Electrical and Optical Properties of Heat-Treated Silicon

Abstract

Single crystals of silicon exhibit optical scattering between 1 and 3 \ensuremath{\mu} after a heat treatment at 1000\ifmmode^\circ\else\textdegree\fi{}C. The Tyndall effect was observed in such samples by using an infrared image tube. The number of donor states, produced in silicon during a 450\ifmmode^\circ\else\textdegree\fi{}C heat treatment, increased rapidly with increasing oxygen concentration of the sample. These effects were found in silicon crystals which were pulled from quartz crucibles; they could not be detected in samples prepared by the floating-zone technique in vacuum.