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A comparison of the performance and stability of ZnO-TFTs with silicon dioxide and nitride as gate insulators

Cross, R.B.M., De Souza, M.M., Deane, S.C. and Young, N.D. (2008) A comparison of the performance and stability of ZnO-TFTs with silicon dioxide and nitride as gate insulators. IEEE Transactions on electron devices, 55 (5). pp. 1109-1115. ISSN 0018-9383


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The performance and stability of thin-film transistors with zinc oxide as the channel layer are investigated using gate bias stress. It is found that the effective channel mobility, on /off ratio, and subthreshold slope of the devices that incorporate SiN are superior to those with $hbox{SiO}_{2}$ as the dielectric. The application of positive and negative stress results in the device transfer characteristics shifting in positive and negative directions, respectively. The devices also demonstrate a logarithmic time-dependent threshold voltage shift suggestive of charge trapping within the band gap and the band tails responsible for the deterioration of device parameters. It is postulated that this device instability is partly a consequence of the lattice mismatch at the channel/insulator interface. All stressed devices recover to near-original characteristics after a short period at room temperature without the need for any thermal or bias annealing.

Item Type: Article
Copyright, Publisher and Additional Information: © Copyright 2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Institution: The University of Sheffield
Academic Units: The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield)
Depositing User: Sherpa Assistant
Date Deposited: 29 May 2008 09:19
Last Modified: 08 Feb 2013 16:56
Published Version: http://dx.doi.org/10.1109/TED.2008.918662
Status: Published
Publisher: IEEE
Identification Number: 10.1109/TED.2008.918662
URI: http://eprints.whiterose.ac.uk/id/eprint/3928

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