The Si(111)/Cu interface studied with surface sensitive techniques

The formation of the Cu/Si interface is described on the basis of joint photoemission (valence band and Si 2p core levels) and Auger lineshape (SiL2,3VV) analysis. The system is characterized by an extended mixed phase where a silicidelike compound of average stoichiometry Cu3Si is formed and appears to be stable for an extended range of Cu coverages and annealing temperatures. The intermixing is strongly temperature dependent, but the chemical reaction between Cu and the top layers of Si can proceed even at 100 K