JP2000248077A - Organic insulation film material for semiconductor and production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject organic insulation film material capable of manifesting excellent electric characteristics, thermal characteristics and low water absorptivity by forming fine pores in a specific polybenzoxazole resin layer. SOLUTION: This organic insulation film material has fine pores in a polybenzoxazole resin layer of formula I (n is 2-1,000; X is a tetravalent organic group; Y is a divalent organic group). The pore size is preferably <=20 nm. The polybenzoxazole resin layer is obtained, for example, by a method of mixing a polybenzoxazole precursor of formula II synthesized from a tetravalent aminophenol and a divalent carboxylic acid with an oligomer, forming the obtained mixture into a film, cycling the polybenzoxazole precursor of the obtained film, heating the resultant film to thermally degrade the oligomer and to gasify and volatilize the oligomer. The organic insulation film material obtained thereby can be applied as an insulation film between layers for a semiconductor, a protecting film, an insulation film between layers of multilayered circuit or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to electrical characteristics, thermal characteristics,
It relates to organic insulating film materials with excellent mechanical and physical properties, such as interlayer insulating films for semiconductors, protective films, interlayer insulating films for multilayer circuits, cover coats for flexible copper clad boards, solder resist films, liquid crystal alignment films, etc. Applicable as

[0002]

2. Description of the Related Art Various materials such as inorganic materials and organic materials are used in semiconductor materials according to required characteristics. For example, as an interlayer insulating film for a semiconductor, an inorganic insulating film such as silicon dioxide manufactured in a chemical vapor phase is used. However, as semiconductors become more sophisticated and more sophisticated in recent years, inorganic dielectric films such as silicon dioxide have problems such as high dielectric constant and high water absorption. As one of the improvement means, application of an organic material is being studied.

[0003] Organic materials for semiconductor applications include heat resistance,
A polyimide resin having excellent mechanical properties and the like is used, and is used for a solder resist, a coverlay, a liquid crystal alignment film, and the like. However, since polyimide resins generally have two carbonyl groups on the imide ring, there are problems in electrical characteristics and water absorption. In response to these problems, attempts have been made to improve the electrical properties, water absorption, and heat resistance by introducing fluorine and trifluoromethyl groups into the polymer. Absent.

[0004] For these reasons, attempts have been made to apply a polybenzoxazole resin, which exhibits better performance in terms of electrical properties and water absorption than a polyimide resin, to an insulating material for semiconductors. It is easy for the polybenzoxazole resin to satisfy only any one of electrical properties, thermal properties, and physical properties. For example, the polybenzoxazole resin is composed of 4,4′-diamino-3,3′-dihydroxybiphenyl and terephthalic acid. Polybenzoxazole resin has excellent heat resistance such as excellent thermal decomposition resistance and high Tg.
Electrical properties such as dielectric constant are not very good. Also, 2,2-
Polybenzoxazole resins composed of bis (3-amino-4-hydroxyphenyl) hexafluoropropane and terephthalic acid exhibit good electrical properties such as a low dielectric constant, but have poor heat resistance and the like. In recent years, a low dielectric constant material having a dielectric constant of less than 2.5 has been expected, and a resin satisfying this requirement and having excellent other electrical, thermal, and physical properties has not been obtained. is the current situation.

[0005]

DISCLOSURE OF THE INVENTION The present invention is directed to an electric property,
It is an object of the present invention to provide an organic insulating film material excellent in thermal characteristics and low water absorption and a manufacturing method.

[0006]

Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned conventional problems, and as a result, have found that the general formula (1)
The organic insulating film material for semiconductors, characterized in that the polybenzoxazole resin layer represented by the formula (1) has fine holes.

That is, it is as described in the items (a) to (h). (A) An organic insulating film material for a semiconductor, wherein the polybenzoxazole resin layer having the structure represented by the general formula (1) has fine pores.

[0008]

Embedded image (However, n in the general formula (1) represents an integer from 2 to 1000. X represents a tetravalent organic group and Y represents a divalent organic group.)

(B) The organic insulating film material for a semiconductor according to item (a), wherein the size of the fine pores in the polybenzoxazole resin layer is 20 nm or less.

(C) a polybenzoxazole precursor or polybenzoxazole resin mixed with an oligomer, formed into a film, and then heated to thermally decompose, vaporize, and volatilize the oligomer to form a polybenzoxazole having fine pores. A method for producing an organic insulating film material for a semiconductor, comprising obtaining a resin layer.

(D) A polybenzoxazole precursor having a structure represented by the general formula (2) synthesized from a tetravalent aminophenol and a divalent carboxylic acid and an oligomer are mixed and formed into a film. A method for producing an organic insulating film material for a semiconductor, characterized in that a benzoxazole precursor is closed, and the oligomer is thermally decomposed, vaporized and volatilized by heating to obtain a polybenzoxazole resin layer having fine pores. Method.

[0012]

Embedded image (However, n in the general formula (2) represents an integer from 2 to 1000. X represents a tetravalent organic group and Y represents a divalent organic group.)

