1.7-kV and 0.55- $\text{m}\Omega \cdot \text {cm}^{2}$ GaN p-n Diodes on Bulk GaN Substrates With Avalanche Capability

We report vertical GaN-on-GaN p-n diodes with a breakdown voltage (BV) of 1.7 kV and a low differential specific ON-resistance
$R_{\mathrm{\scriptscriptstyle ON}}$
of 0.55
$\text{m}\Omega \cdot \text {cm}^{2}$
with current spreading considered (or 0.4
$\text{m}\Omega \cdot \text {cm}^{2}$
using the diode bottom mesa size), resulting in a figure-of-merit (
$V_{B}^{2}/R_{\mathrm{\scriptscriptstyle ON}})$
of 5.3 GW/cm
²
(or 7.2 GW/cm
$^{2})$
. These devices exhibit a current swing over 14 orders of magnitude and a low ideality factor of 1.3. Temperature dependent
$I$
–
$V$
measurements show that the BV increases with increasing temperature, a signature of avalanche breakdown.