An easy technique for determining diffusion and generation-recombination components of the current of pn junctions for better modelling

A method for determining the diffusion and generation-recombination components of the current of a pn junction is presented. It is based on the double derivation of the I-V characteristic and obtains two parameters which can be used for a better modeling of this device, compared with the standard model that includes the extrapolated saturation current and the ideality factor. The technique detects the point where high injection and series resistance acquire importance, in order to extract the desired parameters below this point. As the technique is fully automatic, it is suitable when wafer mapping and statistical data are desired. The system can be applied to any silicon pn junction and the results of a well junction of a standard CMOS circuit are presented as an example