(E) A polybenzoxazole precursor having a structure represented by the general formula (2) synthesized from a tetravalent aminophenol and a divalent carboxylic acid is represented by the following general formula (1): After mixing and forming a polybenzoxazole resin and an oligomer having a structure
A method for producing an organic insulating film material for a semiconductor, characterized in that an oligomer is thermally decomposed, vaporized and volatilized by heating to obtain a polybenzoxazole resin layer having fine pores.

(F) (c), (d) or (d) wherein the skeleton of the repeating unit of the oligomer is an oligomer selected from the group consisting of propylene oxide, ethylene oxide, methyl methacrylate, urethane, α-methylstyrene, styrene and carbonate. e) The method for producing an organic insulating film material for a semiconductor according to item e).

(G) The oligomer has a molecular weight of 100 to 10
(C), (d), (e) or (f).

(H) 5 to 40% of the polybenzoxazole resin having the structure represented by the general formula (1) or the polybenzoxazole precursor represented by the general formula (2) before the oligomer is heated. (C), (d), (e), (f) or (g), the method for producing a material for an organic insulating film for a semiconductor according to the above (c), (d), (e), (f) or (g).

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The tetravalent aminophenol compound used in the synthesis of the polybenzoxazole precursor and resin of the present invention is represented by the general formula (3). -Bis (3-amino-4-hydroxyphenyl) propane, 2,2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 1,4-bis (3-amino-4-hydroxyphenoxy) tetra Fluorobenzene, 1,4-bis (4-amino-3-hydroxyphenoxy) tetrafluorobenzene, 4,4′-bis (3-amino-4-hydroxyphenoxy) octafluorobiphenyl, 4,4′-bis (4 -Amino-3-hydroxyphenoxy) octafluorobiphenyl, 2,2-bis (3-amino-4-hydroxy-5-trifluoro) Methylphenyl) hexafluoropropane, 2,2-bis (4-amino-3-hydroxy-5-trifluoromethylphenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxy-5-pentafluoro Ethylphenyl) hexafluoropropane, 2- (3-amino-4-hydroxy-5-
Trifluoromethylphenyl) -2 ′-(3-amino-
4-hydroxy-5-pentafluoroethylphenyl)
Hexafluoropropane, 1,3-diamino-4,6-
Dihydroxydifluorobenzene, 1,4-diamino-
3,6-dihydroxydifluorobenzene, 1,4-diamino-2,3-dihydroxydifluorobenzene,
1,2-diamino-3,6-dihydroxydifluorobenzene, 1-trifluoromethyl-2,4-diamino-
3,5-dihydroxybenzene, 1-trifluoromethyl-2,5-diamino-3,6-dihydroxybenzene, 1-trifluoromethyl-2,4-diamino-3,
5-dihydroxyfluorobenzene, 1-trifluoromethyl-2,5-diamino-3,6-dihydroxyfluorobenzene, 1,4-bis (trifluoromethyl)-
2,5-diamino-3,6-dihydroxybenzene, 1
-Pentafluoroethyl-2,5-diamino-3,6-
Dihydroxybenzene, 1-perfluorocyclohexyl-2,5-diamino-3,6-dihydroxybenzene, 1,3-diamino-4,6-diethoxydifluorobenzene, 2,7-diamino-3,6-dihydroxytetrafluoro Naphthalene, 2,6-diamino-3,7-
Dihydroxytetrafluoronaphthalene, 1,6-diamino-2,5-dihydroxytetrafluoronaphthalene, 3,6-diamino-2,5-dihydroxytetrafluoronaphthalene, 2,7-diamino-1,8-dihydroxytetrafluoronaphthalene, 1-trifluoromethyl-3,6-diamino-2,7-dihydroxynaphthalene, 1,5-bis (trifluoromethyl) -3,7-
Diamino-2,6-dihydroxynaphthalene, 1-trifluoromethyl-3,6-diamino-2,5-dihydroxynaphthalene, 1-pentafluoroethyl-3,6-
Diamino-2,7-dihydroxynaphthalene, 1-perfluorocyclohexyl-3,6-diamino-2,7
-Dihydroxynaphthalene, 1,5-bis (trifluoromethyl) -3,7-diamino-2,6-dihydroxydifluoronaphthalene, 2,6-diamino-3,7-diethoxytetrafluoronaphthalene, 1,4,5 , 8-
Tetra (trifluoromethyl) -2,7-diamino-
3,6-dihydroxynaphthalene, 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, 4,4′-
Diamino-3,3'-dihydroxy-5,5'-trifluoromethylbiphenyl, 4,4'-diamino-3,
3′-dihydroxy-5,5′-pentafluoroethylbiphenyl, 4,4′-diamino-3,3′-dihydroxy-6,6′-trifluoromethylbiphenyl, 4,
4'-diamino-3,3'-dihydroxy-6,6'-
Pentafluoroethylbiphenyl, 3,3'-diamino-4,4'-dihydroxy-5,5'-trifluoromethylbiphenyl, 3,3'-diamino-4,4'-dihydroxy-5,5'-pentafluoro Ethyl biphenyl, 3,3'-diamino-4,4'-dihydroxy-
6,6′-trifluoromethylbiphenyl, 3,3′-
Diamino-4,4'-dihydroxy-6,6'-pentafluoroethylbiphenyl, 3,4'-diamino-4,
3'-dihydroxy-5,5'-trifluoromethylbiphenyl, 3,4'-diamino-4,3'-dihydroxy-5,5'-pentafluoroethylbiphenyl, 3,
4'-diamino-4,3'-dihydroxy-6,6'-
Trifluoromethylbiphenyl, 3,4'-diamino-
Examples thereof include 4,3′-dihydroxy-6,6′-pentafluoroethylbiphenyl, but are not necessarily limited thereto. It is also possible to use two or more aminophenols in combination.

