Characterization Of Physically Vapor Deposited Af2400 Thin Films

Abstract

ABSTRACTAnti-reflective optical coatings made with Teflon AF2400 had the highest laser damage thresholds recorded for physical vapor deposited coatings at the Lawrence Livermore National Laboratory damage facility. Physical vapor deposited layers of Teflon AF2400, a perfluorinated amorphous polymer, Maintained the bulk optical properties of a high transmittance from 200 nm to 1200 nm, and a low refractive index. In addition, the refractive index can be intentionally reduced by control of two common deposition parameters, deposition rate and substrate temperature. Scanning electron microscopy and nuclear magnetic resonance observations indicated that morphological changes caused the variations in the refractive index rather than compositional changes. The coatings adhered to fused silica and silicon wafers under normal laboratory handling conditions.