JPH01283554A - Thermoresisting photosensitive polymer composition - Google Patents

Abstract

PURPOSE:To make possible to form the thick pattern of the title composition which has high sensitivity, excellent definition and sticking property against a supporting substrate plate by incorporating a specified copolymer, a photopolymerization initiator, a photocrosslinking agent and a sensitizing agent in a prescribed ratio, in the composition. CONSTITUTION:The composition is composed of 100pts.wt. of the copolymer contg. 99.9-50mol.% of a polymer having a repeating unit shown by formula I as a main component and 0.1-50.0mol.% of a polymer having a repeating unit shown by formula II as a main component, the photopolymerization initiator, the photocrosslinking agent and 0.1-30pts.wt. of the sensitizing agent. In formula I, R<1> is >=4 C four valent org. group, R<2> is 3 or 4 valent org. group contg. an aromatic ring group, P<1>, P<2> and P<3> are each a photosensitive group, X is an org. group binding the groups P<2> and R<2>, etc., (n) is 1 or 2. And, in formula II, R<3> and R<4> are each alkylene or phenylene group, R<5>-R<8> are each a lower alkyl or phenyl group, (k) is an integer of 1-5. Thus, the material having the good definition and the high sensitivity and the excellent sticking property against the supporting substrate plate in case of forming the thick film of the composition is obtd.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a heat-resistant photosensitive polymer composition used for semiconductor devices, multilayer wiring boards, microelectronic devices, etc. Regarding photosensitive materials.

[Conventional technology]

As a heat-resistant photosensitive material that can be used as a heat-resistant polymer, (
b) q! In Japanese Publication No. 59-52822, a wholly aromatic polyamic acid and a carbon-carbon compound capable of being diduplexed or polymerized by actinic radiation are disclosed.
Amino group due to carbon double bond? (b) JP-A-56-1
No. 10728 discloses a polyamic acid synthesized from an aromatic tetracarboxylic dianhydride and an aromatic diamine, in which a photosensitive fund is introduced into the aromatic diamine component.

[Problem to be solved by the invention]

However, when the materials (a) and (b) are made into thick films, the resolution decreases. There are problems such as insufficient sensitivity and peeling of fine relief patterns or areas around the relief patterns after development or final curing. For this reason, it can be applied to interlayer insulating films and protective films of semiconductor devices that only require a final cured film thickness of about 2 to 5 μm, but is it possible to apply the film to a film thickness of 10 to 20 μm or more? It is a good idea that it can be applied to required applications such as α-ray shielding films for memory devices and interlayer insulating films for thin-film multilayer substrates.

- Dimensions The reason why the resolution deteriorates when using a thick film of the material in (a) above is because there is no photosensitive group bonded to the polymer main chain, so the curability of the exposed area is low, and the unexposed This is thought to be due to poor solubility of the part. For this reason, if you try to completely dissolve the unexposed areas, if you increase the temperature, development temperature, or lengthen the development time, even the exposed areas will be dissolved9. Patterns with different diameters will have markedly different widths for the mask dimensions, etc. Something happens.

In the case of the material (b) above, the curability of the exposed area is sufficient, but the solubility of the unexposed area is low, resulting in poor resolution of fine patterns.

The main cause of the decrease in resolution is considered to be factors related to the current I solution. That is, the developing solution for dissolving the unexposed portion of the material in (a) above, port C] is N-methyl-2-
The main component must be an aprotic polar solvent such as pyrrolidone or N,N-dimethylacetamide, but since these solvents all have relatively high liquid viscosity, dissolution and diffusion of the unglamorous portion is suppressed. Moreover, since the dissolving power is strong, if the material has an insufficient degree of photocuring, the a-base may also be dissolved.

Further, when a thick film is made of the materials (a) and (b) above, the sensitivity may be insufficient because the number of photosensitive groups per repeating unit is insufficient.

Furthermore, when the materials (a) and (b) above are made into thick films,
Possible causes of peeling I#II in the fine relief pattern or the peripheral area of the relief pattern after the actual fishing or final curing are poor adhesion between the material and the support substrate.

