10 - Selector devices for x-point memory

Abstract

Emerging storage devices based on new physical switching mechanisms (noncharge based) have received great interest to implement ultrahigh-density crossbar arrays. However, in addition to the introduction of these new memory devices, implementing crossbar arrays requires addressing issues such as undesired current flow and data disturbance in nonselected cells. Therefore, an access device called a selector device is required to selectively operate and read the target device in the crossbar array. Though many selector devices have been researched, the ideal selector device to meet the requirements for a crossbar array architecture such as two-terminal structure, highly nonlinear I-V characteristics, fast switching speed, and excellent device uniformity has not been reported yet. Therefore, this chapter reviews the previously reported selector devices and discusses the development direction of the selector devices.