JPS627762A - Photosensitive polymer composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having high wettability to the foreign materials such as floating dust, excellent coatability and suitable for the insulation film of electronic part such as semiconductor element, by compounding a specific polyamic acid, a photosensitive compound and a fluorine-containing compound at specific ratios. CONSTITUTION:The objective composition can be produced by compounding (A) 100pts.wt. of polyamic acid which is a precursor of a polyimide having the recurring unit of formula (R<1> is 3- or 4-valent organic group; R<2> is bivalent organic group; n is 1 or 2) with (B) 5-500pts. of a photo-sensitive compound having amino group and aromatic azide group or aromatic sulfonylazide group, or amino group and double bond in the same molecule) and (C) 1-500pts. of a fluorine-containing compound of formula II (R<3>-R<5> are H or F; R<6> is H, OH, etc.; R<2> is H, lower alkyl, etc.; m is 1-15) or formula III (R<8> is lower alkyl, etc.; R<9> is H or F; l is 0-10) acting as a coatability improver.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention is a precursor of a polyimide-based heat-resistant polymer material suitable as a photoresist. The present invention relates to certain photopolymer compositions.

[Background of the invention]

Conventional photosensitive polymer compositions that are precursors of polyimide-based heat-resistant polymer materials include polyamic acid, which is a precursor of polyimide, and amino groups and aromatic azide groups or aromatic sulfonyl azide groups in the same molecule. A photosensitive polymer composition comprising a photosensitive compound having a group (JP-A-57-102
926), a polyamic acid and actinic radiation (
A photosensitive polymer composition comprising a compound containing a carbon-carbon double bond and an amino group or a quaternized salt thereof that can be dimerized or polymerized by irradiation with radiation (Japanese Unexamined Patent Publication No. 54-145
No. 794) and the like are known.

However, these photosensitive polymer compositions can reduce the number of steps in the polyimide film pattern formation process, compared to a method of forming a polyimide film pattern using a polyimide precursor that does not have photosensitivity. Although it has merits, in practical use, it has the disadvantage that it has poor coverage due to poor wettability against foreign substances such as floating dust generated from the human body and clothes. That is, if foreign matter such as floating dust adheres between applying a solution of these photosensitive polymer compositions to a substrate and forming a photosensitive film,
A problem has arisen in which a portion of the photosensitive polymer composition that is not coated with the photosensitive polymer composition is generated with the foreign matter as a nucleus and is several times to several times the size of the foreign matter.

[Purpose of occurrence]

An object of the present invention is to solve the problems of the prior art described above and to provide a photosensitive polymer composition that has good wettability to foreign substances such as floating dust and excellent coating properties.

[Summary of the invention]

In order to clarify the causal relationship between the component composition of a photosensitive polymer composition and its ability to cover foreign substances, the present inventors tested a solution containing only polyamic acid and a photosensitive compound having an amine group in polyamic acid. When examining the coating properties of the mixed solution containing the photosensitive compound, it was found that the coating properties of the mixed solution containing the photosensitive compound were significantly lower. The reason for this decrease in coverage is that the carboxyl group of the polyamic acid forms an ionic bond with the amino group of the added photosensitive compound, resulting in increased polarity. On the other hand, floating dust is often generated from the human body or clothing, and therefore it is thought that most of it has non-polar interfaces such as lipids and chemical fibers. For this reason, it was thought that repulsion between the polar and non-polar substances deteriorates the wettability between the two, resulting in a decrease in coverage.

Therefore, the present inventors believed that it was necessary to improve the affinity with non-polar substances in order to improve the coating properties, and after conducting extensive research on coating properties improving agents that would make this possible, The compound may have a nonpolar group at one end of the molecule, and a polar group at the other end of the molecule so that it can be dissolved in the apronto polar solvent used in the photosensitive polymer composition. I learned. In addition, in order to maintain the heat resistance of the polyimide film that is finally formed using this photosensitive polymer composition and to avoid adversely affecting the semiconductor properties, in the curing process after patterning the polyimide film, The present invention was completed based on the finding that it is sufficient to impart volatility to the polyimide film so that the added coating properties improver can be removed from the polyimide film.

