Remained p‐GaN effect to turn‐off energy loss ( E off ) in p‐GaN gate power devices

In p‐GaN gate AlGaN/GaN power devices, the p‐GaN etching process to define the gate region is critical to device performance. In some cases, the remained p‐GaN in the ungated region can exist as a result of under‐etching, and can act like a charge reservoir in the p‐GaN gate power device. In this reported work, the effect of this remained p‐GaN layer is investigated for the first time. The main effect of the thick remained p‐GaN on the ungated region is the increments of turn‐off energy loss ( E off ) in spite of the similar turn‐on energy loss ( E on ). This is related to the hole trapping in the remained p‐GaN region which is observed by the change of turn‐off gate voltages.