JPH04341705A - Inter-layer isolating film - Google Patents

Abstract

PURPOSE:To improve adhesiveness and insulation performance, and prevent occurrence of any crack in the case of a thick film by using a silicon oxide film formed under nonaqueous condition. CONSTITUTION:A solid body surface is applied with the organic solvent solution of a silazane compound, and then is baked in an oxidation atmosphere so as to prevent practical existence of a peak in the range of 3200-3600cm<-1> wave number due to the existence of water on an infrared absorption spectrum. In this case the silazane compound is obtained by reacting halogenosilane or organo halogenosilane and ammonia or amine acid in an organic solvent. As amines, lower alkyl amine and the like, such as monomethylamine and aralkyl amine, are used and as the organic solvent, toluene, xylene and the like are used. Thereby adhesion to the substrate is excellent, peeling and a crack do not occur even in the case of a thick film, insulation performance is excellent also, and it is possible to be used, for instance, as an inter-layer isolating film for multi-layer wiring and the like.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a novel interlayer insulating film, and more specifically, a new interlayer insulating film, which is particularly suitable for use in various electronic components, such as semiconductor devices and liquid crystal display devices, and is capable of adhesion without cracking even in thick films. The present invention relates to an interlayer insulating film having excellent properties and insulation properties.

0002

2. Description of the Related Art In the production of various electronic component materials, it is often necessary to form an interlayer insulating film on a solid surface. As this interlayer insulating film, a silica-based film has conventionally been generally used, and is formed on a solid surface by, for example, a vapor phase growth method, a dispersion coating method, a film forming liquid coating method, or the like.

However, the vapor phase growth method is a method of vapor depositing and growing silica on a solid surface using special equipment, and has the drawbacks of requiring expensive equipment and being difficult to mass produce. have. In addition, the dispersion coating method is a method in which silica or glass powder is dispersed in a polymer compound and applied to a solid surface, and it has been attracting attention in recent years because it is simple, but it is a method that allows for homogeneous dispersion. In addition to being difficult, there are drawbacks such as the film thickness tends to be uneven and pinholes are likely to occur. Furthermore, as a film forming liquid coating method, it is known that, for example, a reaction product of carboxylic acid, halogenosilane and alcohol is used as a coating liquid (Japanese Patent Publication No. 16488/1988). The formed silica-based film is hygroscopic, so it absorbs moisture in the atmosphere, reducing adhesion and insulation properties, making it impossible to obtain a practical interlayer insulation film, and cracking occurs when the film is thick. The drawback was that it was easy to do.

0004

Problems to be Solved by the Invention The present invention overcomes the drawbacks of conventional silica-based interlayer insulating films, and provides a silica-based interlayer insulating film that not only has excellent adhesion and insulation properties but also does not cause cracks even when made into a thick film. This was done for the purpose of providing a system interlayer insulating film.

[0005]

[Means for Solving the Problems] The present inventors have overcome the drawbacks of the conventional silica-based interlayer insulating film described above, and as a result of intensive research, have developed a silicon oxide film formed under non-aqueous conditions. It was discovered that the object could be achieved by using the present invention, and the present invention was completed based on this knowledge.

That is, the present invention provides an interlayer insulating film made of a silicon oxide film formed under non-aqueous conditions.

[0007] "Non-aqueous conditions" as used in the present invention means conditions in the absence of water and without the production of water. The silicon oxide film used as a conventional interlayer insulating film is formed in the presence of water or under conditions where water is generated, so its infrared absorption spectrum has a wave number of 3200 to 3600 cm- caused by the presence of water. 1, whereas the silicon oxide film used as the interlayer insulating film of the present invention has substantially no peak in the wavenumber range, and there is clearly a compositional difference between the two. Differences are recognized.

A silicon oxide film having such characteristics can be obtained, for example, by applying an organic solvent solution of a silazane compound to a solid surface, and then baking the solution in an oxidizing atmosphere. This silazane compound is a general term for compounds having Si-N bonds in the molecule, but in the present invention,
It is preferable to use a silazane compound that does not contain an oxygen atom in its molecule.

Such a silazane compound can be obtained by reacting a halogenosilane or organohalogenosilane with ammonia or an amine in an organic solvent. Examples of the halogenosilane used at this time include S
iCl4, HSiCl3, H2SiCl2, H3SiC
Examples of organohalogenosilanes include CH3SiHCl2, CH3S
iH2Cl, CH3SiCl3, (CH3)2SiCl
2, (CH3)3SiCl, C2H5SiCl3, (C
2H5)3SiCl, (C2H5)(C6H5)SiC
l2, (C2H5) (C6H5)2SiCl, (CH3
)3CSiHCl2, (CH3)2CHSiHCl2,
(C6H5)SiHCl2, (C6H5)SiCl3,
(C6H5)2SiCl2, (C6H5)3SiCl,
C6H5CH2SiCl3, (C6H5CH2)2Si
Examples include Cl2, (C6H5CH2)3SiCl, and the like.

On the other hand, examples of amines to be reacted with these halogenosilanes and organohalogenosilanes include lower alkylamines such as monomethylamine, ethylamine, propylamine, and butylamine, polyamines such as ethylenediamine, and aralkylamines such as benzylamine and phenethylamine. etc. can be mentioned.

[0011] Examples of organic solvents used in these reactions include toluene, xylene, diethyl ether,
Examples include dichloromethane.

