Regensburg 2010 – scientific programme

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DS: Fachverband Dünne Schichten

DS 22: Synthesis of Nanostructured Films by Self-organization II (Focused Session)

DS 22.4: Talk

Wednesday, March 24, 2010, 17:00–17:15, H2

Kinetic Monte Carlo simulation of a three-dimensional Si/Ge quantum-dot crystal growth — •Martin Mixa and Václav Holý — Department of Condensed Matter Physics, Charles University, Ke Karlovu 5, 121 16 Prague, Czech Republic

A very regular three-dimensional (3D) arrangement of quantum dots can be achieved by a self-organized growth taking place on a prepatterned substrate. This growth technique has been successfully used at fabrication of 3D quantum-dot crystal of Ge dots in a Si matrix grown on a prepatterned Si(001) surface [1,2].

In our theoretical study we use the kinetic Monte Carlo method for simulation of such a Ge/Si(001) superlattice growth. We developed an efficient and simple kinetic Monte Carlo model [3] describing the surface diffusion and coalescence of deposited adatoms, whereas the shape of the growing dots is not atomistically simulated (it is taken ad hoc from the experiment). The self-organization effect is incorporated in the model via an influence of the strain field induced by buried dots on the hopping probabilities of migrating adatoms.

[1] D. Grützmacher et al., Nano Lett. 7, 3150 (2007). [2] V. Holý et al., Phys. Rev. B 79, 035324 (2009). [3] M. Mixa et al., Phys. Rev. B 80, 045325 (2009).