Application of elastic mid-IR light scattering for inspection of   internal gettering operations
  Recently, the internal gettering process has become one of the main operations for manufacturing of semiconductor devices of CZ Si. However, methods for the direct inspection of the internal gettering efficiency and stability have been practically absent thus far. The purpose of this paper is to present such a method developed on the basis of law-angle mid-IR-light scattering technique (LALS), which has been successfully applied thus far for the investigation of large-scale electrically active defect accumulations (LSDAs) in semiconductor crystals. 
O. V. Astafiev, A. N. Buzynin, V. P. Kalinushkin, V. A. Yuryev
cond-mat.mtrl-sci physics.optics