GaN HEMTs reliability — The role of shielding

Electron trapping in the defect sites of the GaN layer and the interfaces of various layers in HEMT devices are responsible for current collapse in AlGaN/GaN HEMTs. The trapping of electrons is mainly affected by the electric field at the gate edge in these devices. In the present work, an Electro-thermal simulator that couples the Monte Carlo transport kernel, the Poisson kernel and a thermal solver has been developed at ASU. This simulator has been used to model the physics behind the effect of shielding on the thermal and field characteristics of these devices. This work is a first study of this type.