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A double barrier memristive device.

Hansen M, Ziegler M, Kolberg L, Soni R, Dirkmann S, Mussenbrock T, Kohlstedt H - Sci Rep (2015)

Bottom Line: A highly uniform current distribution for the LRS (low resistance state) and HRS (high resistance state) for areas ranging between 70 μm2 and 2300 μm2 were obtained, which indicates a non-filamentary based resistive switching mechanism.In a detailed experimental and theoretical analysis we show evidence that resistive switching originates from oxygen diffusion and modifications of the local electronic interface states within the NbxOy layer, which influences the interface properties of the Au (Schottky) contact and of the Al2O3 tunneling barrier, respectively.The presented device might offer several benefits like an intrinsic current compliance, improved retention and no need for an electric forming procedure, which is especially attractive for possible applications in highly dense random access memories or neuromorphic mixed signal circuits.

View Article: PubMed Central - PubMed

Affiliation: Nanoelektronik, Technische Fakultät Kiel, Christian-Albrechts-Universität Kiel, Kiel 24143, Germany.

ABSTRACT
We present a quantum mechanical memristive Nb/Al/Al2O3/NbxOy/Au device which consists of an ultra-thin memristive layer (NbxOy) sandwiched between an Al2O3 tunnel barrier and a Schottky-like contact. A highly uniform current distribution for the LRS (low resistance state) and HRS (high resistance state) for areas ranging between 70 μm2 and 2300 μm2 were obtained, which indicates a non-filamentary based resistive switching mechanism. In a detailed experimental and theoretical analysis we show evidence that resistive switching originates from oxygen diffusion and modifications of the local electronic interface states within the NbxOy layer, which influences the interface properties of the Au (Schottky) contact and of the Al2O3 tunneling barrier, respectively. The presented device might offer several benefits like an intrinsic current compliance, improved retention and no need for an electric forming procedure, which is especially attractive for possible applications in highly dense random access memories or neuromorphic mixed signal circuits.

No MeSH data available.


Related in: MedlinePlus

Two models to describe the memristive double barrier tunnel junctions.(a) Simplified cross-sectional view of the memristive tunnel junctions. Here, trap states within the NbxOy are assumed. The filling and emptying of traps by injected electrons varies the amount of charge in the NbxOy layer and therefore the resistance. (b) An alternative model to (a). Under forward bias voltages Vbias oxygen ions (orange circles) can move inside the NbxOy layer, where their diffusion region is confined by the Al2O3 layer and the NbxOy/Au interface. Both, the model in (a) as well as the model in (b) describe the memristive I–V characteristics.
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f1: Two models to describe the memristive double barrier tunnel junctions.(a) Simplified cross-sectional view of the memristive tunnel junctions. Here, trap states within the NbxOy are assumed. The filling and emptying of traps by injected electrons varies the amount of charge in the NbxOy layer and therefore the resistance. (b) An alternative model to (a). Under forward bias voltages Vbias oxygen ions (orange circles) can move inside the NbxOy layer, where their diffusion region is confined by the Al2O3 layer and the NbxOy/Au interface. Both, the model in (a) as well as the model in (b) describe the memristive I–V characteristics.

Mentions: Figure 1 shows the cross-section of the double barrier Al/Al2O3/NbxOy/Au memristive device. The thickness of the Al2O3 tunnel barrier is 1.3 nm and that of the NbxOy layer 2.5 nm. In general, two rather different physical mechanisms may describe the memristive characteristics of this double barrier device. In Fig. 1(a), NbxOy acts as a trapping layer for electrons, where localized electronic states within the NbxOy layer are filled or emptied depending on the applied bias voltage polarity. Therefore, the amount of charge within this layer depends on the history of the applied bias voltage, where charged traps and discharged traps will represent the high- and low-resistances state, respectively. The first charge trapping model, originally used to describe resistive switching in metal-insulator-metal (MIM) Al/SiO (20 nm–300 nm)/Au junctions, was developed from Simmons and Verderber31.


