Abstract
The valence-band and the O core-level spectra of ultrathin (about 1 nm) layers [which are formed at the initial stages of oxidation of hydrogen-terminated Si(100) substrates] were measured by high-resolution x-ray photoelectron spectroscopy. The energy difference between the valence band and the core level was found to be greater than that for the bulk A first-principle molecular-orbital calculation was performed on clusters in order to obtain the energy difference (which depends on the structure of layers). A comparison of the experimental data and the molecular-orbital calculations indicates that the intertetrahedral bond angle, is 135° to 140° in the structural transition layers at the interfaces.
- Received 3 August 1998
DOI:https://doi.org/10.1103/PhysRevB.59.5617
©1999 American Physical Society