A method of accurately determining the positions of the edges of depletion regions in semiconductor junctions

The technique of electron beam induced current (EBIC) in the scanning electron microscopy can be used to extract the depletion width in a variety of materials and devices. This article reviews current methods available for identifying the positions of the edges of the depletion layer and proposes an alternative methodology that uses the first derivative of the logarithmic EBIC profile. It was found that the precision of this method is only dependent upon the accuracy in which one can determine the lateral dimension of the beam-sample interaction. The proposed method is then applied to a gallium nitride light emitting diode device to verify the practicality of the technique. (c) 2006 American Institute of Physics.