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

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.
Authors:
; ; ; ; ; ; ;  [1] ; ;  [2]
  1. School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)
  2. Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)
Publication Date:
OSTI Identifier:
22305847
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM OXIDES; ATOMIC FORCE MICROSCOPY; CHARGE TRANSPORT; DIELECTRIC MATERIALS; ELECTRON BEAMS; EPITAXY; FIELD EFFECT TRANSISTORS; FILMS; GRAPHENE; LAYERS; PYROLYSIS; RAMAN SPECTROSCOPY; SCANNING TUNNELING MICROSCOPY; SILICON CARBIDES; SUBSTRATES; TEMPERATURE RANGE 0273-0400 K; THICKNESS