The present invention provides: (a) a repeating compound represented by the general formula [■] (wherein R1 represents a trivalent or tetravalent organic group, R2 represents a divalent organic group, and R is 1 or 2); 1[)0 parts by weight of polyamic acid, which is a precursor of polyimide having units, and (b) an amino group and an aromatic azide group or an aromatic sulfonyl azide group in the same molecule,
Or a photosensitive compound 5 having an amino group and a double bond
~500 parts by weight, (C) General formula [■] [In the formula, R3, R4, R5 are H or F, R' is H or
6 represents a lower alkyl group or a lower perfluoroalkyl group. ), R7 represents H or a lower alkyl group or an acyl group, and the door is an integer from 1 to 15. ] Or, general formula (III) (wherein R3, R'+ R5 is H or F, R' is a lower alkyl group or lower perfluoroalkyl group, R9 is H or Fl is an integer from 0 to 10 .) Fluorine-containing compounds 1 to 50 which are coating property improvers
0 parts by weight, and has extremely excellent wettability, that is, coating ability, against foreign substances such as floating dust. be.

R', R in the polyamic acid represented by the above general formula (I) which is a component constituting the photosensitive polymer composition of the present invention
t is preferably an aromatic ring-containing organic group or a heterocyclic-containing organic group from the viewpoint of heat resistance when formed into a polyimide film. Examples of these are shown in U.S. Pat. No. 3,179,614, U.S. Pat. However, other substituents may be used as long as they provide heat resistance to the polyimide film, and the substituents are not limited to the above-mentioned organic groups.

Specific examples of R1 include substituents represented by the following general formula.

Base, ÷O÷, ÷So, ÷, Da.

CH.

One @-cO ten.

(In the formula, the bond represents a bond with the carbonyl group of the polymer main chain, and the carboxyl group is located at the ortho position to the bond.) In addition, R1 is a substituent represented by the above general formula; It is also possible to mix two or more types.

Specifically, R2 is a resistor represented by the following general formula.

-0-0+0÷.

CH, CH.

CH5CH.

Further, it may have a substituent such as an amino group, an amide group, a carboxyl group, or a sulfonic acid group as long as it does not adversely affect the heat resistance of the polyimide film. moreover,
R2 may be a substituent represented by the above general formula alone, or may be a mixture of two or more.

Preferred specific examples of photosensitive compounds having an amino group and an aromatic azide group or an aromatic sulfonyl azide group in the same molecule, which are components constituting the photosensitive polymer composition of the present invention, include CN, CN, etc. However, the present invention is not particularly limited to these compounds.

As a preferred specific example of the photosensitive compound having an amine group and a double bond in the same molecule, which is a component constituting the photosensitive polymer composition of the present invention, 2-(N,N-dimethylamino)ethyl Acrylate, 2-(N,N-dimethylamino)ethyl methacrylate, 3-(N,N-dimethylamino)propyl acrylate, Ro-(N,N-dimethylamino)propyl methacrylate, 4-(N,N-"/ methylamino)butyl acrylate, 4-(N,N-dimethylamino)butyl methacrylate), 5-(N,N-dimethylamino)pentyl acrylate, 5-(N,N-
dimethylamino)pentyl methacrylate, 67N,N
-dimethylamino)hexylaclay, 6-(N,N-
dimethylamino)hexitacret, 2-(N,N-
dimethylamino)ethylcinnamate, 3-(N,N-dimethylamino)propylcinnamate, sorbitanic acid 3
-(N,N-dimethylamino)propyl, 2-(N,N-dimethylamino)ethyl sorbitanate, 4-(N,N-dimethylamino)-butyl sorbitanate, etc., and the present invention It is not particularly limited to compounds.

The blending ratio of the photosensitive compound added to the photosensitive polymer composition of the present invention is preferably in the range of 5 to 500 parts by weight based on 100 parts by weight of the polyamic acid represented by the general formula [I]. If it deviates from this range, it is not preferable because it will adversely affect the developability and the heat resistance of the polyimide film in the final stage.

In the photosensitive polymer composition of the present invention, examples of the fluorine-containing compound represented by the general formula [I[] or [■] added for the purpose of improving the coverage against foreign substances include CFS CT (20H, CFs (CFJ tCH20
H, CHF2 (CF2)z OI! Oh.

I CHF2 (CF2) t Cl0el (In the formula, t is from 1 to 15 f) M number') , (CF3)2CHO
H, (CF3(CFrij)2CHOH.

(j is an integer from 1 to 10) and the like can be mentioned as suitable examples of compounds.

In the photosensitive polymer composition of the present invention, the blending ratio of the fluorine-containing compound represented by the above general formula [■] or [■], which is added for the purpose of improving the coverage against foreign substances, is expressed by the above general formula [■]. It is preferably used in an amount of 1 to 100 parts by weight based on 100 parts by weight of the polyamic acid having the repeating unit shown. If the above-mentioned blending ratio is less than 1 part by weight, no coating effect on foreign matter can be obtained, and if it exceeds 100 parts by weight, it is not preferable because it will adversely affect the viscosity stability and photosensitivity of the composition.

