Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 20: Epitaxy and growth II

O 20.5: Vortrag

Dienstag, 28. März 2006, 12:15–12:30, WIL B321

Influence of strain on the dynamics of III – V semiconductor surfaces — •Hannes Guhl and Frank Grosse — Halbleitertheorie, Institut für Physik an der Humboldt-Universität Newtonstr. 15, 12489 Berlin

Thermodynamic equilibrium and growth kinetics of the InAs(001) surface under static homogeneous or inhomogeneous strain is investigated by kinetic Monte Carlo simulations. Its input, a strain dependent cluster expansion for the In and As interaction energies, is solely determined by ab initio density functional theory calculations. The surface interactions can be simplified under anneal conditions and mapped onto a multi-state Potts model with generalized interactions. The As-interaction along the As-dimer rows changes from attractive (compressive strain) to repulsive (tensile strain). Furthermore, the overall increased binding of As-dimers on compressed surfaces leads to slower As-dynamics and an increased density. The main step in the island nucleation is the formation of In pairs on the As-dimers rows [1]. Their increased binding energy under tensile strain leads to an increased island density in the initial stages of growth.

[1] F. Grosse, W. Barvosa-Carter, J. Zinck, M. Wheeler, M.F. Gyure, Phys. Rev. Lett. 89, 116102 (2002).