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Power signatures of electric field and thermal switching regimes in memristive SET transitions

Journal of Physics. D, Applied Physics

Hughart, David R.; Gao, Xujiao G.; Mamaluy, Denis M.; Marinella, Matthew J.; Mickel, Patrick R.

We present a study of the 'snap-back' regime of resistive switching hysteresis in bipolar TaOx memristors, identifying power signatures in the electronic transport. Using a simple model based on the thermal and electric field acceleration of ionic mobilities, we provide evidence that the 'snap-back' transition represents a crossover from a coupled thermal and electric-field regime to a primarily thermal regime, and is dictated by the reconnection of a ruptured conducting filament. We discuss how these power signatures can be used to limit filament radius growth, which is important for operational properties such as power, speed, and retention.

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Three-dimensional fully-coupled electrical and thermal transport model of dynamic switching in oxide memristors

ECS Transactions (Online)

Gao, Xujiao G.; Mamaluy, Denis M.; Mickel, Patrick R.; Marinella, Matthew J.

In this paper, we present a fully-coupled electrical and thermal transport model for oxide memristors that solves simultaneously the time-dependent continuity equations for all relevant carriers, together with the time-dependent heat equation including Joule heating sources. The model captures all the important processes that drive memristive switching and is applicable to simulate switching behavior in a wide range of oxide memristors. The model is applied to simulate the ON switching in a 3D filamentary TaOx memristor. Simulation results show that, for uniform vacancy density in the OFF state, vacancies fill in the conduction filament till saturation, and then fill out a gap formed in the Ta electrode during ON switching; furthermore, ON-switching time strongly depends on applied voltage and the ON-to-OFF current ratio is sensitive to the filament vacancy density in the OFF state.

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The susceptibility of TaOx-based memristors to high dose rate ionizing radiation and total ionizing dose

IEEE Transactions on Nuclear Science

McLain, Michael L.; Hjalmarson, Harold P.; Sheridan, Timothy J.; Mickel, Patrick R.; Hanson, Donald J.; McDonald, Joseph K.; Hughart, David R.; Marinella, Matthew J.

This paper investigates the effects of high dose rate ionizing radiation and total ionizing dose (TID) on tantalum oxide (TaOx) memristors. Transient data were obtained during the pulsed exposures for dose rates ranging from approximately 5.0 × 107rad(Si)/s to 4.7 × 108rad(Si)/s and for pulse widths ranging from 50 ns to 50 μs. The cumulative dose in these tests did not appear to impact the observed dose rate response. Static dose rate upset tests were also performed at a dose rate of ∼3.0 × 108rad(Si)/s. This is the first dose rate study on any type of memristive memory technology. In addition to assessing the tolerance of TaOx memristors to high dose rate ionizing radiation, we also evaluated their susceptibility to TID. The data indicate that it is possible for the devices to switch from a high resistance off-state to a low resistance on-state in both dose rate and TID environments. The observed radiation-induced switching is dependent on the irradiation conditions and bias configuration. Furthermore, the dose rate or ionizing dose level at which a device switches resistance states varies from device to device; the enhanced susceptibility observed in some devices is still under investigation. Numerical simulations are used to qualitatively capture the observed transient radiation response and provide insight into the physics of the induced current/voltages.

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Mapping of radiation-induced resistance changes and multiple conduction channels in TaOx memristors

IEEE Transactions on Nuclear Science

Hughart, David R.; Pacheco, Jose L.; Lohn, Andrew L.; Mickel, Patrick R.; Bielejec, Edward S.; Vizkelethy, Gyorgy V.; Doyle, Barney L.; Wolfley, Steven L.; Dodd, Paul E.; Shaneyfelt, Marty R.; McLain, Michael L.; Marinella, Matthew J.

The locations of conductive regions in TaOx memristors are spatially mapped using a microbeam and Nanoimplanter by rastering an ion beam across each device while monitoring its resistance. Microbeam irradiation with 800 keV Si ions revealed multiple sensitive regions along the edges of the bottom electrode. The rest of the active device area was found to be insensitive to the ion beam. Nanoimplanter irradiation with 200 keV Si ions demonstrated the ability to more accurately map the size of a sensitive area with a beam spot size of 40 nm by 40 nm. Isolated single spot sensitive regions and a larger sensitive region that extends approximately 300 nm were observed.

