820-V GaN-on-Si Quasi-Vertical p-i-n Diodes With BFOM of 2.0 GW/cm2

In this letter, we demonstrate GaN-on-Si p-i-n diodes with high breakdown voltage and state-of-the-art Baliga’s figure of merit (BFOM) among GaN-on-Si vertical devices. The growth and doping of the GaN drift layer were optimized, leading to a remarkable electron mobility of 720 cm2/Vs for a Si doping level of2 × 10¹⁶cm−3. With a 4μ m-thick drift layer, we achieved an excellent breakdown voltage of 820 V and ultra-low specific on resistance (Ron,sp) of 0.33mΩcm2. This results in a BFOM of 2.0 GW/cm2, the highest value reported for GaN-on-Si vertical diodes. These results reveal the excellent prospect of GaN-on-Si for cost-effective vertical power devices.