Fault collapsing for flash memory disturb faults

Disturb failures are considered the most predominant failure mode in flash memories. Disturb faults are highly dependant on the core memory cell structure, manufacturing technology, and array organization and operation. In this paper, we develop appropriate fault primitives for all possible disturb faults in flash memories. Further, we analyze the origins of such disturbs and propose a method that uses cell structure and array organization information to identify the relevant disturbs to create reduced list of faults. As an example, the method was used to create a minimized faults list for NOR and NAND flash memory arrays. Moreover, we show how the reduced fault list developed can be used to devise more efficient test algorithms.