A nonvolatile semiconductor memory device of the present invention has an array that includes a bit line, a plurality of word lines arranged perpendicularly to the bit line and a plurality of memory cells each arranged at intersections of the bit line and the word lines. In the nonvolatile semiconductor...http://www.google.es/patents/US6411551?utm_source=gb-gplus-sharePatente US6411551 - Multi-state nonvolatile semiconductor memory device which is capable of regularly maintaining a margin between threshold voltage distributions
Multi-state nonvolatile semiconductor memory device which is capable of ...
