SYMMETRY CONSTRAINTS AND EPITAXIAL-GROWTH ON NON-ISOMORPHIC SUBSTRATE

Symmetry considerations discussed in the paper enable one to determine the constraints on single crystal growth in deposition on non-isomorp hic substrates. Curie's law of symmetry is applied to the two-dimensio nal point symmetries of interfaces. The procedure described in the pap er allows one to draw strict conclusions about the possibility of sing le-crystal growth and the crystallographic orientation of the epilayer . An analysis of three heteroepitaxial systems - A(3)B(5) nitride on s apphire, silicon on sapphire and A(3)B(5) on spinel - serves to illust rate the theoretical approach. The results of this analysis generally agree with data published earlier. Possible causes of the discrepancie s are discussed. It is shown that geometrical match is not the governi ng factor as far as epitaxy on non-isomorphic substrates is concerned.