Open Access Nano Express

Site-controlled quantum dots fabricated using an atomic-force microscope assisted technique

HZ Song1*, T Usuki1, T Ohshima1, Y Sakuma2, M Kawabe2, Y Okada3, K Takemoto1, T Miyazawa1, S Hirose1, Y Nakata1, M Takatsu1 and N Yokoyama1

Author Affiliations

1 Nanotechnology Research center, Fujitsu Lab. Ltd., Morinosato-Wakamiya 10-1, Atsugi, Kanagawa, 243-0197, Japan

2 Nanomaterials Laboratory, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan

3 Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, 305-8773, Japan

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Nanoscale Research Letters 2006, 1:160-166  doi:10.1007/s11671-006-9012-x

Published: 3 August 2006

Abstract

An atomic-force microscope assisted technique is developed to control the position and size of self-assembled semiconductor quantum dots (QDs). Presently, the site precision is as good as ± 1.5 nm and the size fluctuation is within ± 5% with the minimum controllable lateral diameter of 20 nm. With the ability of producing tightly packed and differently sized QDs, sophisticated QD arrays can be controllably fabricated for the application in quantum computing. The optical quality of such site-controlled QDs is found comparable to some conventionally self-assembled semiconductor QDs. The single dot photoluminescence of site-controlled InAs/InP QDs is studied in detail, presenting the prospect to utilize them in quantum communication as precisely controlled single photon emitters working at telecommunication bands.

Keywords:
Quantum dot; Site-Control; Atomic-force microscope; Local oxidation; Quantum computer; Quantum communication