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Dirac point and transconductance of top-gated graphene field-effect transistors operating at elevated temperature

Hopf, T.; Vassilevski, K.V.; Escobedo-Cousin, E.; King, P.J.; Wright, N.G.; O'Neill, A.G.; Horsfall, A.B.; Goss, J.P.; Wells, G.H.; Hunt, M.R.C

Dirac point and transconductance of top-gated graphene field-effect transistors operating at elevated temperature Thumbnail


T. Hopf

K.V. Vassilevski

E. Escobedo-Cousin

P.J. King

N.G. Wright

A.G. O'Neill

A.B. Horsfall

J.P. Goss

G.H. Wells


Top-gated graphene field-effect transistors (GFETs) have been fabricated using bilayer epitaxial graphene grown on the Si-face of 4H-SiC substrates by thermal decomposition of silicon carbide in high vacuum. Graphene films were characterized by Raman spectroscopy, Atomic Force Microscopy, Scanning Tunnelling Microscopy, and Hall measurements to estimate graphene thickness, morphology, and charge transport properties. A 27 nm thick Al2O3 gate dielectric was grown by atomic layer deposition with an e-beam evaporated Al seed layer. Electrical characterization of the GFETs has been performed at operating temperatures up to 100 °C limited by deterioration of the gate dielectric performance at higher temperatures. Devices displayed stable operation with the gate oxide dielectric strength exceeding 4.5 MV/cm at 100 °C. Significant shifting of the charge neutrality point and an increase of the peak transconductance were observed in the GFETs as the operating temperature was elevated from room temperature to 100 °C.

Journal Article Type Article
Acceptance Date Oct 6, 2014
Online Publication Date Oct 17, 2014
Publication Date Oct 17, 2014
Deposit Date Nov 4, 2014
Publicly Available Date Nov 12, 2014
Journal Journal of Applied Physics
Print ISSN 0021-8979
Electronic ISSN 1089-7550
Publisher American Institute of Physics
Peer Reviewed Peer Reviewed
Volume 116
Issue 15
Article Number 154504
Public URL


Published Journal Article (2 Mb)

Copyright Statement
© 2014 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 116, 154504 (2014) and may be found at

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