Patent ID: 6962853
Filing Date: 2005-11-08
Classification: H01L

Abstract:
1. A method for fabricating a semiconductor device, comprising the steps of: (a) depositing a conductive film for gate electrode including at least a polysilicon film on a semiconductor substrate; (b) forming a gate electrode by patterning the conductive film for gate electrode; (c) forming an oxide film on a side face of at least the polysilicon film after the step (b); (d) forming a nitride oxide film on a side face of the gate electrode by nitriding only a surface portion of the oxide film after the step (c); and (e) forming an insulating sidewall on the nitride oxide film provided on the surface portion of the oxide film on the side face of the gate electrode after the step (d), wherein in the step (a), a polysilicon film and a metal film are deposited in this order as the conductive film for gate electrode, in the step (b), a bottom gate electrode made of the polysilicon film and a top gate electrode made of the metal film are formed as the gate electrode, and in the step (d), simultaneously with the formation of the nitride oxide film by nitriding at least a surface portion of the oxide film formed on each side face of the bottom gate electrode, each side face of the top gate electrode is nitrided to form a metal nitride film.