Patent ID: 7759202

Claim:
A method for forming a semiconductor device, comprising: providing a substrate comprising an oxide layer on its surface; forming a lower electrode layer on said oxide layer by a deposition, lithography and etching method and exposing said oxide layer selectively; depositing a silicon layer to cover said lower electrode layer and said oxide layer; etching said silicon layer, said lower electrode layer and said oxide layer to selectively expose said substrate to form a first gate structure and a second gate structure, wherein said first gate structure comprises said silicon layer, said lower electrode layer and said oxide layer and said second gate structure comprises said oxide layer and said silicon layer directly contacting said oxide layer; forming a first source/drain in the proximity of said first gate structure and a second source/drain in the proximity of said second gate structure in said exposed substrate; and forming a gate electrode layer by reacting said silicon layers with a metal to form a fully silicide layer as said gate electrode layer after forming said first gate structure and said second gate structure.