Effects of foreign metals on the thermal stability of noble metal adsorbates at the Si(111) surface

Effects of monolayer foreign metals on the thermal stability of noble metal adsorbates (Au, Ag, and Cu) at the Si(111) surface have been studied by means of LEED-AES-RBS techniques. It is found that the thermal stability of Au atoms at the Si(111) surface does not change due to deposition of both Ag and Cu atoms and subsequent annealing. On the other hand, it is found that the thermal stability of Ag at the Si(111) surface decreases due to coexistence of Au atoms on the post annealing but is not influenced by coexistence of Cu atoms. Moreover, it is shown that Cu atoms deposited on the Si(111)-√3 × √3-Ag and √3 × √3-Au surfaces become very unstable on the post annealing.