JPH10186664A - Positive photosensitive heat-resistant material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the positive photosensitive heat-resistant material superior in developability and enhanced in storage stability in a molten state and the mechanical characteristics of a hardened film. SOLUTION: The positive photosensitive heat-resistant material to be used is a heat-resistant material precursor of a polyimide or polybenzoxazole having fundamental structural units each having a group acidifiable by irradiation with activated rays and a phenolic hydroxyl group represented by formulae I and II in which R1 is a (2m+1)-valent aromatic hydrocarbon group; R2 is a (2+n)-valent organic group having at least 2C; R3 is an H atom and/or an organic group releasable in an acid condition; R4 is a group to be allowed to release an acid by irradiation with activated rays; (m) is an integer of 1-5; (n) is 1 or 2; R5 is same as R1 ; R6 is a tetravalent organic group having at least 2C; R7 is same as R4 ; and (p) is an integer of 1-5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photosensitive heat-resistant material having excellent developability, storage stability in a solution state, and excellent mechanical properties of a cured film.

2. Description of the Related Art Hitherto, a polyimide resin having excellent heat resistance, electrical characteristics, mechanical characteristics, and the like has been used for a surface protective film and an interlayer insulating film of a semiconductor element. However, in recent years, as semiconductor elements have become more highly integrated and larger, there has been a demand for thinner and smaller sealing resin packages, and methods such as LOC (lead-on-chip) and surface mounting by solder reflow have been adopted. Therefore, a polyimide resin having more excellent mechanical properties, heat resistance and the like has been required.

On the other hand, a photosensitive polyimide resin having a photosensitive property imparted to the polyimide resin itself has been used.
By using this, it is possible to simplify the pattern forming process and shorten the complicated manufacturing process.However, since an organic solvent such as N-methyl-2-pyrrolidone is required for development, recently, There has been proposed a positive photosensitive resin that can be developed with an aqueous alkali solution. For example, a method in which a compound having an amino group, an amide group, a urethane group, or the like is mixed with a polyamic acid and heated after exposure in the presence of a photoinitiator (JP-A-6-289626). Polyamide acid-based methods such as a method of mixing quinonediazide with a salt with an amine compound (JP-A-6-161102) and a method of mixing a base generator such as nifedipine with polyamide acid (JP-A-5-5959). Although these have good developability, they do not have a difference in solubility between the exposed and unexposed portions, and the film loss of the unexposed portions during development is large. In addition, since free carboxylic acids and carboxylate salts are present in the system, storage stability is poor and there is a problem in handling.

A mixture of a polybenzoxazole precursor and a diazoquinone compound (Japanese Patent Publication No. 1-46862)
No.) or a polyamic acid having a phenol moiety introduced through an ester bond (Preprints of Annual Meeting of the Society of Polymer Science, p.
(3715, 1991) have introduced a phenolic hydroxyl group instead of a carboxylic acid. However, these compounds have insufficient developability and cause a decrease in the film thickness of an unexposed portion and peeling of the resin from the substrate. You. For the purpose of improving such developability and adhesion, a mixture of a polyamic acid having a siloxane moiety in a polymer skeleton (JP-A-4-31861, JP-A-4-46345, etc.) has been proposed. However, as described above, the use of polyamic acid deteriorates storage stability. In addition, since these use a diazoquinone compound containing a large number of aromatic rings as an acid generator, there is a problem that the mechanical properties after thermosetting are significantly reduced.

