Temperature Dependent Analytical DC Model for Wide Bandgap MESFETs

In this paper, an analytical model has been developed to predict DC characteristics of wide bandgap metal semiconductor field effect transistors (MESFETs). The model evaluates potential distribution inside the channel of the device by dividing the Schottky barrier depletion layer into four distinct regions and predicts I - V characteristics both at the room as well as at elevated temperatures. It also considers selfheating effects caused by the high-drain current and predicts negative output conductance, usually exhibited by wide bandgap MESFETs. The validity of the proposed technique is ensured by applying it on GaN and SiC MESFETs. It has been shown that the developed technique offers ~50% and ~37% improved accuracy in predicting the output characteristics of the device at T = 300 K and T = 500 K, respectively, relative to the best reported model. Thus, the proposed technique can be employed in the device modeling software involving high-power MESFETs.