JPH11153866A - Photosensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the photosensitive composition capable of developing with an aqueous alkaline developing solution and forming a heat resistant pattern superior in photosensitivity and resolution and enhancing storage stability in a state of solution by incorporating a specified hydroxypolyamide and a compound to be allowed to generate an acid by irradiation with radiation and a compound capable of cross-linking the hydroxypolyamide by action of the acid. SOLUTION: This photosensitive composition contains (A) 100 pts.wt. of the hydroxypolyamide having structural units represented by formulae I and II, (B) 0.5-20 pts.wt. of the compound to be allowed to generate the acid by irradiation with radiation, and (C) 3-40 pts.wt. of the compound capable of cross-linking the hydroxypolyamide of (A). In formulae I and II, R1 is a tetravalent aromatic group; each of R2 and R4 is, independently, a divalent organic group; R3 is a divalent organic group; and each of (a) and (b) is each fraction (%) of structural units; (a) is 10-100, (b) is 0-90, and (a+b) is 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a thin film pattern having high heat resistance used as an insulating material for electronic parts or a passivation film, a buffer coat film, an interlayer insulating film, an .alpha.-ray shielding film, etc. in a semiconductor device. And a photosensitive resin composition.

[0002]

2. Description of the Related Art In recent years, polyimide resins having excellent heat resistance, electrical properties, mechanical properties, and the like have been used for applications such as surface protection films and interlayer insulating films of semiconductor devices. In recent years, in particular, with the increase in the degree of integration and size of semiconductor elements, demands for materials having more excellent mechanical properties, heat resistance, and the like have been increasing.

As a material used for such an application, photosensitive polyimide resin is often used because of its feature that a pattern forming process can be simplified and a complicated manufacturing process can be shortened. Since an organic solvent is required, problems remain in terms of safety and environmental problems. Therefore, recently, a photosensitive material that can be developed with an alkaline aqueous solution has been proposed. The following techniques are known as these examples. (1) A compound having an amino group, an amide group, a urethane group, or the like is mixed with a polyamic acid, and after exposure in the presence of a photoinitiator,
(2) Method of mixing quinonediazide with a salt of a polyamic acid and an amine compound having a phenolic hydroxyl group (see JP-A-6-161102) (3) Polyamic acid (See Japanese Patent Application Laid-Open No. 5-5995) The above-mentioned ones are based on a polyamic acid skeleton, but these have relatively good developability. As shown, it is difficult to obtain a difference in solubility between the exposed part and the unexposed part, and the film loss in the pattern part is large. Also, the light sensitivity is not sufficiently high.

A mixture of a polybenzoxazole precursor and a diazoquinone compound (Japanese Patent Publication No. 1-4686)
No. 2) or a polyamic acid in which a phenol moiety is introduced via an ester bond (Japanese Patent Application Laid-Open No. Hei 4-21805).
No. 1), phenolic hydroxyl groups are introduced instead of carboxylic acids, but these compounds have insufficient developability. For example, in the case of a thick film having a thickness of 5 μm or more, the pattern is poor. There is a problem that it cannot be formed. Also,
For the purpose of improving such developability and adhesion, a mixture of a polyamic acid having a siloxane skeleton in the polymer main chain (JP-A-4-31861, JP-A-4-4633)
No. 45 gazette) has been proposed. However,
These seem at first glance to have improved developability, but poorly soluble components remain in the film, resulting in lower resolution. Also, the sensitivity is not enough.

On the other hand, a chemically amplified photosensitive composition comprising a resin component in which a specific protecting group is introduced into a carboxyl group of a polyimide precursor and a compound which becomes acidic upon irradiation with actinic light (Japanese Patent Laid-Open No. No. 1202017). However, in this case, when a protecting group such as a tetrahydropyranyl group, a 1-ethoxyethyl group, a methoxymethyl group, or a trimethylsilyl group is used as the protecting group, the sensitivity is good, but these protecting groups are easily removed. In addition, problems of storage stability in a solution state, and heat treatment after exposure (hereinafter referred to as PEB).
Is practically inadequate, for example, the pattern shape (resolution) and the sensitivity are greatly affected by the standing time until reaching or the PEB temperature.

