HYBRID MATERIAL ACCUMULATION MODE CMOS FET WITH ENTIRELY SURROUNDING CYLINDRICAL GATE

摘要

A hybrid material accumulation mode CMOS FET with entirely surrounding cylindrical gate is provided, which comprises: a PMOS region(400) with a first channel, an NMOS region(300) with a second channel and a gate region(500), wherein, the first channel(401) and the second channel(301) are cylindrical, the first channel is Ge, and the second channel is Si. The gate region entirely surrounds the first and the second channels. There are buried oxide layers(201,202) between the PMOS and the NMOS, and between the PMOS or NMOS and the Si substrate(100). The structure of the CMOS FET is simple, compact and highly integrated. When it is in accumulation mode, the cylindrical channel can obtain high carrier mobility, reduce low low-frequency noise, and avoid polysilicon gate depletion and short channel effect, so as to increase the threshold voltage of the device.