GaN/AlGaN HFETs fabricated on a SiC substrate

Self-heating in GaN/AlGaN HFETs fabricated on sapphire and silicon carbide substrates has been compared. Pulse I-V measurements showed that the thermal resistance of devices on SiC substrates was about 5 lower than for sapphire. This demonstrates the need for SiC substrates to dissipate the enormous power density in these devices.