Effect of crystallinity on the resistive switching behavior of HfAlO x films

Mok, In Su; Kim, Jonggi; Lee, Kyumin; Kim, Young-Jae; Sohn, Hyunchul; Kim, Hyoungsub

doi:10.3938/jkps.64.419

Cited by 6 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A mixed phase (monoclinic and orthorhombic) with a predominant monoclinic phase as well as a ferroelectricity-laden polar orthorhombic phase is evident for HfO 2 deposited at 100 mTorr O 2 partial pressure. For films deposited at lower partial pressures, such as 10 and 1 mTorr during HfO 2 growth, an increase in the orthorhombic/monoclinic ratio, as the dominance of the monoclinic phase in HfO 2 , is seen to be significantly reduced, giving rise to an orthorhombic-rich crystalline phase. , As is borne out in this study, and also noted by others, RS in a single-phase material is always known to render a stable and reliable performance in the case of oxide-based ReRAM devices. − …”

Section: Results and Discussionsupporting

confidence: 66%

“…Hence, for stable RS operations, a controlled optimum density of oxygen defects in the oxide ReRAM device seems absolutely necessary . Such controlled oxygen vacancies within an oxide film also sensitively alter its crystalline nature, thus evidently affecting the RS parameters of that oxide device. , As clearly seen in Figure d, when the O 2 partial pressure is low (10 or 1 mTorr), due to the induced oxygen vacancies, the crystalline nature of HfO 2 gets dominated by the orthorhombic phase over the monoclinic one, and this change of crystalline nature gives rise to stable RS as can be observed through the repetitive endurance cycles, presented in Figure d,e. Hence, it is viable to say that the oxides in ReRAM with single-phase crystalline nature can make RS more stable, and when they are grown with different densities of oxygen vacancies, they produce dependable retention and endurance cycles …”

Section: Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Resistive Switching in HfO_2–x/La_0.67Sr_0.33MnO₃ Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface

Antad

Shaikh

Biswas

et al. 2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

High-performance nonvolatile resistive random access memories (ReRAMs) and their small stimuli control are of immense interest for high-speed computation and big-data processing in the emerging Internet of Things (IoT) arena. Here, we examine the resistive switching (RS) behavior in growth-controlled HfO 2 /La 0.67 Sr 0.33 MnO 3 (LSMO) heterostructures and their tunability in a low magnetic field. It is demonstrated that oxygen-deficient HfO 2 films show bipolar switching with a high on/off ratio, stable retention, as well as good endurance owing to the orthorhombic-rich phase constitution and charge (de)trappingenabled Schottky-type conduction. Most importantly, we have demonstrated that RS can be tuned by a very low externally applied magnetic field (∼0−30 mT). Remarkably, application of a magnetic field of 30 mT causes RS to be fully quenched and frozen in the high resistive state (HRS) even after the removal of the magnetic field. However, the quenched state could be resurrected by applying a higher bias voltage than the one for initial switching. This is argued to be a consequence of the electronically and ionically "active" nature of the HfO 2−x /LSMO interface on both sides and its susceptibility to the electric and low magnetic field effects. This result could pave the way for new designs of interface-engineered high-performance oxitronic ReRAM devices.

show abstract

Section: Results and Discussionsupporting

confidence: 66%

Section: Results and Discussionmentioning

confidence: 99%

Resistive Switching in HfO_2–x/La_0.67Sr_0.33MnO₃ Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface

Antad

Shaikh

Biswas

et al. 2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…The effects of grain boundaries on the behavior of RRAM devices has previously been reported for devices based on HfO 2 thin fi lms. [ 27,28 ] Furthermore, the concave-up nonlinearity in the I -V characteristics below switching threshold is signifi cantly more pronounced in annealed devices, whilst quasi-Ohmic I -V s are readily obtained in unannealed samples. This, in combination with the lower current draw at similar voltages renders annealed devices more suitable for use in crossbar arrays.…”

