DEPTH PROFILE ANALYSIS OF SURFACES PRODUCED BY ANNEALING ULTRA-THIN FILMS OF AU DEPOSITED ON SI(100)

The surface formed when Au is deposited on a low-temperature (173 K) S i(100) substrate was studied as a function of the thickness of deposit ed Au utilizing positron-annihilation induced Auger electron spectrosc opy (PAES). The concentration of Au as a function of depth has been th e subject of some controversy for this system. Ion sputter depth profi les obtained using PAES indicate that the Au concentration is similar to 100% to a depth of similar to 1 ML and then decreases continuously to similar to 0% at depths of 13 and 28 Angstrom for initial Au deposi tions of 5 and 10 Angstrom, respectively. A comparison of PAES and EAE S results indicate that PAES, because of its ability to selectively pr obe the topmost atomic layer, can be used to obtain significantly high er depth resolution in ion sputter depth profiles than is possible usi ng EAES.