Physics‐based mathematical model of 2DEG sheet charge density and DC characteristics of AlInN/AlN/GaN MOSHEMT

In this paper, a physics‐based analytical model for threshold voltage, two‐dimensional electron gas (2DEG) sheet charge density and DC characteristics of the proposed spacer layer‐based AlxIn1−xN/AlN/GaN metal‐oxide‐semiconductor high electron mobility transistor is presented by considering the quasi‐triangular quantum well. 2DEG sheet charge density (ns) is obtained by the variation of Fermi level (Ef) with supply voltage and the formation of energy subbands E0 and E1. An expression for the 2DEG sheet charge density (ns), valid in all regions of device operation, is studied and applied to derive drain current. The proposed model results for sheet charge density and drain current are calculated and verified with experimental data over a full range of applied gate and drain voltages. Scaling of DC performance is studied as a function of gate length to explore the design space of proposed metal‐oxide‐semiconductor high electron mobility transistor. Suppression in the forward gate current is observed because of the insertion of AlN spacer that made it possible to apply a high gate voltage in the transistor operation and is very useful for high power and high frequency applications.