Nonisomorphic ErF3 layers on Si(111) substrates grown by molecular beam epitaxy

ErF3 layers were grown on Si(111) substrates at 400, 550, and 700 degrees C by molecular beam epitaxy. Reflection high-energy electron diffraction in situ and x-ray rocking curve analysis ex situ showed that at the high growt h temperature of 700 degrees C, an ErF3 layer of the native orthorhombic st ructure could be,orown conformably on the hexagonal atomic arrangement of t he Si(111) substrate. The surface morphology and flatness of the resulting layers were studied by atomic force microscopy as a function of growth temp erature and layer thickness. At higher temperatures, layers consist of high ly perfect crystallites aligned with b axes normal to the substrate, and c axes along one of six symmetrically related [01 (1) over bar] directions of the Si substrate. (C) 2060 American Vacuum Society. [S0734-2101(00)04003-3 ].