High performance MoS2 TFT using graphene contact first process

Chih-Shiang Chang Chien; Hsun-Ming Chang; Wei-Ta Lee; Ming-Ru Tang; Chao-Hsin Wu; Si-Chen Lee

doi:10.1063/1.4996136

AIP Advances (Aug 2017)

High performance MoS2 TFT using graphene contact first process

Chih-Shiang Chang Chien,
Hsun-Ming Chang,
Wei-Ta Lee,
Ming-Ru Tang,
Chao-Hsin Wu,
Si-Chen Lee

Affiliations

Chih-Shiang Chang Chien: Department of Electrical Engineering, Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
Hsun-Ming Chang: Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
Wei-Ta Lee: Department of Electrical Engineering, Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
Ming-Ru Tang: Department of Electrical Engineering, Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
Chao-Hsin Wu: Department of Electrical Engineering, Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan
Si-Chen Lee: Department of Electrical Engineering, Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan

DOI: https://doi.org/10.1063/1.4996136
Journal volume & issue: Vol. 7, no. 8
pp. 085018 – 085018-6

Abstract

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An ohmic contact of graphene/MoS2 heterostructure is determined by using ultraviolet photoelectron spectroscopy (UPS). Since graphene shows a great potential to replace metal contact, a direct comparison of Cr/Au contact and graphene contact on the MoS2 thin film transistor (TFT) is made. Different from metal contacts, the work function of graphene can be modulated. As a result, the subthreshold swing can be improved. And when Vg<VFB, the intrinsic graphene changes into p-type, so graphene contact can achieve lower off current by lowering the Fermi level. To further improve the performance of MoS2 TFT, a new method using graphene contact first and MoS2 layer last process that can avoid PMMA residue and high processing temperature is applied. MoS2 TFT using this method shows on/off current ratio up to 6×106 order of magnitude, high mobility of 116 cm2/V-sec, and subthreshold swing of only 0.515 V/dec.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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