Method of forming a fully-depleted SOI ( silicon-on-insulator) MOSFET having a thinned channel region

摘要

A sub-0.05 mum channel length fully-depleted SOI MOSFET device having low source and drain resistance and minimal overlap capacitance and a method of fabricating the same are provided. In accordance with the method of the present invention, at least one dummy gate region is first formed atop an SOI layer. The dummy gate region includes at least a sacrificial polysilicon region and first nitride spacers located on sidewalls of the sacrificial polysilicon region. Next, an oxide layer that is coplanar with an upper surface of the dummy gate region is formed and then the sacrificial polysilicon region is removed to expose a portion of the SOI layer. A thinned device channel region is formed in the exposed portion of the SOI layer and thereafter inner nitride spacers are formed on exposed walls of the fist nitride spacers. Next, a gate region is formed over the thinned device channel region and then the oxide layer is removed so as to expose thicker portions of the SOI layer than de device channel region.