Semiconductor device having insulating film

Abstract

An insulative film, such as SiO.sub.2, Si.sub.3 N.sub.4 and PSG films, is commonly used, for example, the passivation film or to insulate the gate electrode of MISFETs. Stability of the insulative films during the production or operation of the semiconductor devices is enhanced by providing an insulative film which is formed by nitridation, for example, in an NH.sub.3 gas, of an SiO.sub.2 film, preferably a directly thermally oxidized film of silicon. The insulative film according to the present invention is used for a gate insulation film in MISFETs, a capacitor or passivation film for semiconductor devices, and as a mask for selectively forming circuit elements of semiconductor devices. The process for forming the insulative film may comprise successive nitridation, oxidation and nitridation steps.

Dependencies are inferred from the claim text.