Temperature-Dependent Thermal Resistance of GaN-on-Diamond HEMT Wafers

The thermal properties of GaN-on-diamond high-electron mobility transistor (HEMT) wafers from 25 °C to 250 °C are reported. The effective thermal boundary resistance between GaN and diamond decreases at elevated temperatures due to the increasing thermal conductivity of the amorphous SiNx interlayer, therefore potentially counteracting thermal runaway of devices. The results demonstrate the thermal benefit of GaN-on-diamond for HEMT high-power operations, and provide valuable information for assessing the thermal resistance and reliability of devices.