GROWTH-PROCESS OF POLYHEDRAL OXIDE PRECIPITATES IN CZOCHRALSKI SILICON-CRYSTALS ANNEALED AT 1100-DEGREES-C

The growth process of polyhedral oxide precipitates in Czochralski (CZ) silicon crystals has been studied with annealing at 1100 degrees C from 4 h to 16 h, after preannealing at 900 degrees C for 4 h. It was found, from transmission electron microscopy (TEM) observations, that the growth of polyhedral precipitates follows a t(1/2) law. At 1100 degrees C, the concentration of oxygen interstitials at the interface (C-O(i)) is estimated to be 1.2 times the thermal equilibrium concentration (C-O*) on the basis of a theoretical model of oxygen precipitation in silicon. The growth of polyhedral precipitates is explained quantitatively by a diffusion-limited growth model of a spherical precipitate, using the estimated C-0(i).