GROWTH OF DIAMOND FROM ATOMIC-HYDROGEN AND A SUPERSONIC FREE JET OF METHYL RADICALS

The growth of small (similar to-10-micrometer) diamond particles (on 0 .1- or 0.25-micrometer seed crystals) using an effusive glow discharge nozzle for H. and a separate supersonic pyrolysis jet for .CH3 is rep orted. Laser micro-Raman, scanning electron microscopy, and x-ray phot oelectron spectroscopy data are presented as evidence that well-crysta llized diamond is indeed formed. Resonant multiphoton ionization spect roscopy is used as a diagnostic for the gas-phase chemistry indicating that the radical sources are clean and quantitative and that there is no detectable interconversion of .CH3 to C2H2 under the conditions of the experiment. Diamond growth is found at substrate temperatures gre ater than or equal to 650 degrees C with no marked increase in the rat e of growth up to 850 degrees C. Acetylene does not give good quality diamond under similar conditions.