Thermal analysis of AlGaN/GaN high-electron-mobility transistors by infrared microscopy

The channel temperature of the AlGaN/GaN high-electron-mobility transistor was measured by infrared microscopy in an uncapped package. The behaviors of the channel temperature distribution, the peak channel temperature and the thermal resistance under DC bias were investigated. The thermal resistance was determined for a multi-finger device. The correlation of the dissipated power and the base plate temperature, and peak channel temperature of different device structures are compared. Screening conditions were advanced to apply sufficient stress during the reliability test. IR microscopy facilitates the optimization of the device to reduce the thermal resistance, and it facilitates the study of how the device parameters affect reliability.