Formation process of grown-in defects in Czochralski grown silicon crystals

Abstract

We have determined the set of the diffusion coefficients ( D v: vacancies, D i: self-interstitials) and equilibrium concentrations ( C eq v: vacancies, C eq i: self-interstitials) of point defects which has been satisfied with the dependence of two-dimensional defect patterns on V and G (V: growth rate, G: axial temperature gradient) and with the reported product values of D v C eq v and D i C eq i. Recently, it has been reported by direct TEM (Transmission Electron Microscopy) observation that the grown-in defects in the vacancy dominant region are the voids of octahedral shape. The idea that the grown-in defects are the voids formed by the vacancy aggregation has been examined by the simulation model. It is shown that this model can well describe the behaviors of grown-in defect formation during the crystal growth and that it is possible to form the void as the grown-in defect in CZ silicon crystals.