TiO<sub>2</sub>-Based Schottky Diodes as Bidirectional Switches for Bipolar Resistive Memories

Abstract

This study presents TiO2-based Schottky diodes designed as bidirectional switches for bipolar resistive memories. The TiO2 films in these Schottky diodes are prepared through an anodization process. The reverse current of these diodes exhibits an exponential increase with rising reverse voltage, ultimately matching the forward current. When two diodes are connected back-to-back, they demonstrate superior current-voltage symmetry and provide a wider off-state voltage range compared to a single diode, reaching up to 3.65 V. The adjustable off-state voltage range (0.40-3.65 V) of the switch, whether utilizing two diodes or a single diode, correlates well with the TiO2 layer thickness and oxygen partial pressure during Pt electrode sputtering. These diodes possess bidirectional switching characteristics and can serve as effective switch elements to address the sneak-path issue in bipolar resistive memories.