DiSC: A New Diagnosis Method for Multiple Scan Chain Failures

In scan-based testing environments, identifying the scan chain failures can be of significant help in guiding the failure analysis process for yield improvement. In this paper, we propose an efficient scan chain diagnosis method using a symbolic fault simulation to achieve high diagnostic resolution and small candidate list for single and multiple defects in scan chains. The main ideas of the proposed scan chain diagnosis method are twofold: 1) the reduction of the candidate scan cells through the analysis of the symbolic simulation responses, and 2) the identification of final candidate scan cells using the backward tracing method with the symbolic simulation responses. Experimental results show the effectiveness.