Laser plasma CVD diamond reactor

The results of multi-parametric investigations of laser plasmatron in application to CVD of diamond are presented. Different reaction chamber configurations were studied. CH4/H-2/Xe(Ar) and CH4/CO2/H-2/Ar gas mixtures at total pressure 1.0-4.5 atm were used. Both convection and directed gas flows with velocity up to 50 cm/s delivered reactants to the substrate surface. Diamond film deposition rates up to 40-50 mum/h were reached. CW CO2 laser beam power and intensity needed for a stationary plasma maintenance under various experimental conditions were found. Laser radiation absorption in plasma was measured. The possibility to combine laser plasma with an auxiliary electrical discharge is demonstrated. A comparison between laser and other plasma CVD techniques is made. (C) 2001 Elsevier Science B.V. All rights reserved.