ANNEALING BEHAVIOR OF THE OXYGEN DONOR IN SILICON

The behavior of the oxygen donor in Czochralski silicon crystals was investigated by resistivity measurement. Annealing at 475°C was employed to produce an oxygen donor, and the donor concentration was reduced to some extent by heat treatment at 550°C for 20 h. The results were compared with those reported in the 1950's and 1960's. The reduction rate was far smaller than that obtained in the 1950's, and complete annihilation was not observed, even after 20-h annealing. A model was proposed to interpret the difference in the reduction behavior of the oxygen donor between the old and today's crystals, in terms of some species which neutralize the donor. A numerical calculation based on this model was made to predict the reduction behavior and was found to be in reasonable agreement with the experimental results.