PIXE analysis of heavy elements in silicon using MeV heavy ion beams

Abstract

Listen

Translate article

Detection limits of heavy elements such as Fe or Cu near the surface of silicon was investigated by PIXE using slow heavy ions (<90 keV/amu). Fe atoms were implanted in silicon at 343 keV energy to a dose of 1 × 10 13−1 × 10 15Fe/cm 2 and Cu was introduced in silicon to the dose of 5 × 10 14Cu/cm 2. PIXE spectra were obtained by 5.2 MeV 58Ni 3+ and 74Ge 3+ beams in order to enhance the yield of Fe or Cu K X-ray by MO process. The results were compared with those obtained by a 2 MeV proton beam. In the case of slow heavy ion impact, bremsstahlung background above 5 keV was much lower than that of protons. Moreover, Fe Kα X-ray production in Fe implanted silicon was enhanced by using the 5.2 MeV 58Ni 3+ beam. As a result, the detection limit of Fe in silicon was successfully improved. However, Cu Kα X-ray production in Cu contaminated silicon was not so enhanced by using the 5.2 MeV 74Ge 3+ beam and the detection limit could not be improved.