Patent ID: 6838394

Claim:
A method of forming a silicon oxynitride film on a polysilicon film, characterized by the steps of: forming plasma containing therein atomic state oxygen O* and hydrogen nitride radicals NH* in a processing vessel of a microwave processing apparatus, said microwave processing apparatus including, in addition to said processing vessel, a shower plate provided in part of said processing vessel so as to extend parallel with a substrate to be processed, said shower place including a number of apertures for supplying a plasma gas toward said substrate to be processed, and a microwave radiation antenna provided such that said microwave radiation antenna emits a microwave into said processing vessel through said shower plate, said plasma being formed by supplying an inert gas predominantly of Ar or Kr and a gas containing oxygen as a constituent element and a gas containing nitrogen as a constituent element into said processing vessel via said shower plate, and by supplying a microwave into said processing vessel from said microwave radiation antenna through said shower plate; and oxynitriding, in said processing vessel, a surface of said polysilicon film formed on said substrate by said plasma, to form said silicon oxynitride film.