Growth and characterization of epitaxial Si/(LaxY1-x)2O3/Si heterostructures

We have studied the effect of growth temperature on the growth mode and defect density of (LaxY1-x)(2)O-3/Si(111) and Si(111)/(LaxY1-x)(2)O-3/Si(111) heterostructures by transmission electron microscopy. We have also investigated the epitaxial relationships between fluorite and bixbyite oxides on different Si surfaces in the framework of a model which suggests that the mismatch between the oxygen sublattice and the Si substrate is the most important criterion for establishing the epitaxial relation. In addition, during attempts to achieve perfect lattice matching between (LaxY1-x)(2)O-3 and Si by incorporating lanthanum beyond the near-lattice matched composition, we observe the formation of a phase-separated microstructure. A strain energy argument is developed to explain this observation. (C) 2003 American Institute of Physics.