Impact of oxygen concentration at the HfOx/Ti interface on the behavior of HfOx filamentary memristors

Hah, Jinho; West, Matthew P.; Athena, Fabia Farlin; Hanus, Riley; Vogel, Eric M.; Graham, Samuel

doi:10.1007/s10853-022-07067-1

Cited by 10 publications

(7 citation statements)

References 48 publications

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“…1,2 Taking inspiration from biological cognition, neuromorphic computing aims to enable artificial intelligence to perform closer to biological cognition for complex tasks such as self-driving, language translation, pattern and speech recognition, and realtime health monitoring. 3−10 Two-terminal memristors, 11,12 which use adaptive oxides such as TiO x , 13 HfO x , 14 TaO x , 15 AlO x , 16 and NiO 17 as the active layer, exhibit a change in resistance with the application of bias and are being considered for both non-volatile inmemory and brain-inspired neuromorphic computing. Among these, HfO x devices are attractive because of their CMOS compatibility, scalability (<10 nm), fast switching (∼ns), excellent switching endurance (>10 10 cycles), and data retention (10 years).…”

Section: Introductionmentioning

confidence: 99%

“…Two-terminal memristors, , which use adaptive oxides such as TiO x , HfO x , TaO x , AlO x , and NiO as the active layer, exhibit a change in resistance with the application of bias and are being considered for both non-volatile in-memory and brain-inspired neuromorphic computing. Among these, HfO x devices are attractive because of their CMOS compatibility, scalability (<10 nm), fast switching (∼ns), excellent switching endurance (>10 10 cycles), and data retention (10 years) .…”

Section: Introductionmentioning

confidence: 99%

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Trade-off between Gradual Set and On/Off Ratio in HfO_x-Based Analog Memory with a Thin SiO_x Barrier Layer

Athena

West

Hah

et al. 2023

ACS Appl. Electron. Mater.

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HfO x -based synapses are widely accepted as a viable candidate for both in-memory and neuromorphic computing. Resistance change in oxide-based synapses is caused by the motion of oxygen vacancies. HfO x -based synapses typically demonstrate an abrupt nonlinear resistance change under positive bias application (set), limiting their viability as analog memory. In this work, a thin barrier layer of AlO x or SiO x is added to the bottom electrode/ oxide interface to slow the migration of oxygen vacancies. Electrical results show that the resistance change in HfO x /SiO x devices is more controlled than the HfO x devices during the set. While the on/off ratio for the HfO x /SiO x devices is still large (∼10), it is shown to be smaller than that of HfO x /AlO x and HfO x devices. Finite element modeling suggests that the slower oxygen vacancy migration in HfO x /SiO x devices during reset results in a narrower rupture region in the conductive filament. The narrower rupture region causes a lower high resistance state and, thus, a smaller on/off ratio for the HfO x /SiO x devices. Overall, the results show that slowing the motion of oxygen vacancies in the barrier layer devices improves the resistance change during the set but lowers the on/ off ratio.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Trade-off between Gradual Set and On/Off Ratio in HfO_x-Based Analog Memory with a Thin SiO_x Barrier Layer

Athena

West

Hah

et al. 2023

ACS Appl. Electron. Mater.

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“…[8,9] The control of conductivity by an applied electric field is achieved in the oxide layer by charged oxygen vacancies forming and rupturing localized conductive filament paths for the preferential or undesirable transport of charge carriers. [10,11] Conductive filaments were identified to be the directionally aligned crystalline regions in amorphous HfO 2 consisting of monoclinic and orthorhombic oxygen-deficient phases. [12] Recently, HfO 2 layers with a thickness of a few nanometers demonstrated the potential to be implemented in ferroelectric memory devices.…”

Section: Introductionmentioning

confidence: 99%

Interplay of Precursor and Plasma for The Deposition of HfO₂ via PEALD: Film Growth and Dielectric Properties

