Pressure stimulated creation of oxygen-related defects in oxygen-implanted and neutron-irradiated silicon

The present work reports some experimental results based on capacitance measurements on float-zone silicon (Fz-Si) and Czochralski-grown silicon (Cz-Si) subjected to oxygen implantation, subsequent neutron irradiation and finally high-pressure thermal anneals. The purpose of this work was the study of the effect of irradiation on the formation of thermal acceptors and donors in silicon. We found that oxygen ion implantation followed by neutron irradiation results in shallow and deep level acceptor-like defects formation. Prolonged heat treatment leads to thermal donor generation as usual in Cz-Si annealed at 720 K. The most striking result of the study is finding that high-pressure thermal anneals result in extra donor formation even for low oxygen concentration. The effects mentioned above lead to changes in the type of conductivity (p-n junction formation) depending on oxygen content in the material, hydrostatic pressure and an extent of damage caused by the irradiation.