In Situ Rutherford Backscattering Spectrometry Analysis of Films by Combination with Sputter Etching

We have set up an experimental system consisting of an ion gun and a Rutherford backscattering spectrometry(RBS) analysis chamber. Using this system, in situ 2MeV ⁴He⁺ RBS analysis of films is carried out by combination with sputter etching of low energy Ar⁺ ions. As an example of the sputtering/RBS method, the analysis of three samples, i.e., Si/(Ge_xSi_1-x/Si)/Si(100), WSi_x/SiO₂/Si and CoSi_x/Si, is presented in this paper. After an appropriate fraction of the thick layer is removed by sputtering, the back edge of the Ge peak is separated from Si RBS spectrum on the interface and the O peak of the buried SiO₂ layer can be identified. The change of the doped Ti and W concentrations related to Co on the top surface is observed. The advantages of this analytical method and its possible applications in film are discussed.