Stacking fault formation during homo-Epitaxy of 4H-SiC

Synchrotron topographic and optical microscopic studies are presented of stacking faults formed during homo-epitaxy of 4HSiC. Grazing incidence synchrotron white beam x-ray topographs reveal V and Y shaped features which transmission topographs reveal to be 1/4[0001] Frank-type stacking faults. Geometric analysis of the size and shape of these faults indicates that they are fully contained within the epilayer and appear to be nucleated at the substrate/epilayer interface. Detailed analysis shows that the positions of the V shape stacking faults match with the positions of c-axis threading dislocations with Burgers vectors of c or c+a in the substrate and thus appear to result from the deflection of these dislocations during epilayer growth. Similarly, the Y shaped defects match well with the substrate surface intersections of c-axis threading dislocations with Burgers vectors of c or c+a in the substrate which were deflected onto the basal plane during substrate growth. A model for their formation mechanism is presented.