MECHANISM OF ALLOY FORMATION DUE TO NOBLE-METAL DEPOSITION ON SILICON SURFACES AT ROOM-TEMPERATURE - CHEMICAL BONDING MODEL

Room temperature deposition of noble metals of Au, Ag and Cu on a clean Si(111)2×1 surface is studied through photoemission using synchrotron radiation in order to clarify the phenomenon of room temperature alloyed interface formation (RTAIF) at metal (M)-semiconductor(S) contacts. Ag atoms behave differently on a clean Si(111)2×1 surface from the point of view of the RTAIF, in spite of the fact that Ag belongs to the same group as Au and Cu in the periodic table. As for the phenomenon of the RTAIF, experimental results are examined in the light of the "chemical bonding model" proposed by some of the authors and others. © 1989.