The purpose of the present invention is to use a weakly polar solvent with low liquid viscosity and low dissolving power in order to improve the resolution when forming a thick film. In order to achieve the above objective of providing a heat-resistant photosensitive polymer composition that is capable of pattern formation even when used as a developer and has high sensitivity and excellent adhesion to a supporting substrate, it is necessary to It is thought that the structure of a certain polymer may be as follows. In other words, the reason that the above materials (a) and (a) are soluble only in solvents whose main component is aprotic polar solvents such as N-methyl-2-pyrrolidone is because polyamic acid has highly polar carboxyl groups bonded to it. This is thought to be due to the presence of carbon dioxide, so it is possible to use a less polar carboxylic acid ester. Furthermore, in order to increase the sensitivity, it is possible to increase the number of photosensitive groups per repeating unit by introducing photosensitive groups into both the acid dianhydride component and the diamine component, which are raw materials for the polymer. Furthermore, in order to improve the adhesion with the support substrate, it is considered that an Sl-based diamine containing an S1 component that is highly reactive with the support substrate may be copolymerized with the polymer main chain.

Therefore, as a result of careful consideration based on the above idea, Ia
l General formula (1) (However, in formula (1), R' is a tetravalent organic group containing at least 4 or more carbons, W is a trivalent or tetravalent organic group containing an aromatic ring, Pl, R3 , R8 is a photosensitive group, X is PI and R″
represents an organic group connecting 10- or -N-, and n
is 1 or 2) is 999 to 50.0 mole and monomer formula (2) (however, (21 formula 8, R4 is alkylene or 7-
(Nylene, R"%R+", and "%R1" are lower alkyl groups or phenyl groups, k is an integer from 1 to 5)
Polymer f! whose main fraction is the repeating unit represented by f! r:0
．． 100 parts by weight of a copolymer containing 1 to 50.0 moles, an FBL photopolymerization initiator, a photocrosslinking agent, a sensitizer Q, 1 to 50.0 parts by weight;
The photosensitive polymer composition consisting of 30 parts by weight and 1 part can use solvents such as r-butyrolactone and dimethoxyethane as the main components of the developer, which cannot be used with the heat-resistant materials described above. If it has good resolution when formed into a thick film, it will be a material that has high sensitivity even when formed into a thick film, and has excellent adhesion to the supporting substrate without peeling off the relief pattern after development or final curing. I found out what I got.

The present invention will be explained in detail below.

Preferred examples of R' in the polymer represented by the repeating units of general formulas (1) and (21) include, but are not limited to, the following.

More preferable examples include: etc.

kLI may have the above structural formula alone, or two or more types (a mixture of two or more may be used).

Preferred examples of R'' include (where Z is
1-8-1-SO2-1-CO-1-C) and the like, but are not limited thereto.

As a more preferable example, etc.

It may be used in a mixture of 2'M1 or more, or it may be copolymerized with a material that does not have a photosensitive group as long as it does not adversely affect photosensitivity.

Preferred examples of X include -0-5-N-, (representing ren), but are not limited thereto.

More preferred examples of the -C-0-1 photosensitive group P'P"P" include RI+ -CH, CH, 0-C-CH-CH-CH-CHR"I (wherein R1" is hydrogen, cyano group, lower alkino 1
R11 is a group selected from hydrogen, a lower alkyl group, an alkoxy group, R'', R+'', f(
, +4. m-, R1.represents a group selected from hydrogen, a lower alkyl group, and a vinyl group), but is not limited thereto.

More preferable examples include: etc.

P', P'', and P'' may be the same or different groups.

General formula (R8 of the polymer represented by 21 repeating units,
Examples of preferable R4 include +CHt+
j (wherein ) is an integer from 1 to 5), represents a group), etc., but is not limited to these.

More preferable examples include: etc.

R'' and R' may be the same or different.

Preferred examples of ", R1, R', R" include, but are not limited to, lower alkyl groups and tunyl groups.

More preferable examples include methyl group and phenyl group.

R', R,', R' and R1 may be the same or different groups.

k is preferably an integer from 1 to 5, more preferably 1 or 2.

In the copolymer represented by the repeating units of general formulas (1) and (2), the content of the polymer represented by the repeating units of general formula (2) is preferably 1 to 50.0 mol/cl, More preferably, it is 0.1 to 2α0 mol. When the content is higher than this range, sufficient heat resistance cannot be obtained, and when it is lower than this range, adverse effects such as poor adhesion with the supporting substrate occur.

The copolymer represented by the repeating units of general formulas (11 and (21) is a dehydrating agent composed of a tetracarboxylic acid diester having a photosensitive group in the ester residue, an aromatic diamine compound having a photosensitive group, and a diamine compound containing Si. Synthesized by polymerization reaction.

