Patent ID: 6919270

Claim:
A method for forming a silicon carbide film on a semiconductor substrate by plasma CVD, comprising the steps of: (a) introducing a raw material gas containing silicon, carbon, and hydrogen in a molecule and an inert gas at a predetermined mixture ratio of the raw material gas to the inert gas into a reaction chamber; (b) applying radio-frequency power to a reaction zone inside the reaction chamber at the mixture ratio, thereby forming on a semiconductor substrate a curable silicon carbide film having a dielectric constant of about 4.0 or higher; and (c) continuously applying radio-frequency power to the reaction zone at a mixture ratio which is reduced from that in step (b), thereby curing the curable silicon carbide film to reduce the dielectric constant of the curable silicon carbide film. wherein the cured silicon carbide film has a stress change in the atmosphere or at 400° C. and a leakage current when 1 MV/cm voltage is applied, which are about less than ½ of those of the curable silicon carbide film.