GROWTH OF PHOSPHORUS AND NITROGEN CO-DOPED DIAMOND FILMS

The growth and characterization of epitaxial and polycrystalline diamo nd films co-doped with phosphorus and nitrogen using hot filament chem ical vapour deposition are reported. Secondary ion mass spectrometry a nalysis 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 phos phorus and nitrogen, while (100) finds it most difficult to incorporat e these impurities. In all cases of epitaxial diamond films the nitrog en concentration is about one order of magnitude higher than that of p hosphorus. However, for polycrystalline diamond films, the concentrati ons of phosphorus and nitrogen are approximately the same, 2 x 10(19) and 3 x 10(19) atoms cm(-3) respectively.