Abstract: A polyimide copolymer derived from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, oxydiphthalic dianhydride, m-phenylene diamine and 4,4'-oxydianiline, for use as a high-temperature resistant lift-off layer in the fabrication of integrated circuit substrates.

Abstract: A process for nitriding materials containing silicon to form a silicon nitride material predominantly in the alpha phase is disclosed which includes nitriding the silicon-containing material by (a) heating the silicon-containing material in an atmosphere containing at least hydrogen in the temperature range of about 0.degree. C. to about 1420.degree. C. and (b) thereafter, nitriding the silicon-containing material by heating the material in a nitriding atmosphere containing at least nitrogen gas in the temperature range of from about 1000.degree. C. to about 1450.degree. C.

Abstract: A method for preparing inorganic oxide-based materials of spherical form with substantially monomodal distribution, consisting of forming a sol of at least one of the inorganic oxides of interest, adding to said sol a solvent immiscible with the sol, finely dispersing the obtained two-phase mixture into a dispersion of particles of equal diameter, growing said particles by limited coalescence to the desired diameter, gelling said mixture by adding a second solvent containing a gelling agent, and removing the solvent.

Abstract: A method of sidewall doping is described wherein the implantation of the dopant is done after the high temperature sidewall oxidation formation. Therefore, this method allows high concentrations of the dopant to be retained along the sidewall thus deceasing the corner coupling.