On the other hand, there has been proposed a device using a polyamic acid ester which is excellent in storage stability and the like. For example, a method of introducing an orthonitrobenzyl group into a polyimide precursor via an ester bond (Japanese Patent Publication No.
No. 9571), in which the orthonitrobenzyl group is mainly used in the Deep UV region (<300 n).
m), the sensitivity is insufficient for i-line (365 nm) of an ultra-high pressure mercury lamp used exclusively in the industry, and a sufficient pattern cannot be obtained in a practical exposure range. There was a problem. Further, a resin component having a specific protecting group introduced into the carboxyl group of the polyimide precursor,
Chemically-amplified photosensitive composition containing a compound which becomes acidic upon irradiation with actinic rays (Japanese Patent Laid-Open No. 4-120171)
In this case, when a protecting group such as a tetrahydropyranyl group, a 1-ethoxyethyl group, a methoxymethyl group, a trimethylsilyl group or the like is used as the protecting group, the sensitivity is good. The protecting group has a problem in solution preservability since it is easily removed, and is still insufficient for practical use. In addition, when a methyl group, an ethyl group, a propyl group, a butyl group, a benzyl group, or the like is used as a protecting group, the elimination reaction of the protecting group sufficiently occurs even when heating is used in combination with acid generation by irradiation with actinic rays. It is difficult to say that it is a practical material.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a positive photosensitive heat-resistant material which is excellent in developability, storage stability in a solution state and mechanical properties of a cured film.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that heat-resistant material precursors such as polyimides and polybenzoxazoles having both a group exhibiting acidity by irradiation with actinic rays and a phenolic hydroxyl group. It has been found that the above object can be achieved by using the present invention, and the present invention has been completed. That is, the positive photosensitive heat-resistant material of the present invention has the following general formula (1)

Embedded image (Wherein, R ₁ is a (2 + m) -valent aromatic hydrocarbon group, R ₂
Is a (2 + n) -valent organic group having at least two carbon atoms, R ₃ is a hydrogen atom and / or an organic group capable of leaving under acidic conditions, and R ₄ is a group that generates an acid upon irradiation with actinic rays. M represents an integer of 1 to 5 and n represents 1 or 2. )
Or the general formula (2)

[0007]

Embedded image (Wherein, R ₃ is the same as above, R ₅ is a (2 + p) valent aromatic hydrocarbon group, R ₆ is a tetravalent organic group having at least 2 carbon atoms, R ₇ is R ₄ and the following General formula (3)

[0008]

Embedded image (Wherein, R ₈ is an alkylene group having 1 to 4 carbon atoms, R ₉ is an alkyl group having 1 to 3 carbon atoms, R ₁₀ is a hydrogen atom and / or an organic group which can be eliminated under acidic conditions, q is 0 An integer from 3 to r
Represents an integer of 1 to 3), and p is 0 to 5
Represents an integer. ) Containing a polymer having a basic unit having the structure shown in (1).

R ₁ in the structural unit represented by the general formula (1) is a (2 + m) -valent aromatic hydrocarbon group, and m is 1
Is an integer of up to 5. Among them, those in which OR ₃ is located at an adjacent position such as an ortho position with respect to NH can form an oxazole structure by thermosetting, and are therefore preferable from the viewpoint of heat resistance and hygroscopicity.

[0010]

Embedded image (X ₁ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, a halogenated hydrocarbon group, or hydrogen, and each aromatic ring may be substituted with an alkyl group or a phenyl group as necessary. ), And general formula (5)

[0011]

Embedded image And the like, but are not limited thereto.

In the general formula (1), R ₂ is at least 2
A (2 + n) -valent organic group having 2 carbon atoms, where n is 1
Or 2. From the viewpoint of heat resistance, R ₂ is preferably an aromatic ring or an aromatic heterocyclic ring. Specifically, the above-mentioned functional groups and the like mentioned as examples of R ₁ can be mentioned. Among them, a phenyl group and a biphenyl group are preferable because the coefficient of thermal expansion of the obtained polymer is reduced. An aromatic group having an electron-donating substituent such as a contained aromatic group has a low i-line absorption, which is preferable for the purpose of i-line exposure. Further, in the case of an aromatic group containing fluorine, together with the i-line absorption, Since the dielectric constant of the obtained polymer is reduced, it is preferable when a material having a low dielectric constant is obtained,
It is not limited to these.

In the formula, R ₃ is a protecting group for a hydrogen atom and / or a phenolic hydroxyl group, and particularly preferably a group which is easily deprotected by heat treatment such as heating under acidic conditions. As such, for example, a tetrahydropyranyl group,
Examples include a t-butoxycarbonyl group, a 1-ethoxyethyl group, a methoxymethyl group, and a trialkylsilyl group such as a trimethylsilyl group and a t-butyldimethylsilyl group. Of these, a t-butyldimethylsilyl group is particularly preferred.

