Excellent Selector Characteristics of Nanoscale for High-Density Bipolar ReRAM Applications
ABSTRACT We herein present a nanoscale vanadium oxide (VO2) device with excellent selector characteristics such as a high on/off ratio (>; 50), fast switching speed (<; 20 ns), and high current density (>; 106 A/cm2). Owing to extrinsic defects, a large-area device with a 20-nm-thick VO2 layer underwent an electrical short. In contrast, after scaling the device active area (<; 5 × 104 nm2), excellent switching uniformity was obtained. This can be explained by the reduced defects and the metal-insulator transition of the whole nanoscale VO2. By integrating a bipolar resistive random access memory device with the VO2 selection device, a significantly improved readout margin was obtained. The VO2 selection device shows good potential for cross-point bipolar resistive memory applications.