Optimizing Test Length for Soft Faults in DRAM Devices

Soft faults in DRAMs are faults that do not get sensitized directly after an operation is performed, but require a time to pass before the fault can be detected. Tests developed to detect these faults are rather complex and take an exceptionally long time to apply on the memory. This paper discusses a number of methods to optimize the test length for soft faults, based on the electrical design of the memory and the topology of the layout. These methods make it possible to reduce the delay time needed in the test such that it does not scale with the number of cells in the memory