JPH04170431A - Fluorinated aromatic polyamide, derivative thereof, and use and production thereof - Google Patents

Abstract

PURPOSE:To obtain the title polyamide gibing a polybenzoxazole excellent in heat resistance, water absorption properties, dielectric characteristics, etc., by subjecting specific raw materials to condensation by dehydration using dicycloexylcarbodiimide. CONSTITUTION:The title polyamide, having repeating units of formula I (wherein X is group of formula II, III or IV; Y is a group of formula V, VI, VII, VIII, or IX; a is 0.1-1; b is 0.9-0; and a+b is 1) and a reduced viscosity measured in N-methylpoyrrolidone at 25 deg.C of 0.05-0.5, is obtained by subjecting raw materials, such as a carboxylic acid and a diamine, to condensation by dehydration using dicyclohexylcarbodiimide. A varnish prepd. by dissolving the polyamide in a solvent is suitably used for forming a protective or insulating film for an electronic material like a semiconductor.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a novel fluorine-containing aromatic polyamide, a method for producing the same, a polybenzoxazole derived therefrom, and a varnish and positive coating using the polyamide. The present invention relates to a type photosensitive composition varnish.

[Conventional technology]

Polymers suitable for protective films and insulating films used in electronic materials such as semiconductors have been actively researched.

Polybenzoxazole resin, which has excellent heat resistance and electrical properties, is one of the results of these efforts.
Novel polyamides have been developed as precursors for polybenzoxazole used in high temperature positive photoresist compositions as disclosed in Publication No. 3-96162. The polyamide is typically hexafluoro-2,2-
It is a product obtained by condensing bis(3-amino-4-hydroxyphenyl)propane with a mixture of tribasic acid chloride and tribasic acid chloride, and is most related to the fluorine-containing aromatic polyamide of the present invention described below. It can be said to be a deep substance.

[Problems to be Solved by the Invention] However, the polyamide disclosed in the above-mentioned publication has problems when used for interlayer insulating films, passivation films, buffer coat films of devices such as semiconductors, or insulating films of multilayer wiring boards, etc. The heat resistance, which is strongly required for

The present invention meets this need and has a new structure different from the above-mentioned time-opening polyamide, maintains or improves the original low dielectric constant and low water absorption, and further improves the problematic heat resistance. It is an object of the present invention to provide a fluorine-containing aromatic polyamide with improved viscosity, a polybenzoxazole derived therefrom, and uses thereof.

[Means to solve the problem]

In order to solve the above problem, the present inventors investigated the synthesis of various fluorine-containing aromatic polyamides, and as a result found that the problem could be solved by a novel polyamide having the structure of general formula I above, and completed the present invention. .

That is, the present invention provides a fluorine-containing aromatic polyamide having a repeating unit represented by the general formula 1 and having a reduced viscosity (in N-methylpyrrolidone at 25°C) of 0.05 to 0.5 (wherein, X is OHOH Y is OH 1, b=0.9 to O, a+b-1), a method for producing the same, a polybenzoxazole derived therefrom, a varnish using the polyamide, and a positive photosensitive composition varnish It provides:

The present invention will be explained in detail below.

The fluorine-containing aromatic polyamide of the present invention has a structure consisting of repeating units represented by Formula I below.

In the formula, Particularly preferred are substitution positions.

a and b represent the ratio (mole fraction) of the respective repeating units, and a = 0.1 to 1. b=0.9~0. a + b = 1
It is. In particular, it is preferable that a is 0.2 or more in terms of moisture absorption rate and dielectric constant.

Furthermore, the reduced viscosity (η
/C') was 0.05 to 0.5 when measured at 25°C with an Ubbelohde viscometer in a 1% N-methylpyrrolidone p solution.

Next, the method for producing the fluorine-containing aromatic polyamide of the present invention will be explained.

