JPH0452647A - Chemical ray sensitive polymer composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an actinic radiation-sensitive polymer composition, more specifically, to obtaining a high film retention rate during exposure using a G-ray stepper. The present invention relates to a photosensitive polyimide composition which is capable of providing high resolution.

[Prior Art] Photosensitive polyimide compositions include compositions in which a compound containing a carbon-carbon double bond and an amino group or a quaternized salt thereof that can be dimerized or polymerized by actinic radiation is added to polyamic acid (for example, (Japanese Patent Publication No. 59-52822) or a polyimide precursor composition in which photosensitivity is introduced into polyamic acid with an ester group (for example, U.S. Pat. No. 395,751)
No. 2, Specification No. 4040831, etc.) are known.

However, when such conventional compositions are exposed by a stepper using the G-line of a mercury lamp currently used in the manufacture of semiconductor devices, the residual film rate decreases significantly due to the effects of long wavelength exposure and oxygen desensitization, resulting in a desired film thickness. It is difficult to obtain the desired properties, and the film has the disadvantage of causing roughness during development.

Moreover, as a highly sensitive photosensitive polyimide composition, one containing N-phenylglycine was sensitive to scattered light of exposure light, and the resolution could not be improved. For this reason, when polyimide is used as an interlayer insulating film of multilayer wiring, there is a drawback that desired fine peer holes cannot be opened.

[Problems to be Solved by the Invention] The present invention was devised in view of the various drawbacks of the prior art, and its purpose is to solve the above-mentioned drawbacks, that is, to reduce film loss and film roughness during G-line stepper exposure, and to An object of the present invention is to provide an actinic radiation-sensitive polymer composition with good resolution.

[Means for Solving the Problems] The object of the present invention is as follows: (1) (a) General formula % formula % (wherein R1 is a trivalent or tetravalent organic compound having at least two or more carbon atoms) group, R2 represents a divalent organic group having at least two or more carbon atoms, R3 represents hydrogen or an alkali metal counter ion, n is 1 or 2. (b) a compound [2] containing an unsaturated bond that can be dimerized or polymerized by actinic radiation, and an amino group or a quaternized salt thereof; R5/ (R-, R5 are at least A coumarin compound [3] represented by a monovalent organic group having 2 or more carbon atoms, R6 represents a monovalent organic group having at least 3 carbon atoms, and (d) a substituent. This is achieved by an actinic radiation-sensitive polymer composition comprising an aromatic monoazide compound [4] which has no substituents or has a neutral or acidic substituent.

In the present invention, a polymer having a structural unit [1] is a polymer having a structure represented by the above general formula and having an imide ring or its geographical structure by heating or using a suitable catalyst.
Hereinafter, it can be referred to as a polyimide-based polymer).

In the above structural unit [1], R1 is a trivalent or tetravalent organic group having at least two or more carbon atoms. In view of the heat resistance of the polyimide polymer, it is preferable that R1 has a structure in which the bond to the carbonyl group of the polymer main chain is directly formed from an aromatic heterocycle. Therefore, as R1,
Contains an aromatic ring or an aromatic heterocycle, and has 6 to 3 carbon atoms
A trivalent or tetravalent group of o is preferred.

(In the formula, the bond represents a bond with the carbonyl group of the polymer main chain, and the carbonyl group of the polymer side chain is located at the ortho position to the bond, but this bond is not shown in the above structural formula. ), but are not limited to these.

Further, in the polymer having the structural unit [1], R1 may be composed of only one type among these, or may be a copolymer composed of two or more types.

Particularly desirable R1 is (however, in the formula, the definition of the bond is the same as above).

In the above structural unit [1, R2 is a divalent organic group having at least two or more carbon atoms, but from the viewpoint of heat resistance when made into a polyimide polymer, the bond with the amide group of the main chain of the polymer It is preferable to have a structure formed directly from an aromatic ring or an aromatic heterocycle. Therefore, R2 is preferably a divalent group containing an aromatic ring or an aromatic heterocycle and having 6 to 30 carbon atoms.