In the formula, R ₄ is a group that generates an acid upon irradiation with actinic rays, for example, a 2-nitrobenzyl group,
Benzyl derivative residues having a nitro group at the ortho position such as α-methyl-2-nitrobenzyl group, 2,4-dinitrobenzyl group, 4,5-dimethoxy-2-nitrobenzyl group and the like can be mentioned.

In the general formula (1), m represents an integer of 1 to 5, and 1 or 2 is particularly preferable from the viewpoint of heat resistance and hygroscopicity as described above.

In the structural unit represented by the general formula (2), R ₅
Is a (2 + p) -valent aromatic hydrocarbon group, and p is 0 to 5
Is an integer. From the viewpoints of moisture absorption and heat resistance of the cured film, p is preferably 0, 1, or 2, and R ₅ is a group represented by the aforementioned general formula (4) or (5), and diphenyl ether, diphenyl thioether, Benzophenone,
Examples include, but are not limited to, divalent aromatic groups having a skeleton such as diphenylmethane, diphenylpropane, diphenylhexafluoropropane, diphenylsulfoxide, diphenylsulfone, phenyl, pyridine, biphenyl, terphenyl, naphthalene, and perylene. Not something.

In the structural unit represented by the general formula (2), R ₆ is a tetravalent organic group having at least two carbon atoms. From the viewpoint of heat resistance, R ₆ is preferably an aromatic ring or an aromatic heterocyclic ring. Specifically, there can be mentioned, for example, the general formula (4) given as an example of the above R ₁ , but it is not limited to these.

[0018] R ₇ in the general formula (2) is a group containing a phenolic hydroxyl group and / or a protected group represented by the above-described R4 and general formula (3), wherein R ₈
Is an alkylene group having 1 to 4 carbon atoms, and R ₉ is an alkylene group having 1 to 3 carbon atoms.
R ₁₀ is a hydrogen atom and / or an organic group which can be eliminated under acidic conditions, q is an integer of 0 to 3, and r is an integer of 1 to 3. Examples of such are 3-hydroxybenzyl, 4-hydroxybenzyl and their tetrahydropyranyl, t-butoxycarbonyl, 1-ethoxyethyl, trimethylsilyl, t-
Examples thereof include a protected form with a butyldimethylsilyl group and the like, but are not particularly limited thereto.

The polymer of the positive type photosensitive heat-resistant material used in the present invention contains the structure represented by the above general formula (1) or (2) as a basic unit. Can be copolymerized within a range that does not impair the features of the present invention. For example, an aliphatic diamine having a siloxane structure can be copolymerized with a diamine component of R ₁ or R ₅ within a range that does not reduce heat resistance for the purpose of improving adhesion to a substrate. Specific examples include those obtained by copolymerizing bis (3-aminopropyl) tetramethyldisiloxane with 1 to 10 mol%. The weight average molecular weight (Mw) of the polymer of the positive photosensitive heat-resistant material used in the present invention is 5,000 to 100.
000, preferably 10,000 to 50,000.

The polymer of the positive photosensitive heat-resistant material used in the present invention is obtained by reacting a tricarboxylic anhydride or a tetracarboxylic dianhydride with an alcohol to synthesize a tricarboxylic monoester or a tetracarboxylic diester. It can be synthesized by condensing this with a diamine. This condensation reaction can be carried out in the same manner as the condensation reaction between the dicarboxylic acid and the diamine. Specifically, the method is carried out via the state of an acid chloride (for example, JP-B-55-41422), the method using an organic dehydration condensing agent (for example, JP-A-61-72022, JP-A-61-22022).
-127773, JP-A-62-72724, JP-A-62-74331, and the like. The positive photosensitive heat-resistant material of the present invention also includes a material in which a phenolic hydroxyl group in the skeleton is protected by a protecting group that can be removed with an acid, which is protected by the polymer obtained by the above method. It can be obtained by reacting an agent or by using a previously protected monomer and polymerizing it. By protecting the phenolic hydroxyl group in the polymer in this manner, the effect of reducing the film loss of the unexposed portion during development and improving the alkali developability by removing the protecting group in an acidic atmosphere of the exposed portion is obtained. Good lithography characteristics are obtained.

