Optimised plasma enhanced chemical vapour deposition (PECVD) process for double layer diamond-like carbon (DLC) deposition on germanium substrates
|Optimised plasma enhanced chemical vapour deposition (PECVD) process for double layer diamond-like carbon (DLC) deposition on germanium substrates|
|Autor||Jan Heeg, Markus Rosenberg, Christian Schwarz, Torsten Barfels, Marion Wienecke|
Double layer DLC-films were deposited on germanium substrates by the PECVD-method, using ethyne as reactant gas during RF plasma excitation in a parallel plate reactor. The electric field distribution in the plasma chamber was simulated by FEM. The basic concept was the utilization of coatings with graded interfaces and without other materials.
The bias voltage, working pressure and substrate temperature were changed stepwise to create an appropriate combination of an adhesive layer with improved elastic properties and a wear protective layer with increased hardness on the top.
The layer thickness was determined by Scanning Electron Microscopy. Thickness data were used in combination with Infrared Spectroscopy to calculate the Refractive Index of the layer.
Double layered DLC-films with Vickers hardness up to 3500 HV and a refractive index of around 2 were generated, which can be used as wear resistant optical layer on germanium substrates.