Berlin 2008 – scientific programme
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O: Fachverband Oberflächenphysik
O 10: Semiconductor Substrates: Epitaxy and Growth
O 10.9: Talk
Monday, February 25, 2008, 15:15–15:30, MA 042
Impurity induced growth instabilities — •Jörg Megow and Frank Grosse — Institut für Physik der Humboldt Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany
Growth instabilities can be utilized for the formation of semiconductor nanostructures, e.g. regular step bunches might be useful as templates for growth of quantum wires. A possible source for step bunching is the inclusion of small amounts of impurities during growth. The experimentally observed growth instability in the Si1−xCx/Si(118) system is explainable if the impurities (C) are nearly immobile and have reduced binding to the growing species (Si) [1].
We present kinetic Monte Carlo simulations for different growth scenarios. Special emphasis is given to the role of exchange processes leading to the incorporation of the impurities into subsurface sites. The resulting changes of the chemical ordering in the grown crystal are analyzed and related to changes in the step bunch distribution at the surface. The relation of the formation of three dimensional nanostructures on singular (001) surfaces and wetting behavior under different impurity concentrations is demonstrated.
[1] E.T. Croke etal. Appl. Phys. Lett. 77 1310 (2000).