Journal of Vacuum Science and Technology · 1979 · 42 citations · 0 references
Natural SciencesChemistryMaterials ScienceSemiconductor MaterialsSurface ChemistrySurface SciencePhotoelectron SpectroscopySemiconductor SurfacesSurface Chemistry Of SolidsSurface OxidationSurface PhysicsSurface SpectroscopyChemisorptionChemisorption AnalysisExtended X-ray Absorption Fine StructureOxidationSurface Oxidation MechanismsSurface Oxidation StatesSurface SensitivitySurface Structure Determination
Surface extended x-ray absorption fine structure measurements (EXAFS) are reported for the initial oxidation stage of the GaAs(110) surface which is characterized by a +2.9 eV binding energy shift of the As 3d photoemission peak. The surface EXAFS measurements employed a variation of the previously used secondary-electron-collection technique which significantly increased the surface sensitivity. We find oxygen to be chemisorbed in atomic form. The importance of using phaseshifts derived from model systems rather than using theoretically calculated phaseshifts for distance determinations from low Z atoms is pointed out.