M. M. Clark, Lionel M. Raff and H. L. Scott
Physical Rev. B 54, 5914 (1996)
Abstract
We present results of off-lattice kinetic Monte Carlo simulations of
early stages of low-pressure diamond film growth from a C(111) substrate
via methyl radical and hydrogen vapor deposition. Interactions are
governed by a semiempirical interatomic potential energy function. Rates
for surface chemisorption and desorption of hydrogen and chemisorption
of methyl radical that have been calculated by Raff and coworkers are used
to assign real time to the Monte Carlo steps. The rate-determining step
is the deposition or attempted deposition of methyl radicals. Between
methyl surface events, the surface is relaxed by standard Monte Carlo
methods. During the relaxation process, C-C bonds may form and break, and
surface diffusion occurs. We study the rate of formation of pair bonds and
larger clusters of chemisorbed carbon over a 20-ms simulation, during which
the initial surface becomes covered and small diamond ledges begin to form.
The rate of growth is in accord with observed rates for diamond film growth
from methyl radical.