Facet Propagation in Si and SiGe Epitaxy or Etching

The facet propagation during silicon and SiGe epitaxial growth has been studied in terms of morphology and kinetics. Epitaxies were deposited on (001) Si wafers by chemical vapour deposition with the SiH2Cl2/HCl/H2 chemistry. In a similar way the faceting effects during HCl-chemical vapour etching of monocrystalline silicon have been examined. In both cases, the appearance of certain facets in certain experimental conditions has been explained on the basis of the different activation energies of growth kinetics found for the main high density crystal planes. Thus, we demonstrate that this kinetics anisotropy is the root cause of Si epitaxy faceting, and especially of the important {311} facets observed in most of conditions. And finally, we consider that our theoretical frame should be also valid for extended process conditions and various samples configurations.