Combining atomic imaging, growth, and surface spectroscopy

Abstract

UHV transmission electron microscopy brings several advantages to the study of surfaces including direct imaging of surface structures and surface defects with contrast based on atomic scattering and the ability to obtain information from subsurface layers. Over the last several months our research group has implemented several image and diffraction analysis techniques to enhance these advantages and help determine four noble metal induced silicon surface structures. Perhaps the most significant of these techniques are Wiener and Parametric Wiener image filtering to improve signal to noise levels in off axis HREM images of surface structures, two examples of which are shown in Figs. 1 and 2. Figure 1 is a Parametric Wiener filtered, near Schertzer, off-zone HREM image of Si(lll)-(5×2) Au which clearly shows the rows of gold and also contains some information on the silicon structure between the gold rows. With data from images and χ2 diffraction analysis we have found this structure is basically a Si surface dislocation decorated by two rows of gold atoms.