Diagnosis and failure analysis for scan failure

This paper describes a scan test that is widely used for microelectronic devices nowadays, and scan failure that is often ranked as one of the highest yield loss for most microelectronic devices. Due to its nature, the fault isolation of scan failure can't be achieved by conventional current-based fault isolation techniques. So, establishment of scan failure diagnosis capability is very important. The four cases showed in this paper demonstrated that the scan failure could be diagnosed by diagnosis software effectively and various types of defects could be found by this methodology.