Preferred specific examples of R2 include H3 (in the formula, the bond represents a bond with the amide group of the main chain). Further, these may have a nuclear substituent such as an amino group, an azide group, a carboxyl group, or a sulfonamide group within a range that does not adversely affect the heat resistance of the polyimide polymer.

Particularly preferred examples of those having these nuclear substituents include the following.

Examples include.

In the polymer having the structural unit [1], R2 may be composed of only one type among these, or may be a copolymer composed of two or more types.

Furthermore, in order to improve the adhesiveness of the polyimide polymer, it is also possible to copolymerize an aliphatic group having a siloxane bond as R2 within a range that does not reduce the heat resistance. Preferred specific examples include the following.

Specific examples of polymers containing structural unit [1] as main components include pyromellitic dianhydride, 4,4'-diaminodiphenyl ether, and 3.3',4.4'-benzophenonetetracarboxylic dianhydride. and 4,4'-diaminodiphenyl ether, 3.3',4.4'-biphenyltetracarboxylic dianhydride and 4,4'-diaminodiphenyl ether, pyromellitic dianhydride and 3.3'-(or 4 .4
') Diaminodiphenylsulfone, 3.3', 4.
4'-benzophenonetetracarboxylic acid dianhydride and 3
．． 3'-(or 4.4') diaminodiphenylsulfone, 3.3',4.4'-biphenyltetracarboxylic dianhydride; and 3. 3'-(or 4.4') diaminodiphenylsulfone, 3.3', 4,4'-benzophenone tetracarboxylic dianhydride and 4,4'-diaminodiphenylsulfide, 3.3', 4.4' -Biphenyltetracarboxylic dianhydride and 4.4'-diaminodiphenylsulfide, 3.3', 4.4' -Benzophenonetetracarboxylic dianhydride and paraphenylenediamine, 3.3',
4.4'-biphenyltetracarboxylic dianhydride and paraphenylenediamine, 3.3',4.4'-diphenyl ethertetracarboxylic dianhydride and 4.4'-
Polyamic acid synthesized from diaminodiphenyl ether, etc. is preferably used.

The polymer having one structural unit may be composed only of the structural unit [1], or may be a copolymer or a blend with other structural units. The type and amount of structural units used in the copolymerization are desirably selected within a range that does not significantly impair the heat resistance of the polyimide polymer obtained by the final heat treatment.

Typical examples include structural units of polyamideamic acid and polyesteramic acid, but are not limited thereto.

In the present invention, the compound [2] containing an unsaturated bond and an amino group or a quaternized salt thereof that can be dimerized or polymerized by actinic radiation includes a carbon-carbon double bond and an amine group or a quaternized salt thereof in one molecule. Compounds containing amino groups are used.

As compound [2], at least one compound represented by the following general formula [A], [B] or [C] or a quaternized salt thereof is preferably used.

(R12 represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms).

General formula [C] R13[C] (CH2=C-CH-)-, N-H.

(Here, R13 represents hydrogen or a methyl group, and n
+1=3, n=1 to 3).

Preferred specific examples include: \ (where R7 is hydrogen or a phenyl group, R8 is hydrogen or a lower alkyl group having 1 to 6 carbon atoms, Rlo is a substituted or unsubstituted hydrocarbon group having 2 to 12 carbon atoms, R9, R1 each represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms).

General formula [B \ R3 \ CH2CH3.

CH2=CH-CH2-NH2 (CH2=CHCH2)2 NH \ CR3 Compound [2 units are structural units [1 unit is the main component of the polymer containing 0.05 equivalents or more of all carboxyl groups (or salts thereof)] is preferable, more preferably 0.3 equivalent or more and desirably 2 times the equivalent or less mixed with the polymer. Outside this range, photosensitivity may deteriorate,
Care must be taken because the allowable range of development conditions such as development time and temperature may be narrowed.

Examples of the coumarin compound [3] in the present invention include, but are not limited to, the following.

From the viewpoint of actinic radiation sensitivity, amino compounds having an acrylic or methacrylic group as an unsaturated group are particularly desirable.

