Patent ID: 8441035

Claim:
A junction field effect transistor comprising: a first nitride semiconductor layer; a second nitride semiconductor layer formed on said first nitride semiconductor layer, said second nitride semiconductor layer having a band gap energy greater than a band gap energy of said first nitride semiconductor layer; a third nitride semiconductor layer formed on said second nitride semiconductor layer; a fourth nitride semiconductor layer formed on said third nitride semiconductor layer, said fourth nitride semiconductor layer having a band gap energy greater than a band gap energy of said third nitride semiconductor layer; a fifth semiconductor layer formed in a recess provided in said third nitride semiconductor layer and said fourth nitride semiconductor layer; a gate electrode formed on said fifth semiconductor layer; and a source electrode and a drain electrode which are formed in respective regions near lateral sides of said gate electrode, wherein: a channel is formed at a heterojunction interface between said first nitride semiconductor layer and said second nitride semiconductor layer, and said fifth semiconductor layer is in contact with said third nitride semiconductor layer at an inner side surface of said recess.