[0018]

Embedded image (X represents a tetravalent organic group)

The divalent carboxylic acid used in synthesizing the polybenzoxazole precursor and the resin of the present invention is represented by the general formula (4), for example, isophthalic acid, terephthalic acid, Fluoroisophthalic acid,
2-fluoroisophthalic acid, 3-fluorophthalic acid, 2
-Fluorophthalic acid, 2-fluoroterephthalic acid, 2,
4,5,6-tetrafluoroisophthalic acid, 3,4
5,6-tetrafluorophthalic acid, 4,4'-hexafluoroisopropylidenediphenyl-1,1'-dicarboxylic acid, perfluorosuberic acid, 2,2'-bis (trifluoromethyl) -4,4'- Biphenylenedicarboxylic acid, 4,4'-oxydiphenyl-1,1'-dicarboxylic acid, 2,3,4,6,7,8-hexafluoronaphthalene-1,5-dicarboxylic acid, 2,3,4,5 , 7,
8-hexafluoronaphthalene-1,6-dicarboxylic acid, 1,3,4,5,7,8-hexafluoronaphthalene-2,6-dicarboxylic acid, 1-trifluoromethylnaphthalene-2,6-dicarboxylic acid, 1,5-bis (trifluoromethyl) naphthalene-2,6-dicarboxylic acid,
1-pentafluoroethylnaphthalene-2,6-dicarboxylic acid, 1-trifluoromethylnaphthalene-3,7-
Dicarboxylic acid, 1,5-bis (trifluoromethyl) naphthalene-3,7-dicarboxylic acid, 1-pentafluoroethylnaphthalene-3,7-dicarboxylic acid, 1-undecafluorocyclohexylnaphthalene-3,7-dicarboxylic acid , 1-trifluoromethyl-2,4,5,6,8
-Pentafluoronaphthalene-3,7-dicarboxylic acid,
1-bis (trifluoromethyl) methoxy-2,4,
5,6,8-pentafluoronaphthalene-3,7-dicarboxylic acid, 1,5-bis (trifluoromethyl) -2,
4,6,8-tetrafluoronaphthalene-3,7-dicarboxylic acid, 1,5-bis [bis (trifluoromethyl)
[Methoxy] -2,4,6,8-tetrafluoronaphthalene-3,7-dicarboxylic acid and the like, but are not necessarily limited thereto. It is also possible to use two or more carboxylic acids in combination.

[0020]

Embedded image (Y represents a divalent organic group)

The oligomer used in the present invention is more thermally decomposed than the polybenzoxazole resin having the structure represented by the general formula (1) and the polybenzoxazole precursor having the structure represented by the general formula (2). Any oligomer may be used as long as it is an oligomer having a low vaporization temperature, and is not necessarily limited. For example, an oligomer whose skeleton is composed of a repeating unit such as propylene oxide, ethylene oxide, methyl methacrylate, urethane, α-methylstyrene, styrene, and carbonate is exemplified.

The oligomer has a molecular weight of 100 to 100.
A range of 00 is preferred. If the molecular weight is less than 100, the dielectric constant cannot be lowered, and if the molecular weight exceeds 10,000, the voids become too large to lower the mechanical strength of the film, or open cells reaching the film surface are formed. Problems occur.

The oligomer is preferably contained in a weight ratio of 5 to 40% with respect to the polybenzoxazole resin or the polybenzoxazole precursor before heating. If the weight ratio is less than 5%, the dielectric constant cannot be lowered, and if the weight ratio exceeds 40%, the voids become too large,
Problems such as a decrease in mechanical strength, the formation of open cells on the surface of the insulating film, an uneven porosity and a difference in dielectric constant depending on the location occur.

In the method for producing an organic insulating film material of the present invention, first, a uniform mixture of the polybenzoxazole precursor and the oligomer, or a polybenzoxazole resin and a oligomer in which the polybenzoxazole precursor has been closed beforehand is used. Is performed by uniform mixing of That is, a tetravalent aminophenol compound represented by the general formula (3) and a divalent carboxylic acid represented by the general formula (4) are converted into a polybenzoxazole precursor by an active ester method or an acid chloride method. The precursor and the oligomer are uniformly mixed and subjected to a condensation reaction by heating or treating with a dehydrating agent, whereby the benzoxazole is closed at a temperature lower than the temperature at which the oligomer is thermally decomposed and vaporized under nitrogen. Further, this is heated in the atmosphere to thermally decompose, vaporize and volatilize the oligomer, whereby a polybenzoxazole resin layer having fine pores can be obtained.

