Selective X-Ray Analyses of Electron Localizing Sites Using Capacitance or Electrostatic Force

Abstract

For selective analyses of nano structures, an x-ray analysis in which x-ray induced photoionization of electron localizing sites is probed with capacitance (C) or electrostatic force (EF) is proposed. The photoionization of nano structures with localized electrons provides a quasi-stable state with a long lifetime of > ms. The photoionization is rapidly relaxed to initial state within ˜fs at the other sites without localized electrons. Because of high sensitivity of C and EF to the quasi-stable state with long lifetime, selective analyses of nano structure can be achieved. We demonstrate this technique with samples of Cu metal and chemically deposited Si oxide film. We observe the modulation of C and EF with a parallel plate capacitor and electrostatic force microscopy. The C modulation dependent on x-ray photon energy indicated an electronic state of Cu/Cu₂O interface, and the EF modulation realized stoichiometry mapping of thin SiO_x film on Si wafer.