Further, methyl and ethyl groups as protecting groups,
When using a propyl group, a butyl group, a benzyl group, etc.,
Although storage stability in a solution is improved, even if heating is used in combination with acid generation by irradiation with actinic rays, the elimination reaction of the protective group hardly occurs, and it cannot be said that the material is of a practical level.

[0007]

SUMMARY OF THE INVENTION The present invention provides a heat-sensitive pattern which can be developed with an aqueous alkali solution, provides a heat-resistant pattern excellent in photosensitivity and resolution, and has excellent storage stability in a solution state. It is to provide a composition.

[0008]

The photosensitive composition of the present invention comprises (A) 100 parts by weight of a hydroxypolyamide having structural units represented by the following general formulas (1) and (2):

[0009]

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[0010]

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(Wherein R1 is a tetravalent aromatic group, R2, R4
Are independently selected divalent aromatic groups, which may be the same or different. R3 is a divalent organic group.
a and b show the percentage of each structural unit, and a: 10 to 10
0, b: 0 to 90, a + b = 100. ), (B)
It is characterized by containing 0.5 to 20 parts by weight of a compound capable of generating an acid upon irradiation, and 3 to 40 parts by weight of (C) a compound capable of crosslinking the hydroxypolyamide (A) by the action of an acid. It is a photosensitive composition.

These photosensitive compositions of the present invention can be coated on a substrate, exposed to light through a mask having a predetermined pattern, subjected to PEB, patterned by developing, and further heated. Thereby, a thin film pattern having high heat resistance can be obtained. Hereinafter, the photosensitive composition of the present invention will be described in detail.

The photosensitive composition of the present invention comprises a resin component (hereinafter, referred to as A component) and a photosensitive agent component (hereinafter, referred to as B component,
C component). First, the component A containing the structural unit (1) will be described. <A component> The resin component in the photosensitive composition of the present invention includes:
A hydroxypolyamide having the structural units (1) and (2). In the formula, R1 is a tetravalent aromatic group, which is a dihydroxydiamino compound residue. Examples of these are

[0014]

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(Wherein X is a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a halogenated hydrocarbon group, or hydrogen). R2 and R4 are divalent aromatic groups, which may be the same or different, and examples of these are

[0016]

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(Wherein, X is the same as described above). R3 is a divalent organic group;

[0018]

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(Wherein Y is a single bond, -O-, -SO2
-, -C (CX) 2-, wherein X is the same as described above). Among these, an aromatic group is preferable from the viewpoint of heat resistance, but an aliphatic group having a siloxane bond can also be used to enhance adhesiveness. in this case,
The use of 10 mol% or less is preferable from the viewpoint of heat resistance deterioration,
More preferably, it is at most 5 mol%. Further, the present polymer has a structure represented by Chemical Formulas 1 and 2,
The copolymerization ratio is a: 20 to 100, b: 0 to 80, a
+ B = 100 (a and b indicate the percentage of each structural unit), and a preferable value of b is 0 to 50. It is possible to control the alkali solubility of the polymer by the value of b, but when this value is more than 80, the phenolic hydroxyl group concentration in the polymer becomes insufficient, and the alkali solubility of the polymer is extremely reduced. Absent.

This hydroxypolyamide is a polybenzoxazole precursor and is typically synthesized by the following method. That is, condensation of an aromatic dicarboxylic acid dichloride or an active ester of a dicarboxylic acid with an aromatic dihydroxy diamino compound, or in the presence of a suitable condensing agent or a carboxylic acid activator, between an aromatic dicarboxylic acid and an aromatic dihydroxy diamino compound. Obtained by condensation.

