Mechanism of Vfb shift in HfO2 gate stack by Al diffusion from (TaC)1-xAlx 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-xAlx gated HfO2 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 (φm,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 φm,eff change induced by Al diffusion from gate electrode at 700 and 800°C. At above 900°C, Al atoms reach to the HfO2/SiO2 interface and form the AlOx layers, and results in positive Vfb shift due to the bottom interface dipole. We can divide into two components of φm,eff change of gate electrode and the bottom interface dipole due to AlOx 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
PublisherElectrochemical Society Inc.
Pages49-59
Number of pages11
Edition3
ISBN (Electronic)9781607683131
ISBN (Print)9781566779555
DOIs
Publication statusPublished - 2012
Externally publishedYes
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

Other

Other5th International Symposium on Dielectrics for Nanosystems: Materials Science, Processing, Reliability and Manufacturing - 221st ECS Meeting
Country/TerritoryUnited States
CitySeattle, WA
Period12/5/612/5/10

ASJC Scopus subject areas

  • Engineering(all)

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