Accurate determination of SiO2 film thickness by x-ray photoelectron spectroscopy

We established the number of Si 2p photoelectrons emanating from a Si(100) substrate covered with a silicon-oxide film as a function of azimuthal and polar angles using the oxide film thickness as a parameter. The elastic and inelastic scattering cross sections of Si 2p photoelectrons in silicon oxide were deduced by reproducing the experimental results with Monte Carlo simulation for the path of Si 2p photoelectrons in silicon oxide. Based on the simulation, we found that the elastic scattering of Si 2p photoelectrons in silicon oxide could effectively be neglected in several specific directions. We also found that an emitting direction different to these specific directions is indispensable when precisely determining the thickness using XPS with a large receiving angle. (C) 2003 American Institute of Physics.