Redundancy Analysis based on Fault Distribution for Memory with Complex Spares

With the development of memory density and capacity, a redundancy analysis (RA) is widely used to improve memory yield. However, as the probability of fault occurrence on memory increases, repair rates of conventional RAs with a simple spare structure have been not enough to achieve a high memory yield. In this paper, redundancy analysis based on fault distribution (RAFD) for memory with complex spares is proposed to address the problem. It can obtain much higher repair rate than using conventional RAs with a simple spare structure by using complex spares. Also, although use of complex spares can cause analysis time increase but, RAFD solves the problem with the sequential spare allocations through consideration of fault distribution.