Synchrotron-radiation-stimulated desorption of O⁺ ions from an oxidized silicon surface

The photon-stimulated desorption of ions from a naturally oxidized Si(100) surface has been studied using synchrotron radiation (SR). For mass analysis of the PSD ions, the time-of-flight method was utilized. Desorption of O ⁺ ions is clearly observed on the surface during exposure to unmonochromatized SR in the vacuum ultraviolet (VUV) region. Si 2p core level photoemission measurements show that the photoemission peak corresponding to silicon oxide is reduced in intensity after exposure to the radiation. The present experimental results indicate the possibility of removing a thin SiO₂ layer on a Si(100) surface at low temperatures by exposing the surface to SR in the VUV region.