Chemical vapor deposition of diamond films from water vapor rf-plasma discharges

Polycrystalline diamond films have been deposited from water vapor rf-plasma discharges at 1.0 Torr containing various alcohol vapors. No other gases such as H₂, F₂, or Cl₂ were admitted to the growth chamber. Scanning electron microscopy and Raman spectroscopy have been used to characterize the diamond films. In addition, a water-ethanol mixture has been used for homoepitaxial deposition with a full-width-half- maximum narrower than the bulk substrate (2.60 and 2.75 cm^-1, respectively). This technique represents a remarkable new approach to the growth of diamond which does not depend on delivery of hydrogen, fluorine, hydrocarbon, or halocarbon gases that have been typically used by other workers. The nucleation density and topography of the polycrystalline diamond films deposited from the water alcohol mixtures are quite sensitive to the choice of alcohol. Water vapor discharges, by producing H atoms and OH radicals, become the functional equivalent to molecular H₂ discharges producing H atoms characteristic of many other diamond chemical vapor deposition techniques.