamide, dimethylimidazolidinone N-benzyl -2-pyrrolidone, A'-7
*An aprotic polar solvent such as chill-ε-caprolactam, methanol, or ethanol.

Inzorobil alcohol, benzene, toluene.

It can be used as a mixed solution of polyamic acid with a non-solvent such as xylene, metherceronlube, or water.

The relief pattern formed by development is then washed with a rinse solution to remove the development solvent. The rinsing solution uses polyamic acid non-solvents that are highly miscible with the developer, such as methanol ethanol, inzolovyl alcohol, benzene, toluene, xylene, and methyl cellosol.

A suitable example is water.

The relief pattern polymer obtained by the above treatment is a precursor of polyimide and is heated at temperatures between 150°C and 450°C.
Heat-resistant polymers with imide rings and other cyclic groups can be made in relief by processing at heating temperatures selected from a range of up to
It becomes a pattern.

Hereinafter, the present invention will be explained by examples.

Example 4,4'-diaminodiphenyl ether 1 was added under a nitrogen stream.
A diamine solution was prepared by dissolving 0.0t (0.5 mol) in N-methyl-2-pyrrolidone 1388F. Next, while keeping this solution at a temperature of about 15°C by water cooling,
147 t (0.5 mol) of 3.5',4.4-biphenyltetracarboxylic dianhydride were added while stirring. After the addition was completed, the reaction was further carried out at approximately 15°C for 5 hours until the viscosity was 5.
Solution 2 of boboriamic acid (,4) at 0 poise (60°C)
0f (polyamic acid content af), 2,6-bis(paraazidobenzal)-4-hydroxycyclohexanone 0.029 (0,054 mmol), 3-, (AI
, N-dimethylamino)propyl methacrylate2.
5v (0.0146 mol) and 0.3 (l) of glycerin were dissolved and then filtered under pressure using a filter with 1 μm pores.

The obtained solution was spin-coated onto a substrate having an M surface using a spinner, and dried at 90° C. for 20 minutes to obtain a photosensitive film. This film was tightly covered with a photomask having a 20 μm line-and-space striped pattern, and irradiated with ultraviolet rays for 15 seconds using a 500 W high-pressure mercury lamp.

After exposure 4 volumes of N-methyl-2-pyrrolidone, 1 volume of ethanol
A relief pattern was obtained by developing with a mixed solution consisting of 300 ml of water and then rinsing with ethanol.

Next, heat curing was performed at 180° C. for 30 minutes and at 400° C. for 60 minutes in a nitrogen atmosphere to obtain a polyimide relief pattern with a film thickness of 62 μm. At this time, the pattern was firmly adhered to the substrate, and the photomask pattern was faithfully transferred.

Example 2 To 20f of the solution of polyamic acid (A) obtained in Example 1, 0.25F (0.65 mmol) of 2,6-bis(paraazidobenzal)-4-methylolcyclohexanone,
4-(N,N-dimethylamino)butyl methacrylate)
2.5? (0,0135 mol) 1.2 f of tetraethylene glycol was dissolved and then filtered under pressure using a filter with 1 μm pores. Si
The photosensitive coating was spin-coated onto a substrate having a surface of n, and dried at 70° C. for 30 minutes to obtain a photosensitive coating. This film was closely covered with a photomask having a 20 μm line-and-space striped pattern, and irradiated with ultraviolet rays for 15 seconds using a 500 W high-pressure mercury lamp. After exposure, the film was developed with a mixture of 4 volumes of dimethylacetamide and 1 volume of ethanol, and then rinsed with ethanol to obtain a relief pattern. Next, heat curing was performed at 200°C for 30 minutes and at 400°C for 60 minutes in a nitrogen atmosphere to obtain a film thickness of 5.2.
A polyimide relief pattern of μm was obtained. At this time,
The pattern adhered firmly to the substrate, and the photomask pattern was faithfully transferred.

Example 6゜To the solution 201 of polyamic acid (,4) obtained in Example 1, 2,6-bis(paraazidobenzal)=4-carboxycyclohexanone 014t (0.35 mmol),
2.1 f (0,012 mol) of 3-(#, #-cylfk7mino)propyl methacrylate and 0.75 f of triethylene glycol were dissolved and filtered under pressure using a filter with 1 μm pores.

