Source-Field-Plated $\beta$ -Ga2O3 MOSFET With Record Power Figure of Merit of 50.4 MW/cm2

In this letter, source-field-plated β-Ga
₂
O
₃
MOSFETs are fabricated on Si-doped homoepitaxial film on (010) Fe-doped semi-insulating β-Ga
₂
O
₃
substrate. Ohmic contact resistance (R
_c
) between metal- and ion-implanted source/drain layer of 1.0 Ω · mm is obtained by employing the Si-ion implantation. The fabricated source-field-plated β-Ga
₂
O
₃
MOSFETs with source-to-drain distance (L
_sd
) of 11 and 18 μm present high-saturation drain current (I
_ds,sat
) of 267 and 222 mA/mm with low R
_on,sp
of 4.57 and 11.7 mΩ · cm
²
, respectively. The drain extension in the source-field plate effectively suppresses the peak electric field and improves the breakdown voltage greatly. The destructive breakdown voltages (V
_br
) are measured to be 480 and 680 V for the devices with L
_sd
of 11 and 18 μm, respectively. Most of all, the power figure of merit (V
_br
²
/R
_on,sp
) is as high as 50.4 MW/cm
²
, which is the highest value among any β-Ga
₂
O
₃
MOSFETs ever reported.