NON−VOLATILE SEMICONDUCTOR STORAGE DEVICE AND PRODUCTION METHOD THEREOF

摘要

A non−volatile semiconductor storage device including a memory array (10) having a plurality of erasable non−volatile storage elements and a reserved storage element. When a normal operation results in a write failure, the storage element is replaced by the aforementioned reserved storage element (10a) and information on the defective storage element is stored in a predetermined area (10b) of the memory array. When a defective storage element is detected during a test, information on the defective storage element is not stored in the predetermined area of the memory array and a memory device having a ratio of defective storage elements detected in the test not greater than a predetermined value is extracted as a good device.