The obtained solution was spin-coated onto a silicon wafer using a spinner and dried at 85° C. for 20 minutes to obtain a photosensitive film. This film was tightly covered with a photomask having a 20 μm line-and-space striped pattern, and irradiated with ultraviolet rays for 15 seconds using a 500 W high-pressure mercury lamp. After exposure, the film was developed with a mixture of 4 volumes of N-methyl-2-pyrrolidone and 1 volume of water, and then rinsed with water to obtain a relief pattern. Next, under a phoneme atmosphere, 2
Heat curing was performed at 00° C. for 30 minutes and at 400° C. for 60 minutes to obtain a polyimide relief pattern with a film thickness of 5.8 μm. At this time, the pattern was firmly adhered to the substrate, and the photomask pattern was faithfully transferred.

Example 4 A diamine solution was prepared by dissolving paraphenylenediamine 542 (0.5 mol) in N-methyl-2-pyrrolidone 11392 under a nitrogen stream. Next, while keeping this solution at a temperature of about 15°C by water cooling, stir it for 3.3',
4.4'-Biphenyltetracarboxylic dianhydride 147
9 (0.5 mol) was added. Approximately 1 more after adding
The reaction was carried out at 5°C for 5 hours to obtain a 40 poise (30°C) solution of polyamic acid (B).

2.6-bis(paraazidobenzal)-4 was added to the solution 202 of polyamic acid (B) (polyamic acid content 5.of).
-Hydroxycyclohexanone 0.28f (0.75 mmol), 5-(N,N-dimethylamino)propyl methacrylate 2.5f (0.0146 mol), triethylene glycol o, 7r were dissolved and then 1 μm pores were added. A film was formed and patterned under exactly the same conditions as shown in Example 1, and a film thickness of 6.2 μm was obtained.
A relief pattern of polyimide was obtained. At this time, the pattern was firmly adhered to the substrate, and the photomask pattern was faithfully transferred.

Example 5゜An experiment was carried out using the same amounts of chemicals, composition solution preparation method, and pattern forming conditions as in Example 2, except for using the solution 202 of polyamic acid (B) obtained in Example 4. Film thickness5.
A 5 μm polyimide relief pattern was obtained. At this time, the pattern was tightly adhered to the substrate, and the photomask pattern was faithfully transferred.

Example 6゜Other than using the solution 202 of polyamic acid (B) obtained in Example 4, an experiment was conducted using the same amounts of drugs, composition solution preparation method, and pattern forming conditions as in Example 3, Film thickness5.
A 4 μm polyimide relief pattern was obtained. At this time, the pattern adhered strongly (6) to the substrate, and the pattern of the photomask was faithfully transferred.

Example Z Separate phenylene diamine 272 (0,25
mol) and 4,4'-diaminodiphenyl ether 51(
0.25 mol) to N-methyl-2-pyrrolidone 1269
A diamine solution was prepared by dissolving in f. Next, 3.3',4.4'-biphenyltetracarboxylic dianhydride 1a71 (0.5 mol) was added to the solution while stirring, while maintaining the solution at a temperature of about 15°C by cooling with water. After the addition is complete, heat the reaction at approximately 15°C for 5 hours until the temperature reaches 45 poise (30
A solution of polyamic acid (C") represented by a copolymer of repeating units CA) and (B) of

Polyamic acid (C゛) solution 20? The photosensitive polymer composition solutions (a), (b) and (
I got a 9. Using these G), (B), and e9, Example 6
The film thickness is 55 to 6.5μ depending on the pattern formation conditions of
A polyimide relief pattern of m was obtained. All of these patterns adhered firmly to the substrate, and the photomask patterns were faithfully transferred.

Example 8 4,4'-diaminobiphenyl 92f (
0.5 mol) to N-methyl-2-pyrrolidone 1554f
A diamine solution was prepared by dissolving it in Next, this solution was kept at a temperature of about 15°C by water cooling and stirred for 3
, 3', 4,4'-biphenyltetracarboxylic dianhydride 147f (0.5 mol) was added. After the addition was completed, the reaction was further carried out at about 15° C. for 5 hours to obtain a solution of polyamic acid CD) having a temperature of 50 poise (30° C.).

Other than using solution 20f of polyamic acid (1)), photosensitive polymer composition solutions), (e),
I got (to). Using the same pattern forming conditions as in Example 3, the film thickness was 5.5 to 7.
A polyimide relief pattern of μm was obtained. All of these patterns adhered firmly to the substrate, and the photomask patterns were faithfully transferred.