In the case of a compound in which the amine group is not quaternized, it is preferable to combine it with a structural unit in which one R3 is hydrogen. In the case of a compound in which the amino group is quaternized, it is desirable that R3 of the structural unit [1] be combined with an alkali metal ion or an ammonium ion.

(R4 and R5 are small (both 2 or more, preferably 10
R6 is a monovalent organic group having at least 3 carbon atoms, preferably 30 or less carbon atoms. ) is a compound having a coumarin skeleton, and any substituent on the skeleton may be used as long as it absorbs the G-line (436 nm) of a mercury lamp.

However, from the point of view of workability, compounds having absorption in the visible light region are not preferred; for example, the following marine compounds are preferred.

. cormorant. U/ / H3CH2 The coumarin compound [3] is preferably mixed in an amount of 0.1% by weight or more based on the weight of the polymer whose main component is the structural unit [1], and more preferably 0.1% by weight or more based on the weight of the polymer. 5
It is preferable to mix at a ratio of at least 20% by weight and not more than 20% by weight. If it is out of this range, there is a risk that the photosensitivity may deteriorate and the allowable range of development time and development conditions may become narrow, so care must be taken.

Aromatic monoazide compound I having no substituent or having a neutral or acidic substituent in the present invention
I4] is a compound in which an azide group (-N3) is directly bonded to an aromatic ring, and only one azide group exists in the molecule, and the aromatic ring here refers to a benzene ring,
Refers to naphthalene rings, anthracene rings, naphthoquinone rings, anthraquinone rings, etc., and these aromatic rings have no substituents other than an azide group, or have neutral or acidic substituents. It is. These aromatic rings are -〇- group, -〇- group, -5O2- group, -CH2
Those bonded to another aromatic ring substituted with an unsubstituted group or a neutral or acidic substituent via a divalent group such as - group, -CH=CH- group, etc. are also preferably used. It will be done.

The neutral or acidic substituent herein refers to one that does not form a salt with a normal organic carboxylic acid, and naturally does not include an amino group or a substituent containing an amino group. Examples of neutral or acidic substituents include lower (1 to 6 carbon atoms) alkyl groups, alkoxy groups, nitro groups,
Examples include halogen groups, acyl groups, acyloxy groups, carboxyl groups, sulfone groups, and alkyl groups substituted with neutral or acidic groups.

Specifically, aromatic monoazide compounds such as these are preferably used, but are not limited thereto.

Aromatic monoazide compounds (4) may be used alone or in combination of two or more types.

The aromatic monoazide compound [4] is preferably added in a total amount of 0.1% by weight or more based on the weight of the polymer whose main component is the structural unit [1], and more preferably 0.5% by weight based on the weight of the polymer. % or more and 30% by weight or less. If it is out of this range, it may adversely affect the developability and stability of the composition, so care must be taken.

An example of the method for producing the composition of the present invention will be explained. First, a diamine compound and an acid dianhydride are reacted in a solvent to obtain a polymer containing the structural unit [1] as a main component. Next, compounds [2], [3], "4", and other additives as necessary are dissolved and prepared in this solution.

In addition, as the above-mentioned polymer, a solid polyamic acid polymer or a polymer separated and purified from the solution after the reaction may be redissolved and used.

As the solvent used in the above production method, polar solvents are preferably used from the viewpoint of solubility of the polymer, and aprotic polar solvents are particularly suitable. As an aprotic polar solvent,
N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphorotriamide, γ-butyrolactone, and the like are preferably used. As other additives, a sensitizer, a copolymer monomer, or an adhesion improver with the substrate may be included as long as the sensitivity and heat resistance are not significantly reduced.

In addition, if the mixing amount of compound [3] and/or [4 is 0
．． In the case of 5 to 10% by weight, N-phenyldiethanolamine, N-phenylethylamine, N-phenylethanolamine, Mihira ketone, 4,4'bis(diethylamino)benzophenone is used as a sensitizer or sensitizing aid. etc. are preferably used. The actinic radiation sensitivity of the compositions of the invention can be further improved by adding sensitizers or sensitizing aids. Monomaleimide, polymaleimide, or substituted products thereof are preferably used as the copolymerizable monomer.