These polymers disclosed in the present invention are:
It is dissolved in a solvent and used as a varnish. As the solvent, N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, cyclopentanone, cyclohexanone, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, or the like may be used alone or as a mixture. You may. 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
Solvents such as -butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate and methyl-3-methoxypropionate can also be used as a mixture.

The positive photosensitive heat-resistant material of the present invention may optionally contain a compound (photoacid generator) which becomes acidic upon irradiation with actinic rays. The photoacid generator generates an acid together with the photoacid generating group introduced into the polymer by irradiation with actinic rays such as ultraviolet rays, so that the alkali developability of the exposed portion can be improved. Specific examples of such compounds include diallylsulfonium salts, triallylsulfonium salts, dialkylphenacylsulfonium salts, allyldiazonium salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid esters, nitrobenzyl esters, and aromatic sulfamides. And naphthoquinonediazide-4-sulfonic acid ester and naphthoquinonediazide-5-sulfonic acid ester. Such compounds may be used in combination of two or more if necessary,
It can be used in combination with another sensitizer, and is blended in an amount of 50 parts by weight or less, preferably 20 parts by weight or less based on 100 parts by weight of the polymer. The sensitivity of the photoacid generator increases with an increase in the amount of the photoacid generator. However, in many cases, the physical properties of the film after high-temperature curing, the storage stability of the solution, and the image quality may be adversely affected.

It is also possible to add an additive such as a silane coupling agent or the like, or to treat the substrate in advance in order to enhance the adhesion to the substrate. Next, an example of a method for forming an image using the positive photosensitive heat-resistant material of the present invention will be described.

First, the general formula (1) or (2) of the present invention
Is dissolved in the organic solvent to prepare a photosensitive solution. Next, this photosensitive liquid is applied on a substrate so that the film thickness after drying is 1 to 50 μm, preferably 5 to 30 μm. After the applied coating film is dried, exposure is performed through a normal photomask, and if necessary, post-exposure heating (80 to 150 ° C.). Then, an immersion method or a spray method is used to remove an irradiated portion. Perform development processing. 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 (T
MAH), an organic alkaline aqueous solution such as choline or the like is used alone or in combination of two or more. In addition, the alkaline aqueous solution may contain an organic solvent such as an alcohol and various surfactants as necessary. After development, washing with a rinsing liquid gives a positive image of the heat-resistant material precursor. The image obtained as described above can be converted into a heat-resistant material having excellent heat resistance, chemical resistance, and mechanical properties by performing a high-temperature heat treatment (about 200 to 400 ° C.). The cured product has a relief pattern.

Embodiments of the present invention will be described below in detail.

[0025]

Example 1 Benzophenonetetracarboxylic dianhydride (BTDA) 68.9 parts by weight (0.21 mol) 4,5
-Dimethoxy-2-nitrobenzyl alcohol (DMO
NB) 89.5 parts by weight (0.42 mol) was dissolved in 750 parts by weight of γ-butyrolactone, 33.3 parts by weight of pyridine (0.42 mol) was added, and the mixture was stirred at room temperature for 15 hours for esterification. . Then, under ice cooling, 86.7 parts by weight of DCC (dicyclohexylcarbodiimide) (0.42 mol)
And 69.6 parts by weight (0.19 mol) of 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (6FAP) were added, and the mixture was returned to room temperature and stirred for 2 hours to react. Thereafter, ethanol was added, and the mixture was further stirred for 1 hour to remove insoluble components by filtration.
The solution was dropped into 0 liter, and the precipitate was collected by filtration and dried under reduced pressure to obtain Polymer 1. The weight average molecular weight (Mw) of this polymer was 28,000 in terms of polystyrene as a result of measurement by GPC (gel, permeation, chromatography). Further, when infrared absorption measurement was performed by FT-IR, it was found that 1525 cm ⁻¹ , 13
Nitro group to 45cm ^-1, absorption of an ester bond was observed at 1725 cm ^-1, the presence of ortho-nitrobenzyl ester group was confirmed.