As a specific synthesis method, for example, when dicarboxylic acid dichloride is used, a dihydroxydiamino compound and pyridine or triethylamine as an acid scavenger are dissolved in a suitable solvent in advance, and the dicarboxylic acid dichloride dissolved in the solvent is dissolved in the solvent. Can be added. As the solvent used in the present synthesis, N-methyl-
Examples thereof include 2-pyrrolidone, dimethylacetamide, dimethylformamide, γ-butyrolactone, and dimethyldiglycol. <Component B> Next, (B) of the heat-resistant photosensitive composition of the present invention.
The components will be described. The component (B) used in the present invention is a compound that generates an acid upon irradiation, and examples of such a compound include the following compounds. i) Trichloromethyl-s-triazines: tris (2,4,6-trichloromethyl) -s-triazine,
2-phenyl-bis (4,6-trichloromethyl) -s
-Triazine, 2- (3-chlorophenyl) -bis (4,6-trichloromethyl) -s-triazine, 2-
(2-chlorophenyl) -bis (4,6-trichloromethyl) -s-triazine, 2- (4-methoxyphenyl) -bis (4,6-trichloromethyl) -s-triazine, 2- (3-methoxyphenyl) ) -Bis (4,6-
Trichloromethyl) -s-triazine, 2- (2-methoxyphenyl) -bis (4,6-trichloromethyl) -s-triazine, 2- (4-methylthiophenyl) -bis (4,6-trichloromethyl)- s-triazine, 2
-(3-methylthiophenyl) bis (4,6-trichloromethyl-s-triazine, 2- (2-methylthiophenyl) -bis (4,6-trichloromethyl) -s-triazine, 2- (4-methoxynaphthyl) )-Screw (4, 6
-Trichloromethyl) -s-triazine, 2- (3-methoxynaphthyl) -bis (4,6-trichloromethyl)
-S-triazine, 2- (2-methoxynaphthyl) -bis (4,6-trichloromethyl) -s-triazine,
-(3,4,5-trimethoxy-β-styryl) -bis (4,6-trichloromethyl) -s-triazine, 2-
(4-methylthio-β-styryl) -bis (4,6-trichloromethyl) -s-triazine, 2- (3-methylthio-β-styryl) -bis (4,6-trichloromethyl) -s-triazine, -(2-methylthio-β-styryl) -bis (4,6-trichloromethyl) -s-triazine and the like. ii) Diallyliodoniums: diphenyliodonium tetrafluoroborate, diphenyliodonium tetrafluorophosphate, diphenyliodonium tetrafluoroarsenate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium trifluoroacetate, diphenyliodonium-p-toluenesulfonate, 4-methoxy Phenylphenyliodonium tetrafluoroborate, 4-methoxyphenylphenyliodonium hexafluorophosphonate, 4-methoxyphenylphenyliodonium hexafluoroarsenate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, 4-
Methoxyphenylphenyliodonium trifluoroacetate, 4-methoxyphenylphenyliodonium-p-toluenesulfonate, bis (4-ter-butylphenyl) iodonium tetrafluoroborate, bis (4-ter-butylphenyl) iodonium hexafluoroarsenate, Bis (4-ter-butylphenyl)
Iodonium trifluoromethanesulfonate, bis (4-ter-butylphenyl) iodonium trifluoroacetate, bis (4-ter-butylphenyl) iodonium-p-toluenesulfonate and the like. iii) Triallylsulfonium salts: triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphonate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium methanesulfonate, triphenylsulfonium trifluoroacetate, triphenylsulfonium-p-toluene Sulfonate, 4-methoxyphenyldiphenylsulfonium tetrafluoroborate, 4
-Methoxyphenyldiphenylsulfonium hexafluorophosphonate, 4-methoxyphenyldiphenylsulfonium hexafluoroarsenate, 4-methoxyphenyldiphenylsulfonium methanesulfonate,
4-methoxyphenyldiphenylsulfonium trifluoroacetate, 4-methoxyphenyldiphenylsulfonium-p-toluenesulfonate, 4-phenylthiophenyldiphenyltetrafluoroborate, 4-phenylthiophenyldiphenylhexafluorophosphonate, 4-phenylthiophenyldiphenylhexa Fluoroarsenate, 4-phenylthiophenyldiphenyltrifluoromethanesulfonate, 4-phenylthiophenyldiphenyltrifluoroacetate, 4-phenylthiophenyldiphenyl-p-toluenesulfonate and the like.