Comparative Example 1 4,4'-diaminodiphenyl ether/l under nitrogen flow
/ 100 f (0,5 mo#) to N-Meru 2-
A diamine solution was prepared by dissolving in Hyrolidon 1184F. Next, 109 f of pyromellitic dianhydride was added to this solution under stirring while keeping the temperature at about 15°C by water cooling.
(0.5 mol) was added. After adding about 1 more
The reaction was carried out at 5°C for 5 hours to obtain a solution of polyamic acid CE) having a viscosity of 70 poise (30°C).

2.25 f (0,014 mol) of 2-L7V, N-dimethylamino)ethyl methacrylate was dissolved in 20 v of a solution of polyamic acid (I) (polyamic acid content st), and then added using a filter with 1 μm pores. I was oppressed.

Next, the obtained solution was processed under exactly the same film formation, exposure, development, and color conditions as shown in Example 1, but no pattern was obtained. Next, when the irradiation time was increased 20 times to 600 seconds and a patterning process was performed, a relief pattern of polyimide was obtained, but the film thickness decreased as the development time increased and finally disappeared. An attempt was made to shorten the development time to obtain a polyimide pattern with the desired thickness (5 μm or more), but the dependence of the film thickness reduction on development was large;
Difficulties occurred in workability.

Comparative Example 2゜To 2Of the solution of polyamic acid (D) obtained in Comparative Example 1, 5. OB? (0,014 mol) was dissolved,
Then, it was filtered under pressure using a filter with 1 μm pores.

The obtained solution was spin-coated onto a substrate having an M surface using a spinner, and dried at 90° C. for 30 minutes to obtain a photosensitive film. This film was closely coated with a quartz photomask with a 20 μm line-and-space striped pattern, and exposed at 500 F x g.
-E was exposed to ultraviolet light for 15 seconds after exposure to N-methyl-2
- Development with a mixture of 4 volumes of pyrrolidone and 1 volume of ethanol followed by rinsing with ethanol to obtain a relief pattern.

Next, heat curing was performed at 180° C. for 30 minutes and at 400° C. for 60 minutes in the order of nitrogen atmosphere to obtain a polyimide relief pattern. When the film thickness was 2.5 μm, the pattern adhered firmly to the substrate and the photomask pattern was faithfully transferred, but when the film thickness was 5.2 μm, the pattern was partially peeled off.

Comparative Example 3 To the solution 202 of polyamic acid (E) obtained in Comparative Example 1, 0.61 F (1.6 mmol) of 2,6-bis(paraazidobenzal)-4-hydroxycyclohexanone, 3
-(N,N-dimethylamino)propyl methacrylate 2.5f (0,0146 mol), GIJ serine 0.
5Of was dissolved and then filtered under pressure using a 1 μm pore filter.

The resulting photosensitive polymer composition solution was processed under exactly the same film formation, m-light, development, and curing conditions as shown in Example 1 to obtain a polyimide relief pattern. When the film thickness was 32 μm, the pattern adhered firmly to the substrate and the photomask pattern was faithfully transferred, but when the film thickness was 5.8 μm, the pattern was partially peeled off.

〔Effect of the invention〕

As detailed above, according to the photosensitive polymer composition of the present invention, a polyimide pattern having a thickness of 5 μm or more can be formed with high sensitivity and good workability. The photosensitive polymer composition of the present invention is applied as a film material for a surface protection film of a semiconductor element, a wiring interlayer insulation film, an insulation film for thin film devices, a heat-resistant photoresist, and the like.

Claims (1)

[Claims] 1. Polyamic acid, bisazide photocrosslinking agent, amine compound having a carbon-carbon double bond, and compound containing one or more hydroxyl group in the molecule and having a boiling point of 150°C or higher at normal pressure. A photosensitive polymer composition characterized in that the structure of the polyamic acid is represented by the general formula (1'3 repeating units). (represents a valent aromatic ring-containing organic group or a silicon-containing organic group) 2) A bisazide photocrosslinking agent is represented by the general formula (n) (wherein, represents an ester group or an amine group, and the N3 group is located at the meta or para position in the pentene nucleus. The photosensitive polymer composition according to claim 1, characterized in that the amount is 10 parts by weight.