An accurate HJFET current–voltage model including temperature dependence for a circuit simulator

Abstract

We present a new hetero-junction FET (HJFET) current–voltage ( I– V) model intended for implementation with a large signal simulator. The developed model takes into account the temperature dependence of drift current, diffusion current and gate diode current. The drift current model is based on our previous reported model [Hida H, Itoh T, Ohta K. An accurate dc model of 2-DEG FET for implementation on a circuit simulator. IEEE Electron Device Lett 1986;7:393–395.], which is based on gradual channel approximation taking into account the nonlinear field dependence of electron velocity. We found through measurements that transconductance, g m, drain conductance, g D, and threshold voltage, V T, vary as linear functions of temperature. To describe the dependence, we introduced linear functions of temperature into the g m, g D and V T descriptions. We also added the temperature dependence description to the diode current model and the diffusion current model. Although our model describes the temperature dependence using quite simple formulas, the simulated results agree well with the measurements.