Characteristics of Passivated High-Voltage Silicon Carbide Diodes

The processing and characterisation of 6H-SiC PiN diodes is described. Comparisons are made between diodes with different surface passivations, and numerical simulation is used to better understand their behaviour. A ``wet´´ thermal oxide with a deposited silicon nitride layer on top is found to be the best surface passivation. This permits on-wafer high-voltage measurements to be made in air, possibly for the first time. Numerical simulation is used to improve the understanding of the behaviour of these devices.