Industrial Applications of Positron Annihilation
J. Phys. IV France 05 (1995) C1-49-C1-56
Positron Studies of Oxide-Semiconductor StructuresA. Uedono1, L. Wei1, T. Kawano2, S. Tanigawa1, R. Suzuki3, H. Ohgaki3 and T. Mikado3
1 Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305, Japan
2 Radioisotope Center, University of Tsukuba, Ibaraki 305, Japan
3 Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305, Japan
The annihilation characteristics of positrons in SiO2 films grown on Si substrates were studied by using monoenergetic positron beams. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured as a function of incident positron energy for SiO2/Si structures fabricated by various oxidation techniques. From the measurements, it was found that the formation probability of positronium (Ps) atoms in SiO2 films strongly depends on the growth condition of SiO2 films. The present investigation shows that positrons provide a sensitive and nondestructive probe for the characterization of SiO2 films grown on Si substrates.
© EDP Sciences 1995