Alternatively, a dehydrating condensing agent such as polyphosphoric acid or dicyclohexyl dicarbodiimide is prepared by combining a tetravalent aminophenol compound represented by the general formula (3) and a divalent carboxylic acid represented by the general formula (4). The benzoxazole is closed by a condensation reaction method in the presence of to obtain a polybenzoxazole resin. As the polyphosphoric acid used here, it is also possible to use a mixed acid anhydride of phosphorus pentoxide and methanesulfonic acid such as Eaton's reagent (manufactured by Aldrich). The polybenzoxazole resin and the oligomer are uniformly mixed and heated in the air to thermally decompose, vaporize and volatilize the oligomer, whereby a polybenzoxazole resin layer having fine pores can be obtained.

An organic insulating film material for a semiconductor according to the present invention, wherein the polybenzoxazole resin layer having the structure represented by the general formula (1) has fine pores.
The size of the void is at least 20 nm or less, preferably 5 nm or less.
nm or less is desirable. If the size of the gap is larger than 20 nm, problems such as an uneven porosity between the wirings and a bad influence on the adhesion may occur.

If necessary, a surfactant or a coupling agent as various additives is added to a mixture of a polybenzoxazole precursor and an oligomer or a mixture of a polybenzoxazole resin and an oligomer, and an interlayer insulating film for semiconductor, It can be used as a protective film, an interlayer insulating film of a multilayer circuit, a cover coat of a flexible copper clad board, a solder resist film, a liquid crystal alignment film, and the like.

In the present invention, the acid chloride used in the acid chloride method in the synthesis of the polybenzoxazole precursor is:
It is represented by the general formula (5).

[0029]

Embedded image (Y represents a divalent organic group)

As an example of the synthesis of a polybenzoxazole precursor by the acid chloride method, first, 4,4'-hexafluoroisopropylidenediphenyl-1,1'-dicarboxylic acid, which is a divalent carboxylic acid, is converted to N, By reacting at room temperature to 75 ° C. in the presence of a catalyst such as N-dimethylformamide in the presence of an excessive amount of thionyl chloride, the acid chloride 4,4′-hexafluoroisopropylidenediphenyl-1,1-dicarboxylic acid is obtained. Get the chloride.
2,2′-Bis (3-amino-4-hydroxyphenyl) hexafluoropropane is dissolved in N-methyl-2-pyrrolidone dried under a dry nitrogen atmosphere, and γ-butyrolactone is added to 4,4′-hexafluoropropane. A solution in which isopropylidene diphenyl-1,1-dicarboxylic acid chloride is dissolved is added dropwise. Thereafter, a solution of pyridine in γ-butyrolactone was added dropwise. After completion of the dropwise addition, the mixture is returned to room temperature and stirred. The reaction solution was filtered to remove pyridine hydrochloride, and the reaction solution was added dropwise to a mixed solution of distilled water and ethanol,
The precipitate is collected and dried to obtain a polybenzoxazole precursor.

In the present invention, the polybenzoxazole precursor is usually used in an amount of 10 to 40% by weight based on the solvent.
It is preferable to dissolve at a concentration that facilitates the formation of a film, and use it in a varnish form. As the solvent, N-methyl-2-
Pyrrolidone, γ-butyrolactone, ε-caprolactone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, 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, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate, methyl-3-methoxypropionate and the like can be used alone or in combination of two or more.

In the method for producing an organic insulating film for a semiconductor according to the present invention, when a polybenzoxazole precursor is used,
A mixture of the polybenzoxazole precursor and the oligomer is dissolved in the above solvent, and a suitable support, for example, glass,
Apply to metals, silicone wafers, ceramic substrates, etc. As a coating method, spin coating using a spinner,
Spray coating using a spray coater, dipping, printing, roll coating and the like can be mentioned. In this way, after forming the coating film, it is subjected to a heat treatment to convert it into a polybenzoxazole resin, and the resin layer is further heated to thermally decompose and vaporize the oligomer and volatilize to form micropores. Is preferred.

In the case of a mixture of a polybenzoxazole resin and an oligomer, the mixture is dissolved in the above-mentioned solvent and applied to an appropriate support, for example, a glass, metal, silicone wafer or ceramic substrate. Examples of the coating method include spin coating using a spinner, spray coating using a spray coater, dipping, printing, and roll coating.
In this way, after forming the coating film, heat treatment,
Preferably, the solvent is removed, and the oligomer is thermally decomposed, vaporized, and volatilized to form micropores.

The mixture of the polybenzoxazole resin and the oligomer in the present invention can be used as a photosensitive resin composition by using a precursor thereof and a naphthoquinonediazide compound as a photosensitive agent in combination.

[0035]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to the contents of the examples. Hereinafter, "part" indicates "part by weight".

