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) β-Ga
₂
O
₃
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 Ω.mm can be achieved. The GPFP design adopted here using plasma-enhanced chemical vapor deposited (PECVD) SiN
_x
dielectric and SiN
_x
/SiO
₂
wrap-around passivation exhibits up to ~14% improved R
_ON
, up to ~70% improved breakdown voltage ( V
_BR
= V
_DS
-V
_GS
) resulting in up to 3× higher LFOM compared to the non-FP β-Ga
₂
O
₃
lateral MESFETs. The V
_BR
(~2.5 kV) and LFOM (355 MW/cm
²
) measured simultaneously in our GPFP β-Ga
₂
O
₃
lateral MESFET (with L
_GD
= 10μm) is the highest value achieved in any depletion-mode β-Ga
₂
O
₃
lateral device to date.