Threshold Vacuum Switch (TVS) on 3D-Stackable and 4F(2) Cross-Point Bipolar and Unipolar Resistive Random Access Memory

Abstract

A 3D stackable and bidirectional Threshold Vacuum Switching (TVS) selector using the same WO x material as the RRAM element is reported. It provides the highest reported current density of >10(8) A/cm(2) and the highest selectivity of >10(5). Stress test at high current density indicates >10(8) cycle capability for Reset/Set operation. A mechanism based on recombination of oxygen-ions and vacancies is proposed for the observed volatile switching of TVS. Utilizing the threshold characteristics of the TVS selector, a two-step reading waveform offers potential for 3D-stackable and 4F(2) cross-point RRAM applications.