Sputter etching effect of the substrate on the microstructure of -FeSi thin film prepared by ion beam sputter deposition method

Sasase, Masato*; Shimura, Kenichiro*; Yamaguchi, Kenji; Yamamoto, Hiroyuki; Shamoto, Shinichi  ; Hojo, Kiichi

Beta iron disilicide (-FeSi) is one of the candidate materials for a compound semiconductor. We have employed ion beam sputter deposition method to grow highly oriented -FeSi film on a single crystal Si(100) substrate. In the present study, sputter etching effect of the substrate is investigated by the cross-sectional transmission electron microscope (TEM) observation in order to observe nanostructural changes as a function of Ne energy. The observed TEM images show that the 1 keV sputtering provides uniform films with few defects and smooth interface. The number of the produced defects rapidly increases with the energy. The obtained -FeSi tends to form small grains at the higher energy. Quite rough surface is also observed in this condition. Higher energies produce excessive amount of damages for the substrate to form epitaxially grown film. These results imply that a certain fluence is required for better quality of the deposited film.