Excitation spectrum of a PtLi-related center in silicon

Abstract

A Pt-and Li-related line spectrum with a series of sharp lines between approximately 5000 and 8000 cm Ϫ1 has been studied by excitation spectroscopy combined with uniaxial stress. The intensity of the lines are favored when the Pt and Li diffusion was carried out under Li-rich conditions. Phonon replicas involving a បϭ528.6 cm Ϫ1 phonon are detected in the spectrum. The phonon is suggested to be Li related and was also directly observed by local mode vibrational spectroscopy. Yet another set of replicas was observed, displaced about ⌬ϭ2229 cm Ϫ1 to higher energies and was interpreted to originate from shake up effects in the final core state. Uniaxial stress spectroscopy reveals that shallow donor states are involved in the final state of the transitions.