Deposition of in situ surface structured DLC-coatings
A new RF-PACVD processing technology is described that helps to overcome some of the most important limitations of existing technology to generate diamond-like carbon (DLC) coatings on technical substrates. Separating the active inert gas area from the floating reactive-gas-chamber reduces cleaning requirements and improves scalability of the reactor design. It is shown how the films grown from different precursor gases differ in their ability to cover the original surface structure of technical substrates by analyzing the development of roughness, power spectra and statistical anisotropy of the surface topography measured with atomic force microscopy. Parameter studies are presented showing the in situ surface nano-structuring capabilities of the toluene based amorphous hydrogenated carbon (a-C:H) coatings that can be efficiently produced using the described technology.