Chemical reaction at the interface between polycrystalline Si electrodes and HfO 2 Si gate dielectrics by annealing in ultrahigh vacuum

H. Takahashi, S. Toyoda, J. Okabayashi, H. Kumigashira, M. Oshima, Y. Sugita, G. L. Liu, Z. Liu, K. Usuda

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We have investigated the chemical reaction at the interface between polycrystalline-Si (poly-Si) electrodes and Hf O2 Si gate dielectrics by photoemission spectroscopy and x-ray absorption spectroscopy depending on the annealing temperature in an ultrahigh vacuum. From Si 2p and Hf 4f high-resolution core-level photoemission spectra, we revealed that the Hf-silicide formation starts at as low temperature as 700 °C and that the Hf-silicate layer is also formed at the interface between poly-Si electrodes and Hf O2. Crystallization of the amorphous Hf O2 layer even at 700 °C was suggested from valence-band and O K -edge absorption spectra. By the annealing at 800 °C, the Hf O2 layer disappeared completely and the Hf-silicide clusters were formed on the Si substrate. Direct contact between poly-Si electrodes and Hf O2 promotes the interfacial reaction compared to the case without poly-Si electrodes.

Original languageEnglish
Article number012903
JournalApplied Physics Letters
Volume87
Issue number1
DOIs
Publication statusPublished - 2005 Jul 4
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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