xDefects Induced by Helium Implantation: Interaction with Boron and Phosphorus

摘要

High dose He implantation, followed by a thermal annealing, is a suitable technique for metal gettering. Nevertheless, a strong interaction between the dopants and the defect layer has been evidenced. This can largely influence the dopant distribution. In order to study this interaction, p and n-type samples uniformly doped were implanted with helium (40 keV, 5x10~(16) He~+.cm~(-2)) and furnace annealed for various times and temperatures. In this paper, we shed light on the evolution of the dopant segregation. Using isochronal treatment, we found a large dependence of the dopant gettering phenomenon upon annealing temperature. Moreover, stability of the gettered fraction is observed for isothermal annealing. This study permits also to investigate the origin of the trapping mechanism involved for both boron and phosphorus.