Effect of germanium doping on the formation kinetics of vacancy-dioxygen complexes in high dose neutron irradiated crystalline silicon

Abstract

The effect of germanium (Ge) doping on the formation kinetics of vacancy-dioxygen (VO2) complexes in high dose neutron irradiated crystalline silicon (c-Si) has been quantitatively investigated using infrared spectroscopy at 10 K. It is observed that Ge doping of 1019 cm−3 enhances the formation of vacancy-oxygen (VO) complexes by ∼15% during neutron irradiation and slightly suppresses the conversion of VO into VO2 complexes. By studying the generation kinetics of VO2 complexes in the temperature range of 300–345 °C, it is found that the activation energies of VO2 generation are determined to be 1.52 and 1.71 eV in the reference and Ge-doped c-Si, respectively. According to the theory for diffusion limited reactions, it is suggested that Ge doping can retard the VO diffusion in c-Si and therefore reduce the capture probability of Oi for VO complexes. This may be attributed to the temporary trapping of vacancies by Ge atoms. Hence, the formation of VO2 complexes in c-Si is slightly suppressed by Ge doping.