Abstract: There is a vinyl 4-hydroxybenzal-vinylalcohol-vinyl acetate copolymer, a 4-t-butoxycarbonyloxybenzal-vinyl alcohol-vinyl acetate copolymer and a vinyl 4-t-butoxycarbonyloxybenzal-vinyl 4-hydroxybenzal-vinyl alcohol-vinyl acetate copolymer suitable for photoresist and methods for preparing the same. The latter two polymers contain 4-hydroxybenzal groups all or parts of which are protected with t-butoxycarbonyl group. Superior in transparency, thermal stability, mechanical strength, and adhesiveness to silicon wafer, the photoresists prepared from the protected copolymers can enhance the resolution of fine circuit by virtue of low weight loss upon the thermal treatment after exposure.

Abstract: Disclosed is an SrTiO3-based grain boundary barrier layer capacitor which is superb in dielectric constant and temperature characteristics. It is prepared by infiltrating a liquid-phase oxide mixture into a donor-doped SrTiO3matrix to form second-phase dielectric layers at the grain boundaries of the matrix. The liquid-phase oxide mixture comprises CaO and BaO in a particular molar ratio. The SrTiO3-based grain boundary barrier capacitor exhibits a high dielectric constant and a low dieletric loss with stable temperature characteristics.

Abstract: There is a vinyl 4-hydroxybenzal-vinylalcohol-vinyl acetate copolymer, a 4-t-butoxycarbonyloxybenzal-vinyl alcohol-vinyl acetate copolymer and a vinyl 4-t-butoxycarbonyloxybenzal-vinyl 4-hydroxybenzal-vinyl alcohol-vinyl acetate copolymer suitable for photoresist and methods for preparing the same. The latter two polymers contain 4-hydroxybenzal groups all or parts of which are protected with t-butoxycarbonyl group. Superior in transparency, thermal stability, mechanical strength, and adhesiveness to silicon wafer, the photoresists prepared from the protected copolymers can enhance the resolution of fine circuit by virtue of low weight loss upon the thermal treatment after exposure.