Enhancement of epitaxial lateral overgrowth by vapor-phase diffusion

The mathematical model for vapor-phase diffusion-assisted epitaxial lateral overgrowth in homoepitaxy of a compound semiconductor (GaAs-type) thin film is presented. Besides diffusion in vapor phase, the physical mechanisms contributing to the crystal growth and accounted for in the model include surface diffusion and evaporation–recondensation. The evolution equations for the concentrations of bulk and surface species, and for the interface shape are solved by a combination of a finite difference and boundary element methods. Comparison of the results of the modeling to the models that ignore diffusion in vapor shows that the latter enhances the overgrowth on the mask; the degree of this enhancement increases with the widths of the stripe openings in the mask and of the masked regions. 2004 Elsevier Ltd. All rights reserved.