Semiconductor opening switches based on 4H-SIC p/sup +/p/sub o/n/sup +/-diodes

Abstract

4H-SiC p/sup +/p/sub o/n/sup +/- and p/sup +/p/sub o/n/sup +/-type diodes have been fabricated and evaluated as opening switch devices which are known in Si to employ the effect of fast reverse current break after switching the diodes from forward to reverse bias conditions. The recovery properties of p/sup +/p/sub o/n/sup +/-diodes were found to be drastically differ from those of p/sup +/p/sub o/n/sup +/-type ones. In p/sup +/p/sub o/n/sup +/-diodes, recombination processes predetermine soft recovery behavior in a time of approximately 16 ns. In p/sup +/p/sub o/n/sup +/-type diodes, purely drift mechanism was found to be responsible, under proper conditions, for the very fast reverse current break in a time less than 1 ns. P/sup +/p/sub o/n/sup +/-diodes were utilized in a pulse generator, which was fabricated with an inductive energy storing unit. The rise time of 400-V pulses generated, about 3 ns, was found to be equal to the quarter of the oscillation period of the LC-tank consisting of 2-/spl mu/? storing inductance and 2-pF 4H-SiC diode capacitance. The possibility to construct 100-kV, 1-ns 4H-SiC pulse generators is considered.