Advances in Ga2O3 MOSFETs for Power and Radiation-Hard Electronics

β-Ga2O3 is being actively pursued for power switching and harsh environment electronics. State-of-the-art Ga2O3 MOSFETs were realized on unintentionally-doped (UID) β-Ga2O3 (010) epilayers by employing Si-ion (Si+) implantation doping for the channel and ohmic contacts. Depletion-mode devices with a gate-connected field plate (FP) achieved a high off-state breakdown voltage of 755 V, a large drain current on/off ratio (ION/IOFF) of over 109, stable high temperature operation at 300°C, and dispersion-free pulsed output characteristics. Bulk Ga2O3 exhibited high gamma-ray tolerance by virtue of the MOSFETs’stable DC characteristics against irradiation, while radiation-induced dielectric damage and interface trap generation limited the overall radiation hardness of these devices. A large thermal resistance of 48 mm·K/W for room temperature operation highlights the pertinence of thermal management to the performance and reliability of Ga2O3 transistors. Low residual carrier density in UID Ga2O3 enabled full channel depletion at zero gate bias for a positive threshold voltage in Si+-implanted enhancement-mode β-Ga2O3 (010) MOSFETs with low series resistance. Despite strong charge trapping effects associated with an unoptimized gate dielectric, a decent ION of 1.4 mA/mm and large ION/IOFF near 106 were achieved. Progress toward vertical Ga2O3 MOSFETs will also be presented.2nd International Workshop on Gallium Oxide and Related Material