Enhanced diamond nucleation on copper substrates by graphite seeding and CO2 laser irradiation

• Published in: Applied surface science 2008-01, Vol.254 (7), p.2054-2058
• Main Authors: Han, Y.X., Ling, H., Sun, J., Zhao, M., Gebre, T., Lu, Y.F.
• Format: Article
• Language: English
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2007.08.033

Diamond nucleation on copper (Cu) substrates was investigated by graphite seeding and CO2 laser irradiation at initial stages of the combustion-flame deposition. A graphite aerosol spray was used to generate a thin layer of graphite powders (less than 1mum) on Cu substrates. The graphite-seeded Cu substrates were then heated by a continuous CO2 laser to about 750 deg C within 1min. It was found that diamond nucleation density after this treatment was more than three times as much as that on the virgin Cu substrates. As a consequence, diamond films up to 4mum were obtained in 5min. The enhancement of diamond nucleation on the graphite-seeded Cu substrates was attributed to the formation of defects and edges during the etching of the seeding graphite layers by the OH radicals in the flame. The defects and edges served as nucleation sites for diamond formation. The function of the CO2 laser was to rapidly heat the deposition areas to create a favorable temperature for diamond nucleation and growth.