Taneja, D., Sfigakis, F., Croxall, A.F. et al. (5 more authors) (2016) N-type ohmic contacts to undoped GaAs/AlGaAs quantum wells using only front-sided processing: Application to ambipolar FETs. Semiconductor Science and Technology, 31 (6). ISSN 0268-1242
Abstract
We report the development of a simple and reliable, front-sided-only fabrication technique for n-type ohmic contacts to two-dimensional electron gases (2DEGs) in undoped GaAs/AlGaAs quantum wells. We have adapted the well-established recessed ohmic contacts/insulated metal gate technique for inducing a 2DEG in an undoped triangular well to also work reliably for undoped square quantum wells. Our adaptation involves a change in the procedure for etching the ohmic contact pits to optimise the etch side-wall profile and depth. As an application of our technique, we present a front-side-gated ambipolar field effect transistor (FET), where both 2D electron and hole gases can be induced in the same quantum well. We present results of low-temperature (0.3 K - 4 K) transport measurements of this device, including assessment of the n-type ohmic contact quality. On the basis of our findings, we discuss why the fabrication of these contacts is difficult and how our technique circumvents the challenges.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence (https://creativecommons.org/licenses/by/3.0/). Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
Keywords: | undoped; GaAs/AlGaAs; quantum wells; ohmic contacts; etching; etch profiles |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 25 Jul 2016 15:21 |
Last Modified: | 25 Jul 2016 15:21 |
Published Version: | http://dx.doi.org/10.1088/0268-1242/31/6/065013 |
Status: | Published |
Publisher: | IOP Publishing |
Refereed: | Yes |
Identification Number: | 10.1088/0268-1242/31/6/065013 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:101342 |