title: Atomic-layer soft plasma etching of MoS2.
abstract: Transition from multi-layer to monolayer and sub-monolayer thickness leads to the many exotic properties and distinctive applications of two-dimensional (2D) MoS2. This transition requires atomic-layer-precision thinning of bulk MoS2 without damaging the remaining layers, which presently remains elusive. Here we report a soft, selective and high-throughput atomic-layer-precision etching of MoS2 in SF6 + N2 plasmas with low-energy (<0.4 eV) electrons and minimized ion-bombardment-related damage. Equal numbers of MoS2 layers are removed uniformly across domains with vastly different initial thickness, without affecting the underlying SiO2 substrate and the remaining MoS2 layers. The etching rates can be tuned to achieve complete MoS2 removal and any desired number of MoS2 layers including monolayer. Layer-dependent vibrational and photoluminescence spectra of the etched MoS2 are also demonstrated. This soft plasma etching technique is versatile, scalable, compatible with the semiconductor manufacturing processes, and may be applicable for a broader range of 2D materials and intended device applications.
authors.affiliation: Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Xiao
authors.affiliation: Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Xuecheng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Yan
authors.affiliation: Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Gu
authors.affiliation: Analysis &Testing Center, Jiangnan University, Wuxi 214122, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Qin
authors.affiliation: Department of Physics, Southeast University, SEU Research Center of Converging Technology, Nanjing 211189, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Ni
authors.affiliation: CSIRO Manufacturing, P.O. Box 218, 36 Bradfield Road, Lindfield, New South Wales 2070, Australia.
authors.forename: Zhao Jun
authors.initials: ZJ
authors.lastname: Han
authors.affiliation: CSIRO Manufacturing, P.O. Box 218, 36 Bradfield Road, Lindfield, New South Wales 2070, Australia.|School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia.|Institute for Future Environments and School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
authors.forename: Kostya Ken
authors.initials: KK
authors.lastname: Ostrikov
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