Physically based model for trapping and self-heating effects in 4H-SiC MESFETs

In order to accurately and simply extract the trapping parameters in SiC metal semiconductor field effect transistors (MESFETs) a method is proposed based on device dc and ac small-signal models. By combining modeling techniques, material physics, and measured device characteristics, we are able to estimate the important information about the trap property and heat flow in 4H-SiC material and their influences on performance of MESFET devices, including gate lag, frequency-related dispersion, and the self-heating effect. Simulations indicate that the gate lag is due to the traps located at the channel/buffer interface and the transition frequency is up to ∼ MHz at 600 K. PACS 72.15.Jf; 72.20.Jv; 72.15.Eb