Minority carrier lifetime scan maps applied to iron concentration mapping in silicon wafers

Mapping of iron concentration is obtained in p-type monocrystalline and multicrystalline silicon by means of contactless lifetime measurements. The recombination rate induced by interstitial iron (Fei) and iron boron pairs (FeB), which is very sensitive to injection level, is appreciated thanks to comparison between deep level transient spectroscopy (DLTS) and lifetime measurement by the micro-wave phase-shift technique (μW-PS). Calibration is given for samples doped in the range 5×1013–3×1016 cm−3.