Radiation effects of high-fluence reactor neutron on Ni/-Ga₂O₃ Schottky barrier diodes

This study investigates the broad-energy-spectrum reactor-neutron irradiation effects on the electrical characteristics of Ni/beta-Ga2O3 Schottky barrier diodes (SBDs), where the irradiated neutron fluence was up to 1 x 10(16) cm(-2). On the one hand, the high neutron fluence of 10(16) cm(-2) resulted in a reduction in forward current density by two orders of magnitude and an extremely high on-resistance property due to the radiation-generated considerable series resistance in the SBD. On the other hand, the irradiation brought little influence on the Ni/beta-Ga2O3 Schottky contact, since the extracted ideality factor and barrier height from temperature-dependent current-voltage (I-V-T) characteristics showed no significant changes after the radiation. Moreover, the capacitance-voltage (C-V) characterization revealed that the net carrier density in the beta-Ga2O3 material was only reduced by 25% at the neutron fluence of 10(15) cm(-2) but a significant reduction by 2-3 orders at 10(16) cm(-2). Within the neutron fluence range of 2 x 10(14) cm(-2) up to 10(16) cm(-2), the carrier removal rates trended to be saturated with the increased fluences, following an exponential regular. In addition, the C-V measurement on the 10(16) cm(-2) irradiated sample exhibited an obvious frequency dispersion, and the extracted carrier distribution was not uniform.