Synthesis Example of Mixed Varnish of Polybenzoxazole Precursor or Polybenzoxazole Resin and Oligomer "Synthesis Example 1" 4.27 parts of 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane ( 1
1.67 mmol) was dissolved in 20 parts of dry N-methyl-2-pyrrolidone under an atmosphere of dry nitrogen, and at 10 ° C., 20 parts of γ-butyrolactone was added to 4,4′-hexafluoroisopropylidene diphenyl-1,4. What melt | dissolved 5.00 parts (11.67 mmol) of 1'-dicarboxylic acid chloride was dripped over 30 minutes. Then, it returned to room temperature and stirred at room temperature for 2 hours. Thereafter, a solution prepared by dissolving 2.0 parts of pyridine in 20 parts of γ-butyrolactone was added dropwise at 10 ° C. over 30 minutes. After dropping, return to room temperature,
Stirred at room temperature for 24 hours. The reaction solution was filtered to remove pyridine hydrochloride, and the reaction solution was added dropwise to a mixed solution of 0.18 liter of distilled water and 0.54 liter of ethanol, and the precipitate was collected and dried to obtain a polybenzoxazole precursor. I got The number average molecular weight (Mn) of the obtained polybenzoxazole precursor was determined by GPC manufactured by Tosoh Corporation.
When calculated in terms of polystyrene using
Met.

An oligomer having a molecular weight of 2,000 having a main chain of propylene oxide having isocyanate groups at both ends (SBU0620 manufactured by Sumitomo Bayer Urethane Co., Ltd.) and one equivalent of phenol with respect to the isocyanate group are mixed in tetrahydrofuran in the presence of a basic catalyst. To obtain propylene oxide oligomers of carbamates at both ends. This oligomer and the above-mentioned polybenzoxazole precursor were mixed with each other so that the oligomer had a weight ratio of 10% to the polybenzoxazole precursor.
Dissolve in methyl-2-pyrrolidone and mix homogeneously,
% Solution. The mixture was filtered through a 0.2 μm Teflon filter to obtain a varnish.

"Synthesis Example 2" 3.94 parts of 2,2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane and 4,4'-hexafluoroisopropylidenediphenyl-1,1'-dicarboxylic acid 3.92 parts of Eaton's reagent (manufactured by Aldrich) 5
0 ml and 135 g with stirring under a dry nitrogen atmosphere.
C. and stirred for 24 hours. The obtained black-brown solution was treated with an aqueous sodium hydroxide solution (1500 m water).
(a solution of 45 g of sodium hydroxide in 1) was added dropwise to precipitate a polymer. Further, a tetrahydrofuran solution of the polymer obtained in the same manner as described above was added to 1500 ml of water.
The precipitated polymer was filtered, then pulverized, and 200 g of methanol was added thereto and refluxed for 3 hours. The polymer thus obtained was dried at 90 ° C. for 3 hours to obtain a light purple white target polybenzoxazole resin. The number average molecular weight (Mn) of the polybenzoxazole precursor obtained here was 25,000 as calculated as polystyrene using GPC manufactured by Tosoh Corporation.

The oligomer to be mixed with the polybenzoxazole resin is a commercially available diisocyanate SBU0620 having a molecular weight of 2,000 and a main chain of propylene oxide.
(Manufactured by Sumitomo Bayer Urethane Co., Ltd.) and one equivalent of phenol with respect to isocyanate group in tetrahydrofuran in the presence of a basic catalyst. This is an oligomer of propylene oxide of dicarbamate. Polybenzoxazole resin, oligomer is 10% of polybenzoxazole resin
Was dissolved in N-methyl-2-pyrrolidone so as to have a weight ratio of 1 and uniformly mixed to obtain a 15% by weight solution. 0.2
The solution was filtered through a μm Teflon filter to obtain a varnish.

Production Example of Polybenzoxazole Resin Layer Having Micropores [Example 1] The varnish obtained in Synthesis Example 1 was applied to a silicon wafer on which aluminum was deposited by using a spin coater. At this time, the rotation speed and time of the spin coater were set so that the film thickness after the heat treatment was about 1 μm. After the application, the coating was dried on a hot plate at 100 ° C. for 120 seconds, and then heated at 150 ° C./30 minutes and 250 ° C./30 minutes using an oven in which nitrogen was introduced to control the oxygen concentration to 100 ppm or less.
Heat in the order of 30 minutes, 310 ° C./30 minutes, and then 150 ° C./30 minutes, 250 ° C./30 minutes, 400 ° C./3 in the atmosphere.
Heating was performed for 0 minutes to obtain a polybenzoxazole film.
Aluminum was vapor-deposited on the film to perform patterning, thereby forming an electrode having a predetermined size. By measuring the capacity of aluminum on the silicon wafer side and this electrode, etching the film adjacent to the electrode with oxygen plasma after measurement, and measuring the film thickness with a surface roughness meter,
When the dielectric constant at a frequency of 1 MHz was calculated, it was 2.2.
Met. When the IR spectrum of this film was measured by FT-IR, absorption by the amide of oxazole to 1656 cm ^-1 is absorption by oxazole to 1053,1625Cm ^-1 not observed observed, that the polybenzoxazole is generated confirmed. TG-DTA
The 5% weight loss temperature in a nitrogen atmosphere was 513 ° C. When the cross section of this film was observed with a TEM, it was confirmed that pores of 5 nm or less were formed.

