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 cm
²
/Vs for a Si doping level of
$\text {2} \times \text {10}^{\text {16}}$
cm
⁻³
. With a 4
$\mu \text{m}$
-thick drift layer, we achieved an excellent breakdown voltage of 820 V and ultra-low specific on resistance (
${R}_{\text {on,sp}}$
) of 0.33
$\text{m}\Omega $
cm
²
. This results in a BFOM of 2.0 GW/cm
²
, 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.