| Numéro |
J. Phys. IV France
Volume 03, Numéro C4, Septembre 1993
4th International Workshop on Positron and Positronium Chemistry
|
|
|---|---|---|
| Page(s) | C4-177 - C4-183 | |
| DOI | https://doi.org/10.1051/jp4:1993424 | |
4th International Workshop on Positron and Positronium Chemistry
J. Phys. IV France 03 (1993) C4-177-C4-183
DOI: 10.1051/jp4:1993424
1 Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305, Japan
2 Electrotechnical Laboratory, 1-1-4, Umezono, Tsukuba, Ibaraki 305, Japan
© EDP Sciences 1993
J. Phys. IV France 03 (1993) C4-177-C4-183
DOI: 10.1051/jp4:1993424
Characterization of SiO2 films grown on Si substrates by monoenergetic positron beams
A. UEDONO1, L. WEI1, S. TANIGAWA1, R. SUZUKI2, H. OHGAKI2 and T. MIKADO21 Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305, Japan
2 Electrotechnical Laboratory, 1-1-4, Umezono, Tsukuba, Ibaraki 305, Japan
Abstract
Variable-energy positron beams were utilized to characterize SiO2 films grown on Si substrates. For a SiO2 film grown by wet oxidation, a high formation probability of positronium (Ps) was found by measurements of Doppler broadening profiles of the annihilation radiation and those of lifetime spectra. For the SiO2 films grown by a chemical vapor deposition technique, the formation probability of Ps was found to decrease. This was attributed to interactions between positrons and -OH bonds and to the trapping of positrons by point defects. In order to know annihilation characteristics of Ps in the SiO2 films in more detail, a lifetime spectrum for a vitreous silica glass was also measured.
© EDP Sciences 1993