Patent ID: 8441066

Claim:
A semiconductor device comprising a first transistor and a second transistor and being allowed by the first and second transistors to function as an inverter, wherein the first transistor includes: an island semiconductor layer; a first gate insulating film surrounding a periphery of the island semiconductor layer; a gate electrode having a first surface in contact with and surrounding a periphery of the first gate insulating film; a first-conductivity-type upper high-concentration semiconductor layer formed in an upper part of the island semiconductor layer; and a first-conductivity-type lower high-concentration semiconductor layer formed in a lower part of the island semiconductor layer; the second transistor includes: the gate electrode; a second gate insulating film in contact with and surrounding at least a part of a second surface of the gate electrode opposite from the first surface; a semiconductor layer extending about only a portion of the gate electrode and contacting at least a part of a periphery of the second gate insulating film and separated from the gate electrode by the second gate insulating film; a second-conductivity-type upper high-concentration semiconductor layer in an upper part of the semiconductor layer and having an opposite conductivity to the first-conductivity-type upper high-concentration semiconductor layer; and a second-conductivity-type lower high-concentration semiconductor layer in a lower part of the semiconductor layer and having an opposite conductivity to the first-conductivity-type lower high-concentration semiconductor layer, and the semiconductor device further comprises a first contact which electrically connects the first-conductivity-type upper high-concentration semiconductor layer in the first transistor and the second-conductivity-type upper high-concentration semiconductor layer in the second transistor together.