Deposition of highly hydrogenated carbon films by a modified plasma assisted chemical vapor deposition technique

Highly hydrogenated carbon films, with hydrogen content approaching 60 at.%, were deposited with a modified, inductively coupled plasma (ICP) assisted, chemical vapor deposition (CVD) technique. During deposition, flux of ionic species to the substrate surface was reduced by inserting a glass tube-grounded wire-mesh screen assembly between a CH4/Ar ICP and the substrate. Film characterization was accomplished by combining hydrogen elastic recoil detection, Raman spectroscopy, and instrumented nanoindentation. Film thermal stability was studied through high-temperature annealing in vacuum. We suggest that a decreased ratio of ionic to activated neutral species flux to the substrate during deposition is responsible for the increased hydrogen incorporation.