Among these compounds, trichloromethyl-S-triazines include 2- (3-chlorophenyl) -bis (4,6-trichloromethyl) -S-triazine and 2- (4-chlorophenyl) -bis. (4,6-trichloromethyl) -S-triazine, 2- (4-methylthiophenyl) -bis (4,6-trichloromethyl)-
S-triazine, 2- (4-methoxy-β-styryl)
-Bis (4,6-trichloromethyl) -S-triazine, 2- (4-methoxynaphthyl) -bis (4,6-trichloromethyl) -S-triazine and the like, as diaryliodonium salts, diphenyliodonium trifluoro Acetate, diphenyliodonium trifluoromethanesulfonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate,
Methoxyphenylphenyl iodonium trifluoroacetate and the like, and triarylsulfonium salts such as triphenylsulfonium methanesulfonate, triphenylsulfonium trifluoroacetate,
Suitable examples include methoxyphenyldiphenylsulfonium methanesulfonate, 4-methoxyphenyldiphenylsulfonium trifluoroacetate, 4-phenylthiophenyldiphenyltrifluoromethanesulfonate, and 4-phenylthiophenyldiphenyltrifluoroacetate. In addition, the following compounds can also be used. (1) Imidosulfonate derivative

[0023]

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Nitrobenzyl derivative

[0025]

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(Wherein R5 is an alkyl group having 1 to 4 carbon atoms) The amount of the compound capable of generating an acid upon irradiation with radiation is preferably 0.5 to 100 parts by weight of the polymer.
-20 parts by weight. If the amount is less than 0.5 parts by weight, the amount of acid generated upon irradiation is small, and the sensitivity is reduced. On the other hand, if the amount exceeds 20 parts by weight, the mechanical properties after curing may be lowered.

Compounds that generate an acid upon irradiation can be used in combination with a sensitizer. Such sensitizers include, for example, 3-position and / or
Or a coumarin having a substituent at the 7-position, a flavone,
Dibenzalacetones, dibenzal cyclohexanes,
Examples include chalcone, xanthone, thioxanthone, porphyrin, phthalocyanine, acridine, and anthracene having a substituent at the 9-position. <Component C> Next, the component (C) of the composition of the present invention will be described. The component (C) used in the present invention is selected from melamine resins and urea resins in which the N-position is substituted with a methylol group and / or an alkoxymethyl group. Examples of these include melamine resins, benzoguanamine resins, glycoluril resins, urea resins, alkoxymethylated melamine resins, alkoxymethylated benzoguanamine resins, alkoxymethylated glycoluril resins, and alkoxymethylated urea resins. Among these, alkoxymethylated melamine resin, alkoxymethylated benzoguanamine resin, alkoxymethylated glycoluril resin, and alkoxymethylated urea resin are known methylolated melamine resins, methylolated benzoguanamine resins, and methylolated urea resin. It is obtained by converting to an alkoxymethyl group.

Examples of the type of the alkoxymethyl group include a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, a butoxymethyl group, and the like.
01, 303, 370, 325, 327, 701, 26
6,267,238,1141,272,202,11
56, 1158, 1123, 1170, 1174, UF
R65,300 [manufactured by Mitsui Cytec Co., Ltd.], Nikarac MX-750, -032, -706, -708, -4
0, -31, Nikarac MS-11, Nikarac MW-
30 (manufactured by Sanwa Chemical Co., Ltd.) and the like can be preferably used. These compounds can be used alone or as a mixture.

