Cell Size Effects and Distinct Current Conduction Behaviors for Hafnium‐Oxide‐Based Selectors with Vanadium as Top Electrode

Selector devices have been incorporated in the resistance random access memory to realize one‐selector‐one‐resistor device for the achievement of high‐density storage applications. Among many possible materials for selector devices, the metal–insulator transition mechanism of the vanadium oxide (VO x ) is interesting due to its formation under the influence of temperature. Previous studies have also indicated that VO x is formed after high‐temperature annealing. Herein, the V/HfO 2 /TiN with different deice cell sizes is investigated. After the forming process, devices with small cell sizes can exhibit threshold switching (TS) characteristics, while devices with large cell sizes can show resistive switching property. Electrical measurements of DC and AC operations are also conducted to verify stable TS characteristics for selector applications. The current fitting method and the computer‐aid simulation are also carried out to compare different current conduction behaviors of devices with large and small cell sizes, which indicates that heat plays an important role in the formations of VO x layer of the V/HfO 2 /TiN device.