1,720,973 research outputs found
On the origin of resistive switching volatility in Ni/TiO2/Ni stacks
No full textData for the paper "Cortese, Simone, Trapatseli, Maria and Khiat, Ali et al. (2016) On the origin of resistive switching volatility in Ni/TiO2/Ni stacks. Journal of Applied Physics"
The file contains all the current versus voltage measurements described in the paper: the resistive switching mechanism curves are presented, as well as subthreshold effects related to the filament instability. The area dependence of the resistances involved is also present in the file.
Data licensed as GNU GPL (http://www.gnu.org/licenses/gpl-2.0.html).</span
Volatile switching selector for ReRAM crossbar arrays
No full textOutline§ Introduction§ Fabrication§ Device characteristics§ Insight on the Physics§ Conclusion
Selector devices/architectures for ReRAM crossbar arrays
No full textResistive Random Access Memories (ReRAMs) are amongst the most promising next generation memory technologies, due to their small feature size, low power consumption and capacity to be integrated in 3D when arranged in crossbar array. ReRAMs harvest the potential of the resistive switching phenomenon that allows to reversibly change their internal resistive state, from High to Low. This aspect, however, is also a problem when ReRAM cells are tesserated in crossbar array configuration: elements that are programmed in their low resistive state can create low resistance sneak paths in the array fabric making the readout operations strenuous. This challenge is usually mitigated by the use of selector devices. A selector must be able to suppress the currents owing in the sneak paths and, at the same time, allow for ReRAM reliable operations.In this work, the sneak current problem is introduced and defined. Several solutions that have been studied in literature are presented and discussed, creating a solid background for the development of this work. Upon this strong basis, different selector devices technologies were developed. Ni/TiO2/Ni selector devices were first designed, studied and benchmarked against other technologies showing improved performances in term of Voltage Margin without any adverse effect on the maximum current supplied. As this device stack has been designed to have a similar metal-insulator-metal architecture to ReRAM devices, the two were monolithically integrated and characterized.The possibility to exploit volatile resistive switching was also introduced and discussed thoroughly, starting from a TiO2/NiO stack exhibiting a promising threshold behaviour for selectors operations, fostering interests of the community on this approach. The limitations of this approach were studied via SPICE simulations, setting the framework and requirements for their implementation in crossbars: through this ongoing work, it was realised that the selector technologies should not be evaluated in isolation from ReRAM, which has led to contributions towards forming-free ReRAM devices. This research stream employed a TiO2/AlOy bi-layer stack devices able to perform resisting switching with a 2-orders of magnitude ON/OFF ratio and low cycle-to-cycle variability without requiring electroforming: this behaviour is presented and discussed.Herein, overall this work has offered contributions towards reliable ReRAM/selector technologies operations for crossbar arrays in terms of both selector technology, improving existing approach and exploring new ones, and ReRAMs, providing the community with a promising path towards forming free operations
Engineering the switching dynamics of TiOx-based RRAM with Al doping
No full textTitanium oxide (TiOx) has attracted a lot of attention as an active material for Resistive Random Access Memory (RRAM), due to its versatility and variety of possible crystal phases. Although existing RRAM materials have demonstrated impressive characteristics, like ultra-fast switching and high cycling endurance, this technology still encounters challenges like low yields, large variability of switching characteristics and ultimately device failure. Electroforming (EF) has been often considered responsible for introducing irreversible damage to devices, with high switching voltages contributing to device degradation. In this paper, we have employed Al doping for tuning the resistive switching characteristics of titanium oxide RRAM. The resistive switching (RS) threshold voltages of undoped and Al-doped TiOx thin films were first assessed by Conductive Atomic Force Microscopy (C-AFM). The thin films were then transferred in RRAM devices and tested with voltage pulse sweeping, demonstrating that the Al-doped devices could on average form at lower potentials compared to the undoped ones and could support both analog and binary switching at potentials as low as 0.9 V. This work demonstrates a potential pathway for implementing low-power RRAM systems.
Dataset for:
Trapatseli, Maria, Khiat, Ali and Cortese, Simone et al. (2016) Engineering the switching dynamics of TiOx-based RRAM with Al doping. Journal of Applied Physics, 120, 025108.</span
A TiO2-based volatile threshold switching selector service with 10^7 non linearity and sub 100 pA Off Current
No full textData for the conference paper:
A TiO2-based volatile threshold Switching Selector Device with 10^7 non linearity and sub 100 pA Off Current.
The file features the Resistive Switching Characteristics of the volatile selector at both polarities, including electroforming step, showing a non linearity of 10^7 between high and low resistance states. Also, the linearity of the low resistance states is presented, showing that the resistance values are the same at both polarities.</span
Easily integrable metal insulator metal selector devices for high density ReRAM crossbar arrays
No full textImpact of ultra-thin Al<sub>2</sub>O<sub>3–y</sub> layers on TiO<sub>2–x</sub> ReRAM switching characteristics
No full textTransition metal-oxide resistive random access memory devices have demonstrated excellent performance in switching speed, versatility of switching and low-power operation. However, this technology still faces challenges like poor cycling endurance, degradation due to high electroforming (EF) switching voltages and low yields. Approaches such as engineering of the active layer by doping or addition of thin oxide buffer layers have been often adopted to tackle these problems. Here, we have followed a strategy that combines the two; we have used ultra-thin Al2O3–y buffer layers incorporated between TiO2–x thin films taking into account both 3þ/4þ oxidation states of Al/Ti cations. Our devices were tested by DC and pulsed voltage sweeping and in both cases demonstrated improved switching voltages. We believe that the Al2O3–y layers act as reservoirs of oxygen vacancies which are injected during EF, facilitate a filamentary switching mechanism and provide enhanced filament stability, as shown by the cycling endurance measurements
An amorphous Titanium Dioxide Metal insulator Metal selector device with tunable voltage margin
No full textData for the article "An amorphous Titanium Dioxide Metal insulator Metal selector device with tunable voltage margin", Applied Physics Letters.</span
Resistive switching of Pt/TiOx/Pt devices fabricated on flexible Parylene-C substrates
No full textPt/TiOx/Pt resistive switching (RS) devices are considered to be amongst the best candidates for post-flash non-volatile memory (NVM) and the technology transfer to flexible substrates could open the way to new opportunities for flexible memory implementations. Hence, an important goal is to achieve a fully flexible resistive random access memory (RRAM) technology. Nonetheless, several fabrication challenges are present and must be solved prior to achieving reliable device fabrication and good electronic performances. Here, we propose a fabrication method for the successful transfer of Pt/TiOx/Pt stack onto flexible Parylene-C substrates. The devices were electrically characterized, exhibiting both digital and analog memory characteristics, which are obtained by proper adjustment of pulsing schemes during tests. This approach could open new application possibilities of these devices in implantable sensors and bio-compatible neural interfaces.
Data for the paper by of the same name published in
Nanotechnology, Volume 28, Number 2 doi:10.1088/1361-6528/28/2/025303</span
A TiO<sub>2</sub>-based volatile threshold Switching Selector Device with 10<sup>7</sup> non linearity and sub 100 pA Off Current
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