The effects of O precipitation and surface films upon P diffusion in Czochralski material at 1100C were studied. In the case of a high precipitation rate, P diffusion under both types of film was enhanced because of a supersaturation of Si interstitials that was caused by O precipitation. A greater enhancement of P diffusion under Si3N4, than under SiO2 covered with Si3N4 was attributed to the lower recombination velocity of interstitials at the Si3N4/Si interface. The diffusion within a denuded zone resembled that in float-zone Si until interstitials, which were generated under that zone, arrived at the interface.

S.T.Ahn, H.W.Kennel, J.D.Plummer, W.A.Tiller, Z.U.Rek, S.R.Stock: Applied Physics Letters, 1988, 53[1], 34-6