| 摘要 |
PROBLEM TO BE SOLVED: To detect defective cells being repairable out of articles which do not meet the specified standard in a test method by which such cells are detected so that the defective cells of a SRAM pellet provided with redundant cells are switched to redundant cells and switching work is performed. SOLUTION: First, a test (20) is performed of items which are assumed to be unrepairable and to be unrecoverable to normal one even if switched over to a redundant cell including the test of circuit current with power supply applied, and a test (30) of a circuit current after writing '0' to all cells is performed. Then, for the cells bellow the standards, a test (40) is performed to detect a cell having a large current flown after '0' is written. And in the same way, a test (60) is performed for a cell having a large current flown after '1' is written. And they are switched over to redundant cells, including detective cells detected by a function test (70) for all cells.
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