Infrared high spatial-resolution determination of doping levels in p-n junctions

A nondestructive infrared emission-measurement technique, which allows point-by-point determination of the effective doping level within the depletion layer of a reverse-biased p-n junction, is described. The method is an alternative to normal capacitance-voltage techniques which give a value averaged over the entire junction area. With this technique a spatial resolution of about 15 μm is obtainable and a further advantage is that it is unaffected by high reverse currents.