Outdiffusion of oxygen and carbon in Czochralski silicon

The outdiffusion behavior of oxygen and carbon in heat-treated Czochralski (CZ) silicon has been investigated by secondary ion mass spectroscopy. The results show that oxygen diffusion is greatly retarded by oxygen precipitation and strongly support a vacancy-dominant diffusion mechanism for oxygen in silicon. In carbon-doped CZ silicon, the diffusion of both oxygen and carbon is greatly enhanced at 750 °C, but is significantly retarded at 1000 °C. In conjunction with the infrared absorption data, the enhanced diffusion has been attributed to the formation of fast-diffusing O-C complexes, while the retarded diffusion of carbon has been tentatively attributed to the formation of slow-diffusing complexes, such as Si-O-C.