Evaluation of Depth Distribution Function for AR-XPS using Synchrotron Radiation Hard X-ray

Abstract

  It is well-known that angle-resolved X-ray photoelectron spectroscopy (AR-XPS) is a powerful tool for the nondestructive depth profiling of nanometer-scaled thin layers. Recently, high energy XPS (HX-XPS) using hard X-rays reveals the deeper layers up to 20 nm, and enables to clarify the electronic structure and chemical reaction in the nano-materials. Combination of AR-XPS and HX-XPS is going to be a frontier of the analysis of practical nano-devices of which working depth is several tens of nanometer. Emission Depth Distribution Function (EDDF) is a fundamental function for the quantitative nondestructive depth-profiling by using AR-XPS and HX-XPS. We evaluated the EDDF of HX-XPS by the angle-resolved and photon-energy-resolved XPS analysis for Ni 1s photoelectrons excited by synchrotron radiation (SR) linearly-polarized X-rays from 8.5 keV to 14 keV.