Recessed-Gate Ga₂O₃-on-SiC MOSFETs Demonstrating a Stable Power Figure of Merit of 100 mW/cm² Up to 200 °C

Recessed-gate
$\beta $
-gallium oxide (Ga
₂
O
₃
) MOSFETs on the heterogeneous Ga
₂
O
₃
-on-SiC (GaOSiC) wafer are fabricated and characterized. The GaOSiC transistors with an
${L}_{\mathrm {SD}}$
of
$11~{\mu } \text{m}$
exhibit the decent and stable electrical characteristics with the temperature varying from 25 °C to 200 °C, including a breakdown voltage (
${V}_{\mathrm {br}}$
) of 1000 V, a specific ON-resistance (
${R}_{\mathrm{\scriptscriptstyle ON},\mathrm {sp}}$
) of ~100 m
${\Omega }~\cdot $
cm
²
, a drive current of 91 mA/mm, and a power figure of merit (P-FOM) of ~100 MW/cm
²
. Characterization of the transfer length method (TLM) structure fabricated on the same heterogeneous wafer demonstrates that the reduced transfer length (
${L}_{T}$
) at the
$\beta $
-Ga
₂
O
₃
/Ti/Au contact interface compensates for the increased sheet resistance (
${R}_{\mathrm {SH}}$
) of
$\beta $
-Ga
₂
O
₃
film at the elevated temperature, which leads to the stable electrical performance of the GaOSiC devices.