A Monte Carlo simulation of the growth of Si(001)2×1: datom/SA step interactions and growth mechanisms

Results of a solid-on-solid lattice Monte Carlo simulation of the vapor phase epitaxial growth of Si(001)2×1 are described. Comparison of the simulations with published experimental results imply that adatoms are bound to type A surface steps with an energy of 0.1 ± 0.05 eV. There is apparently no significant barrier to adatom motion across the type A step. It is proposed that the motion of the type A step is nucleation limited while that of the type B step is controlled by the rate of attachment of adatoms to the step. The implications of this distinction are discussed. It is suggested that the effective critical nucleus size increases near both SA and SB steps because of coalescence with the SA steps and cluster disruption by vacancies produced at SB steps, respectively.