Thermodynamic Analysis of Dissolved Oxygen in a Silicon Melt and the Effect of Processing Parameters on the Oxygen Distribution in Single-crystal Silicon During Czochralski Growth

The dissolved oxygen in a silicon melt at equilibrium at different temperatures and SiO partial pressures in Ar during Czochralski growth was subjected to thermodynamic analysis. The effect of the pulling rate and crystal/crucible speed on the oxygen distribution in single-crystal silicon was investigated by numerical calculations and experiments. The results showed that the oxygen equilibrium concentration increased as the partial pressure of SiO in Ar increased. The oxygen concentration in single-crystal silicon rods was lower than 14 ppma by using the optimized process in the constant-diameter stage. The crystal pulling rate was 1.6 mm/min, and the rotation speed of the crystal and crucible were about 10 rpm and -4 rpm, respectively. These results provide new ideas for reducing the concentration of oxygen impurities in single-crystal silicon and high-speed crystal growth for industrial single-crystal silicon production.