Source-Field-Plated β-Ga2O3 MOSFET with Record Power Figure of Merit of 50.4 MW/cm2

In this letter, source-field-plated β-Ga2O3MOSFETs are fabricated on Si-doped homoepitaxial film on (010) Fe-doped semi-insulating β-Ga2O3substrate. Ohmic contact resistance (Rc) 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-Ga2O3MOSFETs with source-to-drain distance (Lsd) of 11 and 18 μm present high-saturation drain current (Ids,sat) of 267 and 222 mA/mm with low Ron,spof 4.57 and 11.7 mΩ · cm2, 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 (Vbr) are measured to be 480 and 680 V for the devices with Lsdof 11 and 18 μm, respectively. Most of all, the power figure of merit (Vbr2/Ron,sp) is as high as 50.4 MW/cm2, which is the highest value among any β-Ga2O3MOSFETs ever reported.