Erosion of a-C:H films under interaction with nitrous oxide afterglow discharge

Hydrocarbon film removal using chemically active oxygen formed in a direct current glow discharge with a hollow cathode in nitrous oxide was investigated. In the afterglow region sufficiently fast removal of a-C:H films about 500 nm thick during about 8 h was achieved at N2O pressure of 12 Pa and 370 K. The erosion rate in the afterglow region was directly proportional to the initial pressure and increased two orders of magnitude at temperature rising from 300 to 500 K. The products of a-C:H film plasmolysis were CO, CO2, H2O, and H2. After removal of a-C:H films previously deposited on stainless steel, molybdenum or tungsten 3–30 nm thick oxide films were formed on the substrates. Reactions of oxygen ion neutralization and atomic oxygen recombination suppressed further oxidation of the materials.