Determination of oxygen concentration profiles in silicon crystals observed by scanning IR absorption using semiconductor laser

Abstract
Concentration profiles of interstitial oxygen in silicon crystals were determined by scanning IR absorption using PbTe‐Pb0.82Sn0.18Te semiconductor laser with the wavelength of 9.04±0.02 μm. IR beam was collimated to be 200 μm in diameter. Czochralski‐grown crystals showed a local concentration fluctuation of about 1.8×1017 cm−3 from the average of 1.1×1018 cm−3. This fluctuation corresponds to an oxygen striation in the silicon crystal.