Oxygen Enhanced Surface Roughening of Si(111) Induced by Low-Energy Xe⁺ Ion Sputtering

Abstract

  The secondary electron spectra from the Si (111) surface induced by irradiation of Xe⁺ ions of 300 eV were measured as functions of oxygen exposure time. The intensity of ion-induced secondary electrons decreased with the increase of oxygen exposure time for Xe⁺ irradiation, while the intensity of electron-induced secondary electrons increased. The atomic force microscopy (AFM) observation supported that the decrement of the peak intensity and the peak energy of the ion-induced secondary electron spectra are originated from the surface roughening enhanced by oxidation. This suggests that the ion-induced secondary electron spectroscopy can be applied for the real-time monitoring of the surface roughening during ion sputtering as a complementary method to AFM or scanning tunneling microscopy.