Patent ID: 8519442

Claim:
A semiconductor HEMT device, comprising: a first semiconductor layer; a second semiconductor layer provided on the first semiconductor layer with a heterojunction interface interposed therebetween; a two-dimensional carrier gas layer provided near the heterojunction interface in the first semiconductor layer; a first main electrode electrically connected to one end of the two-dimensional carrier gas layer; a second main electrode electrically connected to the other end of the two-dimensional carrier gas layer; a first gate electrode provided on the second semiconductor layer between a part of the first main electrode and a part of the second main electrode opposite to the part of the first main electrode; and a second gate electrode which is provided on the second semiconductor layer between another part of the first main electrode and another part of the second main electrode opposite to the another part of first main electrode with a separation region interposed between the first gate electrode and the second gate electrode and is controlled independently of the first gate electrode, the separation region reduces a carrier concentration of the two-dimensional carrier gas layer generated under the separation region or prevents the generation of the two-dimensional carrier gas layer to control an increase in sheet resistance of the two-dimensional carrier gas layer under the separation region.