Electron beam evaporation and ion assisted deposition have been
used to prepare BaF2, LaF3 and HoF3 single layers. These fluorides
were chosen as low index materials for laser applications at
10.6 Lm. The films were characterized by Rutherford backscattering
(RBS), x-ray diffraction, scanning electron microscopy (SEM),
stress measurement, laser calorimetry, and spectrophotometry.
The influence of substrate temperature, deposition rate, ion
energy, and ion to molecule arrival ratio on film growth was
analysed and related to the optical properties. Although each
material reacts differently to the deposition parameters, ion
assisted deposition leads to an increase of the absorption loss
at the laser wavelength for all three materials.