Contrast and resolution of SEM charge‐collection images of dislocations

Image profiles obtained in the scanning electron microscope operating in the charge‐collection mode are calculated for a dislocation perpendicular to a surface barrier. The image resolution is not limited by the minority‐carrier diffusion length in the semiconductor, but only determined by the generation volume, in agreement with experiment. The contrast characteristics of a dislocation differ from those of a localized defect, leading to a practical method for distinguishing the two types of imperfections.