Nitrogen bonding configurations at nitrided Si(001) surfaces and Si(001)-SiO2 interfaces: A first-principles study of core-level shifts - art. no. 075307

Using a first-principles approach, we investigate nitrogen bonding configur ations at nitrided Si(001) surfaces and Si(001)-SiO2 interfaces by comparin g calculated core-level shifts with measured photoemission spectra. Fully r elaxed model structures are generated in which N atoms occur in a variety o f positions and bonding configurations that include, in particular, H neare st neighbors and dangling bonds. By establishing a correspondence between t he bonding environment of the N atoms and their 1s core-level shifts, we pr ovide a scheme for the interpretation of experimental photoemission spectra for both the nitrided surface and the nitrided interface. We also calculat e Si 2p core-level shifts focusing on the effects of Si-N bonds, and find g ood agreement with experiment also in this case.