Erbium luminescence in porous silicon doped from spin-on films

Abstract

Erbium photoluminescence at room temperature and at 77 K has been observed from porous silicon doped with erbium from a spin‐on silica gel film. Erbium incorporation into silicon dioxide at the surface of porous silicon and rapid thermal processing at temperatures higher than 1223 K were found to be a necessary prerequisite for erbium‐related luminescence in porous silicon. No erbium diffusion into monocrystalline silicon from the spin‐on films was observed. The depth‐dependent erbium concentration in the bulk of porous silicon was determined by secondary‐neutral‐ and secondary‐ion‐mass spectrometry depth profiling. The laterally resolved erbium distribution in the porous silicon was derived from energy‐dispersive x‐ray analysis. Possible mechanisms of erbium‐related luminescence in porous silicon are discussed.