Repair of Oxygen Vacancies and Improvement of HfO2/MoS2 Interface by NH3-Plasma Treatment

Xinyuan Zhao, Jingping Xu, Lu Liu, Pui To Lai, Wing Man Tang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

4 Citations (Scopus)


The effects of treating the HfO2 gate dielectric in different plasmas (O2, N2, and NH3) on the electrical characteristics of a back-gated MoS2 transistor are investigated. It is found that the electrical properties of the device improved after HfO2 is treated by these plasmas, in which NH3-plasma treatment results in the best electrical characteristics: high ON-OFF ratio of 1.26times 107 , high extrinsic carrier mobility of 61.5 cm2/ textVcdot texts , small subthreshold swing (SS) of 111 mV/dec, low interface-state density of 2.79times 1012 eV -1,,cdot cm-2, and small hysteresis of 43 mV. These should be attributed to the incorporation of more N into the HfO2 film by the NH3 plasma to repair the oxygen vacancies and increase the k value of the HfO2 film. Moreover, H from the NH3 plasma effectively passivates the dangling bonds at/near the HfO2/MoS2 interface, thus creating an excellent MoS2/HfO2 interface.

Original languageEnglish
Article number8811757
Pages (from-to)4337-4342
Number of pages6
JournalIEEE Transactions on Electron Devices
Issue number10
Publication statusPublished - Oct 2019


  • Carrier mobility
  • interface-state density
  • MoS₂ transistors
  • plasma-treated HfO₂

ASJC Scopus subject areas

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


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