Studies on XPS valence state analysis of copper materials

XPS analysis technique can be used for valence state analysis. However, due to the limitation of the energy resolution of XPS, it can be difficult to differentiate the valence state of some elements. In this study, the Scanning XPS Microscope PHI Quantera II was used to analyze and identify Cu2O from Cu. Although the equipment possesses good energy resolution (0.48 eV), it is still difficult to distinguish Cu+ from Cu as their difference of the 2p3 energy (0.20 eV) is less than the energy resolution of the XPS tool. In this paper, we will study the method to identify and distinguish Cu+ from Cu by using LMM energy peak in XPS spectra.