Investigation of the properties of hydrogenated carbon films (a-C:H) deposited on germanium using a linear anode layer ion source

Hydrogenated carbon films (a-C:H) were deposited on single-crystal Ge with ion beams by means of a linear anode layer ion source at a flow rate of C₃H₈ of 1.7-4.4 sccm. An intermediate layer formed by the ion beam with an energy of 3 keV increases the adhesion of the coatings to the substrate and increases the hardness of the coatings. The highest hardness obtained with the use of the intermediate layer was 19±1.9 GPa. The transmission of the germanium substrate coated with a single layer of the a-C:H coating reaches 65-67% at wavelengths of 4.5-6 μm.