AGGREGATION OF MONOCRYSTALLINE BETA-FESI2 BY ANNEALING AND BY SI OVERLAYER GROWTH

beta-FeSi2 films grown on Si(001) by the reactive deposition epitaxy ( RDE) aggregated into islands after annealing at 850 degrees C for one hour in ultrahigh vacuum (UHV). When a 100-nm-thick Si overlayer was g rown epitaxially at 750 degrees C by molecular beam epitaxy (MBE), the beta-FeSi2 islands aggregated further into a spherical shape in Si cr ystals. Observation with cross-sectional transmission electron microsc ope (XTEM) revealed that the epitaxial relationship between the two ma terials and monocrystalline nature were preserved even after the annea ling and the Si overgrowth.