Heterogeneous distribution of interstitial oxygen in annealed Czochralski-grown silicon crystals

It is shown that interstitial oxygen infrared (IR) absorption at 515 cm−1 decreases anomalously compared with the absorption at 1106 cm−1 in heat-treated Czochralski-grown silicon wafers. This phenomenon is described by the close correlation between the absorption coefficient ratio αr (α1106/α515), the half-bandwidth of the 1106-cm−1 peak, and the precipitated oxygen content during heat treatments. As a result, it is suggested that on the basis of IR absorption spectrum data interstitital oxygen atoms distribute heterogeneously in a silicon matrix as the forestage of Si-0 complex precipitation.