Partial Dislocations and Stacking Faults in 4H-SiC PiN Diodes

摘要

Using plan-view transmission electron microscopy (TEM), we have identified stacking faults (SFs) in 4H-SiC PiN diodes subjected to both heavy and light electrical bias. Our observations suggest that the widely-expanded SFs seen after heavy bias are faulted dislocation loops that have expanded in response to stresses within the 4H-SiC film, while faulted screw or 60° threading dislocations do not give rise to widely-expanded SFs. An analysis based on continuum mechanics indicates that the expansion of SFs depends on the Peach-Koehler forces acting on the partial dislocations bounding the SFs, indicating that stress plays a critical role in SF expansion.