Patent ID: 8309988

Claim:
A field effect transistor comprising: a first layer that comprises a p-type III-nitride semiconductor; and a second layer that comprises a III-nitride semiconductor having a band gap energy that is larger than that of said first layer, and having a thickness that is at least 1 nm but not greater than 40 nm; a first contact layer formed in a first region of the first layer and in contact with a source electrode; a second contact layer formed in a second region of the first layer and in contact with a drain electrode; a reduced surface field layer formed in a third region of the first layer and between the source electrode and the drain electrode; and a gate electrode formed between the source electrode and the drain electrode, wherein a body electrode is formed on the opposite side of said second layer from said first layer to remove holes that occur in the first layer by permeating through the second layer by a tunnel effect, and wherein a bottom surface of the source electrode is in contact with the first layer and the first contact layer.