Intrinsic point defects control the formation of grown-in defects in Si crystals. Under steady state conditions, the type of the prevailing point defect species was exclusively determined by the ratio of pull rate and temperature gradient in the crystal at the interface. Simulations were performed for transient growing processes where the pulling rate was abruptly changed. Large reservoirs of interstitials were formed in fast-grown, vacancy-rich crystals near the interface after abruptly reducing the pulling rate for 0.5h. During further growth at high pull rate, these interstitial reservoirs were transformed into large ellipsoidal defect patterns. Experimental results were excellently reproduced if equilibrium concentrations were used as boundary conditions for interstitials and vacancies at all crystal surfaces.

Modelling of Transient Point Defect Dynamics in Czochralski Silicon Crystals. E.Dornberger, W.von Ammon, J.Virbulis, B.Hanna, T.Sinno: Journal of Crystal Growth, 2001, 230[1-2], 291-9