Method of making a MOS field effect transistor in an integrated circuit

Claim 1

In a method of making an MOS field effect transistor of an integrated circuit in a semiconductor body, said body having a surface and a layer of gate oxide disposed on said surface, the steps comprising: (a) forming an undoped silicon gate on said gate oxide having a top surface and a pair of sidewalls; (b) forming a source region in said body adjacent one of said sidewalls and a drain region in said body adjacent the other of said side walls; (c) forming a layer of silicon oxide on said silicon gate including said sidewalls thereof; (d) removing a portion of said layer of silicon oxide leaving said silicon oxide on only said sidewalls thereby leaving an exposed silicon surface on each of said source and drain regions and said undoped silicon gate; (e) forming a layer of refractory metal on only said exposed surfaces; (f) forming a layer of polysilicon on said layer of refractory metal; and (g) heating said layer of refractory metal, said layer of polysilicon, and said body in an oxygen atmosphere thereby forming metal silicide at each of said exposed surfaces.