AVS 46th International Symposium
    Surface Science Division Tuesday Sessions
       Session SS3-TuA

Paper SS3-TuA2
Real-Time Imaging of Step Motion on Cu(100) with the Low Energy Electron Microscope@footnote 1@

Tuesday, October 26, 1999, 2:20 pm, Room 607

Session: Diffusion on Surfaces
Presenter: C.L.H. Devlin, University of California, Davis
Authors: C.L.H. Devlin, University of California, Davis
S. Chiang, University of California, Davis
X.D. Zhu, University of California, Davis
Correspondent: Click to Email
The low energy electron microscope (LEEM) is capable of real-time, real-space imaging of metal and semiconductor surfaces, at the scale of tens of nanometers. We have recently used a new instrument at UC Davis to image the motion of steps on the Cu(100) surface. We have seen a number of intriguing effects at the relatively low temperature range of 100 to 300°C. Impurities pin the step positions, affecting the shapes of the steps over regions of many microns. The kink density of the steps decreases with additional sample cleaning, with the steps becoming more rectilinear. Evidence exists for several different phases on the surface as a function of temperature, as the contrast on terraces changes markedly on the scale of 10-20 nm with increasing temperature. The size of an area corresponding to a particular phase also changes. In some cases, rapid fluctuations of the contrast at the boundaries are evident as the phase shrinks. For curved steps, wave-like motions have been observed along the length of steps. Steps have also been observed to move into and out of an impurity at constant temperature. An X-ray photoemission spectrometer and a commercial variable temperature scanning microscope (VT-STM) (50-800K) have recently been added to the UC Davis LEEM system and are being used to further characterize the Cu(100) system. @FootnoteText@ @footnote 1@Funded by National Science Foundation (DMR-95-12231) .