Diamond film growth in an oxygen atmosphere

We propose a new method for the synthesis of diamond films via a hydrogen-f ree vapor-phase route of pulsed laser ablation of a graphite target in a lo w-pressure pure oxygen atmosphere. The evidence from microscopic, diffracti on and spectroscopic techniques indicates that high-quality diamond crystal s can be nucleated and grown epitaxially on sapphire (single-crystal alumin um oxide) substrates without diamond-powder treatment at temperatures lower than 600 degreesC under the optimized growth conditions of oxygen pressure and pulsed KrF-excimer laser ablation. The spectroscopic property of a las er plasma plume produced during pulsed laser ablation of graphite in an oxy gen atmosphere was examined by using time-resolved optical emission measure ments in order to discuss the vapor-phase reaction and film growth mechanis m. (C) 2001 Elsevier Science B.V. All rights reserved.