  Czochralski-grown silicon crystals were studied by the techniques of the
low-angle mid-IR-light scattering and electron-beam-induced current. The
large-scale accumulations of electrically-active impurities detected in this
material were found to be different in their nature and formation mechanisms
from the well-known impurity clouds in a FZ-grown silicon. A classification of
the large-scale impurity accumulations in CZ Si is made and point centers
constituting them are analyzed in this paper. A model of the large-scale
impurity accumulations in CZ-grown Si is also proposed. In addition, the images
of the large-scale impurity accumulations obtained by means of the scanning
mid-IR-laser microscopy are demonstrated.
