Variable-energy positron annihilation study of subnanopores in SiOCH-based PECVD films

Kenji Ito, Toshitaka Oka, Yoshinori Kobayashi, Ryoichi Suzuki, Toshiyuki Ohdaira

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Subnanoporosity was introduced into SiOCH-based thin films by mixing tetraethyl orthosilicate with hexamethyldisiloxane (HMDSO) in the plasma enhanced chemical vapor deposition process, and was evaluated by the variable-energy positron annihilation lifetime technique. It was found that with increasing the HMDSO fraction both porosity and pore size were enhanced, as evidenced by the decreased refractive index and increased ortho-positronium lifetime. The lifetimes from 2.0 to 6.8 ns suggested the tunable pore volumes within a range of 0.1-0.7 nm3.

Original languageEnglish
Pages (from-to)213-216
Number of pages4
JournalRadiation Physics and Chemistry
Issue number2
Publication statusPublished - 2007 Feb 1
Externally publishedYes


  • Hexamethyldisiloxane
  • Positron annihilation
  • Subnanopore
  • Tetraethyl orthosilicate
  • Thin film

ASJC Scopus subject areas

  • Radiation


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