Effects of nitrogen doping on vacancy-oxygen complexes in neutron irradiated Czochralski silicon

Abstract

We have investigated the effect of nitrogen doping on the evolution of vacancy-oxygen (V-O) complexes in neutron irradiated Czochralski (CZ) silicon. During isothermal anneals in the temperature range of 290–330 °C, it is found that both the annihilation rate of VO and generation rate of VO2 are obviously modified with nitrogen doping. Correspondingly, the activation energies for VO annihilation and VO2 generation are 1.84 and 1.23 eV, both smaller (∼ 0.24 eV) than those of the conventional CZ silicon. Moreover, the critical temperatures for total disappearance of VO and VO2 peaks decrease in nitrogen doped CZ silicon, which means that the conversion processes of VO to VO2 and VO2 to VO3 are promoted, respectively. It is suggested that the nitrogen doping in CZ silicon which introduces a tensile stress enhances the diffusion of vacancy and VO complex, promoting the conversion of V-O complexes.