A field-plated Ga2O3 MOSFET with near 2-kV breakdown voltage and 520 mΩ . cm2 on-resistance

A composite field-plated Ga2O3 MOSFET with highly doped ohmic-capping layer is fabricated. An output current of 20 mA mm(-1) and on-resistance of 520 m Omega . cm(2) shows big improvement upon the previous experiment on similar field plated devices. The breakdown voltage is measured to be 1975 V on an L-gd = 25 mu m device. At elevated temperatures, the breakdown voltage decreases to <1 kV at 130 degrees C, while the on-resistance and saturation current are almost unchanged. The breakdown may be limited by the dielectric liquid strength. The on-resistance is limited by high interface state density that is attributed to the thermal process during the field oxide deposition. (C) 2019 The Japan Society of Applied Physics