Numerical simulation of transconductance of AlGaN/GaN heterojunction field effect transistors at high temperatures

Based on the investigation of the influence of temperatures on parameters, including polarization, electron mobility, thermal conductivity, and conduction band discontinuity at the interface between AlGaN and GaN, the temperature dependence of transconductance for AlGaN/GaN heterojunction field effect transistors (HFETs) has been obtained by using a quasi-two-dimensional approach, and the calculated results are in good agreement with the experimental data. The reduction in transconductance at high temperatures is primarily due to the decrease in electron mobility in the channel. Calculations also demonstrate that the self-heating effect becomes serious as environment temperature increases.