Characterization of Lattice Sites and Compensation Mechanism in Heavily Si-Doped GaAs with Laser Raman Spectroscopy

Abstract
Lattice sites in heavily Si-doped GaAs have been investigated by means of Raman spectroscopy. Localized vibrational modes (LVM) due to SiGa-VGa complex and SiGa were observed as well as SiGa-SiAs pair and SiAs modes. Raman scattering efficiency was obtained from the spectrum area of each mode. The concentrations of these four Si-related sites were estimated, and the results indicate that the carrier compensation mechanism after annealing is dominated by SiGa-VGa acceptors and/or SiGa-SiAs neutral pairs depending on the annealing conditions. The compensation mechanism of the as-grown sample and Si-implanted GaAs has also been studied.