Deposition of diamond from a plasma jet with phenol as the carbon source

Abstract

The deposition of diamond on a molybdenum substrate was studied in an Ar-H2 plasma jet adding phenol (C6H5OH) as a carbon source and was compared with adding benzene (C6H6) to examine the effect of OH species on diamond deposition. Better faceted and larger crystal size diamond was deposited from the Ar-C6H5OH-H2 plasma jet than from the Ar-C6H6-H2 plasma jet. Furthermore, the amount of co-deposited graphite and/or amorphous carbon in the deposit from the Ar-C6H5OH-H2 plasma jet was smaller than that in the deposit from the Ar-C6H6-H2 plasma jet. At the beginning of the exposure to the Ar-C6H5OH-H2 plasma jet, in which OH radicals were identified, the surface of the substrate was slightly oxidized. Oxide formation on the surface of the substrate by reaction with OH radicals would contribute to the purification and increase of crystal size in the diamond deposition with an Ar-C6H5OH-H2 plasma jet. (C) 2000 Elsevier Science S.A. All rights reserved.