Memory and its redundant alternatives

Abstract

The present invention provides a memory and a redundancy replacement method thereof. The redundancy replacement method includes: detecting a working unit that fails to read data; adjusting the matching coefficient of the sense amplifier according to the average output bit line current of each working unit; Re-detect whether the data reading of each working unit is invalid; when the data reading of the working unit is still invalid, use the redundant unit to replace the failed working unit at the same location. The invention can self-adaptively adjust the matching coefficient of the sense amplifier according to different output bit line currents of the memory cells, and replace the failed memory cells by means of redundant replacement, thereby prolonging the service life of the memory.

Description

technical field [0001] The invention relates to the field of integrated circuit design, in particular to a memory and a redundant replacement method thereof. Background technique [0002] Existing semiconductor memories usually use sense amplifiers to detect the difference between the bit line current on the memory cell and the reference current when reading data, so as to determine whether the stored data in the memory cell is a "0" or "1" bit. Such as figure 1 As shown, the traditional sense amplifier mainly includes MOS transistors M2, M3, M5 and M6. Wherein, M3 matches the storage unit M4, and the output current I on M4 can be cell mirrored to the output current on M3, that is, I cell =I m3 ; M2 matches M1, and the output current I on M1 can be ref mirrored to the output current on M2, that is, I ref =I m2 ; M5 matches M6, that is, I m5 =I m6 . The drain voltage Ve of M6 will depend on I m3 with I m6 the size of. When the sense amplifier is used to test the ...

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Problems solved by technology

[0004] Since the traditional method is simply to pre-set the matching coefficient, it is still difficult to avoid logical errors in the detection

In addition, with the long-term use of the memory, after the erasing times of the memory cell reach 100 to 100,000 times, its internal semiconductor structure will age, and the resistance value will increase. The output bit line current will also weaken accordingly, while the reference current remains unchanged, which will eventually lead The matching degree of the sense amplifier decreases, the data in the storage unit cannot be detected, the storage unit fails, and the entire memory is scrapped

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