Behavior of Oxygen in Plastically Deformed Silicon

Abstract

The density of dislocations in silicon crystals is shown to have a marked effect on the annealing of the 9 μ infrared absorption band at 1000°C. (This absorption band had previously been shown to be due to oxygen and to be dependent on the amount of oxygen present.) The annealing behavior has been studied in crystals grown from quartz crucibles and in samples where dislocations have been introduced by plastic bending. For a deformed sample with a dislocation density of ${10}^7$/${\mathrm{cm}}^2$, the amplitude of the 9-μ band is reduced appreciably in 15 minutes at 1000°C, while the undeformed sample with a dislocation density of ${10}^4$/${\mathrm{cm}}^2$ requires about 12 hours. Preliminary light-scattering experiments in deformed and annealed samples show a definite anisotropy of the scattered intensity when the light vector is perpendicular or parallel to the dislocation lines.