The effect of oxygen in Ru gate electrode on effective work function of Ru/HfO2 stack structure

T. Nabatame; K. Segawa; M. Kadoshima; H. Takaba; K. Iwamoto; S. Kimura; Y. Nunoshige; H. Satake; T. Ohishi; Akira Toriumi

doi:10.1016/j.mssp.2006.10.013

The effect of oxygen in Ru gate electrode on effective work function of Ru/HfO₂ stack structure

T. Nabatame, K. Segawa, M. Kadoshima, H. Takaba, K. Iwamoto, S. Kimura, Y. Nunoshige, H. Satake, T. Ohishi, Akira Toriumi

Research output: Contribution to journal › Article › peer-review

16 Citations (Scopus)

Abstract

Effective work function (φ_m,eff) values of Ru gate electrode on SiO₂ and HfO₂ MOS capacitors were carefully examined and discussed from the viewpoint of an effect of oxygen incorporation in Ru gate electrode on φ_m,eff. Annealing at 400 °C in the reduction (3%H₂) and the oxidation (1%O₂) ambient resulted in similar changes in the φ_m,eff of Ru/HfO₂/SiO₂ and Ru/SiO₂ MOS capacitors. Furthermore, the Ru gate MOS capacitor after annealing in the oxidation condition have shown almost the same φ_m,eff value to that of RuO₂ gate MOS capacitors. The oxygen concentration in the Ru/HfO₂ interface after annealing in oxidizing atmosphere is approximately one order of magnitude higher than that after annealing in reducing atmosphere as confirmed by secondary ion mass spectroscopy analysis. Furthermore, the higher oxygen concentration at the Ru/dielectric interface leads to the higher φ_m,eff value, regardless of SiO₂ or HfO₂ dielectrics. This indicates that φ_m,eff of Ru gate MOS capacitor is dominantly determined by the oxygen concentration at the Ru/dielectric layer interface rather than the dipoles originated from the oxygen vacancy in HfO₂.

Original language	English
Pages (from-to)	975-979
Number of pages	5
Journal	Materials Science in Semiconductor Processing
Volume	9
Issue number	6
DOIs	https://doi.org/10.1016/j.mssp.2006.10.013
Publication status	Published - 2006 Dec
Externally published	Yes

Keywords

Effective work function
HfO
Oxygen content of Ru
Ru
RuO

ASJC Scopus subject areas

Materials Science(all)
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

Access to Document

10.1016/j.mssp.2006.10.013

Cite this

@article{67614c5bc6e04d57bbed1a315764116d,

title = "The effect of oxygen in Ru gate electrode on effective work function of Ru/HfO2 stack structure",

abstract = "Effective work function (φm,eff) values of Ru gate electrode on SiO2 and HfO2 MOS capacitors were carefully examined and discussed from the viewpoint of an effect of oxygen incorporation in Ru gate electrode on φm,eff. Annealing at 400 °C in the reduction (3%H2) and the oxidation (1%O2) ambient resulted in similar changes in the φm,eff of Ru/HfO2/SiO2 and Ru/SiO2 MOS capacitors. Furthermore, the Ru gate MOS capacitor after annealing in the oxidation condition have shown almost the same φm,eff value to that of RuO2 gate MOS capacitors. The oxygen concentration in the Ru/HfO2 interface after annealing in oxidizing atmosphere is approximately one order of magnitude higher than that after annealing in reducing atmosphere as confirmed by secondary ion mass spectroscopy analysis. Furthermore, the higher oxygen concentration at the Ru/dielectric interface leads to the higher φm,eff value, regardless of SiO2 or HfO2 dielectrics. This indicates that φm,eff of Ru gate MOS capacitor is dominantly determined by the oxygen concentration at the Ru/dielectric layer interface rather than the dipoles originated from the oxygen vacancy in HfO2.",

keywords = "Effective work function, HfO, Oxygen content of Ru, Ru, RuO",

author = "T. Nabatame and K. Segawa and M. Kadoshima and H. Takaba and K. Iwamoto and S. Kimura and Y. Nunoshige and H. Satake and T. Ohishi and Akira Toriumi",

year = "2006",

month = dec,

doi = "10.1016/j.mssp.2006.10.013",

language = "English",

volume = "9",

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journal = "Materials Science in Semiconductor Processing",

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TY - JOUR

T1 - The effect of oxygen in Ru gate electrode on effective work function of Ru/HfO2 stack structure

AU - Nabatame, T.

AU - Segawa, K.

AU - Kadoshima, M.

AU - Takaba, H.

AU - Iwamoto, K.

AU - Kimura, S.

AU - Nunoshige, Y.

AU - Satake, H.

AU - Ohishi, T.

AU - Toriumi, Akira

PY - 2006/12

Y1 - 2006/12

N2 - Effective work function (φm,eff) values of Ru gate electrode on SiO2 and HfO2 MOS capacitors were carefully examined and discussed from the viewpoint of an effect of oxygen incorporation in Ru gate electrode on φm,eff. Annealing at 400 °C in the reduction (3%H2) and the oxidation (1%O2) ambient resulted in similar changes in the φm,eff of Ru/HfO2/SiO2 and Ru/SiO2 MOS capacitors. Furthermore, the Ru gate MOS capacitor after annealing in the oxidation condition have shown almost the same φm,eff value to that of RuO2 gate MOS capacitors. The oxygen concentration in the Ru/HfO2 interface after annealing in oxidizing atmosphere is approximately one order of magnitude higher than that after annealing in reducing atmosphere as confirmed by secondary ion mass spectroscopy analysis. Furthermore, the higher oxygen concentration at the Ru/dielectric interface leads to the higher φm,eff value, regardless of SiO2 or HfO2 dielectrics. This indicates that φm,eff of Ru gate MOS capacitor is dominantly determined by the oxygen concentration at the Ru/dielectric layer interface rather than the dipoles originated from the oxygen vacancy in HfO2.

AB - Effective work function (φm,eff) values of Ru gate electrode on SiO2 and HfO2 MOS capacitors were carefully examined and discussed from the viewpoint of an effect of oxygen incorporation in Ru gate electrode on φm,eff. Annealing at 400 °C in the reduction (3%H2) and the oxidation (1%O2) ambient resulted in similar changes in the φm,eff of Ru/HfO2/SiO2 and Ru/SiO2 MOS capacitors. Furthermore, the Ru gate MOS capacitor after annealing in the oxidation condition have shown almost the same φm,eff value to that of RuO2 gate MOS capacitors. The oxygen concentration in the Ru/HfO2 interface after annealing in oxidizing atmosphere is approximately one order of magnitude higher than that after annealing in reducing atmosphere as confirmed by secondary ion mass spectroscopy analysis. Furthermore, the higher oxygen concentration at the Ru/dielectric interface leads to the higher φm,eff value, regardless of SiO2 or HfO2 dielectrics. This indicates that φm,eff of Ru gate MOS capacitor is dominantly determined by the oxygen concentration at the Ru/dielectric layer interface rather than the dipoles originated from the oxygen vacancy in HfO2.

KW - Effective work function

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KW - Oxygen content of Ru

KW - Ru

KW - RuO

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