Chemical reactions and temperature‐dependent interface formation of Ti/InP (110)

The reaction of a clean InP(110) surface with thin layers of titanium, deposited at room temperature and 140 K, was studied by core‐ and valence‐level photoemission. We were able to identify reacted interface species by means of curve‐resolving of high‐resolution core‐level spectra. It was found that titanium reacts strongly with InP(110), leading to a reacted layer of ∼9–12 Å thickness, which consists of a TiP compound. In this process, indium is liberated from the substrate and forms metallic islands in the surface region. Further deposition leads to the formation of a metallic Ti film, into which the indium is alloyed. On the basis of annealing experiments, we were able to identify the reacted zone as a diffusion barrier for further interface reaction. The reacted zone was found to broaden at elevated temperature. Our data are discussed with respect to studies of other transition metals with InP(110) and III–V semiconductor surfaces.