BLOCK ALIGNMENT: A METHOD FOR INCREASING THE YIELD OF MEMORY CHIPS THAT ARE PARTIALLY GOOD

Redundant word and hit lines have been used successfully for increasing the manufacturing yield of memory chips since 1979 [1, 2, 3]. During early phases of manufacturing, however, there may not be enough redundancy available to repair all the faults on a chip. Such unfixable chips have often been used as partially good chips [4]. The drawback with the use of such chips is the different combinations of failure patterns that can produce the same number of partially good bits. Each pattern requires a different method for connecting the chips. Because of these different requirements, a number of chips with different part numbers result.

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