Effects of Oxygen and Dopant on Lifetime in Neutron-Irradiated Silicon

Neutron-induced degradation of carrier lifetime in silicon was observed for n- and p-type material containing various amounts of oxygen and different dopant impurities. There was no observable dependence of lifetime degradation on oxygen concentration. No dependence on type of dopant was observed in n-type silicon, and only small effects appeared to occur in p-type material. Evidently the recombination process is dominated by centers within primary defect clusters, rather than by point defects. These studies indicate that the choice of dopant-impurity or growth technique is usually unimportant in determining device failure in a neutron environment.