Journal of Crystal Growth, Vol.210, No.1-3, 226-229, 2000
Microscopic photoluminescence evaluation of bright spots in Fe-doped InP wafers
Microscopic non-uniformity of Fe-doped semi-insulating InP wafers has been investigated by photoluminescence spectroscopy and mapping. A deep-level emission with a peak around 1.1 eV appears at 15 K in addition to the band-edge emission due to the exciton recombination at 1.42 eV. An intensity ratio of the 1.1 eV band to the 1.42 eV band is correlated positively with the Fe concentration, suggesting that the 1.1 eV band is associated with Fe. The intensity of the 1.1 eV band decreases at bright spots and lines with an opposite intensity in contrast to the band-edge emission. This gives strong evidence for the idea that the origin of the bright spot and line is an Fe-depleted region where Fe is gettered by defects, most probably dislocations, through their strain field.