ALIGNED AND TWINNED GROWTH OF ALPHA-FE THIN-FILMS ON ATOMICALLY CLEANED (111)SI AT ROOM-TEMPERATURE

Epitaxial alpha-Fe thin films have been grown on atomically cleaned (111)Si at room temperature under ultrahigh vacuum condition. The alpha-Fe epitaxy on (111)Si was analyzed by transmission electron microscopy (TEM) to be predominantly of twinned epitaxy with a small fraction of epitaxy being aligned with respect to the substrate. High resolution TEM showed that the interface between the epitaxial iron thin film and Si substrate is atomically flat with the presence of a low density of atomic steps. Interfacial dislocations were found to be of edge type with 1/2[110]BAR Burgers vectors. The average spacing of interfacial dislocations was found to be close to the theoretically predicted value.