Optical properties of fluorinated diamond-like carbon films produced by pulsed glow discharge plasma immersion ion processing

Pulsed glow discharge plasma from a 1 Pa gas mixture of acetylene (C2H2) an d hexafluoroethane (C2F6) was used to produce fluorinated diamond-like carb on (F-DLC) films on glass and polymethyl-methacrylate (PMMA) substrate. The composition of the F-DLC coatings was measured by using Rutherford backsca ttering spectroscopy and elastic recoil detection analysis techniques. The transmittance, absorption coefficient, and optical band gap of 100 nm thick F-DLC coatings was measured by using an ultraviolet/visible spectrometer. The friction and wear properties were measured with a conventional pin-on-d isk device. In addition, contact angle measurements were taken in order to determine the nonwetting properties of the coatings. The results showed an increase in nonwetting properties, transmittance, and optical band gap with increasing fluorine content in the coatings. The increased fluorine conten ts suppressed the incorporation of hydrogen and increased the optical band gap energy, which is quite different from the general DLC films whose optic al properties are highly improved with increasing amount of hydrogen incorp orated in the films. Furthermore, the F-DLC coatings on PMMA and glass subs trates proved to have low friction and wear and similar nonwetting properti es such as Teflon(R). [S0021-8979(00)02115-0].