EPITAXY ENHANCEMENT OF BETA-FESI2 GROWN BY ION-BEAM ASSISTED DEPOSITION

Iron silicide layers have been grown by 200 eV Ar+ beam assisted depos ition of Fe onto [001] Si single crystals maintained at high temperatu res. Polycrystalline FeSi has been formed at T=400-degrees-C while par tially epitaxial beta-FeSi2 was obtained after deposition at 500-degre es-C. Samples have been analyzed by Rutherford backscattering spectros copy and transmission electron microscopy. The main effects of the ion beam have been the reduction of the average grain size of the polycry stallites for both phases and the enhancement of the epitaxial fractio n for the beta-FeSi2 phase. The role of the ion beam during the format ion of the iron silicides has been discussed.