On the impact of process variability and aging on the reliability of emerging memories (Embedded tutorial)

Due to the rapid development of smartphones, notebooks and tablets, the need for high density, low power, high performance SoCs has pushed the well-established embedded memory technologies to their limits. To overcome the existing memory issues, emerging memory technologies are being developed and implemented. The focus is placed on non-volatile technologies., which should meet the high demands of tomorrow applications. The emerging technologies are expected to integrate the best features of SRAMs, DRAMs, and Flash memories at the same time. That includes high performance and high density similar to SRAMs and DRAMs respectively, non-volatility, good endurance features, good integration, low power profile, resistance to radiation effects, and ability to scale below 20 nm. The emerging memory technologies being studied today are the magnetic type RAM, the resistive type RAM and the Phase-change RAM. However, since these are new technologies., their modeling is still controversial and their shortcomings not completely cha-racterized. In the paper we present a methodology for memory reliability estimation when process variability and aging phenomena are accounted for at physical level. The method relies on a highly parameterized physical description of emerging memory technologies, based on which, a complete characterization of the memory technology is performed, and the resulting issues of the fabricated cell identified.