In the heat-resistant photosensitive polymer composition according to the present invention, it is essential to add a photopolymerization initiator, a photocrosslinking agent, or a sensitizer. Preferred examples of these include mihiraketone, bis-4
, 4'-diethylaminobenzophenone, benzophenone, benzoin ether, benzoin propyl ether, anthrone, 1,9-benzoanthrone, acridine, nitropyrene, 1,8-dinitropyrene, 5-nitroacenaphthene, 2-nitrofluorene, pyrene- 1
3 .5
-diethylthioxanthone, 3.5-dimethylthioxanthone, 3.5-diisopropylthioxanthone, benzyl, 2.6-di(41-azidobenzal)cyclohexanone, 2.6-di(41-azidobenzal)-4-methylcyclohexanone, 2. 6-di(41-azidobenzal)-4-carboxycyclohexanone, 2.6-di(a+-azidobenzal)-4-hydroxycyclohexanone, 2.6-di(4'-azidocinnamylidene)cyclohexanone, 2.6- Di(41-azidocinnamylidene)-4-methylcyclohexanone, 2,6-di(4
+-azidocinnamylidene)-4-carboxycyclohexanone, 2,6-di(a+-azidocinnamylidene)
-4-hydroxycyclohexanone, 1-phenyl-5
-Merka 7'to 1H-tetrazole, 1-phenyl-
5-melteix, 3-acetylphenanthrene, 1-
Examples include, but are not limited to, indanone, 7-H-benz(de)anthracen-7-one, 1-naphthaldehyde, thioxanthin-9-one, 10-thioxanthenon, 3-acedolindole, and the like.

Among these, more preferred examples include Mihiraketone, bis-4,41-diethylaminobenzophenone, 1-phenyl-5-mercapto-1H-tetrazole, benzyl, 2,4-diethylthioxanthone, 2
．． Examples include 4-dimethylthioxanthone and 2,4-diisopropylthioxanthone.

These may be used alone or in combination.

The preferred blending ratio of the photopolymerization initiator, photocrosslinking agent, and sensitizer used in the present invention is 0.1 parts by weight per 100 parts by weight of the copolymer represented by the repeating units of general formulas (1) and (2). ~3
Preferably, it is blended in an amount of 0 parts by weight, and more preferably,
It is preferable to mix it in the range of 0.5 to 20 parts by weight. Deviation from this range will adversely affect developability.

The sensitizing aid added as necessary in the present invention is used as a polymerization accelerator when using a photopolymerization initiator, and preferred examples include 4-diethylamine ethyl benzoate, 4-dimethylaminoethyl benzoate,
4-dimethylaminoisopropylbenzoate, 4-dimethylaminoinamylbenzoate, ethylene glycol dithioglycolate, ethylene glycol di(5-
mercaptopropionate), trimethylolpropanethioglycol, trimethylolpropane tri(3-mercaptopropionate), pentaerythritol tetrathioglycolate, pentaerythritol tetra(5
-mercaptopropioate), trimethylolethane trithioglycolate, trimethylolethane tri(3
-mercaptopropionate), dipentaerythritol hexa(3-mercaptopropionate), dipentaerythritol hexa(6-mercaptopropionate), thioglycolic acid, α-mercaptopropionic acid, etc. Not limited.

Among these, more preferable examples include 4-dimethylaminoethyl benzoate, 4-dimethylaminoisoamyl benzoate, bare p-erythritol tetrathioglycolate, and pentaerythritol tetra(3-dimethylaminoethyl benzoate).
mercaptopropionate), trimethylolpropanethioacrylate, and the like.

These may be used alone or in combination.

The blending ratio when using a sensitizing aid in the present invention is determined by the general formula (
1), copolymer 1 expressed by f2+ modified units
It is preferably in the range of 0.1 to 60 parts by weight, more preferably in the range of 05 to 20 parts by weight. If the amount is less than this range, a sufficient polymerization promoting effect may not necessarily be obtained, and if it is more than this range, adverse effects such as a decrease in developability may occur.

The heat-resistant photosensitive polymer composition according to the present invention is used in the form of a solution in which the above-mentioned components are dissolved in a suitable organic solvent. The solvent used in this case is preferably an aprotic injection solvent from the viewpoint of solubility.

Specifically, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, hebenzyl-2-pyrrolidone,
N,N-dimethylformamide, he,N-dimethylacetamide, dimethylforfoquinde, hexamethylphosphorotriamide, N-acetyl-8-caprolactam, dimethylimidazolidinone, 1,2-dimethoxyethane,
Suitable examples include 1-acetoxy-2-methoxyethane, r-butyrolactone, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether. These may be used alone or as a mixture of several types.

