GROWTH OF (100) TEXTURED DIAMOND FILMS BY THE ADDITION OF NITROGEN

Localized {100} fiber textured diamond films were grown by addition of 20-200 ppm nitrogen into the gas phase during hot-filament chemical-v apor deposition (CVD). Cathodoluminescence indicates the presence of t he nitrogen-vacancy system in the {100} textured diamond, whereas a bl ue ''band A'' luminescence is normally observed in diamond films grown without nitrogen addition. The results demonstrate that the nature of the substrates used for growth has no appreciable influence on the {1 00} texture, which implies that this fiber texture is obtained by comp etitive growth and selection of facets. The interaction of nitrogen wi th the {100} surface is a highly important factor in this process. Hom oepitaxial growth shows that the addition of a small amount of nitroge n greatly enhances the growth rate of the {100} faces, making [100] th e fastest growth direction in comparison with the [110] and [111] dire ctions. This is attributed to breaking of a part of the dimers on the (2x1) reconstructed {100} surface by nitrogen compounds. The {100} tex ture in narrow, ring-shaped areas on diamond layers grown by the flame technique can also be attributed to the occurrence of a certain amoun t of nitrogen in the gas phase. It is demonstrated that the flame grow n polycrystalline diamond layers have morphologies and cathodoluminesc ence features that are consistent with those observed in the hot-filam ent CVD diamond films grown with the addition of nitrogen. (C) 1996 Am erican Institute of Physics.