Yield Improvement Techniques For Three Dimensional Memory Based On Fault Clustering

Through Silicon Vias(TSVs)can connect wafers vertically,which greatly reduce interconnect length,improve integration density and bandwidth,reduce power consumption.Three-dimensional memory is one of the important applications of three-dimensional integrated circuits.Three-dimensional memory is manufactured by stacking memory dies on each other,and the memory dies are connected by TSVs.Compared with traditional two-dimensional memory,three-dimensional memory has many advantages,such as high bandwidth,low latency,low power consumption and so on.Due to the large storage capacity and density of the three-dimensional memory,faults are easily introduced during the manufacturing and stacking process.As a result,the yield of three-dimensional memory is low,and becomes the biggest challenge in three-dimensional memory technique.A fault in any memory dies that cannot be successfully repaired will result in the failure of the entire three-dimensional memory.To improve the yield of three-dimensional memory,the proposed techniques are as follows:1.A three-dimensional memory built-in self-repair(BISR)structure for fault cross-clustering is proposed.Through the fault cross-clustering scheme,the fault can not only be clustered into the vertical direction,but can also be clustered into the non-vertical direction of the same memory array index.More faults are clustered into other layers,so that a redundant row can repair more faults.In addition,the BISR structure and read-write controller are redesigned according to the fault cross-clustering scheme,and the data is recombined to ensure the correct input or output of data.Experimental results show that the BISR scheme effectively improves the yield of three-dimensional memory.2.A three-dimensional memory BISR scheme for many-to-one and global fault clustering is proposed.To further improve the yield of three-dimensional memory,many-to-one and global fault clustering three-dimensional memory BISR scheme are proposed.By setting a fixed memory layer,the faults in the remaining memory layers are clustered into this layer,In this way,the fault clustering density of three-dimensional memory can be increased greatly.The global fault clustering repair scheme does not have a fixed memory layer.Faults in memory dies may be clustered into any one of the memory dies to further increase the fault clustering density of three-dimensional memory.For the two proposed schemes,the repair structure of many-to-one and global fault clustering scheme is proposed,and the corresponding clustering repair algorithm is presented.Experimental results show that the many-to-one fault clustering scheme and the global fault clustering scheme can effectively improve the yield of three-dimensional memory.Compared to the global fault clustering repair scheme,the many-to-one fault clustering scheme has a lower time overhead.