Furthermore, a sensitizer may be appropriately added to the photosensitive polymer composition of the present invention, if necessary, for the purpose of improving photosensitivity. When a compound having an amine group and a double bond in the same molecule is used as the photosensitive compound to be added in the present invention, it is particularly desirable to use a sensitizer in combination. Preferred specific examples of the sensitizer include anthrone, 1,9-benzaanthrone, acridine, cyanoacridine, nitropyrene, and 1,8-dinitropyrene.

Mihiraketone, 5-nitroacenaphthene, 2-nitrofluorene, pyrene-1,6-quinone.

Preferred are 9-fluorenone, 1,2-benzanthraquinone, anthantrone, 2-,chloro-1,2-benzanthraquinone, 2-bromobenzanthraquinone, 2-chloro-1,8-phthaloylnaphthalene, and the like. The blending ratio of these sensitizers is in the range of 0.1 to 10 parts by weight based on 100 parts by weight of the mixture of the polyamic acid represented by the general formula CI) and the photosensitive compound added thereto. is preferable, and if it deviates from this range, it is not preferable because it will adversely affect the developability of the sensitive polymer composition and the heat resistance of the polyimide film in the final stage.

The photosensitive polymer composition according to the present invention is used in a liquid state by dissolving the composition having the above-mentioned blending ratio in a suitable organic solvent. Protic polar solvents are preferred, e.g.
Methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide,
Examples include dimethyl sulfoxide, hexamethylphosphortriamide, N-acetyl-8-caprolactam, and dimethylimidazolidinone. These may be used alone or in combination.

In order to improve the adhesion between the polyamic acid coating formed using the photosensitive polymer composition of the present invention or the polyimide coating after heat curing and the supporting substrate, the supporting substrate may be appropriately treated with an adhesion aid. I can't help it. As a specific example of the adhesion aid, the present inventors disclosed a previous application (Japanese Patent Application Laid-open No. 57-10
It is desirable to use the adhesion aid disclosed in Japanese Patent No. 2926).

Support substrates include metals, metals, glass, semiconductors, etc.
Metal oxide insulators (e.g. 'rzo, , T(Z20
5, SiO2,', etc.), silicon nitride, etc.

The photosensitive polymer composition according to the present invention can be patterned using conventional microfabrication techniques. The photosensitive polymer composition of the present invention can be applied onto the substrate, which is the support, by means such as spin coating using a spinner, dipping, and spray printing, and the coating method may be selected as appropriate. I can do it. Further, the coating film thickness can be adjusted by the coating means, the solid content concentration of the phenol in the photosensitive polymer composition of the present invention, the viscosity, etc.

Using the photosensitive polymer composition of the present invention, a relief pattern is created by applying ultraviolet rays to polyamic acid, which is coated on a supporting substrate and formed into a film through a drying process, and then the unexposed areas are dissolved and removed using a developer. You can also get 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, hexamethylphosphortriamide, dimethylimidazolidinone, N -Aprontic polar solvents such as benzyl-2-pyrrolidone and N-acetyl-ε-caprolactam alone or in combination with non-solvents for polyamic acids such as methanol, ethanol, inglobil alcohol, benzene, toluene, xylene, methylcellotul 7, water, etc. It can be used as a mixture of

The polyamic acid relief pattern formed by development is then washed with a rinse solution to remove the developing solvent. As the rinsing liquid, a polyamic acid non-solvent with good miscibility with the developer is used, but methanol, ethanol,
Impropyl alkone, benzene, toluene, xylene.

Suitable examples include methyl cellosolve and water.

The polyamic acid in the relief pattern obtained by the above treatment is a precursor of polyimide, and is from 150C to 45C.
By processing at a heating temperature selected in the range up to 0C, a relief pattern of heat-resistant polyimide having imide rings and other cyclic groups is obtained.

[Embodiments of the invention]

An example of the present invention will be described below in more detail.

First, the coverage of the photosensitive polymer composition solution with respect to foreign matter such as floating dust was evaluated as follows.

As model substances for foreign substances, hair was chosen as a substance generated from the human body, and 6,6-nylon was selected as a substance generated from clothing.
, 10 pieces each were formed into small pieces with a length α2 mm, and were dropped onto a coating film of a solution of a photosensitive polymer composition applied on a silicon wafer by a spin coating method, and after being left for 60 minutes, hot air circulation was carried out at 85C for 20 minutes. It was dried in a bath to form a dry film.

