Probing interface defects in top-gated MoS2 transistors with impedance spectroscopy

Show simple item record Zhao, Peng Azcatl, Angelica Gomeniuk, Yuri Y. Bolshakov, Pavel Schmidt, Michael McDonnell, Stephen J. Hinkle, Christopher L. Hurley, Paul K. Wallace, Robert M. Young, Chadwin D. 2017-09-12T08:56:47Z 2017-09-12T08:56:47Z 2017-06-26
dc.identifier.citation Zhao, P., Azcatl, A., Gomeniuk, Y. Y., Bolshakov, P., Schmidt, M., McDonnell, S. J., Hinkle, C. L., Hurley, P. K., Wallace, R. M. and Young, C. D. (2017) 'Probing Interface Defects in Top-Gated MoS2 Transistors with Impedance Spectroscopy', ACS Applied Materials & Interfaces, 9(28), pp. 24348-24356. doi: 10.1021/acsami.7b06204 en
dc.identifier.volume 9 en
dc.identifier.issued 28 en
dc.identifier.startpage 24348 en
dc.identifier.endpage 24356 en
dc.identifier.issn 1944-8244
dc.identifier.doi 10.1021/acsami.7b06204
dc.description.abstract The electronic properties of the HfO2/MoS2 interface were investigated using multifrequency capacitance–voltage (C–V) and current–voltage characterization of top-gated MoS2 metal–oxide–semiconductor field effect transistors (MOSFETs). The analysis was performed on few layer (5–10) MoS2 MOSFETs fabricated using photolithographic patterning with 13 and 8 nm HfO2 gate oxide layers formed by atomic layer deposition after in-situ UV-O3 surface functionalization. The impedance response of the HfO2/MoS2 gate stack indicates the existence of specific defects at the interface, which exhibited either a frequency-dependent distortion similar to conventional Si MOSFETs with unpassivated silicon dangling bonds or a frequency dispersion over the entire voltage range corresponding to depletion of the HfO2/MoS2 surface, consistent with interface traps distributed over a range of energy levels. The interface defects density (Dit) was extracted from the C–V responses by the high–low frequency and the multiple-frequency extraction methods, where a Dit peak value of 1.2 × 1013 cm–2 eV–1 was extracted for a device (7-layer MoS2 and 13 nm HfO2) exhibiting a behavior approximating to a single trap response. The MoS2 MOSFET with 4-layer MoS2 and 8 nm HfO2 gave Dit values ranging from 2 × 1011 to 2 × 1013 cm–2 eV–1 across the energy range corresponding to depletion near the HfO2/MoS2 interface. The gate current was below 10–7 A/cm2 across the full bias sweep for both samples indicating continuous HfO2 films resulting from the combined UV ozone and HfO2 deposition process. The results demonstrated that impedance spectroscopy applied to relatively simple top-gated transistor test structures provides an approach to investigate electrically active defects at the HfO2/MoS2 interface and should be applicable to alternative TMD materials, surface treatments, and gate oxides as an interface defect metrology tool in the development of TMD-based MOSFETs. en
dc.description.sponsorship National Science Foundation (NSF UNITE US/Ireland R&D Partnership for support under NSF-ECCS-1407765); Science Foundation Ireland (under the US-Ireland R&D Partnership Programme Grant SFI/13/US/I2862) en
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.publisher American Chemical Society en
dc.rights This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see en
dc.subject Electrical characterization en
dc.subject High-k dielectrics en
dc.subject Interface defects en
dc.subject Molybdenum disulfide (MoS2) en
dc.subject Top-gated transistors en
dc.subject capacitance−voltage (C−V) en
dc.title Probing interface defects in top-gated MoS2 transistors with impedance spectroscopy en
dc.type Article (peer-reviewed) en
dc.internal.authorcontactother Paul Hurley, Tyndall Micronano Electronics, University College Cork, Cork, Ireland. +353-21-490-3000 Email: en
dc.internal.availability Full text available en Access to this publication is restricted until 12 months after publication at the request of the publisher en 2018-06-26 2017-09-12T08:46:51Z
dc.description.version Accepted Version en
dc.internal.rssid 410774550
dc.contributor.funder National Science Foundation en
dc.contributor.funder Science Foundation Ireland en
dc.description.status Peer reviewed en
dc.identifier.journaltitle ACS Applied Materials & Interfaces en
dc.internal.copyrightchecked No !!CORA!! en
dc.internal.licenseacceptance Yes en
dc.internal.IRISemailaddress en

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