Preischel,

Zanders,

Berning

et al. 2023

Adv Materials Inter

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HfO2 thin films are appealing for microelectronic applications such as high‐κ dielectric layers, memristors, and ferroelectric memory devices. To fulfill the different requirements of each application, the properties of the deposited material need to be tuned accordingly. In this context, plasma‐enhanced atomic layer deposition (PEALD) is a powerful processing route to tailor the properties of HfO2 thin films, especially at low temperatures. Herein, a comprehensive bottom‐up approach is presented, ranging from the synthesis of molecularly engineered Hf precursors to the development of a HfO2 PEALD process and a detailed evaluation where plasma can be exploited to tune the dielectric properties. With the example of the newly synthesized bis‐(dialkylamido)‐bis‐(formamidinato) Hf(IV) precursor, [Hf{η2‐(iPrN)2CH}2(NMe2)2] which is reactive, thermally robust and volatile, successful implementation in a PEALD process for HfO2 at low temperatures is demonstrated. The typical atomic layer deposition (ALD) characteristics of precursor saturation, linearity, and ALD temperature window are demonstrated with constant growth of 0.7 Å per cycle from 125 to 200 °C, yielding high‐purity layers. The effect of plasma pulse duration on the chemical composition alongside structural, topographical, as well as dielectric properties of the films is investigated. For the latter, the films are incorporated in metal‐insulator semiconductor (MIS) structures.

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“…Various engineered materials have recently been reported as the switching layer in memristive devices. Transition metal oxides (TMO) have been extensively investigated due to their thermally stable structures, excellent stochiometric control, sample preparation methods, and scalability [10][11][12][13][14]. Several studies have focused on TiO 2 -based memristive devices, including symmetric devices with an identical top electrode (TE) and bottom electrode (BE) and asymmetric devices with a different TE and BE, and both convincingly realized TiO 2 as a potential contender to be employed as a switching layer in memristive architectures [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

A stable undoped low-voltage memristor cell based on Titania (TiOx)

Ullah,

Tarkhan,

Fredj

et al. 2023

Nano Ex.

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An asymmetric memristive device fabricated with a titania (TiOx)-based switching layer deposited through atomic layer deposition with a thickness of ∼37 nm was investigated. X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy coupled with energy-dispersive x-ray spectroscopy were employed for device structural characterization. A unipolar resistive switching behavior (both at positive and negative voltages) was observed through the memristor’s current–voltage characteristics. A remarkably smaller forming voltage (from the top Pt electrode to the grounded Au electrode) of 0.46 V was achieved, while it approached (positive bias from the Au electrode and holding Pt electrode as grounded) 0.25 V, which is a much smaller forming voltage than has ever been reported for titanium-based oxides without doping. The retention and endurance characterization over 2000 switching cycles were satisfactory without degradation.

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Impact of oxygen concentration at the HfOx/Ti interface on the behavior of HfOx filamentary memristors

Cited by 10 publications

References 48 publications

Trade-off between Gradual Set and On/Off Ratio in HfO_x-Based Analog Memory with a Thin SiO_x Barrier Layer

Trade-off between Gradual Set and On/Off Ratio in HfO_x-Based Analog Memory with a Thin SiO_x Barrier Layer

Interplay of Precursor and Plasma for The Deposition of HfO₂ via PEALD: Film Growth and Dielectric Properties

A stable undoped low-voltage memristor cell based on Titania (TiOx)

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Impact of oxygen concentration at the HfOx/Ti interface on the behavior of HfOx filamentary memristors

Cited by 10 publications

References 48 publications

Trade-off between Gradual Set and On/Off Ratio in HfOx-Based Analog Memory with a Thin SiOx Barrier Layer

Trade-off between Gradual Set and On/Off Ratio in HfOx-Based Analog Memory with a Thin SiOx Barrier Layer

Interplay of Precursor and Plasma for The Deposition of HfO2 via PEALD: Film Growth and Dielectric Properties

A stable undoped low-voltage memristor cell based on Titania (TiOx)

Contact Info

Product

Resources

About

Trade-off between Gradual Set and On/Off Ratio in HfO_x-Based Analog Memory with a Thin SiO_x Barrier Layer

Trade-off between Gradual Set and On/Off Ratio in HfO_x-Based Analog Memory with a Thin SiO_x Barrier Layer

Interplay of Precursor and Plasma for The Deposition of HfO₂ via PEALD: Film Growth and Dielectric Properties