相邻层冗余共享的三维存储器成品率优化方法

Yield Optimization Technique for Three Dimensional Memory Based on Redundancy Sharing Among Adjacent Layers

存储裸片堆叠方案和冗余共享策略对提高三维存储器成品率有重要影响.为提高三维存储器的成品率并且减少行列冗余所需的TSVs数量,提出了一种相邻层冗余共享结构.该冗余共享结构使得每层存储裸片的行列冗余不仅能被本层使用,而且能被相邻层使用.并在此结构的基础上,提出了一种新的存储裸片堆叠方案.该方案通过构建存储裸片的选择限制条件,每次选中适合的存储裸片来堆叠三维存储器以充分利用行列冗余.实验结果表明,与国际上同类方法相比,所提方案有效地提高了三维存储器的成品率,并且减少了行列冗余所需的TSVs数量.

Memory dies stacking strategy and redundancy sharing structure have great effects on the yield of three-dimensional(3D)memory.To improve 3D memory yield and reduce the number of TSVs consumed by row and column redundancies,this paper proposed a redundancy sharing structure among adjacent layers.In the proposed sharing structure,the redundancies in each layer not only can be used to repair the faults in the layer where the redundancies reside,but also can be utilized by adjacent layers.On the basis of this proposed structure,a new die-stacking strategy is presented.Through formularized selection conditions for memory dies,the presented strategy can choose suitable memory dies to stack 3D memory.In this way,the row and column redundancies are fully used.Experimental results illustrate the proposed redundancy sharing structure and die-stacking strategy can effectively improve 3D memory yield and reduce the number of TSVs consumed by spare rows and columns.