Increased throughput for the testing and repair of RAMs with redundancy

The problem of determining whether a redundant random-access memory (RRAM) containing faulty memory cells can be repaired with spare rows and columns is discussed. The approach is to increase the number of working RRAMs manufactured per unit time, rather than per wafer, by presenting a computationally efficient algorithm for detecting unrepairability, a computationally efficient algorithm for optimal repair for special patterns of faulty memory cells and online algorithms that can find an optimal repair or else detect unrepairability during memory testing, aborting unnecessary testing. Experimental validation of the approach is given that is based on industrial device fabrication data