DLC-Schichtabscheidung mit dem Laser-Arc und Eigenspannungsuntersuchungen

The Laser-Arc is a controlled pulsed arc plasma source combining advantages of the pulsed laser deposition (PLD) technique with the high energy efficiency of a vacuum arc (VAD). The influence of deposition temperature on DLC-film properties will be shown by the results of mechanical and optical studies. Elastic modulus (E) was measured by means of ultrasonic surface waves. E-values up to 230 GPa were obtained for substrate temperatures bellow 150 Cel. The very small modulus for T > 150 Cel suggests a drastic decrease of sp (exp 3)/sp (exp 2) onding ratio in the amorphous DLC structure. These results correlate with optical studies, by means of ellipsometry and the behaviour of the complex refractive index. The optical absorption at 10.6 micrometres ranges from 200 to 900 cm (exp -l) and depends on the film thickness and on the substrate material. The results demonstrate that the Laser-Arc is suitable for the preparation of DLC-coatings with optical quality.