Modeling transconductance- and capacitance-voltage characteristics of AlGaAs/GaAs HEMTs

A new simple and accurate analytical model for the transconductance-voltage and capacitance-voltage characteristics of AlGaAs/GaAs HEMT devices is presented. It is suitable for use in device simulation programs. The model is based on a simple formulation of the sheet carrier concentration in the two-dimensional electron gas (2-DEG) in the HEMT. The model takes into account the parasitic conduction in the AlGaAs. The model gives very good agreement with measured transconductance and capacitance characteristics for different HEMT devices.