1 research outputs found
Optical and Mechanical Properties of Thin PTFE Films, Deposited from a Gas Phase
Abstract Thin polytetrafluoroethylene (PTFE) films are produced by deposition from a gas phase by two methods: electronâenhanced vacuum deposition (EVD) and EVD + lowâtemperature plasma (LTP). Structure, morphology, and composition of the films are studied by IR spectroscopy, atomic force microscopy, and Xâray photoelectron spectroscopy. They are close to the structure of bulk PTFE. The roughness of the filmsâ surface is changed with gas pressure and LTP power variations. Films are transparent from UV to nearâinfrared regions. Refractive and extinction indices and their anisotropy are measured by spectral ellipsometry. They are tuned by variations of deposition conditions. Hardness and Young modulus of the films are increased if EVD + low power LTP is used for film deposition. Use of EVD + LTP also increases thermal stability of the films. Contact angle of the films corresponds to the bulk PTFE. The PTFE molecules oriented are preferentially in perpendicular direction to the substrate surface