Response of electron-irradiated silicon carbide Schottky power diodes at elevated temperature

Abstract

Thermal-dependence experiments were executed on silicon carbide Schottky diodes. Devices were exposed to 3 MeV electrons with 10 MGy dose. Current density-voltage (~300 K to ~490 K) characterisation was used for investigation. At highest tested temperature, forward current at 0.3 V increased approximately seven orders of magnitude for unirradiated; and eight orders of magnitude for irradiated devices due to free carriers generation which obtained energy from the temperature. Series resistance of unirradiated increased with increasing temperature due to decrease in free carriers mobility, whilst irradiated devices decreased with increasing temperature which indicates that more free carriers acquired enough energy to escape the radiation-induced traps. Reverse current increased with increasing temperature due to the radiation-induced defects that act as generation-recombination centres. Activation energies of irradiated is higher than unirradiated devices. Also, there are two slopes in the plot of the activation energy-voltage which suggests that the reverse leakage current is due to two different mechanisms.