Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 50: Poster II

HL 50.79: Poster

Thursday, March 30, 2006, 16:30–19:00, P3

Positioning of self-assembled InAs quantum dots by focused ion beam implantation — •Minisha Mehta, Alexander Melnikov, Dirk Reuter, and Andreas D. Wieck — Lehrstuhl für Angewandte Festkörperphysik,Ruhr-Universtät Bochum, Universitätstraße 150, D-44780 Bochum,Germany

Self-assembled quantum dots (QDs) have attracted great interest in the last years for realization of novel nanoelectronic devices based on single quantum dots. For such devices, well controlled positioning of the InAs QDs is necessary.

We have studied a selective positioning method for self-organized InAs quantum dots (QDs) on patterned GaAs substrate by a combination of in-situ focused ion beam implantation (FIB) and self-organized molecular beam epitaxy (MBE) technology. We have proposed square lattice of nanoholes by FIB-implantation of Ga and In ions respectively. These arrays were overgrown with InAs to induced preferred QD formation at the hole positions. The shape and position of the QDs were investigated by scanning electron and atomic force microscopy. We studied the influence of the ion dose, an in-situ thermal treatment and the In amount deposited. By optimizing these parameters, we could achieve a minimum of approximately 7 QDs per hole without having QDs in the unpatterned areas.

Financial support from the DFG GRK384 and the BMBF contract BM451 NanoQuit is gratefully acknowledged.