Steady-state and transient characteristics of 10 kV 4H-SiC diodes

Steady-state and transient characteristics of 10 kV 4H-SiC diodes have been measured in the temperature interval from 293 to 514 K. The results obtained demonstrate a high level of base modulation: at forward current density j(F) = 180 A cm(-2), the differential resistance r(d) of the diode is 24 times lower than the ohmic resistance r(0) of the unmodulated base at room temperature. The minority carrier lifetime pi(p) has been measured by open circuit voltage decay (OCVD) and current recovery time (CRT) techniques. The lifetimes pi(p) values measured by OCVD are 1.55 mus at room temperature and 6.52 mus at T = 514 K, which are the highest reported values for SiC diodes. CRT measurements indicate a uniform distribution of carrier lifetime across the diode base. However, comparison of the experimental results with the results of adequate simulation reveals reduced values of electron lifetime in highly doped part of the p(+)-emitter. (C) 2004 Elsevier Ltd. All rights reserved.