METHOD FOR FORMING ELECTRODE STRUCTURE AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce interfacial resistance between a polysilicon film and a refractory metallic film at a gate electrode with a poly-metal structure. SOLUTION: A polysilicon film 12, a titanium film 14, a titanium nitride film 15A and a tungsten film 18 are deposited on a semiconductor substrate 10 through a gate insulating film 11 and an electrode structure made up of these laminated layers. Then, a heat treatment at 750 deg.C or above is carried out for the electrode structure. Nitrogen in the titanium nitride 15A is diffused in the titanium film 14 and the polysilicon film 12 so that the titanium film 14 changes into the titanium nitride and at the same time, an reactive silicon nitride layer 19 with a small thickness is formed at an interface between the polysilicon film 12 and the titanium nitride film 15B.