F. Lenormand et al., EARLY STAGES OF DIAMOND GROWTH BY CHEMICAL-VAPOR-DEPOSITION MONITOREDBOTH BY ELECTRON SPECTROSCOPIES AND MICROSTRUCTURAL PROBES, Journal of applied physics, 80(3), 1996, pp. 1830-1845
We performed a complete study of the nucleation and growth kinetics of
chemical-vapor-deposition (CVD) diamond on Si(100). The diamond Blm w
as grown using the microwave-assisted MWACVD method and the substrate
was preliminary pretreated by ultrasonic agitation with 300 mu m diamo
nd grains, which provides a high nucleation density at saturation (>10
(8) cm(-2)), The evolution of the diamond particles coverage was inves
tigated by two independent ways. The size distribution, mean size of t
he individual diamond particles, the surface coverage, and the nucleat
ion density were monitored by scanning electron microscopy, including
analysis of the pictures, and the overall carbon coverage was recorded
by x-ray photoemission spectroscopy. Results agree to predict a break
point in the growth law: Initially the kinetics obey a law in t(1/3),
whereas after about 30-45 min the behavior becomes linear. This is in
terpreted as a change of the rate limiting step of the growth which is
governed by the surface coverage of diamond particles. At low diamond
islands surface coverage (S much less than 0.04), the growth process
is limited by an indirect route including the impingement onto the bar
e surface, surface diffusion of the reactive carbon species, and inter
face reactivity. At larger surface coverage, the route through reactiv
ity of the diamond surface is preferred. (C) 1996 American Institute o
f Physics.