Effect of a thick buffer in the OFF state simulation of AlGaN/GaN HEMT

Study of the buffer thickness dependence of the OFF state characteristics of AlGaN/GaN HEMTs has been attempted. The buffer conduction in OFF state has been studied taking into account the effect of buffer traps and the response of those traps under varying Source-Drain voltage in both the pre-breakdown and near breakdown regions. The temperature dependence of the current-voltage characteristics have been addressed and related to the trap occupancy as a function of voltage and temperature. A quantitative measure of the trap concentration has been estimated to observe the expected device characteristics without any artifacts introduced by the buffer.