Resistive Switching in Metal-Oxide-Metal Devices

Abstract

Resistive switching in metal-oxide-metal (MOM) structures forms the basis of resistive random-access memory (ReRAM), a novel non-volatile memory type currently in development at many institutions. æResistive switching is the phenomena in which a dielectric sandwiched between two metallic electrodes can be switched between a high-resistive state (HRS) and low-resistive state (LRS) through the application of voltage; the resistance of such a device is dependent on the history of its current. ææA TiO2-based MOM device with Ti as the bottom electrode and Cu as the top electrode was fabricated by RF-sputtering technique on a Si/SiO2 substrate, and the resistive switching behavior was examined. ææA computer-controlled source-meter was used to conduct appropriate voltage sweeps and make I-V measurements. æThe Ti/TiO2/Cu MOM device was found to exhibit bipolar resistive switching. æThe device was found to switch between a HRS and LRS depending on the direction of the voltage sweep. æCurrent research suggests the mechanism of resistive switching to be a result of a rearrangement of atoms in the TiO2 film, with oxygen vacancies resulting in the formation of conductive filaments through the film. æOxygen vacancies in the TiO2 film are also known to have magnetic properties, which are a subject of interest in future research. æWe acknowledge support of the National Science Foundation grant DMR-CER-0906608.