Ohmic contacts for atomically-thin transition metal dichalcogenide semiconductors

Ning Wang

doi:10.1088/1674-4926/41/7/070401

J. Semicond. > 2020, Volume 41 > Issue 7 > 070401

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Ohmic contacts for atomically-thin transition metal dichalcogenide semiconductors

Ning Wang

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Corresponding author: Ning Wang, phwang@ust.hk

DOI: 10.1088/1674-4926/41/7/070401

References

[1]	Tung R T. Chemical bonding and Fermi level pinning at metal–semiconductor interfaces. Phys Rev Lett, 2020, 84, 6078 doi: 10.1103/PhysRevLett.84.6078
[2]	Cui X, Lee G H, Kim Y D, et al. Multi-terminal transport measurements of MoS₂ using a van der Waals heterostructure device platform. Nat Nanotechnol, 2015, 10, 534 doi: 10.1038/nnano.2015.70
[3]	Liu Y, Guo J, Zhu E, et al. Approaching the Schottky–Mott limit in van der Waals metal–semiconductor junctions. Nature, 2018, 557, 696 doi: 10.1038/s41586-018-0129-8
[4]	Allain A, Kang J, Banerjee K. Electrical contacts to two-dimensional semiconductors. Nat Mater, 2015, 14, 1195 doi: 10.1038/nmat4452
[5]	Kappera R, Voiry D, Yalcin S E, et al. Phase-engineered low-resistance contacts for ultrathin MoS₂ transistors. Nat Mater, 2014, 13, 1128 doi: 10.1038/nmat4080
[6]	Xu S G, Wu Z F, Lu H H, et al. Universal low-temperature Ohmic contacts for quantum transport in transition metal dichalcogenides. 2D Mater, 2016, 3, 021007 doi: 10.1088/2053-1583/3/2/021007
[7]	Wu Z F, Xu S G, Lu H H, et al. Even–odd layer-dependent magnetotransport of high-mobility Q-valley electrons in transition metal disulfides. Nat Commun, 2016, 7, 12955 doi: 10.1038/ncomms12955
[8]	Xu S G, Shen J Y, Long G, et al. Odd-integer quantum Hall states and giant spin susceptibility in p-type few-layer WSe₂. Phys Rev Lett, 2017, 118, 067702 doi: 10.1103/PhysRevLett.118.067702
[9]	Wu Z F, Zhou B T, Cai X B, et al. Intrinsic valley Hall transport in atomically thin MoS₂. Nat Commun, 2019, 10, 611 doi: 10.1038/s41467-019-08629-9
[10]	Cai X B, Wang N, et al. unpublished work (under reviewing 2020) carried out at the Hong Kong University of Science and Technology

Fig. 1. (Color online) Electrical interface between 2H TMDC and metal lead. (a) Interface band alignment of the van der Waals contact. (b) Interface band alignment of the Schottky-limited contact due to the presence of dangling bonds at the TMDC edge. (c) Interface band alignment of the contact based on the 1T–2H interface through locally induced phase transition. (d) Phase transition from 2H to 1T and 1T’.

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Fig. 2. (Color online) (a) Band structure of monolayer MoS₂. (b) The crystal structures and corresponding energy splitting diagrams of Mo/W d-orbital states before and after the phase transition. (c) The contact resistance (measured under different gate voltages V_bg) of the 3L-MoS₂ FET made by oxygen-plasma-induced phase transition.

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[1]	Tung R T. Chemical bonding and Fermi level pinning at metal–semiconductor interfaces. Phys Rev Lett, 2020, 84, 6078 doi: 10.1103/PhysRevLett.84.6078
[2]	Cui X, Lee G H, Kim Y D, et al. Multi-terminal transport measurements of MoS₂ using a van der Waals heterostructure device platform. Nat Nanotechnol, 2015, 10, 534 doi: 10.1038/nnano.2015.70
[3]	Liu Y, Guo J, Zhu E, et al. Approaching the Schottky–Mott limit in van der Waals metal–semiconductor junctions. Nature, 2018, 557, 696 doi: 10.1038/s41586-018-0129-8
[4]	Allain A, Kang J, Banerjee K. Electrical contacts to two-dimensional semiconductors. Nat Mater, 2015, 14, 1195 doi: 10.1038/nmat4452
[5]	Kappera R, Voiry D, Yalcin S E, et al. Phase-engineered low-resistance contacts for ultrathin MoS₂ transistors. Nat Mater, 2014, 13, 1128 doi: 10.1038/nmat4080
[6]	Xu S G, Wu Z F, Lu H H, et al. Universal low-temperature Ohmic contacts for quantum transport in transition metal dichalcogenides. 2D Mater, 2016, 3, 021007 doi: 10.1088/2053-1583/3/2/021007
[7]	Wu Z F, Xu S G, Lu H H, et al. Even–odd layer-dependent magnetotransport of high-mobility Q-valley electrons in transition metal disulfides. Nat Commun, 2016, 7, 12955 doi: 10.1038/ncomms12955
[8]	Xu S G, Shen J Y, Long G, et al. Odd-integer quantum Hall states and giant spin susceptibility in p-type few-layer WSe₂. Phys Rev Lett, 2017, 118, 067702 doi: 10.1103/PhysRevLett.118.067702
[9]	Wu Z F, Zhou B T, Cai X B, et al. Intrinsic valley Hall transport in atomically thin MoS₂. Nat Commun, 2019, 10, 611 doi: 10.1038/s41467-019-08629-9
[10]	Cai X B, Wang N, et al. unpublished work (under reviewing 2020) carried out at the Hong Kong University of Science and Technology