AVS 51st International Symposium
    Applied Surface Science Tuesday Sessions
       Session AS-TuM

Paper AS-TuM10
Oxygen Environmental Electron Spectroscopy and Microscopy: A New Concept for Reducing Harmful Electron Beam Effects on Insulating Samples

Tuesday, November 16, 2004, 11:20 am, Room 210A

Session: Electron Spectroscopies
Presenter: Y. Ji, Beijing University of Technology, China
Authors: Y. Ji, Beijing University of Technology, China
H. Guo, Beijing University of Technology, China
V. Kempter, Technische Unviversität Clausthal, Germany
Correspondent: Click to Email
Charging phenomena occur on insulating surfaces in many types of surface analysis techniques. In the case of electron spectroscopy and microscopy using an electron beam as probe, the charging phenomena can seriously distort the spectra and images, even make the analysis impossible. In addition, the electron beam can change the surface composition through electron stimulated desorption (ESD) and electron stimulated adsorption (ESA). These effects on oxide samples in Auger electron spectroscopy analysis can be markedly reduced or eliminated in oxygen pressures @<=@ 6*10@super -@@super 6@ Pa. Using oxygen environment to reduce the surface charging-up is based on a novel concept: Reducing the charging effects through eliminating electron traps resulting from electron beam damage, specifically, the ESD of surface oxygen. This is a breakthrough in the understanding of the charging mechanism, as the existing methods for reducing charging-up are mostly based on considerations such as increasing the surface conductivity by coating a conducting layer, increasing the secondary electron yield by applying an additional low energy electron beam, neutralizing the negative surface charges by providing positive charges, increasing the bulk conductivity by sample heating, etc. The significance of this method is that it can also compensate the depletion of the surface oxygen due to ESD and eliminate the surface contamination from background adsorption; it is applicable to other analysis techniques such as scanning electron microscopy, electron probe microanalysis, electron diffraction, electron energy loss spectroscopy.