Patent ID: 8716799

Claim:
A MOSFET, comprising: an SOI wafer, which comprises a semiconductor substrate, a buried insulator layer, and a semiconductor layer, the buried insulator layer being disposed on the semiconductor substrate, and the semiconductor layer being disposed on the buried insulator layer; a gate stack, which is disposed on the semiconductor layer; a source region and a drain region, which are disposed in the semiconductor layer and on opposite sides of the gate stack; and a channel region, which is disposed in the semiconductor layer and between the source region and the drain region, wherein the MOSFET further comprises a back gate disposed in the semiconductor substrate, and wherein the back gate comprises first, second, and third compensation doping regions, the first compensation doping region is disposed under the source region and the drain region; the second compensation doping region extends in a direction away from the channel region and adjoining the first compensation doping region; and the third compensation doping region is disposed under the channel region and adjoining the first compensation doping region.