Non Volatile Memory signatures extraction for defects diagnosis purpose

The purpose of this paper is to present Non Volatile Memories analog signatures extraction. This work focuses on Flash and EEPROM memories. Analog signatures can be specific voltage or current values representative of the memory cell behavior. These signatures can be used to give a visual indication of relative cell signatures of a whole memory matrix. A spatial distribution of analog signatures is proposed as a 2D and 3D bitmap. Thanks to this new approach, it is possible to investigate more finely the change of memory array signature distributions during write/erase cycles and to diagnosis memory defects. Besides, the influence of peripheral circuits on memory cells behavior can be detected.