Annealing Effect of Cd+ Ion-Implanted Liquid Encapsulated Czochralski-GaAs

Abstract

AbstractFurnace annealing (FA) and rapid thermal annealing (RTA) were made for Cd+ ion-implanted GaAs with Cd concentration, [Cd] from 1×1016cm−3 to 3×1021 cm−3. In FA samples, Raman scattering spectra exhibited a single peak at 292 cm−1 for entire [Cd] range which is LO-phonon mode from (100) GaAs. In RTA samples, LO-phonon mode is a single peak for [Cd]<1×1019cm−3 but with growing [Cd], TO-phonon mode appears for [Cd] 1×1020cm3 and becomes a dominant signal for [Cd]=3×1021 cm−3. The quenching of LO-phonon mode with increasing [Cd] was more clearly observed in RTA samples than in FA ones. Hall-effects results, however, showed that activation rate of RTA samples is 6–7 times larger than that of FA ones for [Cd] 1×1021 cm−3. 2K photoluminescence spectra revealed that in FA samples multiple shallow emissions associated with Cd are formed while in RTA ones the dominant emission is the band to Cd acceptor transition.