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Abstract: Si films with <111> preferred orientation have been prepared on 6H–SiC(000−1) C-face. HRTEM and SAED results indicate that the Si film has epitaxial connection with the 6H–SiC substrate and the parallel-plane relationship of the Si/6H–SiC heterostructure is (111)Si//(000−1)6H–SiC. Using fast Fourier transform and Fourier mask filtering technique, misfit dislocations are clearly observed at the Si/6H–SiC interface, which accommodate the most of lattice mismatch strain. Every four Si (111) lattice planes are registered with five 6H–SiC(000−1) lattice planes along the interface. Based on the 4:5 lattice matching mode, the lattice structure of the Si/6H–SiC interface and its stability were energetically investigated by molecular dynamics simulations. When the Si films grow preferentially along <111> orientation on 6H–SiC(000−1) C-face, the misfit strain in Si layer significantly reduces due to the relaxation of C atoms in SiC layer near the Si/6H–SiC interface, and thus the Si/6H–SiC heterostructure has a stable interface with a small interface formation energy of −14.24eV. [Copyright &y& Elsevier]

Abstract: SiCGe/SiC heterojunction structure is required in development of SiC optoelectronic devices and light-activated switching devices. We present in this paper a primary attempt to grow the ternary alloy SiCGe on SiC substrates under varied growth conditions in a conventional hot-wall CVD system. SiH4, GeH4 and C3H8 were employed as silicon, germanium and carbon sources, respectively. The samples were measured by means of SEM, XPS, XRD, optical absorption, etc. Two different growth modes i.e., island growth and porous growth were observed. It has been shown that germanium atoms can be effectively incorporated into the ternary alloys, which makes their optical gaps to be narrowed with increasing Ge content. However, incorporation of Ge induces a heavy lattice mismatch, which limits the film thickness by the formation of mismatch defects. It has been shown that use of a buffer layer can effectively improve the growth quality of the ternary alloy. [Copyright &y& Elsevier]