Dual Conical Conducting Filament Model in Resistance Switching TiO2 Thin Films

Kim, Kyung Min; Park, Tae Hyung; Hwang, Cheol Seong

doi:10.1038/srep07844

Cited by 49 publications

(38 citation statements)

References 32 publications

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“…The CFs generated via this mechanism have been proposed to have a conical structure, which has been observed in TiO 2 . 132, 239,240 This CF growth process is schematically shown in Fig. 14(a).…”

Section: What Happens In An Oxide During Unipolar Switching?mentioning

confidence: 99%

Resistive switching phenomena: A review of statistical physics approaches

Lee

Noh

2015

Applied Physics Reviews

393

239

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Resistive switching (RS) phenomena are reversible changes in the metastable resistance state induced by external electric fields. After discovery $50 years ago, RS phenomena have attracted great attention due to their potential application in next-generation electrical devices. Considerable research has been performed to understand the physical mechanisms of RS and explore the feasibility and limits of such devices. There have also been several reviews on RS that attempt to explain the microscopic origins of how regions that were originally insulators can change into conductors. However, little attention has been paid to the most important factor in determining resistance: how conducting local regions are interconnected. Here, we provide an overview of the underlying physics behind connectivity changes in highly conductive regions under an electric field. We first classify RS phenomena according to their characteristic current-voltage curves: unipolar, bipolar, and threshold switchings. Second, we outline the microscopic origins of RS in oxides, focusing on the roles of oxygen vacancies: the effect of concentration, the mechanisms of channel formation and rupture, and the driving forces of oxygen vacancies. Third, we review RS studies from the perspective of statistical physics to understand connectivity change in RS phenomena. We discuss percolation model approaches and the theory for the scaling behaviors of numerous transport properties observed in RS. Fourth, we review various switching-type conversion phenomena in RS: bipolarunipolar, memory-threshold, figure-of-eight, and counter-figure-of-eight conversions. Finally, we review several related technological issues, such as improvement in high resistance fluctuations, sneak-path problems, and multilevel switching problems. V

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Section: What Happens In An Oxide During Unipolar Switching?mentioning

confidence: 99%

Resistive switching phenomena: A review of statistical physics approaches

Lee

Noh

2015

Applied Physics Reviews

393

239

View full text Add to dashboard Cite

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“…FEM in COMSOL Multiphysics software has been utilized for the simulation. It has been assumed that the active switching layer in the device constitutes a 'dual conical conductive filament' made of oxygen vacancies in the oxide layer, as proposed by Kim et al [3]. It is a simplified geometry of the complex non-linear curvature of the actual filament, which utilizes discontinuous cone geometry, with different slopes for the two sections of the dual-cone.…”

Section: Device Simulationmentioning

confidence: 99%

“…A wide range of materials such as transition metal oxides (e.g. HfO 2 [2], TiO 2 [3], Al 2 O 3 [4], Ta 2 O 5 [5], ZnO [6], VO 2 [7], etc. ), perovskite oxides (e.g.…”

Section: Introductionmentioning

confidence: 99%

Role of GO and r-GO in resistance switching behavior of bilayer TiO₂ based RRAM

et al. 2018

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Graphene-based resistance random access memory devices (RRAMs) have shown promise as a suitable replacement for flash memories, owing to their fast switching speed, low programming voltage, better scalability and great reliability. Furthermore, recent research works have shown bi-layer RRAM devices exhibiting better performance along the same parameters, where titania is one of the most commonly used materials. In the present work, we have studied the resistance switching behavior in a bi-layer RRAM device structure of TiO with graphene oxide (GO) and reduced graphene oxide (rGO). Switching mechanism in these devices has been investigated by detailed experimental characterization in conjunction with a finite element modeling (FEM) simulation. A dual conical conductive filament has been used in the present work, based on the modeling of the electroforming process carried out by FEM. It has been demonstrated that for the GO/TiO based hybrid RRAM device structure, GO acts as an active filament formation layer, whereas in the rGO/TiO bi-layer structure, rGO acts as a mere electrode.

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“…Other authors have reported RS behavior in structures such as Pt/TiO 2 /Pt [8,14,15], but large fluctuations in the I-V sweep curves exist during the reset operations, which are one of the big hurdles that the RS memory has to overcome to become a viable device [12]. Recently, a model has been proposed to explain these large fluctuations [16], that might have their origin in the stochastic nature of the set processes during the repeated RS via the I-V sweeps.…”

Section: Introductionmentioning

confidence: 97%