Cho, J., Li, Z., Bozorg-Grayeli, E., Kodama, T., Francis, D., Altman, D., Ejeckam, F., Faili, F., Asheghi, M., Goodson, K.E., “Thermal Characterization of Composite GaN Substrates for HEMT Applications,” Government Microcircuit Applications & Ctritical Technology (GomacTech) Conferfence 2012, March 18-20, Las Vegas, Nevada



High-power operation of AlGaN/GaN high-electron-mobility transistors (HEMTs) requires efficient
heat removal through the substrate. GaN composite substrates including high-thermal-conductivity substrates such as SiC and diamond are promising, but these composite substrates require careful attention to thermal resistances at GaN-substrate interfaces. We report on thermal characterization of GaN-on-SiC and GaN-ondiamond substrates using a combination of picosecond time-domain thermoreflectance (TDTR) and DC Joule heating techniques.