VARIABLE GROWTH MODES OF CAF2 ON SI(111) DETERMINED BY X-RAY PHOTOELECTRON DIFFRACTION

Chemical discrimination of bulk and interface Ca 2p x-ray photoelectro n diffraction modulations is used to identify three growth regimes dur ing the initial stages of CaF2 epitaxy on Si(111). Low flux, high temp erature conditions produce island growth atop a nonwetting, chemically reacted Ca-F interface layer. Changing the growth kinetics by increas ing the flux produces more laminar growth. Lowering the substrate temp erature produces a more stoichiometric CaF2 interface layer that resul ts in immediate wetting and laminar growth.