Kinetics and characterization of hydrogenated carbon with ruthenium interlayer

Amorphous hydrogenated carbon films were prepared by hot filament Plasma Enhanced Chemical Vapor Deposition using acetylene as precursor. NiP-coated Al substrate was sputtered with thin layer of ruthenium film prior to carbon deposition for its impact on carbon film growth. Film thickness measured and fitted using X-ray Reflectometry showed carbon film growth is an exothermic reaction with apparent activation energy of 914.6 J mol^{- 1} in the temperature range studied. Carbon film density and surface roughness changed with substrate temperature, more profound when substrate is pre-heated at 300 °C and above, in sync with abrupt I_D/I_G increase at temperature higher than 300 °C. Substrate temperature higher than 200 °C and below 300 °C is preferred for hard and dense structure. Higher deposition rate and porosity were observed at higher C₂H₂ flow rate due to more H incorporation. Film surface morphology studied by Atomic Force Microscope showed Root Mean Square roughness increased at higher C₂H₂ flow rate due to less energetic ion peening effect. Atomic bonding structure with sp² and sp³ contents in the films deposited at varied temperature and C₂H₂ flow was analyzed using XPS.