Abstract:
Localized {100} fiber textured diamond films were grown by addition
of 20-200 ppm nitrogen
into the gas phase during hot-filament chemical-vapor deposition (CVD).
Cathodoluminescence indicates the presence of the nitrogen-vacancy
system in the {100}
textured diamond, whereas a blue ''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 {100} texture,
which implies that this fiber
texture is obtained by competitive growth and selection of facets.
The interaction of nitrogen
with the {100} surface is a highly important factor in this process.
Homoepitaxial growth shows
that the addition of a small amount of nitrogen greatly enhances the
growth rate of the {100}
faces, making [100] the fastest growth direction in comparison with
the [110] and [111]
directions. This is attributed to breaking of a part of the dimers
on the (2x1) reconstructed
{100} surface by nitrogen compounds. The {100} texture in narrow, ring-shaped
areas on
diamond layers grown by the flame technique can also be attributed
to the occurrence of a
certain amount of nitrogen in the gas phase. It is demonstrated that
the flame grown
polycrystalline diamond layers have morphologies and cathodoluminescence
features that are
consistent with those observed in the hot-filament CVD diamond films
grown with the addition
of nitrogen