Extension of the C-V doping profile technique to study the movements of alloyed junction and substrate out-diffusion, the separation of junctions, and device area trimming

Digital data acquisition provides accurate data on capacitance vs. voltage (C-V) measurement and facilitates incorporation of improved analyses based on more complete models. The avalanche field check is an independent means of determining the junction area, and can be used as a quality-control indicator in device production or as a monitoring tool during area trimming of diodes hidden from view. Iterative fitting techniques can yield accuracies sufficient for studying alloyed junction movement from the C-V data. The nature of the doping profile in a nonabrupt junction can be inferred. The profile in the middle layer of a back-to-back junction structure in many practical cases can also be determined. Experimental examples are shown to support the interpretations.>