A simple DC model for dual channel high electron mobility transistors

In this paper, a DC model for the dual channel high electron mobility transistor (DC-HEMT) is presented. The model is developed based on a single charge expression that describes four different charge components: two dimensional electron gas on the top and bottom channels, free electrons and the neutralized donors in the AlGaAs layer. This expression not only shows the smoothness of the charges over a wide range of applied gate voltages but also shows a good agreement with the numerical solution of the charges. The current-voltage characteristics are derived including the effect of the parasitic source and drain resistances, the mobility degradation and channel length modulation through a quasi two dimensional Poisson equation in the high field region of the channel. Finally, the theoretical predictions of the model are compared with the experimental data and found to be in good agreement