Estimation of the critical condition for expansion/contraction of single Shockley stacking faults in 4H-SiC PiN diodes

Abstract

The critical condition for expansion/contraction of single Shockley-type stacking faults (1SSFs) was experimentally estimated by monitoring the electroluminescence from 1SSFs in 4H-SiC PiN diodes with different p/n structures while varying the current density and the temperature. The “threshold current density” for expansion/contraction of 1SSF was determined by observing the 1SSF behavior, and it was converted to the “threshold excess carrier density” using the numerical calculation by device simulation. The threshold excess carrier density was almost independent of the diode structures though the threshold current densities were very different among the various diodes, which means that the 1SSF behavior does not depend on the current density but on the excess carrier density. The threshold excess carrier density at room temperature was estimated to be about 4×1014 cm−3, which agrees with the result calculated by a theoretical model previously proposed. In addition, the conduction type- and the doping concentration-dependences of the threshold excess carrier density were discussed.