STM AND PHOTOELECTRON-SPECTROSCOPY STUDIES OF SILICON CERIUM DIOXIDE INTERFACE FORMATION

Scanning tunnelling microscopy (STM) and photoelectron spectroscopy (P ES) have been used to investigate the initial growth of cerium dioxide on the Si(111) 7 x 7 surface at room temperature. The Si adatom struc ture is disrupted and chemically reacted by cerium oxide adsorption. B oth Si 2p core level spectra as well as the STM images show that the a datoms and piedestal atoms serve as the primary reaction site at low c overage. A multitude of adsorbate induced configurations are found by STM on the surface:atomic oxygen inserted into the adatom back bond, a tomic Ce in hollow sites and a variety of CeOx. (C) 1998 Elsevier Scie nce Ltd. All rights reserved.