A precise physics-based compact model for 2-DEG charge density in GaAs HEMTs applicable in all regions of device operation

In this paper we present a precise physics based analytical model for the two-dimensional electron gas density ns in AlGaAs/GaAs high electron mobility transistors. The model is developed by considering the variation of Fermi-level Ef, the first sub-band E0, the second sub-band E1, and ns with the applied gate voltage Vg. Taking into account the interdependence between Ef and ns, we have developed an explicit expression for ns in terms of bias voltages. The developed expression for ns is valid in all the regions of device operation, with gate-voltage ranging from below to above the cut-off voltage. The proposed model is in very good agreement with numerical calculations.

► An analytical model of 2-DEG charge density in GaAs HEMTs valid in all the regions.
► The model is physics based and has no empirical or fitting parameters.
► Excellent agreement with numerical solution for typical temperature and bias ranges.