The polyamide can be manufactured according to a general polyamide manufacturing method. For example, there is an acid chloride method in which diamine is polycondensed with a carboxylic acid chloride obtained from a reagent such as thionyl chloride and a carboxylic acid, or a DCC method in which dehydration condensation is performed using dicyclohexylcarbodiimide (hereinafter abbreviated as DCC). be.

However, when these are used for electronic materials, impurities such as chlorine ions can cause problems such as corrosion of metal wiring and electrical errors, so it is difficult to remove chlorine ions generated during synthesis from the polymer. The acid chloride process is problematic and DCC can be produced with inherently low impurity concentrations.
The method is preferable.

For details of this DCC method, please refer to Japanese Patent Application Laid-Open No. 61-7202.
It is described in "Method for producing polyamide" in Publication No. 2.

A method of using the fluorine-containing aromatic polyamide of the present invention will be explained.

First, the polyamide is dissolved in a solvent and used as a varnish solution. As this solvent, an aprotic polar solvent that is soluble in the polyamide is suitable, and is selected from, for example, dimethylacetamide, γ-butyrolactone, cyclopentanone, N-methylpyrrolidone (hereinafter abbreviated as NMP), etc. be able to.

When using this varnish as a protective film for ■C, etc., apply the varnish to a base material such as a silicon wafer using a method such as a spin code, and heat it at an appropriate temperature of 50 to 150°C using an oven or hot plate. After drying at a temperature of 300-50
Heat treatment is performed at a temperature of 0° C., followed by dehydration and ring closure to form a polybenzoxazole to form a protective film.

Next, if it is necessary to form a pie-hole pattern such as a bonding pad on the coating film, a positive photoresist can be used to form the pattern. That is, after applying and drying the fluorine-containing aromatic polyamide varnish of the present invention, a positive photoresist is coated on the coating film, and after drying, pattern exposure is performed, and then a developer consisting of an alkaline aqueous solution for positive photoresists is applied. By this, the underlying fluorine-containing aromatic polyamide varnish coating film of the present invention can be developed all at once. Further, after removing the upper positive type photoresist using a stripping solution or the like, heat treatment is performed at a temperature of 300 to 500° C., thereby forming a polybenzoxazole pattern.

Furthermore, when high-resolution pattern formation is required, this can be accomplished using a positive photosensitive composition varnish using the fluorine-containing aromatic polyamide of the present invention. This positive photosensitive composition varnish can be obtained by dissolving the polyamide and a specific quinonediazide compound in the above-mentioned solvent. Examples of the quinonediazide compound used here include those having the structures shown below.

RO0R ROOR OR H3 ■ For details of this quinonediazide compound, see Japanese Patent Publication No. 1-468.
It is described in Publication No. 62.

The positive photosensitive composition varnish of the present invention is coated on a substrate such as a silicon wafer by a method such as a spin code, dried, exposed to light in a pattern, and further developed with a developer consisting of an alkaline aqueous solution. When heat-treated at a temperature of C, the quinonediazide compound evaporates, the polymer undergoes dehydration and ring closure, and a fine pattern of polybenzoxazole is formed. The alkali for the developing solution used here is preferably an organic alkali in order to prevent contamination by metal ions, and for example, choline hydroxide, tetramethylammonium hydroxide, etc. are preferable. Further, by adding a small amount of alcohol, glycol ether, or the above-mentioned aprotic polar solvent as a component of this developer, the wettability and solubility of the coating film can be improved.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 300 ml of dimethylacetamide (hereinafter abbreviated as DMAe) was added to 59.3 g of phthalic anhydride, and while stirring, 3,3'-dihydroxy to 4.4'
-Diaminobiphenyl (hereinafter abbreviated as HAB) 43
．． 3g was added. This was stirred at room temperature (approximately 25°C) for 12 hours. Next, add 2.2′-bis(4
-carboxyphenyl)hexafluoropropane (hereinafter abbreviated as BCPF) 78.5g and pyridine 63Jf
was added and heated at 45° C. for 30 minutes while stirring. Subsequently, hydroxybenztriazole (hereinafter abbreviated as HOBT) 182.2 was added, and the mixture was further heated and stirred at 45° C. for 30 minutes. This reaction solution was cooled to -5°C, and a solution of 167.1 g of dicyclohexylcarbodiimide (hereinafter abbreviated as DCC) dissolved in 84 ml of DMAc was added dropwise to precipitate dicyclohexylurea (hereinafter abbreviated as DC, U). I let it happen. After that, HAB82.
2 g was added again, and the reaction solution was returned to room temperature, stirred for 2 hours, 20 ml of ethanol was added, and the DCU was filtered. The filtrate was dropped into 4p ethanol to precipitate a sticky polymer. After dissolving this sticky polymer in 300 ml of tetrahydrofuran, 4 g
was added dropwise to ion-exchanged water to precipitate the polymer. Next, this was filtered again and then vacuum dried to form a polymer powder P-
I got 1. The structure of P-1 is as follows.

