Journal of Crystal Growth, Vol.254, No.1-2, 137-143, 2003
Healing defects in SiC wafers by liquid-phase epitaxy in Si melts
Silicon carbide epitaxial layers were grown by liquid-phase epitaxy on 6H-SiC-modified Lely crystals containing a high density of micropipes (MP) and other defects. The geometrical configuration of the seed crystals inside the crucible during LPE was such that the epitaxial layer growth occurred simultaneously on both the faces of the seed crystals. Layers in the range of 20-30 mum thickness were deposited on both the faces of the crystals. X-ray diffraction, optical and scanning electron microscopy analyses were carried out to investigate these layers. It was found that dislocation and NIP density in the substrate after LPE growth has been significantly reduced: Several NIP were observed to decompose into non-hollow core dislocations. The growth centre associated with MP reduces in size in general and shifts to new centres due to the decomposition of the MP. As a result these new centres dominate the growing surfaces in LPE and make the healed MP completely invisible. (C) 2003 Elsevier Science B.V. All rights reserved.
Keywords:crystal morphology;crystal structure;optical microscopy;supersaturated solutions;growth from melt;liquid-phase epitaxy