Chasing subtle embedded RAM defects for nanometer technologies

A design´s increasing density, as well as its number of embedded memories increases its vulnerability to a variety of potential manufacturing defects. Standard March test algorithms used for obtaining good defect coverage must be augmented by new algorithms that target defects not screened by embedded BIST controllers. This paper presents our experience diagnosing address decode open faults (ADOF) using scan patterns. Subsequently, tests were added in the BIST controller to target ADOF. Other tests were added to screen potential bit/byte write-enable faults in memories with bit/byte write-enable controls