Vapor Deposition Growth of Sic Crystal on 4h-Sic Substrate by Molecular Dynamics Simulation

Abstract

The vapor deposition growth of SiC crystal on 4H-SiC substrate has been investigated by molecular dynamics computer simulation method. Three different lattice planes of 4H-SiC ((0001), (11-20) and (-1100)) were selected as the surface of substrate, and three different temperatures (2200 K, 2300 K and 2400 K) were used for the substrate in growth. The characteristics of formation of different polytypes of SiC and dislocations in the grown crystals were examined. The results show that the SiC crystals were grown by a subsurface nucleation and growth mode in the vapor deposition process. For substrates with (0001) plane as the surface, 3C-SiC single crystal was obtained in the deposited thin film. For substrates with (11-20) or (-1100) plane as the surface, 4H-SiC single crystal was obtained instead. The temperature of the substrate was found to have a significant effect on the dislocation density generated in the grown crystals. The formation mechanism of Frank partial dislocations during the growth of SiC crystals has been analyzed, and it gives good explanation of the temperature effect on dislocation formation in the grown crystals. These results can be insightful for experimental vapor deposition growth of SiC single crystals and high-quality epitaxial layers.

Keywords: Growth from vapor, Molecular dynamics simulation, SiC, Polytypes, Defects formation in growth, Dislocation nucleation