Electron-beam-induced current and cathodoluminescence study of dislocation arrays in 4H-SiC homoepitaxial layers

The electrical and optical properties of dislocation arrays (DAs) in 4H-SiC homoepitaxial layers were studied by using electron-beam-induced current (EBIC) and cathodoluminescence (CL) techniques. EBIC observations show that under electron-beam irradiation, the DAs are easily dissociated to form rhombic stacking faults (SFs), whereas the single threading dislocations are not. CL results demonstrate that a new peak (417 nm) appears at the formed SFs, which is the same as the phenomenon observed from dissociating basal plane dislocations. The dissociation mechanisms of DAs are proposed based on the assumption that small basal segments exist. The dissociation velocity of each dislocation in the DAs is discussed according to its recombination activity.