6711%
A 1% NMP solution of 33-year-old 1% P-1 was prepared and the reduced viscosity was determined using an Ubbelohde viscometer, and it was found to be η8. /
The temperature was C-0.17 (25°C). Also, NMP of P-1
The glass transition temperature of the film obtained by coating and drying the solution and heat-treating it at 400°C for 2 hours was measured using a thermomechanical analyzer (TMA) and found to be 340°C, which was similar to DTG (
When the thermal decomposition onset temperature was measured using a differential thermal balance, it was 45.
It was 0°C. Further, the dielectric constant of the above film is 1 kHz.
z is 2.9, and the water absorption rate is 85°C x 85% I?
, H, 24 hours later, it was 0.8 vt%.

Example 2 33.2 g of isophthalic acid and 78.5 g of B CP F
to 300 ml of DM A e and 83.3 ml of pyridine.
g was added and dissolved by heating and stirring to 50° C. to obtain a homogeneous solution.

This solution was cooled to 0°C, and DCC187,1g-D
After dropping 84 ml of MAc solution, 82.2 g of HA B was added. After the reaction solution was returned to room temperature, it was stirred for 2 hours and then treated in the same manner as in Example 1 to obtain polymer powder P-
I got 2.

The structure of P-2 is as follows.

50 poems 1%
50@o1% Next, various physical properties of P-2 were measured in the same manner as in Example 1, and the following results were obtained.

rt　Sp/　C-0,17, Glass transition temperature -340℃, Thermal decomposition start temperature -450℃, Dielectric constant -2.9 (1kHz), Water absorption rate - ○, 8 vt%.

Example 3 BCPF 158.8g and DM Ac 470m
1 and 83.3 g of pyridine were added and stirred to dissolve.

After further adding 162.2 g of HoB T , the mixture was cooled to -5°C.

Add 187 DCC, 1 g of DM Ac 84 to this solution.
After dropping the m1 solution, 5 g of HAB8B was added. After the reaction solution was returned to room temperature, it was stirred for 2 hours, and then Example 1
Polymer powder P-3 was obtained by processing in the same manner as above.

The structure of P-3 is as follows.

Next, various physical properties of P-3 were measured in the same manner as in Example 1, and the following results were obtained.

ηSp/C-0,19, Glass transition temperature -360℃, Thermal decomposition start temperature -460℃, Dielectric constant -2.8 (1kHz), Water absorption rate - o,'y vt%.

Comparative Example 1 BCPF 15B, 8g and DM Ac 330m
1 and pyridine 83JIr were added and stirred to dissolve.

This solution was cooled to 0°C, a solution of 37.1 g of DCC1t in 84 ml of DMAc was added dropwise, and 2,2'-bis(
139.2 g of 4,4'-dihydroxy-3,3'-diamino)hexafluoropropane were added. After the reaction solution was returned to room temperature, it was stirred for 2 hours, and then Example 1
Polymer powder P-4 was measured in the same manner as above.

