Overview of emerging semiconductor non-volatile memories

In this article, emerging new semiconductor non-volatile memories are reviewed. We are reaching the integration limit of Flash memories and new types of memories replacing Flash have been actively proposed. Each type of memory is briefly introduced and the possibility of replacing Flash is discussed. FeRAMs, MRAMs, and PCRAMs are already in production and the physics behind the operations and reliabilities are well understood. ReRAMs are now approaching to practical use. However, the operation mechanisms of the other memories have not been understood perfectly. Therefore, it is not fruitful to compare the superiority of each technology at this moment because some innovative idea might enhance a specific technology that happened from time to time.