In addition, as the crosslinking agent, a monomer of the resin described above may also be used, and examples thereof include hexamethoxymethylmelamine and dimethoxymethylurea. The amount of the compound capable of crosslinking by the action of these acids is preferably 3 to 40 parts by weight based on 100 parts by weight of the polymer. If the amount is less than 3 parts by weight, crosslinking may be insufficient and patterning may be difficult. Also,
If the amount exceeds 40 parts by weight, the alkali solubility of the entire composition becomes too high, so that the residual film ratio after development or the mechanical properties after curing tends to decrease.

The composition of the present invention is used in the form of a varnish by dissolving the polymer of the component (A) in a solvent. As the solvent, N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, N, N-dimethylacetamide (DMA
c), cyclopentanone, cyclohexanone, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether and the like may be used alone or in combination. For the purpose of improving the coating properties, 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, , 3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate, methyl-3-methoxypropionate, and other solvents can be used in combination. At this time, a silane coupling agent or the like may be added to enhance the adhesiveness to the substrate.

Next, an example of a method for forming an image using the heat-resistant photosensitive composition thus obtained will be described. First, the composition varnish is dried on a substrate to a film thickness of 1 to 5
The coating is performed so as to have a thickness of 0 μm, preferably 5 to 30 μm. At this time, it is also possible to previously treat the substrate with an adhesion aid such as a silane coupling agent. After drying the applied coating film, exposure is performed through a normal photomask, and then heat treatment (PEB) is performed. This PEB
The step is a process for sensitizing the sensitivity of the composition,
It is indispensable to achieve the object of the present invention. The processing temperature is preferably from 90 to 160 ° C, and more preferably from 100 to 150 ° C, in consideration of the sensitivity, the obtained pattern shape, and the like. The substrate that has been subjected to the heat treatment after irradiation with radiation can be transferred with a fine resin pattern onto the substrate by being developed with an alkali aqueous solution having an appropriate concentration. The developer used at this time is preferably one capable of completely dissolving and removing the exposed film within an appropriate time, and is preferably an inorganic alkaline aqueous solution such as sodium hydroxide or potassium hydroxide, or propylamine, butylamine, monoethanolamine, tetraethanol or the like. Methyl ammonium hydroxide (TM
AH), an organic alkaline aqueous solution such as choline or the like is used alone or in combination of two or more.

Further, the alkaline aqueous solution may contain an organic solvent such as alcohols and various surfactants as necessary. After development, a negative image of the heat-resistant material precursor is obtained by washing with a rinse solution. The image thus obtained can be converted to a heat-resistant material having excellent heat resistance, chemical resistance, and mechanical properties by high-temperature heat treatment (about 200 to 400 ° C.). It becomes a cured product having a pattern.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described based on examples. Synthesis of polymer (A component)

[0034]

Reference Example 1 A 1 L separable flask was charged with isophthalic acid (0.27 mol, 44.9 g) and N, N-dimethylaminopyridine (0.03 mol, 3.7 g) in DMAc (6 g).
00g) solution at room temperature with thionyl chloride (0.63 mol, 7
5.0 g) was added dropwise and stirred for 1 hour. 1 L of this solution
2,2-bis (3-amino-4) in a separable flask
-Hydroxyphenyl) -hexafluoropropane (0.30 mol, 109.9 g) in DMAc (300
g) is added at 0 ° C to the solution, and stirred at room temperature for 6 hours. This was diluted with DMAc (1000 g), then added dropwise to water with stirring, and the precipitated polymer was filtered.
Vacuum drying was performed at 0 ° C. to obtain a polymer (P-1). Reduced viscosity ηsp of this polymer (concentration = polymer: 1 g / NM
P: 100 mL, 30 ° C.) was 0.40 [dL / g].

[0035]

Reference Examples 2 to 6 Polymers were synthesized in the same manner as in Reference Example 1 except that the aromatic dicarboxylic acid and diamine were changed as shown in Table 1.

