Role of oxygen transfer for high-k/SiO2/Si stack structure on flatband voltage shift

Toshihide Nabatame, Akihiko Ohi, Toyohiro Chikyow

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

7 Citations (Scopus)


We investigate the difference of flatband voltage (Vfb) behavior in high-k/SiO2/Si stack structure due to oxygen vacancy (Vo) and additional oxygen generated by the reduction and oxidation annelaing processes, respectively. The Vfb of Mg and La-incorporated Hf-based high-k dielectrics is also influenced by Vo generation in high-k layer. We found that the non-linear relationships of Vfb behavior appears in HfSiOx, Mg 2+-HfSiOx, and La3+-HfSiOx dielectrics as a function of the oxidation annealing temperature, while the HfO2, N3+-HfSiOx, Mg2+-HfO 2, and La3+-HfO2 dielectrics show the linear relationships of Vfb shift by introducing additional oxygen. Furthermore, it is clear that the Vfb shift of all high-k materials satisfies the diffusion equation; which indicates that the oxygen transfer in high-k layer is a dominant factor in determining Vfb. We found that the oxygen diffusion in high-k materials can be ordered as follows: Mg2+-HfO2, La 3+-HfO2 and N3+-HfSiOx > HfO 2 >> La3+-HfSiOx > HfSiOx and Mg2+-HfSiOx. Note that the oxygen transfer in high-k materials is very important to recognize mechanism of Vfb shift for high-k/SiO2/Si stack structure.

Original languageEnglish
Title of host publicationSilicon Nitride, Silicon Dioxide, and Emerging Dielectrics 11
PublisherElectrochemical Society Inc.
Number of pages14
ISBN (Electronic)9781607682158
ISBN (Print)9781566778657
Publication statusPublished - 2011
Externally publishedYes

Publication series

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

ASJC Scopus subject areas

  • Engineering(all)


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