The effect of light illumination in photoionization of deep traps in GaN MESFETs buffer layer using an ensemble Monte Carlo simulation

Abstract

Deep traps can produce serious degradation in the drain current and consequently the output power of GaN based FETs. This current collapse phenomenon represents a significant impediment to the incorporation of these devices in electronic systems. In this article trapping of hot electron behavior by deep trap centers located in buffer layer of a wurtzite phase GaN MESFET has been simulated using an ensemble Monte Carlo simulation. The simulated results show the trap centers are responsible for current collapse in GaN MESFET at low temperatures. These electrical traps degrade the performance of the device at low temperature. On the opposite, a light-induced increase in the trap-limited drain current, results from the photoionization of trapped carriers and their return to the channel under the influence of the built in electric field associated with the trapped charge distribution.