Method for error test, recordation and repair
AssigneeMicron Technology, Inc.
InventorsChristian Mohr, Timothy Cowles
Life of this patent
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Abstract
In a memory device, an on-die register is provided that is configured to store a row address as well as a column address of a memory cell that fails a test. Storing the row address frees testing from being limited to activating at one time only rows related to a common redundant segment. Storing the row address also guides repair using segmented redundancy. As an addition or alternative, information may be stored in an anti-fuse bank that is designed to provide access to a redundant cell but has not yet enabled access to that cell. If the information stored in the anti-fuse bank relates to the failure of the redundant cell, such information may be used to avoid repairing with that redundant cell.
Claims11
A memory testing method, comprising:
- testing a plurality of memory cells in a memory array;
- storing data in a register in the memory array indicating at least one defective memory cell in the memory array;
- and
- selecting a redundant segment of redundant memory cells based on the data to effect repair of the at least one defective memory cell in the memory array.
A method of testing and repairing a memory array, comprising:
- activating a quantity of rows in a memory array wherein the quantity of rows spans at least two redundant segments of memory cells;
- writing test data to at least one column of memory cells for the quantity of rows;
- comparing the test data in the at least one column of memory cells of the rows spanning a first one of the at least two redundant segments;
- effecting repair of defective memory cells using the first one of the at least two redundant segments when defects are identified therein;
- continuing comparing the test data in the at least one column of memory cells of the rows spanning a second one of the at least two redundant segments;
- and
- effecting repair of defective memory cells using the second one of the at least two redundant segments when defects are identified therein.
Dependencies are inferred from the claim text.