Contactless measurement of bulk lifetime and surface recombination velocity in silicon wafers

A method based on two phase shift measurements at two different modulation frequencies is proposed to determine simultaneously the actual bulk lifetime τb and the surface recombination velocity S in silicon wafers. Such a determination works, irrespectively, of the physical state of the surface or the passivation level, and is based on a microwave contactless technique, which allows mapping of τb and S with a spatial resolution of 50 μm.