Next, a method for using the composition of the present invention will be explained. The compositions of the present invention can be patterned using well-known microfabrication techniques using actinic radiation.

First, the composition of the present invention is coated on a suitable support. Possible coating methods include spin coating using a spinner, spray coating using a spray coater, dipping, printing, and roll coating. The coating film thickness can be adjusted by the coating means, solid content concentration, and viscosity of the composition.

Examples of the material of the support to which the composition of the present invention is applied include metals, glass, semiconductors, metal oxide insulators, and silicon nitride.

In order to improve the adhesion between the coating film of the composition of the present invention or the polyimide film after heat treatment and the support, an adhesion aid may be used as appropriate.

As an adhesion aid, oxypropyltrimethoxysilane,
Organosilicon compounds such as γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, aluminum monoethylacetoacetate diisopropylate, aluminum tris (acetylacetonate), etc. Aluminum chelate compounds such as or titanium chelate compounds such as titanium bis(acetylacetonate) are preferably used.

Next, the composition of the present invention, which has become a coating film on the support, is irradiated with actinic radiation in a desired pattern. Examples of actinic radiation include X-rays, electron beams, ultraviolet rays, visible light, etc., but ultraviolet rays and short-wavelength visible rays, that is, in the wavelength range of 200 to 500 nm, are preferred.

Then, a relief pattern is obtained by dissolving and removing the unirradiated areas with a developer. An appropriate developer is selected depending on the structure of the polymer.

The developer contains N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphorotriamide, etc., which are the solvents of this composition. It can be used alone or as a mixture with a non-solvent composition such as methanol, ethanol, isopropyl alcohol, water, methylcarpitol, ethylcarpitol, toluene, xylene, or the like. In many cases, ammonia water or other alkaline aqueous solutions can also be used.

Development can be carried out by spraying the above-mentioned developer onto the coated film surface, immersing it in the developer, or applying ultrasonic waves while immersing it.

It is desirable that the relief pattern formed by development is then washed with a rinsing solution.

As the rinsing liquid, methanol, ethanol, isopropyl alcohol, isobutyl alcohol, butyl acetate, etc., which have good miscibility with the developer, are preferably used.

The relief nobutan polymer obtained by the above treatment is a precursor of a heat-resistant polyimide polymer, and by heat treatment becomes a heat-resistant polymer having an imide ring or other cyclic structure. The heat treatment is usually carried out in a temperature range of 135 to 400° C. while increasing the temperature stepwise or continuously.

The actinic radiation-sensitive polymer composition of the present invention can be used as a passivation film for semiconductors, a knockoff coat film for passivation films, an interlayer insulating film for multilayer integrated circuits, an interlayer insulating film or surface protective film for hybrid integrated circuits, and solder for printed circuits. With protective film,
It is used for forming alignment films for liquid crystals, interlayer insulation films for mounting boards, etc. Furthermore, it can be used as a highly heat-resistant photoresist for metal adhesion and dry etching processes.

It can be applied to other known uses of polyimide.

[Effects of the Invention] As described above, the present invention comprises a polymer having the structural unit [1] as a main component, and a compound containing an unsaturated bond and an amino group or a quaternized salt thereof that can be dimerized or polymerized by actinic radiation [
2], a coumarin compound [3], and an aromatic monoazide compound [4].It has an actinic radiation-sensitive composition that exhibits excellent photosensitivity and is superior to conventional photosensitive polyimides. It exhibits high sensitivity through exposure using the invisible G-line of a high-pressure mercury lamp, and can obtain patterns with even better resolution.

[Examples] Next, the present invention will be specifically described based on Examples, but the present invention is not limited thereto.

