Anomalous Diffusion of B and P in Si Directly Masked with Si3N4

Diffusion of B and P in Si directly masked with Si3N4 films is found to have anomalous characteristics depending on temperature, time, and Si crystal growing method. The discrepancy in diffusion between CZ and FZ substrates under Si3N4 films is explained well assuming the Si–SiO2 interface acts as a sink for super-saturated interstitials. The Si–Si3N4 interface does not have such an effect. It is also found that super-saturated interstitials enhance the diffusion of B and P in CZ Si crystals directly masked with Si3N4 films.