Formation and stability of the Cu(110)+c(2×2)-Si surface alloy studied by high resolution XPS

High-resolution synchrotron radiation photoemission has been used to investigate the formation of the Cu(110)+c(2×2)-Si surface alloy. The complex spectra of the Si 2p core-level are analyzed as multiple component spectra for different Si coverages and annealing temperatures of the surface alloy. The results show that c(2×2) islands are formed from the very beginning of the growth and that Si has a high diffusion length on Cu. The thermal stability of the surface alloy has been studied by measuring real-time photoemission spectra at different temperatures. The surface alloy is stable up to 180°C. Above this temperature disruption of the surface alloy and clustering of the Si atoms can be observed.