Resonance Raman studies of annealing in He-, Na-, Cd-implanted cuprous oxide

Abstract

The 488.0- and 476.5-nm Ar laser lines have been used to obtain Raman spectra near resonance with the ’’blue’’ and ’’violet’’ excitons in Cu2O implanted with helium, sodium, or cadmium ions. The dose dependence of the Raman spectra was obtained for Cd doses ranging from 1.5×1011 to 1.5×1015 ions/cm2 and was then used for monitoring the repair of implantation-produced damage during anneal treatments. All samples showed a strong anneal stage near 270°C, well below the melting temperature of 1050°C, during which at least 99% of the implantation-produced damage was removed. The Na-implanted sample showed a prominent extrinsic luminescence band near 483 nm after annealing. This first study of annealing in ion-implanted Cu2O demonstrates that resonance Raman scattering is a particularly sensitive probe of damage in semiconductors. The technique exploits the high damage sensitivity of the exciton states with the detailed information on short-range order displayed in the damage dependence of the phonon Raman spectra.