15 kV SiC PiN diodes achieve 95% of avalanche limit and stable long-term operation

This paper reports on ultra-high voltage, >15 kV SiC PiN rectifiers exhibiting >95% of the avalanche rating and 115 V/μm. This is one of a few reports on > 15 kV blocking voltages measured on any single semiconductor device, and the highest percentage of the avalanche limit ever reported on devices fabricated on > 100 μm thick SiC epilayers. Excellent stability of on-state voltage drop (V_F) is displayed by 5.76 mm² and large-area, 41 mm² PiN rectifiers, when continually biased at high current densities for several days. The impact of carrier lifetime on the device performance for SiC bipolar devices with ultra-thick (≥100 μm) base layers is investigated by comparing I-V-T characteristics of SiC PiN rectifiers fabricated on 100 μm and 130 μm thick epilayers.