Computation of integrated-circuit yields from the distribution of slice yields for the individual devices

This correspondence calculates the average yield for multiple devices as a function of the average yield ( ) of single devices assuming several simple forms of distribution function for slice yields. It shows that the usual calculation = ( is too pessmistic by an appreciable factor even when no "within slice" correlation exists. Using an actual distribution of transistor slice yields, the ( calculation is shown to give a yield which is a factor of 5 too low for groups of eight good devices.