PLAN-VIEW SI(111) SAMPLES FOR SURFACE SCIENCE AND TEM STUDIES

Versatile Si(111) samples consisting of both, Si bulk material for var ious surface science studies and thin Si films for transmission electr on microscopy (TEM) studies were prepared using a combination of mecha nical and chemical treatments. The bulk and surface quality of these s amples was controlled by different experimental techniques. In-situ lo w-energy electron diffraction (LEED), Auger electron spectroscopy (AES ) and scanning tunneling microscopy (STM) have been performed under UH V conditions to characterize surface properties of the thick parts as well as of the thin films. Ex-situ X-ray topography and TEM have been used to analyse the quality of the bulk material. The preparation meth od described below enables us to use the same specimen in its whole, f irst in surface science experiments, e.g. formation and characterizati on of a metal/Si interface under UHV, and subsequently in TEM, without further sample preparation in a non-destructive and complementary way . In addition, the samples proved to be an interesting new type of spe cimen as far as the study of vicinal Si(111) surfaces is concerned. A remarkable morphology was found on the treated rear side. During sampl e preparation the Si(111) planes are cut under continuously changing p olar angles in all azimuthal directions. The result is a dimple consis ting of a large number of vicinal (111) surfaces with varying polar an d azimuthal misorientations. An UHV heat treatment of these samples le ads to the build-up of (111)-oriented terraces separated by step bunch es. All terraces are reconstucted in the 7 x 7 periodicity.