Atomic structure of conducting nanofilaments in TiO2 resistive switching memory

Abstract

Resistance switching in metal oxides could form the basis for next-generation non-volatile memory. It has been argued that the current in the high-conductivity state of several technologically relevant oxide materials flows through localized filaments, but these filaments have been characterized only indirectly, limiting our understanding of the switching mechanism. Here, we use high-resolution transmission electron microscopy to probe directly the nanofilaments in a Pt/TiO(2)/Pt system during resistive switching. In situ current-voltage and low-temperature (approximately 130 K) conductivity measurements confirm that switching occurs by the formation and disruption of Ti(n)O(2n-1) (or so-called Magnéli phase) filaments. Knowledge of the composition, structure and dimensions of these filaments will provide a foundation for unravelling the full mechanism of resistance switching in oxide thin films, and help guide research into the stability and scalability of such films for applications.

Nonvolatile Resistive Switching inPt/LaAlO3/SrTiO3Heterostructures

“…It helps to elucidate the mechanism by comparing the Pt/LAO/STO devices studied here with commonly reported capacitor-type RS structures made of transitionmetal oxides such as TiO 2 [32,33]. In such devices, the switching oxide layers are usually at least 1 order of magnitude thicker than the LAO layers in our devices, and they are sandwiched between two metal electrodes.…”

“…Besides logic FET, memory devices are the other vital component of integrated nanoelectronics. A resistive switching (RS) device has electronic conduction that can be switched between nonvolatile ''ON'' (lowresistance) and ''OFF'' (high-resistance) states in the CPP configuration [30][31][32][33][34]. In fact, these RS systems represent a particular class of dynamic circuit element known as the ''memristor'' [35,36].…”

Forming-free resistive switching of tunable ZnO films grown by atomic layer deposition

“…Among the many contenders for the next-generation of memory device, resistive switching memory based on metal oxides has emerged as the leading candidate [1]. Many metal oxides have been reported to show resistive switching properties such as TiO2 [2], HfO2 [3,4], Ta2O5 [5] etc. For resistive memory in general, highvoltage forming process is needed to initiate the switching, which will normally lead to high power consumption and increased circuit and operational complexity [1].…”

Atomic Scale Modulation of Self‐Rectifying Resistive Switching by Interfacial Defects

“…Conductive filament (CF) has been recognized as the key structural element that contributed to resistive switching performance 6, 7, 9, 10, 11. Recently, a number of approaches, such as electrochemical redox reaction,12, 13 metal nanodots doping,14 micrsostructural transitions,15, 16 and current compliance capping17 have been explored to address the controlled formation and rupture mechanism of CFs.…”