Positron beam study of defects in SiO 2

M. Fujinami, N. B. Chilton, K. Ishii, Yoshimichi Ohki

Research output: Chapter in Book/Report/Conference proceedingChapter

2 Citations (Scopus)


Defects in crystalline and amorphous SiO 2 were studied by variable-energy positron annihilation spectroscopy in an attempt to clarify what defects in SiO 2 are observable in positron annihilation studies. The level of the S parameter in amorphous SiO 2 films grown by plasma chemical vapor deposition (CVD) in a tetraethylorthosilicate (TEOS) and O 2 atmosphere was found to be correlated to the concentration of Si-OH in the silicon dioxide layer. The difference in S parameter between crystalline and amorphous SiO 2 is assumed to be due to the effects of para-Ps self-annihilation in free volumes in the amorphous sample. The S parameters in crystalline and thermally grown silicon dioxide were both found to decrease after C ion implantation (1×10 14 cm -2, 140 keV) or alternatively, ArF excimer laser (6.4 eV) irradiation. Both methods are expected to produce numerous types of Frenkel defects of which, it is most likely that negatively charged species such as ≡Si-O - are the trapping sites. In the case of ion implantation into amorphous SiO 2 a greatly lowered S parameter is observed, this is explained as a combination of defect trapping and reduction in para Ps production after ion implantation.

Original languageEnglish
Title of host publicationJournal De Physique. IV : JP
EditorsI. Billard
PublisherPubl by Editions de Physique
Number of pages7
Publication statusPublished - 1993 Sep
Externally publishedYes
EventProceedings of the 4th International Workshop on Positron and Positronium Chemistry - Le Mont Sainte-Odile, Fr
Duration: 1993 Jun 201993 Jun 24


OtherProceedings of the 4th International Workshop on Positron and Positronium Chemistry
CityLe Mont Sainte-Odile, Fr


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Fujinami, M., Chilton, N. B., Ishii, K., & Ohki, Y. (1993). Positron beam study of defects in SiO 2 In I. Billard (Ed.), Journal De Physique. IV : JP (4 ed., Vol. 3, pp. 169-175). Publ by Editions de Physique.