Improved electrical performance of multilayer MoS2transistor with NH3-Annealed ALD HfTiO gate dielectric

Ming Wen, Jingping Xu, Lu Liu, Pui To Lai, Wing Man Tang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

15 Citations (Scopus)


The carrier mobility of MoS2transistors can be greatly improved by the screening effect of high-k gate dielectric. Therefore, in this paper, atomic layer deposited HfTiO annealed in different ambients (N2, O2, and NH3)is used to replace SiO2as gate dielectric for fabricating back-gated multilayer MoS2transistors. As a result, excellent electrical properties are achieved for the sample annealed in NH3at 400 °C for 10 min: the field-effect mobility of 31.1 cm2/(V s) and the subthreshold swing of 100 mV/decade, which are six times higher and three times smaller compared with that of the control sample, respectively. The enhanced electrical performance should be associated with the passivation effects of the NH3annealing, which reduces defective states in the HfTiO dielectric and at/near the HfTiO/MoS2interface. The capacitance equivalent thickness of the gate dielectric (HfTiO) is only 6.79 nm, which is quite small for back-gated MoS2transistor and is conducive to the scaling down of the device.
Original languageEnglish
Article number7831447
Pages (from-to)1020-1025
Number of pages6
JournalIEEE Transactions on Electron Devices
Issue number3
Publication statusPublished - 1 Mar 2017


  • Annealing
  • electron field mobility
  • FETs
  • high-k gate dielectric
  • multilayer MoS 2

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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