Infineon Technologies Ag

Wilfried Daehn

Erwin Hammerl

Wolfgang Helfer

In a method for checking the functioning of memory cells of an integrated semiconductor memory, a first group of the memory cells is tested. The test results, separately for each tested memory cell, are buffer-stored in at least triple copies in a second group of the memory cells. A comparison is made between the copies of each of the test results and the evaluation thereof. The addresses of the respective memory cells of the second group are determined by an address transformation. The latter is configured in such a way that significant clusters of functional errors in an error-affected second group of the memory cells do not influence the result of the test method.

Method for checking the functioning of memory cells of an integrated semiconductor memory

A method and apparatus for processing defect addresses includes a reduced number of defect addresses to the extent necessary for later evaluation of the defect situation. Preferably, defect addresses are not stored when more than a predetermined number of defects are known for a column in the case of column-by-column checking of a matrix-type memory or per row in the case of row-by-row checking of a matrix-type memory.

Method and apparatus for processing defect addresses

An integrated memory has addressable memory cells combined into groups of column lines and row lines. The addresses of the memory cells each include a first address part addressing the respective groups of column lines and row lines. In a method for checking operation, the memory cells are successively tested in the intersection of two groups to ensure that there are no faults. Memory cells in another group are then tested. If a match between compared first address parts of faulty memory cells exists, the address of at least one of the faulty memory cells is processed further for evaluation purposes, and the addresses of other faulty memory cells are not processed further. This permits extensive compaction of addresses of faulty memory cells.

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Celle, Germany

Wilfried Daehn