An automated technique to identify defective CMOS devices based on linear regression analysis of transient signal data

Transient signal analysis is a digital device testing method that is based on the analysis of voltage transients at multiple test points and on I_DD switching transients on the supply rails. We show that it is possible to identify defective devices by analyzing the transient signals measured at test points on paths not sensitized from the defect site. The small signal variations generated at these test points are analyzed in both the time and frequency domain. Linear regression analysis is used to show the absence of correlation in these signals across the outputs of bridging and open drain defective devices. A statistical method and an algorithm for identifying defective devices are presented that is based on the standard deviation of regression residuals computed over a compressed representation of these signals