In addition, toluene, xylene,
An aromatic solvent such as methoxybenzene may be mixed as long as it does not adversely affect the dissolution of the polymer.

In order to further improve the adhesion between the coating film of the heat-resistant photosensitive polymer composition of the present invention or the polyimide film after heat curing and the support substrate, the support substrate may be appropriately treated with an adhesion auxiliary agent.

The uninvented heat-resistant photosensitive polymer M paraboloid can be patterned using ordinary textile processing techniques. To apply the Kigumi Paramonto onto the support substrate, methods such as spin coating using a spinner, dipping, and spray printing can be selected as appropriate. The coating film thickness can be adjusted by the coating means, the solid content concentration of the composition, and the like.

A desired relief pattern is formed by irradiating the composition according to the present invention, which has become a coating film on a support substrate through a drying process, with ultraviolet rays through a photomask, and then dissolving and removing the unexposed areas with a developer. obtain.

The main components of the developer include r-butyrolactone, 1.2
-Polar solvents such as dimethoxynitane, 1-acetoxy-2-methoxyethane, and diethylene glycol dimethyl ether can be used.

Depending on the purpose, more polar and highly soluble N-methyl-2-pyrrolidone, N,N-dimethylacetamide,
Aprotic polar solvents such as dimethyl sulfoxide and dimethylimidazolidinone, aromatic solvents with low polarity such as toluene and xylene, and non-solvents for copolymerized polymers represented by repeating units of general formulas (1) and (2). It is also possible to use it in a mixed system with alcohol and water. Depending on the application, development may also be carried out using a mixed system of a highly soluble polar solvent, alcohol, and water.

The relief pattern formed by development is then washed with a rinse solution to remove the development solvent.

The rinsing liquid has good miscibility with the developer and has general formula (1).
, (21 repeating units) are used. Suitable examples include methanol, ethanol, isopropyl alcohol, benzene, toluene, xylene, and water.

The relief pattern polymer obtained by the above treatment is a precursor of polyimide, and by treatment at a heating temperature selected from the range of 150°C to 450°C,
A pattern of heat-resistant polymer is obtained.

[Effect J As described above, according to the present invention, even if a weakly polar solvent with relatively low liquid viscosity and low dissolving power is used as a developer,
Sufficient solubility of the unexposed portions can be ensured, and dissolution and diffusion of the unexposed portions can also be made good, while dissolution of the exposed portions can be sufficiently suppressed. . .

Therefore, even in the case of a thick film, excellent resolution can be obtained.

Furthermore, since photosensitive groups are introduced into both the acid dianhydride component and the diamine component, which are the raw materials for the copolymer that is the main component, it is possible to increase the number of photosensitive groups per repeating unit.

Furthermore, Si containing a Si component that is highly reactive with the supporting substrate
Since the system diamine is copolymerized with the polymer main chain, it is possible to improve the adhesion to the supporting substrate.

〔Example〕

The present invention will be explained in detail below.

Example 1 7.35 g (0.025 mol) of 3.3.4.4'-biphenyltetracarboxylic dianhydride and 6.5 g (0.05 mol) of 2-hydroxyethyl methacrylate were added to 50 g under a nitrogen stream. N-methyl-2-pyrrolidone (abbreviation N
MP), then 6.5 g of pyridine (abbreviation Py) (
α05 mol) was added thereto, and the mixture was reacted at 40°C for 5 hours. To the obtained homogeneous solution, 5.02 g (3,5-diamino(2'-methacryloyloxyethyl)benzony) (0
,019 mol) and 0.25 g (1001 mol) of bis(3-aminopropyl)tetramethyldisiloxane,
Then dicyclohexylcarbodiimide (abbreviation DDC)
10.3 g (0.05 mol) was added and reacted at room temperature for 5 hours (Formula 1).

(Left below) The resulting reaction mixture was slowly poured into 700-t methanol with vigorous stirring. As soon as the reaction mixture was mixed with methanol, polymer (I) began to precipitate. The precipitated polymer was collected by suction filtration and further washed three times with 20 od of methanol each. Further drying was carried out under reduced pressure to finally obtain 4.1 g of Polymer I.

2.5 g of polymer (I) obtained above, 0.075 g of 2,4-diethylthioxanthone, 0.15 g of 4-dimethylaminoethylbenzox-)? Near, 1 gON
, was dissolved in N-dimethylaminoacetamide, and then filtered under pressure using a filter with 1 μm pores to obtain a photosensitive varnish.

