Hot filament assisted deposition of diamond films.

摘要

A novel hot filament assisted chemical vapor deposition reactor for diamond was designed and built. The substrate is an independently heated, isothermal wire. This provides for the decoupling and independent control of substrate and hot filament temperatures, which is not possible in conventional diamond reactors. The reactor was used for: (1) the measurement of energy flows during diamond deposition, (2) estimation of hydrogen recombination rates on the substrate and (3) study of deposition of diamond and other forms of carbon outside of the normal parameter space for diamond deposition.;The recombination rate of atomic hydrogen on the substrate was measured as a function of substrate temperature and methane concentration. The gas phase concentration of atomic hydrogen at the substrate was estimated. A detailed analysis of the energy transport to the substrate was performed showing that atomic hydrogen recombination on the substrate is a major mechanism of energy transport. The conditions under which the transport of atomic hydrogen to the substrate is diffusion limited were found. This reactor also permitted broad investigation of the experimental parameter space. It was discovered that graphite fibers can be deposited by the vapor-liquid-solid mechanism by making modest variations in the diamond growth conditions. Diamond can be deposited on these fibers resulting in a new composite material which may have numerous technological applications.