The actinic radiation sensitivity of the composition of the present invention was evaluated by applying grayscale (Kodak Company P.
photographic 5tep tablet N
This was done by irradiating the film with light from a high-pressure mercury lamp that had passed through a filter (Y-43, manufactured by Toshiba Glass Co., Ltd.) through a filter (Y-43, manufactured by Toshiba Glass), and then developing the film and examining the film roughness and film loss after development. In addition, evaluation of the resolution of the composition of the present invention was performed by applying a test pattern mask (manufactured by Inu Nippon Printing) to a filter (Y-4 manufactured by Toshiba Glass Co., Ltd.) on a film formed on a support substrate.
3) was irradiated with light from a high-pressure mercury lamp, and then developed to examine the resolution.

Example 1 192°2 g of 4.4'-diaminodiphenyl ether,
1.9.94 g of 3-bis(3-aminopropyl)tetramethyldisiloxane was dissolved in 18 g of N-methyl-2-pyrrolidone.
90g to prepare an amine solution. Add 315% of benzophenonetetracarboxylic dianhydride to this amine solution.
Add 7g, react at 50℃ for 3 hours, and react at 25℃ for 15
A 0 poise polymer solution (A) was obtained. This polymer solution (
A).

370 g of diethylaminoethyl methacrylate was mixed into the mixture, followed by 10.35 g of 3,3'-carbonyl-bis(7-dinithylaminocoumarin).

20.71 g of p-azidobenzalacetophenone.

A solution of 10.35 g of Michler's ketone dissolved in 100 g of N-methyl-2=pyrrolidone was mixed and filtered.

The obtained solution was spin-coated onto a silicon wafer using a spinner, and then placed in a clean oven (manufactured by Yamato Scientific Co., Ltd.).
DE-42 type) for 45 minutes at 80°C. The thickness of the resulting coating film was 13.0 μm. Next, this coating film was exposed using an exposure machine (PLA-501 manufactured by Canon Corporation).
F) and gray scale (Kodak Pho
tographc 5tep tablet No22
1steps) and filter (Toshiba Glass Y-43
) for 2 minutes. The intensity of the ultraviolet rays at this time was 5 mW/Cm2 (436 nm). Developing is N
, N-dimethylformamide (45 parts), N-methyl-
Immersion development was performed using a mixed solvent of 2-pyrrolidone (25 parts), xylene (15 parts) and water (15 parts). Development was continued for an additional 60 seconds immediately after the unexposed areas were dissolved. It was then rinsed with isopropanol for 20 seconds and spun dry with a spinner. When the film thickness after development was measured, it was 12.0 μm (film reduction amount = 1.0 μm
). Thereafter, heat treatment was performed at 200'C and 350C for 30 minutes each, and the pattern was observed using an optical microscope, and a good pattern with no film roughness was shown at an exposure dose of 300 mJ or more.

Further, in order to evaluate the resolution, the obtained solution was spin-coated onto silicone ware using a spinner, and then dried at 80° C. for 45 minutes using the clean oven. The film thickness of this coating film was 13.0 μm. Next, the coating film is placed in the exposure machine mentioned above, and the test pattern mask (
Inu Nippon Printing) and filter (Toshiba Glass Y-43)
) for 60 seconds. The intensity of the ultraviolet rays at this time is 5
mW/cm2 (436 nm). After developing, rinsing, and drying under the same conditions as above, the film thickness was measured to be 12.0 μm (film reduction amount = 1.0 μm).
).

After that, heat treatment was performed at 200°C and 350°C for 30 minutes each.
When the pattern was observed using an optical microscope, it was found that 20μ
m peer holes were resolved on the entire surface of the board.

Example 2 1.4-bis(4-aminophenoxy)benzene56.
12g, p-phenylenediamine 62゜28g, 1.3
7.94 g of -bis(3-aminopropyl)tetramethyldisiloxane was dissolved in 1250 g of N-methyl 2-pyrrolidone to prepare an amine solution. Add 3. to this amine solution.
230.6 g of 3',4゜4'-biphenyltetracarboxylic dianhydride and 178 g of N-methyl-2-pyrrolidone were added and reacted at 50°C for 3 hours, and the polymer solution (B) was heated to 180 poise at 25°C. I got it. To this polymer solution (B) was mixed 251.2 g of diethylaminoethyl methacrylate, 3.51 g of 3,3'-carbonyl-bis(7-dinithylaminocoumarin), 14.28 g of p-azidobenzalacetophenone, 7. Michler's ketone. 14g
, a solution of 7.14 g of N-phenyldiethanolamine dissolved in 100 g of N-methyl-2-pyrrolidone was mixed and filtered.

