The surface charge profiler (SCP) offering non-contact electrical characterization of the near-surface region of silicon wafers is discussed. The system permits fully automatic handling of 300- and 200-rnm wafers. The SCP method, based on a low intensity illumination a c. surface photo-voltage principle, does not require any surface preparation. It allows for a fast (600 points/min), high-resolution mapping of the active doping concentration in the near-surface region as well as surface recombination lifetime. The capabilities of the SCP method for process monitoring and development are illustrated with 200- and 300-mm wafers, focusing on the effects of epi growth conditions on the layer uniformity and its resistivity.
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