Investigation of silicon diffusion into yttrium using x-ray photoelectron spectroscopy

Abstract

The reactions of yttrium (Y) metal on silicon (Si) are investigated by x-ray photoelectron spectroscopy (XPS). Low-temperature annealing studies are performed to investigate the diffusion of Si. It is found that Si diffusion occurs even under low annealing temperatures of <300°C in an ultrahigh vacuum environment. This is attributed to the weakening of the Si–Si covalent bonds by metallic Y. XPS depth profiling of room-temperature-oxidized films revealed a possible oxygen-mediated pathway which allowed significant Si diffusion at room temperature for silicate formation.