Memory yield and complexity of built-in self-repair

This work describes the implementation of two different BISR algorithms for memories with spare rows and columns. The choice of BISR technology must depend on the final net yield due to area, susceptibility to defects, and repair probability. The Single Deferral algorithm has near the minimal memory requirement. The greedy algorithm is a standard heuristic algorithm that iteratively repairs the line with the most excess defects. The memory requirement for the greedy algorithm is quadratic in the number of spares while Single Deferral is linear. Since the repair probability with Single Deferral is near optimal, it is more cost-effective than greedy.