Positive temperature coefficient of breakdown voltage in 4H-SiC pn junction rectifiers

It has been suggested that once silicon carbide (SiC) technology overcomes some crystal growth obstacles, superior SiC semiconductor devices would supplant silicon in many high-power applications. However, the property of positive temperature coefficient of breakdown voltage, a behavior crucial to realizing excellent power device reliability, has not been observed in 4H-SiC, which is presently the best-suited SiC polytype for power device implementation. This paper reports the first experimental measurements of stable positive temperature coefficient behavior observed in 4H-SiC pn junction rectifiers. This research indicates that robust 4H-SiC power devices with high breakdown reliability should be achievable after SiC foundries reduce material defects such as micropipes, dislocations, and deep level impurities.