Surface structures on -FeSi formed by heat-treatment in ultra-high vacuum and their influence for homoepitaxial growth

Matsumura, Seidai*; Ochiai, Kunihito*; Udono, Haruhiko*; Esaka, Fumitaka  ; Yamaguchi, Kenji; Yamamoto, Hiroyuki; Hojo, Kiichi

The surface structures on the surface of -FeSi substrate after heat treatment in ultra high vacuum and their influence on homoepitaxial growth were investigated. It was found that the dip structures appeared on the surface of -FeSi (100) substrate after heat treatment above 1023 K, where the evaporation of surface oxide layer (SiO) occurred. The composition of the dip structure was Fe-rich as compared to nominal -FeSi composition (Si/Fe=2). This result indicates that the decomposition from -FeSi to -FeSi would occur on the surface. The surface morphology observed after heat treatment depended on the orientation of the substrate. In addition, homoepitaxial films with smooth surface on -FeSi (111) substrate at the growth temperature of 973 and 1073 K were obtained.