Intermixing of InGaAsP/InGaAsP quantum-well structures using dielectric films

Abstract

The enhancement of quantum-well intermixing by SiOxNy and commercial spin-on glass dielectric films deposited on InP-based practical laser structures with all-quaternary active regions has been studied. Migration of semiconductor atoms into the dielectric films was observed using secondary ion mass spectrometry, and this migration behaviour has been correlated with the amount of band-gap change. Based on the results presented, it is suggested that the enhanced intermixing effect is due to the injection of group V interstitials into the underlying laser structure. These are formed at the dielectric/semiconductor interface as Ga and In atoms migrate into the dielectric layer. However, some interfacial process appears to influence the release of the interstitials from the interface region depending on the composition of the SiOxNy film.