Laser plasma CVD diamond reactor

The results of multi-parametric investigations of laser plasmatron in appli cation to CVD of diamond are presented. Different reaction chamber configur ations were studied. CH4/H-2/Xe(Ar) and CH4/CO2/H-2/Ar gas mixtures at tota l pressure 1.0-4.5 atm were used. Both convection and directed gas flows wi th velocity up to 50 cm/s delivered reactants to the substrate surface. Dia mond film deposition rates up to 40-50 mum/h were reached. CW CO2 laser bea m power and intensity needed for a stationary plasma maintenance under vari ous experimental conditions were found. Laser radiation absorption in plasm a was measured. The possibility to combine laser plasma with an auxiliary e lectrical discharge is demonstrated. A comparison between laser and other p lasma CVD techniques is made. (C) 2001 Elsevier Science B.V. All rights res erved.