Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.63: Poster

Montag, 8. März 2004, 16:30–19:00, Poster A

Observation of aligned and self-assembled InAs quantum dots on a cleaved (110) GaAs surface — •R. Schulz, E. Uccelli, J. Bauer, D. Schuh, M. Bichler und G. Abstreiter — Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, D-85748 Garching

We report on a new approach for the spatial self-aligning of InAs quantum dots at well defined positions on a (110) GaAs surface. In contrast to other attempts [1-3] our method requires no lithografic processes but uses molecular beam epitaxy (MBE) itself for generating the template. By MBE on (001)GaAs, we have fabricated a GaAs/AlAs superlattice with different periods. Using the cleaved edge overgrowth technique (CEO), we obtain a smooth (110) surface with alternating GaAs and AlAs-layers in (001)-direction. After deposition of InAs on this surface, we observe the formation of InAs quantum dots. These are well aligned along the AlAs layers. The structural properties of these quantum dots have been investigated by AFM for different growth temperatures, different coverages of InAs, and different superlattice periods.

[1] R. Songmuang, S. Kiravittaya, O. G. Schmidt, Appl. Phys. Lett. 82(17)2892 (2003)

[2] H. Lee, J. A. Johnson, J. S. Speck, P. M. Petroff, J. Vac. Sci. Technol. B 18(4)2193 (2000)

[3] T. Mano, R. Nötzel, G. J. Hamhuis, Z.J. Eijkemans, J. H. Wolter Appl. Phys. Lett. 81(9)1705 (2002)