TEM Characterization of a Complex Twinning System in 3C-SiC

摘要

This work was performed on a SiC sample grown on a 4H-SiC seed by chemical vapour deposition with the addition of GeH_4 gas to the classical SiH_4+C_3H_8 precursor system. In the present work, the defect structure and the polytypes "competition" are described. A complex 3C twinning system is also studied. This V-shape defect is nucleated inside the 3C layer contrary to what is generally observed (nucleation of twin at the 3C/4H interface). Using TEM diffraction, we identified the V-shape defect as a fourfold twin configuring three twin planes. Two of them are {111} twins, though the third one has been identified as a (11-5) twin.