The structure of P-4 is as follows.

Next, various physical properties of P-4 were measured in the same manner as in Example 1, and the following results were obtained.

ηSp/C-0,16, Glass transition temperature -280℃, Thermal decomposition start temperature -400'C1 Dielectric constant -2,8(lk)12), Water absorption rate -0.7wt%.

From the above results, it can be seen that Comparative Example P-4 has a glass transition temperature and a thermal decomposition start temperature lower than those of Examples, and is inferior in terms of heat resistance. The reason is the above-X of formula I
is a group with a fluorine-containing structure, and it is presumed that this is the reason why the heat resistance of polybenzoxazole after heat treatment is reduced.

Example 4 Polymer P-1 obtained in Example U was mixed with IOg and 2
,2'-bis[4-(1,2-naphthoquinone-(2
)-Diazido-5-sulfonyl)phenyl]propane 2
g to NMP23.5. dissolved in. This varnish solution was spin-coded onto a silicon wafer and then dried in a circulation oven at 80° C. for 20 minutes to obtain a coating film with a thickness of 10 μm. After exposing this coated wafer to an energy of 3GO+aJ/cJ (measured with 3B5nXO) using an ultra-high pressure mercury lamp through a photomask, 1% of tetramethylammonium hydroxide, 5% of methanol, 5% of diethylene glycol dimethyl ether, and 1% of dimethylformamide were used.
It was developed using a developer consisting of a 0% aqueous solution. As a result, a sharp positive pattern with one-own line/space resolution was obtained. This wafer was heat treated at 400° C. for 2 hours in a nitrogen stream to convert it into polybenzoxazole.

Example 5 10 g of polymer P-2 obtained in Example 2 was NM
Dissolved in 23.5g of P. After spin-coding this solution onto a silicon wafer, it was placed on a pot plate at 150°C.
After drying for one layer, a coating film with a thickness of 4 μm was obtained. A commercially available positive photoresist (
For example, 0FPR-800 manufactured by Tokyo Ohka Co., Ltd.) was spin-coded and dried to form a coating film with a thickness of 2 μm. This wafer was heated to 40 mJ/cd <385 na using an ultra-high pressure mercury lamp.
2.
The layers were developed simultaneously to form a pattern. Next, the positive photoresist remaining on the top was removed by immersing it in acetone.

This wafer was heat treated at 350''C for 1 hour in a nitrogen stream to obtain a polybenzoxazole pattern.

〔Effect of the invention〕

The fluorine-containing aromatic polyamide of the present invention has the advantage of being excellent in heat resistance, and also has the effect of being a precursor of polybenzoxazole, which is also excellent in water absorption and dielectric properties.

Therefore, a varnish using this material is extremely useful as a protective film or an insulating film for electronic materials such as semiconductors, either by itself or as a positive photosensitive composition varnish, and is expected to make many contributions in this technical field. I can say that.

Patent applicant: Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] 1. It has a repeating unit represented by the general formula I and has a reduced viscosity (in N-methylpyrrolidone at 25°C) of 0.05 to 0.
．． 5, a fluorine-containing aromatic polyamide. ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・
I (In the formula, X is a ▲ mathematical formula, chemical formula, table, etc.
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and Y represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas, etc.
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
Represents either , ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼. a=0.1-1, b=0.9-0, a+b=1) 2. The method for producing a fluorine-containing aromatic polyamide according to claim 1, characterized in that the dehydration condensation is carried out using dicyclohexylcarbodiimide. . 3. A polybenzoxazole obtained by thermally dehydrating and ring-closing the fluorine-containing aromatic polyamide according to claim 1. 4. A varnish comprising the fluorine-containing aromatic polyamide according to claim 1 and a solvent. 5. A positive photosensitive composition varnish comprising the fluorine-containing aromatic polyamide according to claim 1, a quinonediazide compound, and a solvent.