Abstract
The interaction of the nitrous oxide (NO) molecule with the Si(001)2×1 surface at 25–1150 °C was investigated by high-resolution photoemission using synchrotron radiation. N O and Si core-level spectra are systematically analyzed. At room temperature, the dissociative adsorption of NO yields two distinct components for both N and O core levels indicating different adsorption species. The major N species is found to be stable up to 850 °C and is assigned to be in the configuration. These N adsorbates are thought to incorporate into the surface and subsurface Si layers. The minor adsorbate species both for N and O are unstable for an annealing above 650 °C. The core-level spectra also indicate that a further annealing at ∼950 °C converts parts of the incorporated N into the stoichiometric silicon nitride on the surface while the desorption of oxygen starts already at ∼850 °C. The Si spectra for the NO-dosed surfaces could be decomposed with four oxide- or nitride-related components shifted from the bulk component by 0.8, 1.3, 2.1, and 2.9 eV, respectively. The origin of these components is discussed.
- Received 2 November 2001
DOI:https://doi.org/10.1103/PhysRevB.65.155310
©2002 American Physical Society