The present thesis offers a detailed description about the modeling of single- and multi-channel laterally-gated AlGaN/GaN heterojunction field effect transistors (HFETs) through device investigation in the Comsol Multiphysics® simulation environment. After two decades of research, studying GaN HFETs continues to be a very interesting area of investigation. This is because of the interest in using these devices in high frequency applications as well as low frequency power management. Laterally-gated GaN HFETs have recently drawn the attention of semiconductor devices engineers that search for obtaining higher current densities, higher linearity, better stability at higher frequencies, and better power management while increasing packing density.
The presented simulations offer an in-depth analysis of the observations made at thermal equilibrium and the results obtained for the DC characteristics of these devices, along with the comparison of these characteristics with those of the top-gated varieties. These observations demonstrate the improved effectiveness of lateral gating in controlling multiple vertically stacked 2DEG channels. Although there is improvement on several parameters like current density, linearity, and ON resistance (Ron), as the number of channels increases, simulations demonstrate a certain degree of degradation of drain-induced barrier lowering (DIBL) and knee voltage (Vknee). For these simulations, the devices’ self-heating at higher current densities was not considered. Also, the ohmic contacts were assumed to be ideal.