Measurements of current-voltage characteristics of high-speed SiC and GaN power devices in nanosecond time scale

Abstract

Wide gap semiconductors such as GaN and SiC have extremely large values of breakdown fields. Measurements of current–voltage characteristics of the wide gap semiconductor devices using power electrical pulses can induce damage of the devices due to Joule heating. In our experiments the 4H-SiC sample and the GaN Gunn diode were placed in series to the transmission line, and a gauge resistor was used for the determination of incident pulse amplitude, in order to perform measurements using nanosecond pulses and, by this, to eliminate Joule heating. It is argued that the devices operating at high electric field (over 50 kV/cm) can be damaged by electrical pulses of nanosecond duration due to overheating which begins at submicron inhomogeneities during the pulse rise time.
Keywords: GaN, 4H-SiC, pulsed VACH measurement, high electric field effects
PACS: 65.40.-b, 71.55.Eq, 72.20.Ht, 73.50.Fq