Best test pattern failure analysis flow for functional logic failure localization by IR-OBIRCH technique

The optical IR-OBIRCh technique is a standard failure analysis tool used to localize defects that are located at interconnects layers levels. For a functional logic failure, a failing test pattern is used to condition the device into a particular logic state to generate the failure. Commonly, the defect is detected for a set of test patterns. All test patterns will not provide the same IR-OBIRCh response. A random selection of test patterns may not lead to localize the defect by IR-OBIRCh technique or give fake results. We have performed an extended study of IR-OBIRCh response of a functional logic failure in function of test patterns. Based on these results a best test pattern failure analysis flow has been developed and implemented in order to localize a functional logic failure with IR-OBIRCh technique.