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Hybrid architecture for shallow accumulation mode AlGaAs/GaAs heterostructures with epitaxial gates


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Authors

Macleod, SJ 
See, AM 
Hamilton, AR 
Ritchie, DA 

Abstract

jats:pAccumulation mode devices with epitaxially grown gates have excellent electrical stability due to the absence of dopant impurities and surface states. We overcome typical fabrication issues associated with epitaxially gated structures (e.g., gate leakage and high contact resistance) by using separate gates to control the electron densities in the Ohmic and Hall bar regions. This hybrid gate architecture opens up a way to make ultrastable nanoscale devices where the separation between the surface gates and the 2D electron gas is small. In this work, we demonstrate that the hybrid devices made from the same wafer have reproducible electrical characteristics, with identical mobility and density traces over a large range of 2D densities. In addition, thermal cycling does not influence the measured electrical characteristics. As a demonstration of concept, we have fabricated a hybrid single-electron transistor on a shallow (50 nm) AlGaAs/GaAs heterostructure that shows clear Coulomb blockade oscillations in the low temperature conductance.</jats:p>

Description

Keywords

51 Physical Sciences, 40 Engineering, 4018 Nanotechnology, 5104 Condensed Matter Physics

Journal Title

Applied Physics Letters

Conference Name

Journal ISSN

0003-6951
1077-3118

Volume Title

106

Publisher

AIP Publishing
Sponsorship
Engineering and Physical Sciences Research Council (EP/J003417/1)
This project was supported by the Australian Government under the Australia-India Strategic Research Fund and by the Australian Research Council (ARC) DP scheme. A.R.H. acknowledges an ARC Outstanding Researcher Award. Devices were fabricated using the facilities at the NSW Node of the Australian National Fabrication Facility (ANFF). J.R., A.L., and A.D.W. acknowledge support from Mercur Pr-2013-0001, BMBF-Q.com-H 16KIS0109, and DFH/UFA CDFA-05-06.