Influence of Dislocations on I–V Characteristics of Schottky Diodes Prepared on n‐Type 6H‐SiC

The quantitative effects of dislocations on the I-V characteristics of n-type 6H-SiC Schottky diodes were determined by deliberately introducing dislocations into localized regions. Schottky diodes were fabricated upon scratched {0001} surfaces with a diamond scriber. Transmission electron microscopy observations showed differences in dislocation type and character introduced along the scratched faces whereas the dislocation density did not vary. On the other hand, only weak differences in the I-V characteristics were observed. Whatever the scratched {0001} face may be, the current-voltage characteristics obtained after the deformation step exhibited a bulge toward the low forward bias which was unambiguously attributed to the presence of dislocations on the basal plane within the space charge region. A mechanism involving tunneling effect from dislocation cores has been suggested.