Light effect in photoionization of traps in GaN MESFETs
Keywords:Buffer layer, current collapse, light-induced, photoionization, drain current
Trapping of hot electron behavior by trap centers located in buffer layer of a wurtzite phase GaN MESFET has been simulated using an ensemble Monte Carlo simulation. The results of the simulation show that 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. The simulated device geometries and doping are matched to the nominal parameters described for the experimental structures as closely as possible, and the predicted drain current and other electrical characteristics for the simulated device including trapping center effects show close agreement with the available experimental data.
Received: 10 November 2009, Accepted: 26 November 2009; Edited by: A. Goñi; DOI: 10.4279/PIP.010006
Editor's Note: This paper has been published at a later date in the Journal of Electronic Science and Technology, vol. 8, no. 1, pags. 51-54 (2010) in breach of the authors' CreativeCommons License agreement with Papers in Physics.