Hydrogen-terminated single crystal diamond MOSFET with the dielectric of Ga₂O₃

In this work, the first fabrication and investigation of normally-off single crystal hydrogen-sterminated diamond MOSFETs with Ga₂O₃ dielectric has been successfully carried out. 50-nm-thick Ga₂O₃ was deposited by electron-beam evaporation technique at room temperature. The maximum drain current was −36 mA/mm, which was 164 times larger than previous work. Based on the transfer characteristic curve, the threshold voltage, on/off ratio and extrinsic transconductance were −0.37 V, 2.3 × 10⁷, and 9.8 mS/mm, respectively. The effective mobility of the MOSFET was calculated to be 264.1 cm²/V ⋅s at V_GS = − 1 V. This work may significantly promote the application of H-diamond FETs.