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Characterization of Switching Filament Formation in TaOx Memristive Memory Films

Marinella, Matthew J.; Marinella, Matthew J.; Howell, Stephen W.; Howell, Stephen W.; Decker, Seth D.; Decker, Seth D.; Hughart, David R.; Hughart, David R.; Lohn, Andrew L.; Lohn, Andrew L.; Mickel, Patrick R.; Mickel, Patrick R.; Apodaca, Roger A.; Apodaca, Roger A.; Bielejec, Edward S.; Bielejec, Edward S.; Beechem, Thomas E.; Beechem, Thomas E.; Wolfley, Steven L.; Wolfley, Steven L.; Stevens, James E.; Brennecka, Geoffrey L.

Abstract not provided.

Development characterization and modeling of a TaOx ReRAM for a neuromorphic accelerator

Marinella, Matthew J.; Mickel, Patrick R.; Lohn, Andrew L.; Hughart, David R.; Bondi, Robert J.; Mamaluy, Denis M.; Hjalmarson, Harold P.; Stevens, James E.; Decker, Seth D.; Apodaca, Roger A.; Evans, Brian R.; Aimone, James B.; Rothganger, Fredrick R.; James, Conrad D.; DeBenedictis, Erik

This report discusses aspects of neuromorphic computing and how it is used to model microsystems.

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Rutherford forward scattering and elastic recoil detection (RFSERD) as a method for characterizing ultra-thin films

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

Lohn, Andrew J.; Doyle, Barney L.; Stein, Gregory J.; Mickel, Patrick R.; Stevens, James E.; Marinella, Matthew J.

We present a novel ion beam analysis technique combining Rutherford forward scattering and elastic recoil detection (RFSERD) and demonstrate its ability to increase efficiency in determining stoichiometry in ultrathin (5-50 nm) films as compared to Rutherford backscattering. In the conventional forward geometries, scattering from the substrate overwhelms the signal from light atoms but in RFSERD, scattered ions from the substrate are ranged out while forward scattered ions and recoiled atoms from the thin film are simultaneously detected in a single detector. The technique is applied to tantalum oxide memristors but can be extended to a wide range of materials systems. © 2014 Published by Elsevier B.V.

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A comprehensive approach to decipher biological computation to achieve next generation high-performance exascale computing

Howell, Jamie D.; Lohn, Andrew L.; Marinella, Matthew J.; Baca, Michael J.; Finnegan, Patrick S.; Wolfley, Steven L.; Dagel, Daryl D.; Spahn, Olga B.; Harper, Jason C.; Pohl, Kenneth R.; Mickel, Patrick R.

The human brain (volume=1200cm3) consumes 20W and is capable of performing > 10^16 operations/s. Current supercomputer technology has reached 1015 operations/s, yet it requires 1500m^3 and 3MW, giving the brain a 10^12 advantage in operations/s/W/cm^3. Thus, to reach exascale computation, two achievements are required: 1) improved understanding of computation in biological tissue, and 2) a paradigm shift towards neuromorphic computing where hardware circuits mimic properties of neural tissue. To address 1), we will interrogate corticostriatal networks in mouse brain tissue slices, specifically with regard to their frequency filtering capabilities as a function of input stimulus. To address 2), we will instantiate biological computing characteristics such as multi-bit storage into hardware devices with future computational and memory applications. Resistive memory devices will be modeled, designed, and fabricated in the MESA facility in consultation with our internal and external collaborators.

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A CMOS Compatible, Forming Free TaOx ReRAM

ECS Transactions (Online)

Stevens, James E.; Mickel, Patrick R.; Hughart, David R.; Marinella, Matthew J.

Resistive random access memory (ReRAM) has become a promising candidate for next-generation high-performance non-volatile memory that operates by electrically tuning resistance states via modulating vacancy concentrations. Here, we demonstrate a wafer-scale process for resistive switching in tantalum oxide that is completely CMOS compatible. The resulting devices are forming-free and with greater than 1x105 cycle endurance.

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54 Results
54 Results