Section: Resultsmentioning

confidence: 99%

Role and Optimization of the Active Oxide Layer in TiO₂‐Based RRAM

Regoutz

Gupta

Serb

et al. 2015

Adv Funct Materials

View full text Add to dashboard Cite

TiO2 is commonly used as the active switching layer in resistive random access memory. The electrical characteristics of these devices are directly related to the fundamental conditions inside the TiO2 layer and at the interfaces between it and the surrounding electrodes. However, it is complex to disentangle the effects of film “bulk” properties and interface phenomena. The present work uses hard X‐ray photoemission spectroscopy (HAXPES) at different excitation energies to distinguish between these regimes. Changes are found to affect the entire thin film, but the most dramatic effects are confined to an interface. These changes are connected to oxygen ions moving and redistributing within the film. Based on the HAXPES results, post‐deposition annealing of the TiO2 thin film was investigated as an optimisation pathway in order to reach an ideal compromise between device resistivity and lifetime. The structural and chemical changes upon annealing are investigated using X‐ray absorption spectroscopy and are further supported by a range of bulk and surface sensitive characterisation methods. In summary, it is shown that the management of oxygen content and interface quality is intrinsically important to device behavior and that careful annealing procedures are a powerful device optimisation technique.

show abstract

“…The characteristics of Pt/Al 2 O 3 /Ta/Pt memristors are determined by the energetics of formation and dissolution of conductive filaments. ,, In addition, the grain boundaries of the Al 2 O 3 layer and regions of a low local atomic density in the Al 2 O 3 layer constitute potential pathways for the formation of conductive filaments in the Pt/Al 2 O 3 /Ta/Pt memristors. − As a result, the characteristics of Pt/Al 2 O 3 /Ta/Pt memristors can be estimated by quantifying the dimension and connectivity of grain boundaries and regions of a low local atomic density in the Al 2 O 3 layer. To quantify this, a connected component analysis (using DFS) of low-density voxels was performed (details can be found in the Molecular Dynamics Simulations of Methods section).…”

Section: Resultsmentioning

confidence: 99%

Memristive Device Characteristics Engineering by Controlling the Crystallinity of Switching Layer Materials

Yang

Chen

Song

et al. 2020

ACS Appl. Electron. Mater.

View full text Add to dashboard Cite

Memristive devices (i.e., memristors) can be highly beneficial in many emerging applications that may play important roles in the future generations of electronic systems, such as bioinspired neuromorphic computing, high density nonvolatile memory, and field programmable gate arrays. Therefore, the memristor characteristics (such as operation voltage, on/off ratio, and the number of conductance states) must be engineered carefully for different applications. Here, we demonstrate a method to modify the memristor characteristics specifically by controlling the crystallinity of the switching layer material. Through setting the temperature of atomic layer deposition, the crystallinity of deposited Al 2 O 3 can be controlled. Using different crystalline Al 2 O 3 as the memristor switching layer, the characteristics of the corresponding Pt/Al 2 O 3 /Ta/Pt cross-point memristors can be modified precisely. The high I-V linearity, high on/off ratio (around 10 8 ), low pulse operation voltage (2.5 V), and multilevel conductance states (314 states) of the Pt/Al 2 O 3 /Ta/Pt cross-point memristor are demonstrated. More importantly, the mechanism behind this phenomenon is studied. This work deepens our understanding of the working mechanism of memristors and paves the way for using memristors in a broad spectrum of applications.

show abstract

Effect of crystallinity on the resistive switching behavior of HfAlO x films

Cited by 6 publications

References 20 publications

Resistive Switching in HfO_2–x/La_0.67Sr_0.33MnO₃ Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface

Resistive Switching in HfO_2–x/La_0.67Sr_0.33MnO₃ Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface

Role and Optimization of the Active Oxide Layer in TiO₂‐Based RRAM

Memristive Device Characteristics Engineering by Controlling the Crystallinity of Switching Layer Materials

Contact Info

Product

Resources

About

Effect of crystallinity on the resistive switching behavior of HfAlO x films

Cited by 6 publications

References 20 publications

Resistive Switching in HfO2–x/La0.67Sr0.33MnO3 Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface

Resistive Switching in HfO2–x/La0.67Sr0.33MnO3 Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface

Role and Optimization of the Active Oxide Layer in TiO2‐Based RRAM

Memristive Device Characteristics Engineering by Controlling the Crystallinity of Switching Layer Materials

Contact Info

Product

Resources

About

Resistive Switching in HfO_2–x/La_0.67Sr_0.33MnO₃ Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface

Resistive Switching in HfO_2–x/La_0.67Sr_0.33MnO₃ Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface

Role and Optimization of the Active Oxide Layer in TiO₂‐Based RRAM