Abstract: The present invention provides a polysilazane-treating solvent which has excellent dissolving power and stability, has no influence on a substrate as an underlying layer and the properties of a polysilazane, is excellent in shape of cut edge, and further has high safety to the human body. The treating solvent comprises a solvent selected from the group consisting of tetralin, p-menthane, p-cymene, ?-pinene, 1,8-cineol, and mixtures thereof, and a polysilazane treatment method using the same. This solvent may further comprise a solvent selected from the group consisting of aliphatic hydrocarbons, alicyclic hydrocarbons, and mixtures thereof.

Abstract: There are provided a process for producing a siliceous film having excellent insulating properties, and a coating composition for use in the process. The coating composition comprises a perhydropolysilazane or modified perhydropolysilazane having a number average molecular weight of 100 to 50,000 and an aluminum compound, the composition having an aluminum content of not less than 10 ppb and not more than 100 ppm in terms of the molar ratio of the aluminum atom to the silicon atom. The siliceous film is produced by coating the coating composition onto a substrate and firing the coated substrate in an atmosphere containing steam, oxygen, or a mixed gas composed of steam and oxygen.

Abstract: There is provided a method for trench isolation structure formation, which produces neither voids nor cracks within a groove. This method comprises the steps of: forming a groove on a surface of a silicon substrate; coating a polysilazane solution; prebaking the coating at a prebaking temperature regulated so that the temperature is raised in a temperature range of 50° C. to 400° C. over time; curing the coating at a temperature above the maximum prebaking temperature; and polishing and etching the film. The prebaking is carried out while raising the temperature either stepwise in two or more stages or in a monotonically increasing manner.

Abstract: A stabilized polysilazane obtained by reacting an inorganic polysilazane having a number average molecular weight of about 100 to about 100,000 with an alcohol, an organic acid, an ester, a ketone, an aldehyde, a mercaptan, or an alkysilazane preferably at a molar ratio of from 50/50 to 99.99/0.01 is described.

Abstract: A molded body formed of a silicon nitride-based ceramic containing Si and N and optionally O, C and/or a metal. The ceramic is formed from a polysilazane. A molded body may be a composite body which is composed of a matrix of the ceramic and a reinforcing material such as powder or fiber embedded within the matrix or which is composed of ceramic powder bound with a binder formed of the silicon nitride-based ceramic.