FORMATION OF EPITAXIAL GAMMA-FESI(2) AND BETA-FESI(2) LAYERS ON (111)SI

Polycrystalline beta-FeSi2 layers, 85 nm thick, thermally grown on (11 1) Si substrates have been irradiated by 25 ns ruby-laser pulses in th e energy density range 0.4-1.2 J/cm2. Formation of the epitaxial metas table gamma-FeSi2 has been observed in a selected energy density range . The stability of gamma-FeSi2 has been tested by annealing in the 300 -800-degrees-C temperature range. The precipitation of the gamma phase into the stable beta occurred at temperatures above 600-degrees-C. Th e beta-FeSi2 films maintained epitaxy with Si and presented a reductio n of the roughness with respect to the thermally grown film.