OCVD carrier lifetime in P+NN+ diode structures with axial carrier lifetime gradient

The OCVD (open circuit voltage decay) method is the generally used method for the determining of carrier lifetime in the structures of semiconductor devices. This paper is focused on power diode (P+NN+) structures, in which is realised a carrier lifetime gradient to influence the current and voltage waveforms during the reverse recovery process. A theoretical analysis of the general features of voltage decay courses in OCVD measurements on diode structures with an axial carrier lifetime gradient in the diode base is presented. Some results obtained from both simulations and experimental measurements are discussed in the paper.