Patent ID: 8319293

Claim:
A semiconductor device comprising: an island-shaped silicon layer; a first gate dielectric film surrounding the island-shaped silicon layer; a gate electrode surrounding the first gate dielectric film; a second gate dielectric film surrounding the gate electrode; a tubular silicon layer surrounding the second gate dielectric film; a first n+-type diffusion layer disposed on top of the island-shaped silicon layer; a second n+-type diffusion layer disposed underneath the island-shaped silicon layer; a first p+-type diffusion layer disposed on top of the tubular silicon layer; a second p+-type diffusion layer disposed underneath the tubular silicon layer, and formed to contact directly with the second n+-type diffusion layer; a third n+-type diffusion layer formed to contact directly with bottom of the second n+-type diffusion layer and bottom of the second p+-type diffusion layer; and a silicon-metal compound layer formed to contact directly with a part where the second p+-type diffusion layer contacts with the third n+-type diffusion layer.