A double barrier memristive device.

Hansen M, Ziegler M, Kolberg L, Soni R, Dirkmann S, Mussenbrock T, Kohlstedt H - Sci Rep (2015)

Two models to describe the memristive double barrier tunnel junctions.(a) Simplified cross-sectional view of the memristive tunnel junctions. Here, trap states within the NbxOy are assumed. The filling and emptying of traps by injected electrons varies the amount of charge in the NbxOy layer and therefore the resistance. (b) An alternative model to (a). Under forward bias voltages Vbias oxygen ions (orange circles) can move inside the NbxOy layer, where their diffusion region is confined by the Al2O3 layer and the NbxOy/Au interface. Both, the model in (a) as well as the model in (b) describe the memristive I–V characteristics.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562229&req=5

f1: Two models to describe the memristive double barrier tunnel junctions.(a) Simplified cross-sectional view of the memristive tunnel junctions. Here, trap states within the NbxOy are assumed. The filling and emptying of traps by injected electrons varies the amount of charge in the NbxOy layer and therefore the resistance. (b) An alternative model to (a). Under forward bias voltages Vbias oxygen ions (orange circles) can move inside the NbxOy layer, where their diffusion region is confined by the Al2O3 layer and the NbxOy/Au interface. Both, the model in (a) as well as the model in (b) describe the memristive I–V characteristics.
Mentions: Figure 1 shows the cross-section of the double barrier Al/Al2O3/NbxOy/Au memristive device. The thickness of the Al2O3 tunnel barrier is 1.3 nm and that of the NbxOy layer 2.5 nm. In general, two rather different physical mechanisms may describe the memristive characteristics of this double barrier device. In Fig. 1(a), NbxOy acts as a trapping layer for electrons, where localized electronic states within the NbxOy layer are filled or emptied depending on the applied bias voltage polarity. Therefore, the amount of charge within this layer depends on the history of the applied bias voltage, where charged traps and discharged traps will represent the high- and low-resistances state, respectively. The first charge trapping model, originally used to describe resistive switching in metal-insulator-metal (MIM) Al/SiO (20 nm–300 nm)/Au junctions, was developed from Simmons and Verderber31.

Bottom Line: A highly uniform current distribution for the LRS (low resistance state) and HRS (high resistance state) for areas ranging between 70 μm2 and 2300 μm2 were obtained, which indicates a non-filamentary based resistive switching mechanism.In a detailed experimental and theoretical analysis we show evidence that resistive switching originates from oxygen diffusion and modifications of the local electronic interface states within the NbxOy layer, which influences the interface properties of the Au (Schottky) contact and of the Al2O3 tunneling barrier, respectively.The presented device might offer several benefits like an intrinsic current compliance, improved retention and no need for an electric forming procedure, which is especially attractive for possible applications in highly dense random access memories or neuromorphic mixed signal circuits.

View Article: PubMed Central - PubMed

Affiliation: Nanoelektronik, Technische Fakultät Kiel, Christian-Albrechts-Universität Kiel, Kiel 24143, Germany.

ABSTRACT
We present a quantum mechanical memristive Nb/Al/Al2O3/NbxOy/Au device which consists of an ultra-thin memristive layer (NbxOy) sandwiched between an Al2O3 tunnel barrier and a Schottky-like contact. A highly uniform current distribution for the LRS (low resistance state) and HRS (high resistance state) for areas ranging between 70 μm2 and 2300 μm2 were obtained, which indicates a non-filamentary based resistive switching mechanism. In a detailed experimental and theoretical analysis we show evidence that resistive switching originates from oxygen diffusion and modifications of the local electronic interface states within the NbxOy layer, which influences the interface properties of the Au (Schottky) contact and of the Al2O3 tunneling barrier, respectively. The presented device might offer several benefits like an intrinsic current compliance, improved retention and no need for an electric forming procedure, which is especially attractive for possible applications in highly dense random access memories or neuromorphic mixed signal circuits.

No MeSH data available.


Related in: MedlinePlus