The dependence of ring-like distributed stacking faults on the axial temperature gradient of growing Czochralski silicon crystals

The ring diameter of ring-like distributed oxidation induced stacking faults (OSF) in Czochralski grown silicon crystals has been investigated as a function of pull rate and the calculated axial temperature gradient G at the solid/liquid interface of the growing crystals. It is shown that the radial position of the OSF ring can be predicted horn the empirically found equation V/G(r) = 1.3 x 10(-3) cm(2) min(-1) K-1, where r is the radial distance from the center of the crystal. This equation is only in accordance with experimental results, if G(r) is calculated directly at the growth interface. As G(r) is strongly dependent on the axial distance from the growth interface, it is concluded that the radial location of the OSF ring is predominantly determined by point-defect processes in the close vicinity of the growth interface of the growing crystal. It is shown that the presently known theoretical approaches to explain the radial OSF ring variation are probably not consistent with the above results.