Reactive deposition epitaxial growth of &bgr;‐FeSi2film on Si(111) has been studied byinsituobservation of reflective high energy electron diffraction combined withexsituAuger electron spectroscopy depth profile analysis. The direct phase formed at the top surface after iron coverage has been determined to be mixture Fe3Si and Fe5Si3, FeSi, and &bgr;‐FeSi2, respectively, according to the results of different deposit temperature. Diffraction patterns as well as the depth profile for the Fe/Si ratio have been discussed. ©1995 American Institute of Physics.