1.0 cm2 silicon carbide P-i-N diodes for pulsed power applications

Silicon carbide diodes are being pursued by the Army as a compact, power-dense replacement for silicon diodes in various applications. Diodes are typically needed to protect other circuit components from reverse voltages and currents. Improvements in micropipe density and manipulation of basal plane dislocations, along with increased wafer size, allow for fabrication of larger area silicon carbide devices with higher voltage capability. The diodes evaluated in this study are double the area of the last generation of SiC P-i-N diodes (reported at IEEE PPC 2007) and designed for voltage blocking of 6 kV. Each module contains two 10 mm × 10 mm P-i-N diodes on a single cathode base plate. The modules exhibit forward voltage drop of 3.9 V at 100 A and 14 V at 6.8 kA of pulse current. The diodes were pulsed in series with a GTO to determine peak current and reverse blocking capabilities when subjected to a 1-ms wide half sine shaped pulse. Most of the diode modules conducted 6.8 kA at the 1-ms pulse width without degradation. This paper details the evaluation methods and results from diode pulse characterization.