P. Torchio et R. Occelli, DETECTION AND MAPPING OF OXYGEN IN SILICON-WAFERS BY SCANNING INFRARED-ABSORPTION, International journal of infrared and millimeter waves, 18(2), 1997, pp. 491-499
Scanning Infrared Absorption (S.I.R.A.) setup was carried out for inve
stigating and mapping of microdefects distribution in Czochralski sili
con wafers. Using CO2 laser, this non destructive, non contact test me
thod allows transmitted beam local attenuation from oxygen precipitate
s to be determined. Transmitted intensity I-t maps from peak height of
the 1080 cm(-1) absorption band were obtained. An inhomogeneous initi
al oxygen distribution is found in as-grown samples. The samples were
then submitted to preannealing at 750 degrees C for 16 hours, followed
by annealing at 900 degrees C for 24 hours. The obtained It fluctuati
ons mapping depicts a ring-shaped distribution of oxygen precipitates.