Characterization of ion-implanted GaAs by ellipsometry

Abstract

Ion‐implanted GaAs has been studied by ellipsometry. The profiles of the implantation damage at a dose of 10¹²–10¹⁵ ions/cm² as revealed by the extinction coefficient were compared with the damage theory and the LSS projectile theory. The damage which remains after thermal or laser annealing was also examined by ellipsometry. Recovery of the crystallinity of the implanted GaAs is similar to that observed in Rutherford backscattering (RBS), Hall measurements, and other studies. As opposed to the case of thermal annealing, electrical activation of the implanted after annealing by a Q‐switched ruby laser is more subject to the influence of the damage profile created by implantation. The damage profiles indicate that the high degree of damage in the narrow region (probably an amorphous state) is necessary for liquid‐state epitaxial growth after laser annealing.