It was established that O aggregation in Czochralski-type material at 450C was strongly affected by large hydrostatic pressures. An increased production of shallow thermal donors, with ionization energies of 0.030 to 0.040eV, and deep donors at EC - 0.1eV, was observed under a pressure of 1GPa. On the other hand, the concentration of well-known double thermal donors was much lower than that in Czochralski-type material which had been heat-treated in the absence of stress. The latter effect was suggested to be associated with the involvement of self-interstitials in their formation. An enhanced production of other thermal donors was thought to be caused by an increased O diffusivity under high stresses.

V.V.Emtsev, B.A.Andreev, A.Misiuk, W.Jung, K.Schmalz: Applied Physics Letters, 1997, 71[2], 264-6