SURFACE-MORPHOLOGY AND EPITAXY OF BETA-FESI2 OBTAINED BY ION-BEAM-ASSISTED GROWTH

Semiconducting beta-FeSi2 layers, approximately 130 nm thick, have bee n grown by deposition of Fe onto [001] single crystal Si kept at high temperature with concurrent low energy Ar+ beam bombardment. Ions with energies of 100, 200 and 300 eV, and current density of a few muA/cm2 have been used. Scanning electron microscopy and transmission electro n microscopy analyses show an improvement of the surface morphology an d strong enhancement of the epitaxial fraction with respect to a film grown without ion beam assistance. In particular the gradual densifica tion of the film is observed when the ion energy or current is increas ed.