Theoretical Study of RF Breakdown in GaN Wurtzite and Zincblende Phase MESFETs

In this paper, we present a comparison of the RF breakdown behaviors of representative wurtzite and zincblende phase GaN MESFET structures based on a theoretical analysis. The calculations are made using a full band ensemble, Monte Carlo simulation that includes a numerical formulation of the impact ionization transition rate. Calculations of the RF breakdown voltages are presented for submicron MESFET devices made from either wurtzite or zincblende phase GaN. The devices are otherwise identical. It is found that the RF-breakdown voltage of the devices increases with increasing frequency of the applied large signal RF excitation.