Deflection of threading dislocations in patterned 4H-SiC epitaxial growth

Deflection of threading dislocations in patterned 4H-SiC epitaxial growth is investigated by applying multiple dry etching to create stair-like patterns growing toward <11¯00> on <112¯0> off-cut Si-face and C-face substrates. Forced deflection of most threading dislocations in the substrate is accomplished in the patterned C-face epitaxial growth; although no remarkable deflection of threading dislocations takes place in the patterned Si-face growth. The morphology of the patterned steps and behavior of threading and deflected dislocations are examined by optical microscopy and synchrotron X-ray topography, respectively. The interactions between the patterned steps and dislocations as well as the dependency of the deflection ratios of threading dislocations on the morphology of patterned steps are discussed.