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

doi:10.1109/TED.2019.2934186

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 publication › Journal article › Academic research › peer-review

7 Citations (Scopus)

Abstract

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 language	English
Article number	8811757
Pages (from-to)	4337-4342
Number of pages	6
Journal	IEEE Transactions on Electron Devices
Volume	66
Issue number	10
DOIs	https://doi.org/10.1109/TED.2019.2934186
Publication status	Published - Oct 2019

Keywords

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

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

More information

10.1109/TED.2019.2934186

Cite this

@article{bb949d2f2e794a31b7ccc29f4044b5b2,

title = "Repair of Oxygen Vacancies and Improvement of HfO2/MoS2 Interface by NH3-Plasma Treatment",

abstract = "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.",

keywords = "Carrier mobility, interface-state density, MoS₂ transistors, plasma-treated HfO₂",

author = "Xinyuan Zhao and Jingping Xu and Lu Liu and Lai, \{Pui To\} and Tang, \{Wing Man\}",

year = "2019",

month = oct,

doi = "10.1109/TED.2019.2934186",

language = "English",

volume = "66",

pages = "4337--4342",

journal = "IEEE Transactions on Electron Devices",

issn = "0018-9383",

publisher = "IEEE",

number = "10",

}

TY - JOUR

T1 - Repair of Oxygen Vacancies and Improvement of HfO2/MoS2 Interface by NH3-Plasma Treatment

AU - Zhao, Xinyuan

AU - Xu, Jingping

AU - Liu, Lu

AU - Lai, Pui To

AU - Tang, Wing Man

PY - 2019/10

Y1 - 2019/10

N2 - 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.

AB - 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.

KW - Carrier mobility

KW - interface-state density

KW - MoS₂ transistors

KW - plasma-treated HfO₂

UR - https://www.scopus.com/pages/publications/85077738076

U2 - 10.1109/TED.2019.2934186

DO - 10.1109/TED.2019.2934186

M3 - Journal article

AN - SCOPUS:85077738076

SN - 0018-9383

VL - 66

SP - 4337

EP - 4342

JO - IEEE Transactions on Electron Devices

JF - IEEE Transactions on Electron Devices

IS - 10

M1 - 8811757

ER -