Structural and electrical studies of partial dislocations and stacking faults in (11-20)-oriented 4H-SiC

Abstract

This paper presents cathodoluminescence, electrical and structural characteristics of (11-20)-oriented 4H-SiC substrates, aiming at determining properties of some extended defects. As-grown basal plane dislocations with the Burgers vector b = 1/3 < 11-20 > previously revealed to be associated to a radiative recombination level at 1.80 eV. Well controlled dislocations were here introduced by annealing the sample under compressive stress at 973 K. After the annealing, double stacking faults were detected, formed by two Shockley partial dislocations gliding in two successive basal planes. These defects proved to introduce a rectifying behaviour during forward voltage operation, with a corresponding barrier height value of 0.58 eV at room temperature. Cathodoluminescence measurements allowed to attribute a radiative level at 1.80 eV to the extended defects, giving rise to a double luminescence peak.