EPITAXY OF BETA-FESI2 ON SI(111)

The epitaxial relationships of beta-FeSi2 films grown on Si(111) by solid-phase epitaxy and reactive-deposition epitaxy were investigated by x-ray diffraction. The beta(101) and beta(110) epitaxies were unambiguously detected by use of the beta space-group extinction rules. Three orientations, as expected from the Si bulk 3m symmetry, are developed in equal proportions. They can be related to a B-type fluoritelike epitaxy. Intensity profiles around Bragg nodes proved the intrinsic presence of beta(100) [011]/2 stacking faults. An electron-microscopy analysis has pointed out the role of the beta(100) orientation in the growth mechanism. An additional orientation was equally revealed which concerns beta islands with (001) [or (010)] facets parallel to inward Si(110) planes.