FORMATION KINETICS AND INFRARED-ABSORPTION OF CARBON-OXYGEN COMPLEXES IN CZOCHRALSKI SILICON

The study of nucleation kinetics and infrared absorption measured at 8 K provides the models of nucleation reactions of carbon-oxygen complexes formed during annealing at 500 degrees C and 650 degrees C. We have, for the first time, found that the reduction ratio of interstitial oxygen in the 450-650 degrees C range obeys the Johnson-Mehl-Avrami equation with a reaction rate constant expressed by k=83.9 exp (-1.0 eV/k(B)T) cm(-1). Nucleation at 650 degrees C follows first-order kinetics, while that at 500 degrees C follows third-order kinetics. The 1104-cm(-1) band due to carbon-oxygen pairs formed above 1000 degrees C decreases throughout annealing at 650 degrees C, whereas it increases upon annealing at 500 degrees C for up to 64 h. Five bands appear at 1026, 1052, 1099, 1107.5 and 1112 cm(-1), and their intensities increase throughout the annealing process at 500 OC for up to 64 h and remain constant from 64 to 128 h, and decrease beyond 128 h. From these findings, carbon-oxygen complexes formed at 650 degrees C and at 500 degrees C are concluded to be C-s-O-n with n = 1, 2, 3, and C-s-O-i-O-2, respectively.