Subnanosecond 4H-SiC diode current breakers

Abstract

Mesa epitaxial 4H-SiC-based p +-p-n 0-n + diodes have been fabricated and their reverse recovery characteristics have been measured in modes typical of fast semiconductor current breakers, drift step recovery diodes, and SOS diodes. It has been found that, after the short (∼10 ns) pulsed injection of nonequilibrium carriers by a forward current with a density of 200–400 A cm−2 and the subsequent application of a reverse voltage pulse (with a rise time of 2 ns), diodes can break a reverse current with a density of 5–40 kA cm−2 in a time of about (or less than) 0.3 ns. A possible mechanism for ultrafast current breaking is discussed.