On the charge control of the two-dimensional electron gas for analytic modeling of HEMTs

A simple charge control model is developed for the two-dimensional electron gas (2-DEG) of high-electron-mobility transistors (HEMTs). This model explicitly takes into account the effective distance of the 2-DEG from the heterointerface and has been developed for use in analytic I-V and C-V modeling. In this model, the Fermi energy level versus the 2-DEG sheet carrier-concentration is represented by a simplified expression derived from the triangular potential well approximation and is shown to be dominated by terms with different functional forms in two distinct operation regions: a moderate carrier-concentration region and a subthreshold region. The validity of the analytic charge control model is supported by the calculated results of a self-consistent quantum mechanical model.<
>