Growth of erbium-silicide films on (100) silicon as characterised by electron microscopy and diffraction

Erbium-silicide thin films were grown on Si(100) substrates under high vacuum either by single deposition of Er or by co-deposition of Er and Si, followed by annealing at 800-870 degrees C for 30 min. The crystalline quality of the films as well as the growth characteristics were analysed by electron microscopy and diffraction techniques. The films have a thickness between 35 and 50 nm and consist of patches up to a few hundreds of nm. In the single Er deposited samples the epitaxial growth of a tetragonal phase with a single epitaxial mode was found. This phase is considered to be induced by the substrate orientation. In the co-deposition samples the same epitaxy occurs in combination with ''multiple variant epitaxy'' of patches with the hexagonal ErSi2 structure. The epitaxial relationships are analysed in detail.