A model for the formation of donor centers in silicon layers implanted with erbium and oxygen ions

Abstract

Formation of donor centers in the course of annealing of layers of single-crystal silicon FZ-Si (grown by the float-zone method) and Cz-Si (grown by the Czochralski method) implanted with Er+ and O+ ions was simulated. The diffusion-kinetics equations accounting for the formation of erbium-related donor centers of three types were solved numerically. These centers were formed with the involvement of oxygen in the substrate or implanted oxygen and also self-interstitials I produced during annealing of implantation-induced defects; i.e., the Er-I, Er-O, and Er-O-I centers were considered. The results of calculations satisfactorily describe the concentration profiles of donor centers and also the influence of oxygen in the substrate and implanted oxygen on the dependence of the donor-activation coefficient of erbium on the annealing temperature in the range of 600–1200°C.