Temperature optimization for AlGaN/GaN HEMT with the etched AlGaN layer based on 2-D thermal model

Abstract

When the AlGaN/GaN HEMT is working for a long time under the high-power and high-temperature conditions, the internal heat will reduce its reliability. Here, the author first proposed a 2-D temperature distribution model to explain the mechanism of internal charge modulation to reduce the junction temperature of AlGaN/GaN HEMT. The etched AlGaN layer affects the channel 2DEG distribution and a new hot spot is generated in the thermal field, which effectively reduces the temperature and gets a more uniform temperature distribution. A quantitative analysis of the temperature model has been given to describe the effect of structure parameters on temperature optimization, and deeper etching depth is beneficial to reduce the junction temperature. The model is verified through simulation results and experimental tests, which prove its applicability. It is concluded that this model can effectively describe the temperature optimization of AlGaN/GaN HEMTs with the gate-edge etching technique.