Abstract:
The surface morphology of homoepitaxial diamond films grown by hot
filament assisted chemical vapour
deposition has been studied by phase sensitive optical microscopy.
As substrates natural diamond plates, of
varying orientations were used. The growth experiments were carried
out for several methane-hydrogen gas
phase compositions at different temperatures. From surface topography
it was deduced that the faces near
{111} and {100} grow by a step mechanism. For the {111} faces growth
involves lateral interaction between
adjacent growth steps over 4 nm; for the {100} faces no evidence for
surface diffusion was found. The {110}
facets are characterized by a hill and valley pattern. At higher methane
fractions amorphous carbon forms on
{111} and {110}, while single crystal diamond growth still persists
on {100}.