Spectroscopic Indications of Tunnel Barrier Charging as the Switching Mechanism in Memristive Devices

Benedikt Arndt,Donald A Maclaren,Francesco Offi,Rainer Waser,Thorsten Meiners,Giancarlo Panaccione,Pedro Parreira,Monifa Phillips,Francesco Borgatti,Stephan Menzel,Regina Dittmann,Katharina Skaja

doi:10.1002/adfm.201702282

Abstract

AbstractResistive random access memory is a promising, energy‐efficient, low‐power “storage class memory” technology that has the potential to replace both flash storage and on‐chip dynamic memory. While the most widely employed systems exhibit filamentary resistive switching, interface‐type switching systems based on a tunable tunnel barrier are of increasing interest. They suffer less from the variability induced by the stochastic filament formation process and the choice of the tunnel barrier thickness offers the possibility to adapt the memory device current to the given circuit requirements. Heterostructures consisting of a yttria‐stabilized zirconia (YSZ) tunnel barrier and a praseodymium calcium manganite (PCMO) layer are employed. Instead of spatially localized filaments, the resistive switching process occurs underneath the whole electrode. By employing a combination of electrical measurements, in operando hard X‐ray photoelectron spectroscopy and electron energy loss spectroscopy, it is revealed that an exchange of oxygen ions between PCMO and YSZ causes an electrostatic modulation of the effective height of the YSZ tunnel barrier and is thereby the underlying mechanism for resistive switching in these devices.

Highlights

IntroductionResistance random access memory (ReRAM) has drawn coninterface-type resistive switching system based on the mixed valence manganite Pr1−xCaxMnO3.[30] Manganite thin films generally form an ohmic contact with noble metals, such as siderable attention as a replacement for current nonvolatile Pt and Au,[30,31] while a nonlinear current–voltage relationship memories.[1] It is based on the different resistance states that is observed when applying oxidizable metals, such as Al, Ti, can be set by specific electrical stimulation of a large variety or Ta.[9,30] Non-noble metals typically form an interface oxide of binary and complex transition metal oxides, including layer that governs the resistance of the whole stack.[22,32,33,34]
We investigated an Resistance random access memory (ReRAM) has drawn coninterface-type resistive switching system based on the mixed valence manganite Pr1−xCaxMnO3.[30]. Manganite thin films generally form an ohmic contact with noble metals, such as siderable attention as a replacement for current nonvolatile Pt and Au,[30,31] while a nonlinear current–voltage relationship memories.[1]
We have investigated the origin of the resistive switching mechanism for ReRAM devices incorporating yttria-stabilized zirconia (YSZ) as a TO and epitaxially grown Pr0.48Ca0.52MnO3 (PCMO) as the conductive metal oxide (CMO) layer

Summary

Introduction

Resistance random access memory (ReRAM) has drawn coninterface-type resistive switching system based on the mixed valence manganite Pr1−xCaxMnO3.[30] Manganite thin films generally form an ohmic contact with noble metals, such as siderable attention as a replacement for current nonvolatile Pt and Au,[30,31] while a nonlinear current–voltage relationship memories.[1] It is based on the different resistance states that is observed when applying oxidizable metals, such as Al, Ti, can be set by specific electrical stimulation of a large variety or Ta.[9,30] Non-noble metals typically form an interface oxide of binary and complex transition metal oxides, including layer that governs the resistance of the whole stack.[22,32,33,34]. Borgatti Consiglio Nazionale delle Ricerche Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN) via P.

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Discussion

Conclusion