GROWTH OF PHOSPHORUS AND NITROGEN CO-DOPED DIAMOND FILMS

The growth and characterization of epitaxial and polycrystalline diamond films co-doped with phosphorus and nitrogen using hot filament chemical vapour deposition are reported. Secondary ion mass spectrometry analysis indicates that for epitaxial diamond films, the concentration of phosphorus ranges from 2 x 10(16) to 3.6 x 10(17) atoms cm(-3) and that of nitrogen from 4 x 10(17) to 3 x 10(18) atoms cm(-3), depending on the diamond substrate orientations. The experimental results also show that (111) is the orientation most ready to incorporate both phosphorus and nitrogen, while (100) finds it most difficult to incorporate these impurities. In all cases of epitaxial diamond films the nitrogen concentration is about one order of magnitude higher than that of phosphorus. However, for polycrystalline diamond films, the concentrations of phosphorus and nitrogen are approximately the same, 2 x 10(19) and 3 x 10(19) atoms cm(-3) respectively.