J. Phys. IV France
Volume 132, March 2006
Page(s) 83 - 86
Published online 11 March 2006
10th International Conference on the Formation of Semiconductor Interfaces
C. Girardeaux, et al.
J. Phys. IV France 132 (2006) 83-86

DOI: 10.1051/jp4:2006132016

Valence charges for ultrathin SiO2 films formed on Si(100)

K. Hirose1, M. Kihara2, H. Okamoto2, H. Nohira2, E. Ikenaga3, Y. Takata4, K. Kobayashi3 and T. Hattori2

1  Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan
2  Musashi Institute of Technology, 1-28-1 Tamazutzumi, Setagaya, Tokyo 158-8557, Japan
3  JASRI/SPring-8, 1-1-1 Kouto, Mikazuki, Sayo, Hyogo 679-5198, Japan
4  RIKEN/SRring-8, 1-1-1 Kouto, Mikazuki, Sayo, Hyogo 679-5148, Japan

We measure the relative chemical shift between Si 1s and Si 2p, $\Delta $E $_{\rm 1s}- \Delta $E$_{\rm 2p}$, for 0.20-1.96-nm-thick SiO2 films formed on Si substrates using high-resolution high-energys x-ray radiation. It is found that $\Delta $E $_{\rm 1s}- \Delta $E$_{\rm 2p}$ is independent of SiO2 film thickness for films thicker than 1.0 nm, whereas it is smaller for films thinner than 0.5 nm. The result, in conjunction with first principles molecular orbital calculations, indicates that the valence charge of the Si atom is larger for in ultrathin SiO2 films than in the thicker SiO2 films.

© EDP Sciences 2006