Low Temperature (∼420°C) Epitaxial Growth of CaF2/Si(111) by Ionized-Cluster-Beam Technique

Abstract
A CaF2 single crystal has been grown on Si(111) by ionized cluster beam (ICB) epitaxial technique at a low temperature of around 420°C. A streaky reflection high energy electron diffraction (RHEED) pattern was observed for layers grown with electron ionization current I e=400 mA, whereas the pattern was ring-shaped when I e=100 mA. The acceleration voltage dependence of crystallinity was obtained by Rutherford backscattering spectroscopy, and the most suitable acceleration voltage for crystallinity was found to be V a=1-2 kV at I e=400 mA.