25 parts by weight of this polymer were added to N-methyl-2
-After dissolving in 50 parts by weight of pyrrolidone (NMP)
The solution was filtered through a 0.2 μm Teflon filter to obtain a photosensitive varnish. The varnish was spin-coated on a silicon wafer to obtain a coating having a thickness of 5 μm after drying. This coating,
Ultraviolet light was applied through a mask on which a pattern was drawn, using an ultra-high pressure mercury lamp while changing the exposure amount. Next, the exposed portion was dissolved and removed by immersion in a 3% TMAH aqueous solution for 60 seconds, and then rinsed with water. As a result, a good pattern could be obtained by irradiation with an exposure dose of 600 mJ / cm ² . The film thickness after development at this time is 4.5 μm
And the residual film ratio showed a high value of 90%. After the varnish was allowed to stand at room temperature for 30 days, the change in viscosity was examined. As a result, there was no decrease in the viscosity, and no change was observed in the photosensitive characteristics, showing extremely stable characteristics. Separately from this, a film was obtained on an aluminum plate so that the film thickness after curing at 400 ° C. was finally 10 μm using the varnish. Thereafter, the aluminum plate is removed by etching, and the obtained film is subjected to JIS.
When measured by the test method of K 6760, it showed very excellent mechanical properties with a tensile strength of 13 kg / mm ² and an elongation of 40%.

[0027]

Example 2 Trimellitic anhydride (TAA) 38.4
Parts by weight (0.2 mol) and 42.6 parts by weight (0.2 mol) of DMONB are dissolved in 750 parts by weight of γ-butyrolactone, and 119 parts by weight of pyridine (1.5 mol) are added.
The mixture was stirred at room temperature for 2 hours to perform esterification. Thereafter, 47.6 parts by weight (0.4 mol) of thionyl chloride was added.
It was reacted with 66.0 parts by weight (0.18 mol) of FAP at room temperature for 2 hours. Next, 19.6 parts by weight of t-butyldimethylchlorosilane (TBDMSC) (0.13 parts) was added to the reaction solution.
Mol) was added under ice-cooling, and the reaction was allowed to proceed for 3 hours. The reaction solution was added dropwise to 10 liters of distilled water, and the precipitate was collected by filtration, washed several times with water, collected, and dried under reduced pressure to obtain Polymer 2. The polymer was measured by GPC and FT-IR in the same manner as in Example 1. As a result, the weight-average molecular weight was 32,000, and the nitro group (1
525 cm ^-1 , 1345 cm ^-1 ), ester group (172
Absorption of 5 cm ^-1 ) and silyl group (1100 cm ^-1 ) were observed, confirming the presence of orthonitrobenzyl ester group and silyl group.

After dissolving 20 parts by weight of this polymer in 50 parts by weight of NMP, the solution was filtered through a 0.2 μm Teflon filter to obtain a photosensitive varnish. The varnish was spin-coated on a silicon wafer in the same manner as in Example 1 to obtain a coating having a thickness of 7 μm after drying, and this was exposed through a mask using an ultrahigh pressure mercury lamp. Subsequently, after heating at 80 ° C. for 10 minutes, the exposed portion was dissolved and removed by immersion in a 3% TMAH aqueous solution for 70 seconds, and rinsed with water.
As a result, a good pattern was obtained by irradiation with an exposure dose of 400 mJ / cm ² . The film thickness after development at this time was 6.7.
μm, and the residual film ratio was as high as 95%. Also,
Examination of the change in viscosity of this varnish after standing at room temperature for 2 weeks showed no decrease in viscosity and no change in photosensitive characteristics. In the same manner as in Example 1, a film was formed on an aluminum plate so that the film thickness after curing at 400 ° C. was finally 10 μm, and then the aluminum plate was removed by etching to obtain a film. It was measured. As a result, excellent mechanical properties such as a tensile strength of 15 kg / mm ² and an elongation of 30% were exhibited.

