Effect of basal plane dislocations on characteristics of diffused 4H-SiC p-i-n diodes

The effect of basal plane dislocations (BPDs) on the characteristics of diffused 4H-SiC p-i-n diodes was investigated. BPDs were intentionally introduced in the active regions of the device by means of epi-layer surface damage followed by high temperature annealing. Secondary electron microscopy images of the fabricated diodes clearly show the presence of the deliberately introduced BPDs. The current-voltage and electroluminescence spectra measurements did not reveal any noticeable effect of the BPDs on the electrical and optical properties of the diodes. All tested diodes with and without BPDs have no forward voltage drift during long-term on-state operation. A possible reason for stable device performance may be the immobilization of defects responsible for forward voltage drift due to interaction with the diffused dopants.