Multi-kV Class β-Ga₂O₃ MESFETs With a Lateral Figure of Merit Up to 355 MW/cm²

We demonstrate over 3 kV gate-pad-connected field plated (GPFP) $\beta $ -Ga2O3 lateral MESFETs with high lateral figures of merit (LFOM) using metalorganic vapor phase epitaxy (MOVPE) grown channel layers and regrown ohmic contact layers. Using an improved low-temperature MOVPE selective area epitaxy process, we show that a total contact resistance to the channel as low as $1.4~\Omega $ .mm can be achieved. The GPFP design adopted here using plasma-enhanced chemical vapor deposited (PECVD) SiNx dielectric and SiNx/SiO2 wrap-around passivation exhibits up to ~14% improved $\text{R}_{{\text {ON}}}$ , up to ~70% improved breakdown voltage ( $\text{V}_{{\text {BR}}}= \text {V}_{{\text {DS}}}-\text {V}_{{\text {GS}}}$ ) resulting in up to $3\times $ higher LFOM compared to the non-FP $\beta $ -Ga2O3 lateral MESFETs. The $\text{V}_{{\text {BR}}}$ (~2.5 kV) and LFOM (355 MW/cm2) measured simultaneously in our GPFP $\beta $ -Ga2O3 lateral MESFET (with $\text{L}_{{\text {GD}}} = {10}\mu \text{m}$ ) is the highest value achieved in any depletion-mode $\beta $ -Ga2O3 lateral device to date.