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 stu died 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 d eposition of both Ag and Cu atoms and subsequent annealing. On the oth er hand, it is found that the thermal stability of Ag at the Si(111) s urface decreases due to coexistence of Au atoms on the post annealing but is not influenced by coexistence of Cu atoms. Moreover, it is show n that Cu atoms deposited on the Si(111)-root 3 X root 3-Ag and root 3 x root 3-Au surfaces become very unstable on the post annealing.