Core-level binding-energy shifts, thermodynamic predictions, and morphologies for metal-Si and metal-Ge interfaces

Abstract

High-resolution core-level photoemission results show two or more distinct reacted chemical species for a wide variety of metal-Si and metal-Ge interfaces. Assuming that the first reacted species at the interface have \ensuremath{\sim}50 at. % Si (or Ge) and the second species are solid solutions of Si (or Ge) in metal matrices, we find reasonable agreement between calculated and experimental chemical shifts. These analyses allow correlation between the reaction products observed at metal-semiconductor interfaces and the bulk thermodynamic properties of the constituents. These results are in agreement with those obtained from a morphological model for evolving interfaces developed by Butera, del Giudice, and Weaver.