DIAMOND GROWTH USING REMOTE METHANE INJECTION IN A DIRECT-CURRENT ARCJET CHEMICAL-VAPOR-DEPOSITION REACTOR

A significant enhancement in the quality of diamond films grown using a remote CH4 carbon source was observed in a direct current arcjet che mical vapor deposition reactor. The linewidths of the diamond peak at 1332 cm-1 in the Raman spectra from these films were reduced from 9.0 to 6.5 cm-1 with no reduction in mass deposition rate as compared to f ilms grown using premixed reactor gas feeds. For diamond growth condit ions, the percentage of the reactor feed carbon reaching the substrate was measured to be approximately 35 %. The enhanced quality of the fi lms is attributed to reduced residence times of the carbon source in t he plasma, which would limit the ps phase chemistry from proceeding be yond CH3 formation before the gas reaches the substrate.