A Sequential Write Scheme for Phase Change Memory Based Serial Interface EEPROM

A 1Mb Serial EEPROM compatible non-volatile memory (NVM) with phase change memory (PCM) device has been developed in 40nm CMOS technology. The storage element PCM device was integrated and fabricated by AMS Fab (Jiangsu Advanced Memory Semiconductor Corp., AMS) with additional masks added to the baseline process. The production chip operates at a voltage between 1.7V and 3.3V over the temperature range between −40°C and 85°C. We propose sequential shift write scheme that reduces the maximum SET and RESET write current by 62% and 75%, respectively. The chip features 30MHz read access frequency on Serial Peripheral Interface (SPI). Maximum write throughput is 1Mb/s.