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Title: Bottom-gate coplanar graphene transistors with enhanced graphene adhesion on atomic layer deposition Al{sub 2}O{sub 3}

A graphene transistor with a bottom-gate coplanar structure and an atomic layer deposition (ALD) aluminum oxide (Al{sub 2}O{sub 3}) gate dielectric is demonstrated. Wetting properties of ALD Al{sub 2}O{sub 3} under different deposition conditions are investigated by measuring the surface contact angle. It is observed that the relatively hydrophobic surface is suitable for adhesion between graphene and ALD Al{sub 2}O{sub 3}. To achieve hydrophobic surface of ALD Al{sub 2}O{sub 3}, a methyl group (CH{sub 3})-terminated deposition method has been developed and compared with a hydroxyl group (OH)-terminated deposition. Based on this approach, bottom-gate coplanar graphene field-effect transistors are fabricated and characterized. A post-thermal annealing process improves the performance of the transistors by enhancing the contacts between the source/drain metal and graphene. The fabricated transistor shows an I{sub on}/I{sub off} ratio, maximum transconductance, and field-effect mobility of 4.04, 20.1 μS at V{sub D} = 0.1 V, and 249.5 cm{sup 2}/V·s, respectively.
Authors:
; ; ;  [1] ;  [2]
  1. Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
  2. Department of Biomedical Engineering, and Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
Publication Date:
OSTI Identifier:
22395709
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ADHESION; ALUMINIUM OXIDES; ANNEALING; COMPARATIVE EVALUATIONS; DEPOSITION; DIELECTRIC MATERIALS; FIELD EFFECT TRANSISTORS; GRAPHENE; HYDROXIDES; MOBILITY; PERFORMANCE; SURFACES