The obtained solution was spin-coated onto a silicon wafer using a spinner, and then dried in the same manner as in Example 1 to obtain a coating film with a thickness of 15 μm. Next, this coating film was exposed, developed, rinsed and dried under the same conditions as in Example 1. When the film thickness was measured after development, it was 13°5μm (film reduction amount: 1.5μm).
m).

After that, heat treatment was performed at 200°C and 350°C for 30 minutes each.
The pattern was observed using an optical microscope, but the exposure amount was 2.
At 00 mJ or more, a good pattern with no film roughness was shown.

Further, in order to evaluate the resolution, the obtained solution was spin-coated onto silicone ware using a spinner, and dried in the same manner as in Example 1 to obtain a coating film with a thickness of 15.0 μm. Next, this coating film was exposed, developed, rinsed and dried under the same conditions as in Example 1. When measuring the film thickness after development,
It was 13.5 μm (film reduction amount: 1.5 μm).

After that, heat treatment was performed at 200°C and 350°C for 30 minutes each.
The pattern was observed using an optical microscope, and it was found that 20 μm peer holes were resolved over the entire surface of the substrate.

Comparative Example 1 251.2 g of diethylaminoethyl methacrylate was mixed into the same polymer solution (B) used in Example 2, and then 7.14 g of N-phenyldiethanolamine was added.
14.286 g of 4-azidobenzalacetophenone
A solution dissolved in 300 g of -methyl-2-pyrrolidone was mixed and filtered.

The obtained solution was spin-coated onto a silicon wafer using a spinner, and then dried in the same manner as in Example 2 to give a film thickness of 13.0.
A coating film of μm was obtained. Next, this coating film was exposed, developed, rinsed and dried under the same conditions as in Example 2. When the film thickness after development was measured, it was 7°0 μm (film reduction amount: 6.
0μm). After that, heat treatment was performed at 200°C and 350°C for 30 minutes each, and the pattern was observed using an optical microscope.
Even when the exposure amount was 600 mJ, film roughness occurred.

Further, the resolution was evaluated in the same manner as in Example 2, but the smallest opening was a pier hole of 50 μm, and the resolution was poor.

Comparative Example 2 251.2 g of diethylaminoethyl methacrylate was mixed with the same polymer solution (B) used in Example 2, followed by 3.51 g of N-phenylglycine, 14.286 g of 4-azidobenzalacetophenone, and Michler's ketone. 7.14g to 100g N-methyl-2-pyrrolidone
The solution was mixed and filtered.

The obtained solution was spin-coated onto a silicon wafer using a spinner and dried in the same manner to obtain a coating film with a thickness of 15.0 μm. Next, this coating film was exposed, developed, rinsed and dried under the same conditions as in Example 2.

When the film thickness after development was measured, it was 13.5 μm (film reduction amount = 1.5 μm). Thereafter, heat treatment was performed at 200° C. and 350° C. for 30 minutes each, and the pattern was observed using an optical microscope, and a pattern with no film roughness was observed at an exposure dose of 300 m or more.

On the other hand, when the resolution was evaluated in the same manner as in Example 2,
The smallest opening was a 100 μm peer hole, and the resolution was poor.

Claims (1)

[Claims] (1) (a) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, in the formula, R_1 is a trivalent or tetravalent organic group having at least 2 or more carbon atoms, and R_2 is a (b) Chemical The lines indicate a compound [2] containing a dimerizable or polymerizable unsaturated bond, an amino group, or a quaternized salt thereof, and (c) General formula ▲ Numerical formula, chemical formula, table, etc. is a monovalent organic group having at least 2 carbon atoms, and R_6 is a monovalent organic group having at least 3 carbon atoms.); An actinic radiation-sensitive polymer composition comprising an aromatic monoazide compound [4] which has no substituent or has a neutral or acidic substituent.