A semiconductor memory device including at least three of the following cell structures: an NVRAM cell structure, an FERAM cell structure, a DRAM cell structure, and an SRAM cell structure. The cell structures are disposed on the same substrate and preferably have gate surfaces which are substantially...http://www.google.es/patents/US6141242?utm_source=gb-gplus-sharePatente US6141242 - Low cost mixed memory integration with substantially coplanar gate surfaces
Low cost mixed memory integration with substantially coplanar gate surfaces
