Use of angle resolved x-ray photoelectron spectroscopy for determination of depth and thickness of compound layer structures

A new graphical technique has been developed to characterize complex layered structures by angle resolved x-ray photoelectron spectroscopy. The technique enables estimation of layer composition, layer thickness, and depth of all the layers in a multilayer structure within a region up to several electron escape depths from the surface by measuring at two different escape angles with respect to the surface. These data are fit by the graphical technique to provide a layer depth profile. The technique requires making assumptions. The resulting limitations of the technique are discussed. We have tested the technique on a layer structure consisting of silicon, silicon dioxide, and platinum and have compared the results to a transmission electron microscope image. We also demonstrate this analysis technique for a GaAs/AlAs layer structure grown by molecular beam epitaxy