Characterization of metal/high-k structures using monoenergetic positron beams

Akira Uedono, Tatsuya Naito, Takashi Otsuka, Kenichi Ito, Kenji Shiraishi, Kikuo Yamabe, Seiichi Miyazaki, Heiji Watanabe, Naoto Umezawa, Toyohiro Chikyow, Toshiyuki Ohdaira, Ryoichi Suzuki, Yasushi Akasaka, Satoshi Kamiyama, Yasuo Nara, Keisaku Yamada

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


The impact of TiN deposition on thin high-k (HfO2 and HfSiON) films formed on Si substrates was studied using monoenergetic positron beams. For the predeposition sample, the positrons implanted into Si diffuse toward the high-k/Si interface under the influence of the electric field, suggesting the presence of negative charges in the high-k films. After TiN was deposited on HfO2, positive charges were introduced at the TiN/HfO2 interface, which were associated with the incorporation of nitride into HfO 2, resulting in the formation of positively charged oxygen vacancies (Vos). From the isochronal annealing experiments for TiN/HfSiON/Si, it was found that positively charged defects (such as Vo) were introduced into HfSiON after annealing at 700-900°C. These defects were introduced by the interaction between TiN and HfSiON, resulting in the formation of polycrystalline TiO2 at the interface. The positively charged defects were annealed out at 1100°C, but the dielectric properties of HfSiON degraded.

Original languageEnglish
Pages (from-to)3214-3218
Number of pages5
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Issue number5 B
Publication statusPublished - 2007 May 17
Externally publishedYes


  • Defects
  • HfO
  • HfSiON
  • High-k
  • Metal gate
  • Positron annihilation
  • TiN

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)


Dive into the research topics of 'Characterization of metal/high-k structures using monoenergetic positron beams'. Together they form a unique fingerprint.

Cite this