Process of fabricating field effect transistor having reliable polycide gate electrode

摘要

A field effect transistor has a polycide structure having a doped polysilicon strip on a gate oxide layer and a crystal tungsten silicide strip on the doped polysilicon strip, and the polycide structure is formed through a process sequence having the steps of patterning an amorphous tungsten silicide layer into an amorphous tungsten silicide strip, crystallizing the amorphous tungsten silicide strip and patterning a doped polysilicon layer into the doped polysilicon strip, thereby preventing the crystal tungsten silicide strip from undesirable warp without contamination of the gate oxide layer.