Particularly suitable silazane compounds include HSiCl3, H2SiCl2, H3SiCl2 in the organic solvent.
It is obtained by dissolving halogenosilane such as and blowing ammonia gas into it.

In the present invention, the reaction mixture of halogenosilane or organohalogenosilane and ammonia or amines thus obtained can be used as a coating liquid as it is, or the reaction mixture can be distilled under reduced pressure or the like. After removing the solvent and recovering the desired silazane compound as an oily substance or solid substance, this can be dissolved in a suitable organic solvent to prepare a coating solution.

Examples of the organic solvent in this case include methanol, ethanol, propanol, butanol, cyclohexanol, benzyl alcohol, dimethylolbenzene, furfuryl alcohol, tetrahydrofurfuryl alcohol, diacetone alcohol, ethylene glycol monoalkyl ether, and diethylene glycol. Alcohols such as monoalkyl ether, triethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, acetic acid alkyl ester, diethylene glycol monoalkyl ether acetate, triethylene glycol monoalkyl ether acetate,
Propylene glycol monoalkyl ether acetate, acetoacetic acid ethyl ester, lactic acid alkyl ester,
Esters such as benzoic acid alkyl ester, benzyl acetate, glycerin diacetate, ketones such as acetone, methyl ethyl ketone, cyclohexanone, acetylacetone, isophorone, diethyl ketone, methyl isobutyl ketone, methyl n-butyl ketone, acetonyl acetone, n-pentane, Examples include hydrocarbons such as n-hexane, isohexane, n-heptane, n-octane, isooctane, benzene, tonene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, and tetralin. These organic solvents may be used alone or in combination of two or more.

The coating liquid used for forming the interlayer insulating film of the present invention contains a silazane compound in an amount of 1 to 60% by weight, preferably 10 to 30% by weight, and has a viscosity of 0.5 to 30% by weight at room temperature. 50 centipoise, preferably 1~
A value in the range of 20 centipoise is practically suitable. The viscosity can be adjusted by appropriately selecting the type and amount of the organic solvent depending on the desired film thickness and the like.

The interlayer insulating film of the present invention can be prepared by applying the coating solution prepared as described above onto a desired solid surface using a spinner method.
After coating by a conventionally used method such as a spray method or a dipping method, it is dried at a temperature of about 50 to 200°C to form a polysilazane film, and then coated in the air or an oxygen atmosphere at a temperature of usually 200 to 800°C. The polysilazane film can be formed by baking at a temperature in the range of 15 to 60 minutes to convert the polysilazane film into a silicon oxide film.

The interlayer insulating film thus formed is
It is a continuous film made of silicon oxide that is homogeneous and has low hygroscopicity without cracks and has a thickness of 0.2 to 3.0 μm, but it does not contain nitrogen atoms or carbon atoms to the extent that the purpose of the present invention is not impaired. You can.

[0018]

[Effects of the Invention] The interlayer insulating film of the present invention has low hygroscopicity, is made of a homogeneous and dense silicon oxide film, has excellent adhesion to the substrate, and is free from peeling and cracking even in thick films. It has excellent insulation properties and is suitable for use, for example, as an interlayer insulating film for multilayer wiring in electronic components.

[0019]

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

Example TEFP (TEFP), which is a 20% by weight xylene solution of a reaction product of halogenosilane and ammonia, was placed on a silicon wafer on which an aluminum circuit pattern was formed.
(manufactured by Tonen Co., Ltd.) at 2000 rpm and heated to 150°C.
After drying for 30 minutes to form a polysilazane-based film, the film was baked in the air at 500° C. for 60 minutes to form an insulating film made of a silicon oxide film. No cracks were observed on the surface of this silicon oxide film, and it was a highly homogeneous film. Furthermore, no peak indicating the presence of water was observed in the infrared absorption spectrum of this silicon oxide film.

Next, aluminum was vapor-deposited on the formed silicon oxide film, and TSMR-V50 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is an i-ray sensitive positive type photoresist, was applied with a spinner at 4000 rpm for 20 seconds, and then applied on a hot plate. 1.0μ by drying at 90℃ for 90 seconds
After forming a resist film with a thickness of m, it was selectively exposed to i-line using an i-line reduction projection exposure device LD-5011iA (manufactured by Hitachi, Ltd.), and then exposed to 2.35% by weight tetramethylammonium hydroxide aqueous solution. A resist pattern was formed by dipping for 1 minute and dissolving and removing the i-ray irradiated portion. Next, OAP using carbon tetrachloride gas
When aluminum was etched in RIE mode using M-400 (manufactured by Tokyo Ohka Kogyo Co., Ltd., plasma processing equipment), a highly accurate aluminum pattern was obtained on the insulating film.

Comparative Example Instead of the TEFP (manufactured by Tonen Corporation) used in the example, a coating liquid with an SiO2 equivalent concentration of 12% by weight, obtained by partially hydrolyzing tetraethoxysilane in the presence of ethyl alcohol, was used. An insulating film made of a silicon oxide film was formed by the same operation as in the example except for the above. From the infrared absorption spectrum of this silicon oxide film, 3200 to 360
An absorption peak was confirmed in the 0 cm-1 range. Next, an aluminum pattern was formed on this by the same operation as in the example, and a peeling phenomenon was observed in the aluminum pattern.

Claims (1)

[Claims] 1. An interlayer insulating film comprising a silicon oxide film formed under non-aqueous conditions.