Identification of defective CMOS devices using correlation and regression analysis of frequency domain 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/sub DD/ switching transients on the supply rails. We show that it is possible to identify defective devices by analyzing the transient signals produced at test points on paths not sensitized from the defect site. The small signal variations produced at these test points are analyzed in the frequency domain. Correlation analysis shows a high degree of correlation in these signals across the outputs of defect-free devices. We use regression analysis to show the absence of correlation across the outputs of bridging and open drain defective devices.