DEPTH ANALYSIS OF PHASE-FORMATION IN SI AFTER HIGH-DOSE FE ION-IMPLANTATION BY DEPTH-SELECTIVE CONVERSION-ELECTRON MOSSBAUER-SPECTROSCOPY

Fe+ ions of 200 keV in energy were implanted into Si(111) at 350 degre es C with a dose of 7 x 10(17) cm(-2). The depth distribution of the t wo formed phases (epsilon-FeSi and beta-FeSi2) was investigated nondes tructively up to a depth of about 800 Angstrom by depth-selective conv ersion-electron Mossbauer spectroscopy (DCEMS) in combination with dep th-profiling (destructive) Auger electron spectroscopy (AES). Near the surface only beta-FeSi2 is formed, while a mixture of beta-FeSi2 and epsilon-FeSi is formed at larger depths. The Fe-concentration depth pr ofile calculated from the DCEMS results is in good agreement with that measured by AES. (C) 1997 American Institute of Physics.