Impact of the Oxidation Temperature on the Interface Trap Density in 4H-SiC MOS Capacitors

Despite the material advantages of Silicon-Carbide (SiC), the on resistance of 4H-SiC metal-oxide-semiconductor transistors are severely degraded by high trap densities near the oxide/SiC interface (Dit). In this work, the effect of the oxidation ambient (oxygen flow rates of 0.05 l/min-2.5 l/min) and oxidation temperature (1200°C-1600°C) on the Dit is investigated. The Dit was reduced by up to an order of magnitude using a combination of a low oxygen flow rate and a high temperature. The Dit was extracted from capacitance-voltage measurements made on MOS capacitors.