Microscopic Compound Formation at the Pd-Si(111) Interface

Photoemission studies of Pd on clean Si (111) surfaces show that formation of the Pd₂Si compound dominates the microscopic chemistry and properties of the Pd-Si interface. No evidence is found for interface dipoles or occupied metal-induced interface states in this system. The Pd₂Si reaction product (a metal) has an electronic structure more like that of the noble metals than the transition metals, with an occupied 4d band located 2. 75 eV below the Fermi energy.