Example 2 A polybenzoxazole resin film was formed in the same manner as in Example 1 except that the varnish obtained in Synthesis Example 2 was used instead of the varnish obtained in Synthesis Example 1. It was fabricated and evaluated. As a result, the frequency 1
The dielectric constant at MHz was 2.2. Further, when the IR spectrum of this film was measured by FT-IR, absorption by the amide of oxazole to 1656 cm ^-1 is absorption by oxazole to 1053,1625Cm ^-1 not observed observed, polybenzoxazole is generated It was confirmed that. The 5% weight loss temperature in a nitrogen atmosphere measured by TG-DTA was 513 ° C.
Further, when the cross section of this film was observed with a TEM, it was confirmed that pores of 5 nm or less were formed.

Example 3 In Synthesis Example 1, N-methyl-2 was prepared by uniformly mixing the oligomer with the polybenzoxazole precursor at a weight ratio of 10% to 20%.
-Except that it is dissolved in pyrrolidone to give a 20% by weight solution
A varnish was obtained in the same manner as in Synthesis Example 1. A film of a polybenzoxazole resin was prepared and evaluated in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.1. The 5% weight loss temperature was 505 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

"Example 4" In Synthesis Example 1, the oligomer to be mixed with the polybenzoxazole precursor was a commercially available propylene oxide-terminated diisocyanate oligomer having a molecular weight of 2,000 (manufactured by Sumitomo Bayer Urethane Co., Ltd.) A varnish was obtained in the same manner as in Synthesis Example 1 except that a varnish having a molecular weight of 1,000 was used. A film of a polybenzoxazole resin was prepared and evaluated in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.2. The 5% weight loss temperature was 510 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

Example 5 In Example 4, the oligomer was uniformly mixed at a weight ratio of 10% with respect to the polybenzoxazole precursor at a weight ratio of 30% to obtain N-methyl-2.
-Except that it is dissolved in pyrrolidone to give a 20% by weight solution
A film of a polybenzoxazole resin was prepared and evaluated in the same manner as in Example 3. As a result, the dielectric constant is 2.0
Met. The 5% weight loss temperature was 502 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

Example 6 The procedure of Synthesis Example 1 was repeated except that the oligomer had a molecular weight of 2 with a commercially available propylene oxide as the main chain.
2,000 terminal diisocyanate oligomer (manufactured by Sumitomo Bayer Urethane Co., Ltd.) and the oligomer was uniformly mixed at a weight ratio of 5% to the polybenzoxazole precursor to give N-methyl-2. -A varnish was obtained in the same manner as in Synthesis Example 1 except that the varnish was dissolved in pyrrolidone to make a 20% by weight solution. A film of a polybenzoxazole resin was prepared and evaluated in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.1. The 5% weight loss temperature was 510 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

Example 7 In Synthesis Example 1, the molecular weight was 2,000 instead of propylene oxide, which is an oligomer.
A varnish was obtained in the same manner as in Synthesis Example 1 except that ethylene oxide was used. A polybenzoxazole film was produced in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant is
2.2. The 5% weight loss temperature was 516 ° C. Also, this polybenzoxazole film has a thickness of 5n.
It was confirmed that pores of m or less were formed.

Example 8 In Synthesis Example 1, a molecular weight of 1000 was used instead of propylene oxide as an oligomer.
Synthesis Example 1 was repeated except that methyl methacrylate was used as it was, and the polybenzoxazole precursor was uniformly mixed at a weight ratio of 10% and dissolved in N-methyl-2-pyrrolidone to form a 20% by weight solution. A varnish was obtained in the same manner. A polybenzoxazole film was produced in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.1. 5
The% weight loss temperature was 511 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

Example 9 In Synthesis Example 1, a molecular weight of 5000 was used instead of propylene oxide which is an oligomer.
A varnish was obtained in the same manner as in Synthesis Example 1 except that urethane was used. A polybenzoxazole film was produced in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.1. The 5% weight loss temperature was 505 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

Example 10 In Synthesis Example 1, a molecular weight of 500 was used instead of propylene oxide as an oligomer.
The synthesis was carried out except that α-methylstyrene of 0 was uniformly mixed with the polybenzoxazole precursor at a weight ratio of 10% and dissolved in N-methyl-2-pyrrolidone to form a 20% by weight solution. A varnish was obtained in the same manner as in Example 1. A polybenzoxazole film was produced in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.1. 5%
The weight loss temperature was 509 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

Example 11 In Synthesis Example 1, a molecular weight of 300 was used in place of propylene oxide as an oligomer.
0, and uniformly mixed with the polybenzoxazole precursor at a weight ratio of 10% with N
A varnish was obtained in the same manner as in Synthesis Example 1 except that the varnish was dissolved in -methyl-2-pyrrolidone to make a 20% by weight solution. A polybenzoxazole film was produced in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.1. The 5% weight loss temperature was 510 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

Example 12 Varnish Obtained in Synthesis Example 2
Was coated with aluminum using a spin coater.
Coated on con-wafer. At this time, the film thickness after heat treatment is
Set the rotation speed and time of the spin coater to about 1 μm.
Set. After coating, 12 on a hot plate at 100 ° C.
After drying for 0 seconds, nitrogen was introduced to reduce the oxygen concentration to 100 p.
pm or less using an oven controlled to below pm
℃ / 30min, 250 ℃ / 30min, 400 ℃ / 30min
Heating gave a polybenzoxazole film. On the film
Aluminum is deposited and patterned to achieve a predetermined size.
The size of the electrode was formed. Aluminum on silicon wafer side
And the capacitance of this electrode.
The extremely adjacent part is etched with oxygen plasma to obtain a rough surface.
The frequency is 1 MHz by measuring the film thickness
The dielectric constant was calculated to be 2.2. this
The IR spectrum of the film was measured by FT-IR.
1656cm ^-1Of oxazole by amide
Is not seen 1053, 1625cm^-1To oxazole
Is observed and polybenzoxazole is formed.
It was confirmed that. Heat resistance by TG-DTA
Evaluation showed that the 5% weight loss temperature in a nitrogen atmosphere was 51%.
6 ° C. Also, the cross section of this film was observed by TEM.
Observation confirmed that pores of 5 nm or less were formed.
I accepted.

