Spectroscopic ellipsometry and Raman scattering study of the annealing behavior of Be-implanted GaAs

Abstract

The annealing of the lattice damage induced by Be-ion implantation in GaAs has been studied by spectroscopic ellipsometry and Raman scattering after each step of an isochronal thermal treatment. These two optical (i.e., nondestructive) techniques are shown to be very sensitive both to the lattice recovery and to the electrical activation of the implants. It has been observed that the latter process occurs after the lattice perfection recovery at T=550 °C, while for the ultimate annealing temperatures (T>750 °C) a significant Be redistribution takes place resulting in a decrease of the electrical activity which is confirmed by differential Hall effect measurements.