A 800 V β‐Ga2O3 Metal–Oxide–Semiconductor Field‐Effect Transistor with High‐Power Figure of Merit of Over 86.3 MW cm−2

Herein, a high‐performance β‐gallium oxide (β‐Ga 2 O 3 ) metal–oxide–semiconductor field‐effect transistor (MOSFET) on sapphire substrate with a high breakdown voltage of more than 800 V and a high‐power figure of merit of more than 86.3 MV cm −2 is demonstrated. The atomic force microscopy (AFM) image and Raman peaks that are first characterized to ensure a nanomembrane with high quality are used for the device fabrication. A saturation drain current of 231.8 mA mm −1 , an R ON,sp of 7.41 mΩ cm 2 , an ON/OFF ratio of 10 8 , and a subthreshold swing of 86 mV dec −1 are obtained at a channel doping concentration of 4.47 × 10 17 cm −3 and a source‐to‐drain distance of 11.4 μm. Furthermore, a high breakdown voltage over 800 V is also achieved, corresponding to a record‐high direct current (DC) power figure of merit of 86.3 MW cm −2 . Technology computer aided design (TCAD) simulation is also performed to extract the distribution of the electric field along the β‐Ga 2 O 3 channel surface.