Protection device for normally-on and normally-off high electron mobility transistors

Abstract

A transistor device includes a compound semiconductor body, a normally-on high electron mobility field effect transistor (HEMT) formed in the compound semiconductor body and a protection device monolithically integrated in the same compound semiconductor body as the normally-on HEMT. The normally-on HEMT has a source, a drain, a gate, and a threshold voltage. The protection device has a source and a drain each shared with the normally-on HEMT, a gate and a positive threshold voltage that is less than a difference of the threshold voltage of the normally-on HEMT and a gate voltage used to turn off the normally-on HEMT. The protection device is operable to conduct current in a reverse direction when the normally-on HEMT is switched off. A transistor device including a normally-off HEMT and a monolithically integrated protection device is also provided.

Dependencies are inferred from the claim text.