J. Phys. I France
Volume 3, Numéro 4, April 1993
Page(s) 935 - 950
DOI: 10.1051/jp1:1993174
J. Phys. I France 3 (1993) 935-950

Island formation in submonolayer epitaxy

Lei-Han Tang

Institut für Theoretische Physik, Universität zu Köln, Zülpicher Str. 77, D-5000 Köln 41, Germany

(Received 27 October 1992, accepted in final form 13 November 1992)

A minimal model for molecular-beam-epitaxy in the submonolayer at room temperature is investigated by simulations and analytically. Aggregation of diffusing monomers leads to immobile islands which further grow by absorbing deposited and diffusing atoms. In the intermediate stage of growth, islands assume a fractal shape similar to diffusion-limited-aggregates. It is shown that the maximum density of islands in the submonolayer decreases approximately as a 1/3-power of the beam intensity F, in agreement with a prediction based on rate equations. A detailed analysis of adatom-adatom and adatom-island collisions explains some discrepancies between simulation data and simple rate-equation results.


© Les Editions de Physique 1993