Characterization of CNx/SiOy films prepared by the inductively coupled RF discharge

Hard films were deposited in an inductively coupled rf discharge at the frequency of 3.5 MHz by the chemical transport of carbon from the graphite target in nitrogen atmosphere combined with the evaporation of a quartz tube. The nitrogen flow varied from 1.0 to 4.0 sccm. The supplied rf power was in the range of 3 kW. Silicon substrates were placed on the graphite holder whose temperature was 750 degreesC. The films had the hardness of 35 GPa maximum and they showed high elastic recovery up to 88%, good fracture toughness and adhesion to the substrate. The hardness of deposited films increases with increasing CNx/SiOy ratio. This ratio is influenced by the deposition time.