Voltage‐Tunable Ultra‐Steep Slope Atomic Switch with Selectivity over 1010

Atomic switch‐based selectors, which utilize the formation of conductive filaments by the migration of ions, are researched for cross‐point array architecture due to their simple structure and high selectivity. However, the difficulty in controlling the formation of filaments causes uniformity and reliability issues. Here, a multilayer selector with Pt/Ag‐doped ZnO/ZnO/Ag‐doped ZnO/Pt structure by the sputtering process is presented. A multilayer structure enables control of the filament formation by preventing excessive influx of Ag ions. The multilayer selector device exhibits a high on‐current density of 2 MA cm−2, which can provide sufficient current for the operation with the memory device. Also, the device exhibits high selectivity of 1010 and a low off‐current of 10−13 A. The threshold voltage of selector devices can be controlled by modulating the thickness of the ZnO layer. By connecting a multilayer selector device to a resistive switching memory, the leakage current of the memory device can be reduced. These results demonstrate that a multilayer structure can be used in a selector device to improve selectivity and reliability for use in high‐density memory devices. In this study, an atomic switch device is introduced with threshold voltage‐tunable and ultra‐high on/off ratio properties for cross‐point memory array. The multilayered selector device is fabricated using the sputtering process. The fabricated device exhibits tunable threshold voltage from 0.3 to 0.7 V with a high selectivity of 1010, which can be used for high‐density cross‐point memory array.