METHOD FOR FORMING TUNGSTEN SILICIDE

摘要

PURPOSE: A method for forming a tungsten silicide is provided to prevent generation of a void on a polysilicon layer by performing a preprocess for a surface of the polysilicon layer using hydrogen compound gases of the group 3 and the group 5. CONSTITUTION: A wafer is loaded in a reaction chamber. Argon gases are laid on the reaction chamber during 60 seconds under the pressure of the reaction chamber of 9.5 torr and the substrate temperature of 610 degrees centigrade(S30). A PH3 gas of 120 sccm is implanted into the reaction chamber during 60 seconds(S32). A mixed gas including Ar-1 gas of 20 sccm, DCS gas of 300 sccm, and PH3 gas f 60 sccm is injected into the reaction chamber during 10 seconds. A tungsten silicide core is formed on a surface of a polysilicon layer by implanting WF6 gas of 1 sccm(S34). A tungsten silicide layer is deposited and grown on a surface of the wafer by implanting Ar-1 gas of 150 sccm, Ar-2 gas of 200 sccm, WF7 of 7 sccm, and DCS gas of 85 sccm during 40 seconds.