[0029]

Example 3 Example 5 was replaced with BTDA,
5 '-[2,2,2-trifluoro-1- (trifluoromethyl) ethylidene] bis-1,3-isobenzofurandione (6FDA) 93.2 parts by weight (0.21 mol), DMONB 35. 8 parts by weight (0.168 mol) and 31.3 parts by weight of 3-hydroxybenzyl alcohol (0.252 mol), 4,4'-diaminodiphenyl ether (DDE) instead of 6FAP
Polymer 3 was synthesized in exactly the same manner except that 38 parts by weight (0.19 mol) was used. Mw of the obtained polymer
Was 34000, and the presence of an orthonitrobenzyl ester group was confirmed by FT-IR. Compound (NQD) 10 obtained by reacting 30 parts by weight of this polymer with 2.5 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride in 1 mol of 1,1,1-tris (4-hydroxyphenyl) ethane A part by weight was dissolved in 50 parts by weight of NMP and then filtered through a 0.2 μm Teflon filter to obtain a photosensitive varnish.

The varnish was spin-coated on a silicon wafer so as to have a thickness of 6 μm after drying, and this was exposed through a mask with an ultra-high pressure mercury lamp. Next, the exposed portion was dissolved and removed by immersion in a 3% TMAH aqueous solution for 60 seconds, and then rinsed with water. As a result, the exposure amount was 500 mJ
A good pattern could be obtained by irradiation at / cm ² .
At this time, the film thickness after development was 5.4 μm, and the residual film ratio was as high as 90%. The varnish was placed at room temperature 2
Even when left for a week, there was almost no change in viscosity, and no change was observed in the photosensitive characteristics. Further, a film having a film thickness of 10 μm after curing at 400 ° C. was prepared, and the mechanical properties were measured. The tensile strength was 12 kg / mm ² and the elongation was 35%.
And showed very good mechanical properties.

[0031]

Embodiment 4 In Embodiment 2, 6F is used instead of TAA.
93.2 parts by weight of DA (0.21 mol), 35.8 parts by weight of DMONB (0.168 mol) as an alcohol component and 31.3 parts by weight (0.252 mol) of 3-hydroxybenzyl alcohol, 3 instead of 6FAP Polymer 4 was synthesized in exactly the same manner except that 41.1 parts by weight (0.19 mol) of 3'-dihydroxy-4,4'-diaminobiphenyl was used. GPC for this polymer
As a result, Mw was 30,000. FT-IR confirmed the presence of an orthonitrobenzyl ester group and a silyl group. After dissolving 20 parts by weight of this polymer in 50 parts by weight of NMP, 0.2
The solution was filtered through a μm Teflon filter to obtain a photosensitive varnish.

The varnish was spin-coated on a silicon wafer in the same manner as in Example 2 to obtain a coating film having a thickness of 6 μm after drying, which was exposed through a mask using an ultra-high pressure mercury lamp. Subsequently, after heating at 80 ° C. for 10 minutes, 3%
The exposed portion was dissolved and removed by immersion in a TMAH aqueous solution for 70 seconds, and rinsed with water. As a result, a good pattern was obtained by irradiation with an exposure amount of 350 mJ / cm ² . At this time, the film thickness after development was 5.7 μm, and the residual film ratio was as high as 95%. When the varnish was allowed to stand at room temperature for 2 weeks, the change in viscosity was examined. As a result, no decrease in viscosity was observed, and no change was observed in the photosensitive characteristics. Further, a film having a thickness of 10 μm after curing at 400 ° C. was prepared, and the mechanical properties were measured. As a result, it was found that the tensile strength was 14 kg / mm ² and the elongation was 32%, which was very excellent.

[0033]

Comparative Example 1 Polymer 5 having no phenolic hydroxyl group in the polymer side chain was synthesized in exactly the same manner as in Example 3 except that only 89.5 parts by weight (0.42 mol) of DMONB was used as the alcohol component. The Mw of the polymer was 36,000, and the presence of an orthonitrobenzyl ester group was confirmed by FT-IR. 30 parts by weight of this polymer and 10 parts by weight of the NQD are mixed with NMP50.
After being dissolved in parts by weight, the solution was filtered through a 0.2 μm Teflon filter to obtain a photosensitive varnish. The varnish was spin-coated on a silicon wafer after drying so as to have a film thickness of 6 μm, and this was irradiated with an ultra-high pressure mercury lamp through a mask at the same exposure amount of 500 mJ / cm ² as in Example 3, and 3% TM
Development was performed with an AH aqueous solution. At this time, it takes 300 seconds until the exposed portion is completely dissolved and removed, and the film thickness after development is 4.
2 μm (residual film ratio: 70%) and a film reduction in an unexposed portion were observed. In the obtained pattern, seepage from unexposed portions was observed, and a clear pattern was not obtained.

