“…Nowadays, the mainstream Si-based FLASH memories are expected to run into physical limits of scaling in the near feature. As a prominent alternative, resistive switching memories have emerged and attracted great attention. − In general, the resistive memory consists of two metallic electrodes separated by an insulator layer, which exhibits electrically switchable resistance state between a high (HRS) and a low (LRS) level in a nonvolatile fashion. − On the basis of various materials and different mechanisms, many resistive devices have been proposed in the past decades, such as the resistance random access memories that are functioned by the formation/rupture of conductive filaments inside the insulators − and the ferroelectric-resistive memories that are realized by the polarization modulation on the band alignment across the metal/ferroelectric/metal devices. − An important feature of the resistive switching memories is the two-terminal structure, making the integration of them into passive crossbar array feasible. − The resistive devices, therefore, have great potential to achieve fast write/read access, low power consumption, and, more importantly, high data-storage density with the cell size reduced to 4 F 2 ( F = minimum feature size).…”