| 摘要 |
PURPOSE: A method for fabricating a semiconductor device is provided to prevent an increase of sheet resistance and a degradation of thermal stability of a metal silicide due to disuniformity of grain boundary thereof during the formation of titanium or cobalt silicide. CONSTITUTION: After an insulating layer(22) is formed on a semiconductor substrate(21), the first polysilicon layer(23) having a crystalline structure is formed thereon. Next, a silicon nitride layer(24) is formed on the first polysilicon layer(23) by flowing nitrogen gas. And, the second polysilicon layer having an amorphous structure is formed on the silicon nitride layer(24), and then a refractory metal layer is formed thereon. Thereafter, by reacting the refractory metal layer with the second polysilicon layer in heat treatment, a metal silicon layer(27) is formed. The formation of the polysilicon layers and the silicon nitride layer is made in-situ in the same deposition chamber. The second polysilicon layer is separated from the first polysilicon layer by the silicon nitride layer(24) and thereby not affected from the grain of the first polysilicon layer during heat treatment. Also, the silicon nitride layer(24) acts as a barrier for preventing a diffusion of cobalt atoms.
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