[0036]

[Table 1]

The compounds of component B and component C used in this example are shown in Tables 2 and 3, respectively.

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

Example 1 100 parts by weight of polymer (P-1), 2 parts by weight of component (B-1), and 15 parts by weight of component (C-1) were NM
After dissolving in 250 parts by weight of P, the mixture was filtered through a 0.2 μm Teflon filter to obtain a photosensitive varnish. The varnish was spin-coated on a silicon wafer previously treated with a silane coupling agent to obtain a coating having a thickness of 9 μm after drying. The coating film was irradiated with an i-line stepper (manufactured by Nikon Corporation) while changing the exposure amount using a reticle on which a test pattern was drawn. After exposure, the silicon wafer is
Heat on hot plate at 0 ° C for 1 minute, then 2.38%
The unexposed portions were dissolved and removed by immersion in a TMAH aqueous solution for 2 minutes, followed by rinsing with water. As a result, the exposure amount 1
A good pattern with a resolution of 4 μm could be obtained by irradiation at 50 mJ / cm 2.

[0041]

Examples 2 to 6 Using the compositions of the components shown in Table 4, the same operations as in the Examples were carried out to obtain the results shown in Table 4.

[0042]

[Table 4]

[0043]

Comparative Example 1 The patterning evaluation was performed in the same manner as in Example 1 except that the amount of the component (C-1) was 2 parts by weight. As a result, even if an exposure dose of 800 mJ / cm 2 was required, the resolution up to 10 μm was the limit. This indicates that sufficient sensitivity and resolution cannot be obtained when the addition amount of (C-1) is 2 parts by weight.

[0044]

Comparative Example 2 In the polymer of Reference Example 2, aromatic diamine was 2,2-bis (3-amino-4-hydroxyphenyl) -hexafluoropropane [0.03 mol, 11.0 g] and 4,4'-diaminodiphenyl ether [0.27 mol, 54.
1 g] to synthesize a polymer (P-7). The reduced viscosity ηsp of the obtained polymer is
It was 0.5 [dL / g]. Using this polymer, a photosensitive composition was prepared and patterned and evaluated in the same manner as in Example 2. However, even when a high-concentration 10% TMAH aqueous alkaline solution was used, unexposed portions were not dissolved, and development was not possible. Was.

[0045]

COMPARATIVE EXAMPLE 3 In Example 1, development and rinsing were performed without performing a heat treatment operation after exposure.
A pattern of 10 μm could not be resolved even at J / cm 2. This indicates that heating after exposure is essential for the patterning process using this material.

[0046]

[Application Example 1] The patterns obtained in Examples 1 to 6 were each heated and cured at 400 ° C. for 2 hours in a nitrogen atmosphere, and the patterns were observed. Had.

[0047]

Application Example 2 The cured pattern was partially peeled off, and the heat resistance was evaluated by thermogravimetric analysis (TG). as a result,
The starting temperature for 5% weight loss under a nitrogen atmosphere was 500 ° C. or higher, indicating high heat resistance.

[0048]

According to the present invention, a photosensitive composition which can be developed with an alkaline aqueous solution and has excellent photosensitivity and resolution is provided. A good cured film pattern with excellent properties is obtained.

Claims (1)

[Claims] (A) a hydroxypolyamide comprising structural units represented by the following general formulas (1) and (2):
0 parts by weight Embedded image (In the formula, R1 is a tetravalent aromatic group, R2 and R4 are independently selected divalent aromatic groups, and may be the same or different. R3 is a divalent organic group. A , B indicate the percentage of each structural unit, a: 20 to 100, b: 0 to 8
0, a + b = 100. ), (B) 0.5 to 20 parts by weight of a compound capable of generating an acid upon irradiation, and (C) 3 to 40 parts by weight of a compound capable of crosslinking the hydroxypolyamide (A) by the action of an acid. A photosensitive composition comprising: