Nitrogen-Implanted Guard Rings for 600-V Quasi-Vertical GaN-on-Si Schottky Barrier Diodes With a BFOM of 0.26 GW/cm2

This work demonstrates a novel Nitrogen-implanted (N-implanted) guard ring (GR) technology for the 600-V quasi-vertical GaN-on-Si Schottky barrier diode (SBD). The GR parameters are designed and studied in detail by the TCAD simulation. With a 4.4-
$\mu \text{m}$
-thick GaN drift layer, seven GRs with a precise design greatly enhance the breakdown voltage of GaN SBDs from ~290 to ~600 V, and barely degrade the ON-state characteristics, including a high
${I}_{ {\scriptscriptstyle { \mathrm {ON}}}}/{I}_{ {\scriptscriptstyle { \mathrm {OFF}}}}$
of 10
¹¹
, a low ideality factor of 1.06, a low turn-on voltage of 0.64 V (at 1 A/cm
²
), and a low-specific ON-resistance (
${R}_{ {\scriptscriptstyle { \mathrm {ON}}},{\mathrm {sp}}}$
) of 1.40
$\text{m}\Omega ~\cdot ~{\mathrm {cm}}^{2}$
, leading to a record Baliga’s figure of merit (BFOM) of 0.26 GW/cm
²
among all the reported vertical GaN-on-Si SBDs. At 175 °C, the SBD with seven GRs shows a slightly increased
${R}_{ {\scriptscriptstyle { \mathrm {ON}}},{\mathrm {sp}}}$
of 1.86
$\text{m}\Omega ~\cdot ~{\mathrm {cm}}^{2}$
and an excellent electrical characteristic even under a reverse bias of 380 V, implying a high-temperature operation capability of N-implanted GRs.