Methodology to Optimize E-Mode GaN HEMT with P-Type Doping under 2DEG Layer

This article presents the methodology to optimize the enhancement-mode (E-mode) GaN high electron mobility transistor (HEMT). The focus is on the recessed Schottky gate with a p-type GaN under the two-dimensional electron gas (2DEG) layer. Design of experiment 3 factors (t(AlGaN), L-gate, P-GaN) at 4 levels for technology computer-aided design (TCAD) simulation produced 2 responses (V-T, R-ON). 128 sets of observations are fed into the analysis of variance (ANOVA) and artificial neural network (ANN) models, where they narrowed down the list of potential optimum E-mode GaN HEMTs. The best device with t(AlGaN) = 4 nm, L-gate = 2 mu m, and P-GaN = 1.2 x10(19) cm(-3) is predicted V-T = 1.263 V and R-ON = 3.317 Omega. The verification by TCAD gives V-T = 1.224 V and R-ON = 3.235 Omega which is very close to the ANOVA-ANN prediction. The p-type GaN under 2DEG created a local GaN p-n junction that depletes electrons in 2DEG at the thermal equilibrium.