Characterization and physical modeling of MOS capacitors in epitaxial graphene monolayers and bilayers on 6H-SiC
2016 (English)In: AIP Advances, ISSN 2158-3226, E-ISSN 2158-3226, Vol. 6, no 8, 085010Article in journal (Refereed) Published
Capacitance voltage (CV) measurements are performed on planar MOS capacitors with an Al2O3 dielectric fabricated in hydrogen intercalated monolayer and bilayer graphene grown on 6H-SiC as a function of frequency and temperature. Quantitative models of the CV data are presented in conjunction with the measurements in order to facilitate a physical understanding of graphene MOS systems. An interface state density of order 2 . 10(12)eV(-1)cm(-2) is found in both material systems. Surface potential fluctuations of order 80-90meV are also assessed in the context of measured data. In bilayer material, a narrow bandgap of 260meV is observed consequent to the spontaneous polarization in the substrate. Supporting measurements of material anisotropy and temperature dependent hysteresis are also presented in the context of the CV data and provide valuable insight into measured and modeled data. The methods outlined in this work should be applicable to most graphene MOS systems. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Place, publisher, year, edition, pages
AMER INST PHYSICS , 2016. Vol. 6, no 8, 085010
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-132078DOI: 10.1063/1.4961361ISI: 000383909100010OAI: oai:DiVA.org:liu-132078DiVA: diva2:1038407
Funding Agencies|European Science Foundation (ESF) under EUROCORES Program EuroGRAPHENE; EU ; Swedish Foundation for Strategic Research (SSF); Knut and Alice Wallenberg Foundation (KAW)2016-10-182016-10-172016-11-11