Example 13 In Synthesis Example 1, 2,2-
2.52 parts (11.67 mmol) of 4,4′-diamino-3,3′-dihydroxybiphenyl was replaced with 4.27 parts (11.67 mmol) of bis (3-amino-4-hydroxyphenyl) hexafluoropropane. 4,4 '
-Hexafluoroisopropylidene diphenyl-1,
5.00 parts of 1'-dicarboxylic acid chloride (11.67 m
mol) and 2.37 parts of terephthalic acid chloride (1
A varnish was obtained in the same manner as in Synthesis Example 1 except that 1.67 mmol) was dissolved. A polybenzoxazole film was produced in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.2. 5% weight loss temperature is 530 ℃
Met. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

[Comparative Example 1] In a separable flask equipped with a stirrer, a nitrogen inlet tube and a dropping funnel, 14.65 g (0. 0,2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane was added. 04mol) was dissolved in 200 g of dried dimethylacetamide, and pyridine7.
After adding 92 g (0.20 mol), dry nitrogen was introduced.
At -15 ° C, 4,4'-
Hexafluoroisopropylidene diphenyl-1,1 '
16.92 g (0.04 ml) of dicarboxylic acid chloride
Was dissolved and added dropwise over 30 minutes, and the precipitate was recovered and dried to obtain a powder of a polybenzoxazole precursor. The number average molecular weight (Mn) of the polybenzoxazole precursor obtained here was determined to be 17000 by polystyrene conversion using GPC manufactured by Tosoh Corporation. This was dissolved in N-methyl-2-pyrrolidone and dissolved in 20%
Solution. The mixture was filtered through a 0.2 μm Teflon filter to obtain a varnish.

The varnish was applied on a silicon wafer on which aluminum was deposited by using a spin coater. At this time, the rotation speed and time of the spin coater were set so that the film thickness after the heat treatment was about 1 μm. After the coating, the coating was dried on a hot plate at 100 ° C. for 120 seconds, and then heated at 150 ° C./30 minutes, 250 ° C./30 minutes, 310 using an oven in which nitrogen was introduced to control the oxygen concentration to 100 ppm or less.
Heat in order of 30 ° C / 30 min.
0 minutes, heated at 250 ° C / 30 minutes, 400 ° C / 30 minutes,
A film of polybenzoxazole was obtained. Aluminum was vapor-deposited on the film to perform patterning to form an electrode having a predetermined size. Measure the capacitance between the aluminum on the silicon wafer side and this electrode, etch the film adjacent to the electrode with oxygen plasma after measurement, and measure the film thickness with a surface roughness meter to calculate the dielectric constant at a frequency of 1 MHz. The result was 2.6. When the IR spectrum of this film was measured by FT-IR,
Absorption at 1656 cm ^-1 due to the amide of oxazole absorption by oxazole to 1053,1625Cm ^-1 not observed observed, it was confirmed that polybenzoxazole is generated. When the heat resistance was evaluated by TG-DTA, the 5% weight loss temperature in a nitrogen atmosphere was 516.
° C.

Comparative Example 2 In Synthesis Example 1, the oligomer was mixed with a polybenzoxazole precursor at a weight ratio of 10% at a weight ratio of 50%, dissolved in N-methyl-2-pyrrolidone, and dissolved at 20% by weight. A varnish was obtained in the same manner as in Synthesis Example 1 except that the varnish was changed to a% solution. A polybenzoxazole resin was prepared and evaluated in the same manner as in Example 1 except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant varied from 2.0 to 2.4 depending on the measurement location and was non-uniform. 5% weight loss temperature is 50
It was 0 ° C. It was also confirmed that the polybenzoxazole film had pores having a size of about 100 nm.

"Comparative Example 3" In Synthesis Example 1, a commercially available propylene oxide (manufactured by Sumitomo Bayer Urethane Co., Ltd.) mixed with a polybenzoxazole precursor was replaced by an oligomer having a molecular weight of 88 instead of an oligomer having a main chain of polybenzoxazole. The oxazole precursor was mixed at a weight ratio of 10%, dissolved in N-methyl-2-pyrrolidone and dissolved in 20% by weight.
A varnish was obtained in the same manner as in Synthesis Example 1 except that the solution was used. A polybenzoxazole film was produced in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. As a result, the dielectric constant was 2.6. 5
The% weight loss temperature was 516 ° C. It was also confirmed that the polybenzoxazole film had pores of 5 nm or less.

