On-Chip Thermal Insulation Using Porous GaN

This study focuses on the thermal characterization of porous gallium nitride (GaN) using an extended 3ω method. Porous semiconductor materials provide a solution to the need for on-chip thermal insulation, a fundamental requirement for low-power, high-speed and high-accuracy thermal sensors. Thermal insulation is especially important in GaN devices, due to the intrinsically high thermal conductivity of the material. The results show one order of magnitude reduction in thermal conductivity, from 130 W/mK to 10 W/mK, in line with theoretical predictions for porous materials. This achievement is encouraging in the quest for integrating sensors with opto-, powerand RF-electronics on a single GaN chip.