Nitrogen-doped channel β-Ga₂O₃ MOSFET with normally-off operation

A normally-off lateral Ga2O3 metal-oxide-semiconductor field effect transistor (MOSFETs) was fabricated on a single crystal β-Ga2O3 (010) substrate. The top Ga2O3 layer forming a channel was grown by plasma-assisted molecular beam epitaxy, and the doping of N functioning as a deep acceptor was performed during the growth. Subsequently, Si ion implantation was employed to form ohmic contacts with source and drain electrodes, resulting in a clear linear region in the DC output characteristics of the MOSFET. Furthermore, the device showed a rise in the drain current at a gate voltage of over 5 V, indicating a positive threshold voltage. Consequently, the normally-off characteristic of the Ga2O3 (010) MOSFET with N-doped channel was demonstrated.