Method for making a non-sticking diamond-like nanocomposite

A process for coating in a vacuum chamber a substrate at least in part with a diamond-like nanocomposite composition, comprising the steps of:

• a) plasma etching of the substrate by bombardment of the substrate by ions of an inert gas;
• b) introducing in the vacuum chamber, at a working pressure of between 5×10−3 and 5×10−2 mbar, a liquid organic precursor containing the elements C, H, Si, O to be deposited in proportions, which proportions remain substantially constant during a deposition process;
• c) forming a plasma from the introduced precursor by an electron assisted DC-discharge using a filament with a filament current of 50-150 A, a negative filament bias DC voltage of 50-300 V and with a plasma current between 0.1 and 20 A;
• and
• d) depositing the composition on the substrate, to which a negative DC-bias or negative RF self-bias voltage is applied, in order to attract ions formed in the plasma, wherein the frequency of the RF voltage is between 30 and 1000 kHz,
• wherein the diamond-like nanocomposite composition comprises networks of a-C:H and a-Si:O, wherein the H-concentration is between 85% and 125% of the C-concentration, and wherein the diamond-like nanocomposite composition has a hardness of at least 10 GPa as measured by nanoindentation.