Comparative Example 4 In Synthesis Example 1, the oligomer to be mixed with the polybenzoxazole precursor was replaced with a commercially available propylene oxide-terminated diisocyanate oligomer having a molecular weight of 2,000 (manufactured by Sumitomo Bayer Urethane Co., Ltd.) having a main chain of propylene oxide. Using α-methyl methacrylate having a molecular weight of 30,000, the mixture was directly mixed with the polybenzoxazole precursor at a weight ratio of 10% to give N-methyl-2-
A varnish was obtained in the same manner as in Synthesis Example 1, except that the varnish was dissolved in pyrrolidone to make a 20% by weight solution. A polybenzoxazole film was produced in the same manner as in Example 1, except that the varnish obtained in Example 1 was replaced with the varnish obtained here. as a result,
The dielectric constant could not be measured because the upper and lower electrodes were short-circuited. 5
The% weight loss temperature was 503 ° C. The polybenzoxazole film had pores of 1 μm.

The polybenzoxazole precursor and oligomer of the present invention of Examples 1 to 13 were blended or blended with a polybenzoxazole resin, and the polybenzoxazole containing micropores in which the oligomer was thermally decomposed and vaporized and volatilized by a heating operation. Each of the oxazole films had good characteristics of a low dielectric constant of 2.0 to 2.2 and a high heat resistance.

In Comparative Example 1, the polybenzoxazole resin did not contain pores, so the heat resistance was the same and good, but the dielectric constant was 2.6, which was significantly higher than Examples 1 to 13.

In Comparative Example 2, the weight ratio of the oligomer was 50
%, The dielectric constant was a non-uniform value of 2.0 to 2.4.

In Comparative Example 3, the oligomer had a molecular weight of 100
The dielectric constant was 2.6, which was smaller than
It was much higher than 3.

In Comparative Example 4, the oligomer had a molecular weight of 100
Since it was a high molecular weight substance exceeding 00, when a film having a thickness of about 1 μm was formed, a hole penetrating vertically was formed, and the upper and lower electrodes were short-circuited.

[0063]

The organic insulating film material of the present invention has electrical characteristics,
The present invention relates to a resin having excellent thermal properties, mechanical properties, and physical properties. Therefore, various fields where electrical, thermal, mechanical and physical properties are required, such as interlayer insulating films for semiconductors, protective films, interlayer insulating films for multilayer circuits, cover coats for flexible copper clad boards, solder resist films And a liquid crystal alignment film.

Claims (9)

[Claims] 1. An organic insulating film material for a semiconductor, wherein a polybenzoxazole resin layer having a structure represented by the general formula (1) has fine pores. Embedded image (However, n in the general formula (1) represents an integer from 2 to 1000. X represents a tetravalent organic group and Y represents a divalent organic group.) 2. The organic insulating film material for a semiconductor according to claim 1, wherein the size of the fine pores in the polybenzoxazole resin layer is 20 nm or less. 3. A polybenzoxazole resin having micropores by mixing and forming a polybenzoxazole precursor or a polybenzoxazole resin with an oligomer, and then heating to thermally decompose, vaporize, and volatilize the oligomer. A method for producing an organic insulating film material for a semiconductor, comprising obtaining a layer. 4. A polybenzoxazole precursor having a structure represented by the general formula (2), which is synthesized from a tetravalent aminophenol and a divalent carboxylic acid, and an oligomer are mixed and formed into a film. A method for producing an organic insulating film material for a semiconductor, comprising: subjecting an oxazole precursor to ring closure and further heating to thermally decompose, vaporize and volatilize the oligomer to obtain a polybenzoxazole resin layer having fine pores. . Embedded image (However, n in the general formula (2) represents an integer from 2 to 1000. X represents a tetravalent organic group and Y represents a divalent organic group.) 5. A compound represented by the general formula (1) in which a polybenzoxazole precursor having a structure represented by the general formula (2) synthesized with a tetravalent aminophenol and a divalent carboxylic acid is closed. After mixing with a polybenzoxazole resin having a structure and an oligomer, forming a film, and further heating, the oligomer is thermally decomposed, vaporized and volatilized to obtain a polybenzoxazole resin layer having fine pores. Of producing an organic insulating film material for a semiconductor. 6. The oligomer according to claim 3, wherein the skeleton of the repeating unit of the oligomer is an oligomer selected from the group consisting of propylene oxide, ethylene oxide, methyl methacrylate, urethane, α-methylstyrene, styrene and carbonate. A method for producing an organic insulating film material for a semiconductor. 7. The oligomer has a molecular weight of 100 to 1000.
The method for producing an organic insulating film material for a semiconductor according to claim 3, 4, 5, or 6, which is 0. 8. The method according to claim 3, wherein the oligomer is contained in the polybenzoxazole resin having a structure represented by the general formula (1) in a weight ratio of 5 to 40% before heating. 8. The method for producing an organic insulating film material for a semiconductor according to 5, 6, or 7. 9. The method according to claim 3, wherein the oligomer is contained in a weight ratio of 5 to 40% with respect to the polybenzoxazole precursor having a structure represented by the general formula (2) before heating. 8. The method for producing an organic insulating film material for a semiconductor according to 4, 6 or 7.