Parallel testing of parametric faults in a three-dimensional dynamic random-access memory

A testable design of dynamic random-access memory (DRAM) architecture which allows one to access multiple cells in a word line simultaneously is presented. The technique utilizes the two-dimensional (2-D) organization of the DRAM and the resulting speedup of the conventional algorithm is considerable. The failure mechanism in the three-dimensional (3-D) DRAM with trench-type capacitor is specifically investigated. As opposed to the earlier approaches for testing parametric faults that used sliding diagonal-type tests with O(n/sup 3/2/) complexity, the algorithms discussed here are different and have O( square root n/p) complexity, where p is the number of subarrays within the DRAM chip. These algorithms can be applied externally from the chip and also they can be easily generated for built-in self-test applications.<
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