[0034]

Comparative Example 2 The procedure of Example 3 was repeated, except that only 52.2 parts by weight (0.42 mol) of 3-hydroxybenzyl alcohol was used as the alcohol component.
Polymer 6 containing only phenolic hydroxyl groups in the polymer side chain was synthesized. The Mw of this polymer was 34,000. 30 parts by weight of this polymer and 30 parts by weight of NQD were dissolved in 50 parts by weight of NMP, and then filtered through a 0.2 μm Teflon filter to obtain a photosensitive varnish.

The varnish was spin-coated on a silicon wafer to a film thickness of 6 μm after drying, and this was exposed to an ultra-high pressure mercury lamp through a mask and exposed to light in the same manner as in Example 3 at a dose of 500 mJ.
/ Cm ² and developed with 3% TMAH aqueous solution. At this time, it takes 30 minutes until the exposed portion is completely dissolved and removed.
0 seconds was required, and the film thickness after development was 4.5 μm (residual film ratio 75
%) And a decrease in film thickness in the unexposed area was observed.

[0036]

Comparative Example 3 6FDA 46.6 parts by weight and DDE 19 parts by weight were reacted in NMP 262 parts by weight, and a polyamic acid having the same skeleton as polymer 5 (resin concentration =
20%) 100 parts by weight of polymer 5:30 parts by weight, N
In addition to 30 parts by weight of QD and 50 parts by weight of NMP, lithography evaluation was performed with a film thickness of 6 μm as in Comparative Example 2. In the same manner, irradiation was performed at an exposure amount of 500 mJ / cm ² , and development was performed with a 3% TMAH aqueous solution. In 60 seconds, the exposed portion was completely dissolved and removed, and the film thickness after development was 5.5 μm.
m (residual film ratio 92%), which is almost the same as that of Example 3.

When this varnish was allowed to stand at room temperature for 2 weeks and the change in viscosity was examined, the viscosity was reduced to about 1/2 of the initial value, and the storage stability was poor. Further, a film having a thickness of 10 μm after curing at 400 ° C. was prepared, and the mechanical properties were measured. As a result, the film was brittle with a tensile strength of 7 kg / mm ² and an elongation of 6%.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/312 H01L 21/312 B

Claims (2)

[Claims] 1. A compound of the general formula (1) (Wherein, R ₁ is a (2 + m) -valent aromatic hydrocarbon group, R ₂
Is a (2 + n) -valent organic group having at least two carbon atoms, R ₃ is a hydrogen atom and / or an organic group capable of leaving under acidic conditions, and R ₄ is a group that generates an acid upon irradiation with actinic rays. M represents an integer of 1 to 5 and n represents 1 or 2. )
Or a compound of the general formula (2) (Wherein, R ₃ is the same as above, R ₅ is a (2 + p) valent aromatic hydrocarbon group, R ₆ is a tetravalent organic group having at least 2 carbon atoms, R ₇ is R ₄ and the following General formula (3) (Wherein, R ₈ is an alkylene group having 1 to 4 carbon atoms, R ₉ is an alkyl group having 1 to 3 carbon atoms, R ₁₀ is a hydrogen atom and / or an organic group which can be eliminated under acidic conditions, q is 0 An integer from 3 to r
Represents an integer of 1 to 3), and p is 0 to 5
Represents an integer. A positive-type photosensitive heat-resistant material containing a polymer having a basic unit having the structure represented by the formula (1). 2. The positive photosensitive heat-resistant material according to claim 1, wherein R ₄ (group generating an acid upon irradiation with actinic rays) is an orthonitrobenzyl ester derivative residue.