Covalent nature in la-silicate gate dielectrics for oxygen vacancy removal

Takamasa Kawanago, Kuniyuki Kakushima, Parhat Ahmet, Kazuo Tsutsui, Akira Nishiyama, Nobuyuki Sugii, Kenji Natori, Takeo Hattori, Hiroshi Iwai

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


This letter focuses on studying the characteristic behavior of oxygen in La-silicate dielectrics by comparison with HfO 2 dielectrics. V FB shift of La-silicate caused by oxygen annealing is found to be stable even after reduction annealing unlike with HfO 2. Moreover, reduced gate leakage current and improved effective mobility of nMOSFETs with La-silicate are observed by oxygen incorporation, suggesting the annihilation of oxygen vacancy. Since the oxygen in La-silicate covalently exists adjacent to the Si atom, stability of oxygen in La-silicate can be understood in terms of strong bonding of covalent nature.

Original languageEnglish
Article number6129473
Pages (from-to)423-425
Number of pages3
JournalIEEE Electron Device Letters
Issue number3
Publication statusPublished - 2012 Mar
Externally publishedYes


  • Covalent nature
  • HfO
  • La-silicate
  • high-k gate dielectrics
  • ionic nature
  • oxygen vacancy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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