An analytical expression for Fermi level versus sheet carrier concentration for HEMT modeling

A simple second-order analytical expression of Fermi-level variation with two-dimensional electron gas density in a high-electron-mobility transistor (HEMT) has been developed. This empirical expression was found to give better results near cutoff and in saturation than the linear approximation currently being used in many models. It can be used in the development of a more accurate charge control model and hence in the development of an improved analytical model for the HEMT.>