Monolithically integrated HEMT and current protection device

摘要

A transistor device includes a high electron mobility field effect transistor (HEMT) and a protection device. The HEMT has a source, a drain and a gate. The HEMT switches on and conducts current from the source to the drain when a voltage applied to the gate exceeds a threshold voltage of the HEMT. The protection device is monolithically integrated with the HEMT so that the protection device shares the source and the drain with the HEMT and further includes a gate electrically connected to the source. The protection device conducts current from the drain to the source when the HEMT is switched off and a reverse voltage between the source and the drain exceeds a threshold voltage of the protection device. The protection device has a lower threshold voltage than the difference of the threshold voltage of the HEMT and a gate voltage used to turn off the HEMT.