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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.


Interface contributions.Absolute current density /J/ versus applied bias voltage of (a) an Al/Al2O3/NbxOy tunnel junction, (b) an Nb/NbxOy/Au Schottky contact and (c) for comparison the Al/Al2O3/NbxOy/Au double barrier device. Insets: Simplified cross-sectional view of the devices.
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f3: Interface contributions.Absolute current density /J/ versus applied bias voltage of (a) an Al/Al2O3/NbxOy tunnel junction, (b) an Nb/NbxOy/Au Schottky contact and (c) for comparison the Al/Al2O3/NbxOy/Au double barrier device. Insets: Simplified cross-sectional view of the devices.

Mentions: To get a deeper understanding of the transport mechanism, two additional devices were investigated to separate the particular interfacial contributions. Therefore, Al/Al2O3/NbOx tunnel junctions excluding the Schottky contact, as well as Nb/NbxOy/Au Schottky contacts without the tunnel barrier were prepared, as shown in Fig. 3. Here, Nb is used as the electrode to keep the difference in work function between the electrode and NbxOy layer low. The obtained I–V curves are compared in Fig. 3(a,b). While memristive behavior is clearly visible for the Nb/NbxOy/Au contact, no change in the device resistance behavior was observed for Al/Al2O3/NbxOy tunnel junctions (Fig. 3(a)). This indicates that the NbxOy/Au Schottky-like interface contributes to the resistive switching observed in the double-barrier device. Memristive devices with oxide-metal Schottky contacts have been studied extensively, and the origin of the resistive switching is supposed to be the modulation of the Schottky barrier height15. Nonetheless, the aforementioned observations indicate that the two interfaces Al2O3/NbxOy and NbxOy/Au cannot be treated as separate entities and involve a very strong mutual interdependence. However, the following analysis considers the influence of both interfaces individually, while taking into account that both mechanisms should be treated simultaneously.


A double barrier memristive device.

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

Interface contributions.Absolute current density /J/ versus applied bias voltage of (a) an Al/Al2O3/NbxOy tunnel junction, (b) an Nb/NbxOy/Au Schottky contact and (c) for comparison the Al/Al2O3/NbxOy/Au double barrier device. Insets: Simplified cross-sectional view of the devices.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: Interface contributions.Absolute current density /J/ versus applied bias voltage of (a) an Al/Al2O3/NbxOy tunnel junction, (b) an Nb/NbxOy/Au Schottky contact and (c) for comparison the Al/Al2O3/NbxOy/Au double barrier device. Insets: Simplified cross-sectional view of the devices.
Mentions: To get a deeper understanding of the transport mechanism, two additional devices were investigated to separate the particular interfacial contributions. Therefore, Al/Al2O3/NbOx tunnel junctions excluding the Schottky contact, as well as Nb/NbxOy/Au Schottky contacts without the tunnel barrier were prepared, as shown in Fig. 3. Here, Nb is used as the electrode to keep the difference in work function between the electrode and NbxOy layer low. The obtained I–V curves are compared in Fig. 3(a,b). While memristive behavior is clearly visible for the Nb/NbxOy/Au contact, no change in the device resistance behavior was observed for Al/Al2O3/NbxOy tunnel junctions (Fig. 3(a)). This indicates that the NbxOy/Au Schottky-like interface contributes to the resistive switching observed in the double-barrier device. Memristive devices with oxide-metal Schottky contacts have been studied extensively, and the origin of the resistive switching is supposed to be the modulation of the Schottky barrier height15. Nonetheless, the aforementioned observations indicate that the two interfaces Al2O3/NbxOy and NbxOy/Au cannot be treated as separate entities and involve a very strong mutual interdependence. However, the following analysis considers the influence of both interfaces individually, while taking into account that both mechanisms should be treated simultaneously.

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.