A 15ns 4Mb NVSRAM in 0.13u SONOS Technology

SONOS based 4Mb nvSRAM has been developed which combines a fast access CMOS SRAM array with a highly reliable non-volatile memory array. The overall architecture and operation of the integrated architecture is discussed The non-volatile memory characteristics including endurance and retention at both the SONOS transistor-level as well as 4Mb product-level are demonstrated The nonvolatile memory uses Fowler-Nordheim program and erase to achieve excellent reliability, with EOL window > 1V after 10 years of retention at 85degC and 200K endurance cycles.