Nanometer scale x-ray absorption spectroscopy and chemical states mapping of ultra thin oxides on silicon using electrostatic force microscopy

Electrostatic force microscopy (EFM) was used to obtain highly spatially resolved spectroscopic and image information of semiconductor surface region. EFM with x-ray source (X-EFM) can probe x-ray induced photoionization of near surface electron trapping. The X-EFM signal dependent on x-ray photon energy results in nanometer scale x-ray absorption spectra. Furthermore, probing tip scanning at fixed x-ray photon energy provides chemical states imaging of the trapping. The authors demonstrate characterization of substoichiometric chemical oxidation of a Si surface with less than 1 nm spatial resolution. (c) 2007 American Institute of Physics.