The above varnish was spin-coated onto a silicon wafer using a spinner, and then dried at 90 tons for 50 minutes to obtain a coating film of 31 μm. This coating film was closely covered with a photomask having a stripe pattern, and irradiated with ultraviolet rays for 10 seconds using a 500W high-pressure mercury lamp. The intensity of ultraviolet rays at the light receiving surface is 3
It was 5 mW/- at a wavelength of 65 nm. Developed with a mixed solution consisting of 7 troughs of r-butyrolactone and 3 troughs of xo L/n,
Then rinse with isopropyl alcohol to reduce the
m line-and-space patterns were resolved.

The degree of g, defined as the dose at which the film thickness after development becomes 1/2 of the film thickness before development, was 22 mJ/d. Next, this pattern was heated at 200° C. for 30 minutes and at 350° C. for 30 minutes to obtain heat-resistant polyimide butter 7 with a thickness of 22 μm. In this pattern, no peeling from the substrate was observed after development and after final curing.

Examples 2 to 16 In Examples 2 to 13, the same operations as in Example 1 were performed using one composition shown in Table 1. The obtained results are shown in the same table.

(Left below) Comparative example Diaminodiphenyl ether 11gyN-methyl-2-
It was dissolved in 5t8g of pyrrolidone to prepare an amine solution.

12 g'i of pyromellitic anhydride was added to this amine solution and reacted at 50° C. for 3 hours to obtain a polyamide m solution.

115g of Mihiraketone to 50g of the above polyamic acid solution
was dissolved in 3.0 g of N,N-dimethylacetamide and 10.2 g of diethylaminomethacrylate was dissolved in 10
A solution prepared by dissolving 1 g of N,N-dimethylacetamide was mixed and filtered under pressure using a filter with 1 μm pores.

The obtained solution was applied onto silicone Ueno\ using a spinner and dried at 100°C for 5 minutes to obtain a 27 μm coating film. It was exposed for 1 minute using the same exposure device and photomask as in Example 1, and developed for 10 minutes at 25°C with a mixture of 5 volumes of N%N-dimethylformamide and 2 volumes of methanol, but the unexposed areas were completely removed. It did not dissolve and the pattern was not resolved. Therefore, the development temperature was raised to 55° C., but in this case, the entire pattern, including the exposed portion, was dissolved and no pattern was obtained. Next, the exposure time was set to 5 minutes, and development was carried out at 35° C. for 15 minutes. At this time, the minimum dimension of the resolved pattern is 1
Although the thickness was 50 nm, peeling from the substrate was observed around the pattern. In the dark, at 200℃ for 30 minutes, and more!
The final film thickness obtained by heating at 150°C for 30 minutes was 8 μm.

〔Effect of the invention〕

As detailed above, according to the present invention, it is possible to provide a heat-resistant photosensitive polymer composition capable of forming a thick film pattern with high sensitivity and excellent resolution and adhesion to a supporting substrate. Yes, α+I of LSI memory! It has become possible to use it as a shielding film or an interlayer insulating film material for thin-film multilayer substrates.

Claims (1)

[Claims] 1. (a) General formula (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (However, in the formula (1), R^1 contains at least 4 or more carbons. Tetravalent organic group, R^2 is a trivalent or tetravalent organic group containing an aromatic ring, P^1, P^2, P^3 are photosensitive groups, X
is an organic group connecting P^3 and R^2 or -O- or ▲
There are mathematical formulas, chemical formulas, tables, etc. 99.9 to 50.0 mol% of a polymer whose main component is a repeating unit represented by ▼, where n is 1 or 2), and general formula (2) ▲Math. , chemical formulas, tables, etc.▼...(2) (However, in formula (2), R^3 and R^4 are alkylene or phenylene, and R^5, R^6, R^7, and R^8 are lower alkyl. or phenyl group, k is an integer from 1 to 5).
．． A heat-resistant photosensitive polymer composition consisting of 100 parts by weight of a copolymer containing 1 to 50.0 mol%, and (b) 0.1 to 30 parts by weight of a photopolymerization initiator, a photocrosslinking agent, and a sensitizer. . 2. 0.1 to 100 parts by weight of the above copolymer
Claim 1 further comprising 30 parts by weight of a sensitizing aid.
The heat-resistant photosensitive polymer composition described in 1.