Mechanism of Vfb shift in HfO 2 gate stack by Al diffusion from (TaC) 1-xAl x gate electrode

T. Nabatame, M. Kimura, H. Yamada, A. Ohi, T. Ohishi, T. Chikyow

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We investigate Vfb behavior of (TaC) 1-xAl x gated HfO 2 MOS capacitors as a function of post metal annealing (PMA) temperature. The positive Vfb shift appears in PMA temperature at above 700°C, while the negative Vfb shift occurs at below 600°C. At below 600°C, the effective work function (φ m,eff) of gate electrode becomes lower by increasing Al atoms with a low work function. We found that the positive Vfb shift occurs dominantly due to the φ m,eff change induced by Al diffusion from gate electrode at 700 and 800°C. At above 900°C, Al atoms reach to the HfO 2/SiO 2 interface and form the AlO x layers, and results in positive Vfb shift due to the bottom interface dipole. We can divide into two components of φ m,eff change of gate electrode and the bottom interface dipole due to AlO x layer as a function of PMA temperature.

Original languageEnglish
Title of host publicationDielectrics for Nanosystems 5
Subtitle of host publicationMaterials Science, Processing, Reliability, and Manufacturing -and- Tutorials in Nanotechnology: More than Moore - Beyond CMOS Emerging Materials and Devices
Pages49-59
Number of pages11
Edition3
DOIs
Publication statusPublished - 2012 Nov 19
Event5th International Symposium on Dielectrics for Nanosystems: Materials Science, Processing, Reliability and Manufacturing - 221st ECS Meeting - Seattle, WA, United States
Duration: 2012 May 62012 May 10

Publication series

NameECS Transactions
Number3
Volume45
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

Conference

Conference5th International Symposium on Dielectrics for Nanosystems: Materials Science, Processing, Reliability and Manufacturing - 221st ECS Meeting
CountryUnited States
CitySeattle, WA
Period12/5/612/5/10

ASJC Scopus subject areas

  • Engineering(all)

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    Nabatame, T., Kimura, M., Yamada, H., Ohi, A., Ohishi, T., & Chikyow, T. (2012). Mechanism of Vfb shift in HfO 2 gate stack by Al diffusion from (TaC) 1-xAl x gate electrode. In Dielectrics for Nanosystems 5: Materials Science, Processing, Reliability, and Manufacturing -and- Tutorials in Nanotechnology: More than Moore - Beyond CMOS Emerging Materials and Devices (3 ed., pp. 49-59). (ECS Transactions; Vol. 45, No. 3). https://doi.org/10.1149/1.3700871