The normalized difference unit as a metric for comparing IV curves

A new quantitative measure of difference is proposed for comparing sets of transistor current-voltage (IV) curves. Conventional qualitative comparisons used, for example, to compare pulsed and static IV data are subjective. The proposed normalized difference unit (NDU) is a metric which can be used to state quantitatively the difference between two sets of IV curves. It is shown that a plot of NDU versus pulse length can be used to isolate thermal and trapping time constants. In addition, the NDU can be used to describe and compare the quality of model fits numerically.