In the above dried film, the film thickness of the insufficiently covered part around the foreign object is 175 or less than the film thickness of the part without the foreign object, and the area thereof is at least 3 times the diameter of the foreign object, and each When all 10 of the above foreign substances were present, it was judged as poor, when there was one or more less than 10, it was judged as somewhat poor, and when there were 0, it was judged as good.

Next, a photosensitivity confirmation test was conducted as follows.

A solution of the photosensitive polymer composition was spin-coated onto a silicon wafer using a spinner, and then dried at 85C for 20 minutes.
A photosensitive film with a thickness of 5 μm was formed.

This film is closely covered with a striped quartz photomask,
UV irradiation for 5 minutes with a 500W X5-Hp lamp, then N
- Developed with a mixed solution consisting of 4 volumes of methyl-pyrrolidone and 1 volume of ethanol, and rinsed with ethanol. A positive relief pattern could be obtained in any of the Examples shown below. The obtained relief pattern was heated to 400C.
After heating for 60 minutes, a polyimide film pattern with high heat resistance was obtained.

(Example 1) Repeating unit, 15% by weight of N-methyl-2- of polyamic acid represented by
Add 3.28 f (0,014
mol) of 2-(N,N-dimethylamino)ethyl paraazidobenzoate was dissolved to obtain a solution having a viscosity of 40 poise (25C).

For solution A2 (l), as shown in Table 1 (, general formula (I
A fluorine compound as a coating property improver represented by [] or [■] was blended and filtered under pressure using a filter with 1 μm pores, and the coating properties of the obtained solution were evaluated by the above-described evaluation method. The results are shown in Table 1. As is clear from the table, coating properties were good in all cases containing the fluorine-containing compound of the present invention. In addition, in the sense of comparison with the examples of the present invention, the coating property was poor in the case of only solution A to which no fluorine-containing compound was added.

(Example 2) Repeating unit, 15% by weight of N-methyl-2- of polyamic acid represented by
Balaazidocinnamic acid 2-(N
, N-dimethylamino)ethyl 3.129 (0,01
Solution B with a viscosity of 35 poise (25C)
I got it.

For solution B20f, as shown in Table 2, general formula CI
A fluorine-containing compound represented by [] or [m] as a coatability improving agent was blended, and the coatability was determined and evaluated in the same manner as in Example 1. As shown in Table 2, the products containing the fluorine-containing compound of the present invention show good coverage in all cases, but the comparative examples that do not contain the fluorine-containing compound show poor coverage. there were.

Blank space below (Example 3) 2.3+5 t (o, o 1 s mol) of 2-(N,N-dimethylamine)ethyl methacrylate was added to an N-methyl-2-pyrrolidone solution 209 of a polyamic acid represented by a repeating unit. 0.3t of Mihiraketone was dissolved and the viscosity was 35 poise (2
Solution C of 5C) was obtained. A coatability improver represented by formula (II) or [■] as shown in Table 3 was added to this, and the coatability was determined and evaluated in the same manner as in Example 1 above. The results are shown in Table 3. As is clear from the table, the composition containing the fluorine-containing compound of the present invention is
Although good coverage was exhibited in all cases, the coverage was poor in the comparative example in which no coverage improver was added.

〔Effect of the invention〕

As explained in detail above, the photosensitive polymer composition according to the present invention has extremely good coverage against foreign substances such as floating dust, and when using it to fabricate semiconductor elements, thin film devices, etc. When used as a photoresist, the product yield and workability are significantly improved, and the product has great industrial value.

Claims (1)

[Claims] (a) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] (In the formula, R^1 is a trivalent or tetravalent organic group, R^2 is 2
represents a valent organic group, and n is 1 or 2. ) 100 parts by weight of polyamic acid, which is a precursor of polyimide having the repeating unit shown in (b) an amino group and an aromatic azide group or an aromatic sulfonyl azide group, or an amino group and a double bond in the same molecule. Photosensitive compound having 5~
500 parts by weight, (c) General formula [II] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] [In the formula, R^3, R^4, R^5 are H or F, R^6
is H or OH, lower alkyl group or ▲ mathematical formula, chemical formula, table, etc. ▼ group (however, R^8 represents a lower alkyl group or lower perfluoroalkyl group), R^
7 represents H or a lower alkyl group or an acyl group, m
is an integer from 1 to 15. ] Or, General formula [III] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [III] (In the formula, R^3, R^4, R^5 are H or F, R^8
is a lower alkyl group or a lower perfluoroalkyl group,
R^9 is H or F, and l is an integer from 0 to 10. ) Fluorine-containing compounds 1 to 50 which are coating properties improvers
1. A photosensitive polymer composition comprising, as a main component, a composition comprising: 0 parts by weight.