Charge Collection From Within a Collecting Junction Well

This paper provides the analytical equation for the charge collection from a collecting region with a finite dimension. Electron-beam-induced current has widely been used for semiconductor characterization. The availability of analytical expressions would further enhance the study and development of various measurement techniques. Nevertheless, most devices are fabricated with junctions that have finite dimensions, which are usually either L shaped or U shaped. For these cases, the analytical expressions are lacking. This paper provides the derivation of the electric current profile when an electron beam scans from within the collecting region for these two cases. The computation was verified with a semiconductor device simulation program on a computer and was found to be in good agreement. This paper then gives a discussion on the effects of certain parameters such as the junction depth and junction width, the diffusion length, and the depth of the generation volume.