Review of electrical stimulus methods of<i>in situ</i>transmission electron microscope to study resistive random access memory

Zhang, Yewei; Wang, Chaolun; Wu, Xing

doi:10.1039/d2nr01872a

Cited by 8 publications

(2 citation statements)

References 97 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unlike most RRAM devices, the ITO/ZrO x /TaN device investigated herein can be formed using two methods: a single-step, single-forming (SF), and a two-step, double-forming (DF) process [23]. These two forming mechanisms are presented using energy band diagram analysis based on transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) lines and X-ray photoelectron (XPS) analysis [24,25]. Subsequently, we compare the I-V curves obtained using each method and conduct durability tests to assess performance.…”

Section: Introductionmentioning

confidence: 99%

Improved Resistive and Synaptic Characteristics in Neuromorphic Systems Achieved Using the Double-Forming Process

Kim,

Ju,

Kang

et al. 2023

Nanomaterials

View full text Add to dashboard Cite

In this study, we investigate the electrical properties of ITO/ZrOx/TaN RRAM devices for neuromorphic computing applications. The thickness and material composition of the device are analyzed using transmission electron microscopy. Additionally, the existence of TaON interface layers was confirmed using dispersive X-ray spectroscopy and X-ray photoelectron analysis. The forming process of the ZrOx-based device can be divided into two categories, namely single- and double forming, based on the initial lattice oxygen vacancies. The resistive switching behaviors of the two forming methods are compared in terms of the uniformity properties of endurance and retention. The rationale behind each I–V forming process was determined as follows: in the double-forming method case, an energy band diagram was constructed using F-N tunneling; conversely, in the single-forming method case, the ratio of oxygen vacancies was extracted based on XPS analysis to identify the conditions for filament formation. Subsequently, synaptic simulations for the applications of neuromorphic systems were conducted using a pulse scheme to achieve potentiation and depression with a deep neural network-based pattern recognition system to display the achieved recognition accuracy. Finally, high-order synaptic plasticity (spike-timing-dependent plasticity (STDP)) is emulated based on the Hebbian rule.

show abstract

Section: Introductionmentioning

confidence: 99%

Improved Resistive and Synaptic Characteristics in Neuromorphic Systems Achieved Using the Double-Forming Process

Kim,

Ju,

Kang

et al. 2023

Nanomaterials

View full text Add to dashboard Cite

show abstract

“…The electrical characteristics of individual devices can indeed be measured by micro or nano four-point probe techniques and atomic force microscopy (AFM), in which conducting tips can map local resistivity with remarkable spatial resolution even across cross-sectional samples of devices. , In situ TEM can monitor structural and chemical modifications within resistive devices during current flow, , but measuring changes in resistance within a device during operation is much more challenging. In this paper, we show how electron holography can be used to measure the local resistivity distribution within the active layer after changing the state in situ .…”

mentioning

confidence: 99%

Measuring Electrical Resistivity at the Nanoscale in Phase-Change Materials

Zhang,

Lorut,

Gruel

et al. 2024

Nano Lett.

View full text Add to dashboard Cite

Electrical resistivity is the key parameter in the active regions of many current nanoscale devices, from memristors to resistive random-access memory and phase-change memories. The local resistivity of the materials is engineered on the nanoscale to fit the performance requirements. Phase-change memories, for example, rely on materials whose electrical resistance increases dramatically with a change from a crystalline to an amorphous phase. Electrical characterization methods have been developed to measure the response of individual devices, but they cannot map the local resistance across the active area. Here, we propose a method based on operando electron holography to determine the local resistance within working devices. Upon switching the device, we show that electrical resistance is inhomogeneous on the scale of only a few nanometers.

show abstract

Operando Spectroscopic Investigation of the Valence Change Mechanism in La₂NiO_4+δ‐Based Memristive Devices

Khuu,

Koroleva,

Moncasi

et al. 2024

Adv Elect Materials

View full text Add to dashboard Cite

Valence change memory devices, based on redox reactions and oxygen dynamics, are considered to be one of the most promising candidates for the next generation of non‐volatile memory devices and neuromorphic architectures. Devices based on La2NiO4+δ have demonstrated analog resistive switching behavior, but the underlying mechanism is not fully understood. To get a profound understanding of the device's behavior, the employment of element‐selective techniques to provide direct information on oxygen migration is of paramount importance. In this work, TiN/La2NiO4+δ/Pt devices are studied using an original operando X‐ray absorption near edge spectroscopy (XANES) methodology based on monitoring absorbance intensity changes at a fixed energy position which, in combination with in situ electron energy‐loss spectroscopy (EELS) measurements, has provided valuable insights into the resistive switching mechanism. This approach allows to study the formation of the TiNxOy interlayer at the TiN/La2NiO4+δ interface and directly monitor oxygen migration between TiNxOy and La2NiO4+δ. An energy shift of the Ni K‐edge spectra is consistently measured during the device operation as it underwent cycling in both voltage polarities, thus confirming the pivotal role of the valence change mechanism in the resistive switching behavior of these devices. Furthermore, a switching model based on the coexistence of filamentary and interfacial switching is proposed.

show abstract

Review of electrical stimulus methods ofin situtransmission electron microscope to study resistive random access memory

Abstract: Resistive random access memory (RRAM) has been demonstrated to be a promising solution for the implementation of a neuromorphic system with high-density synapses due to the simple device structure, nanoscale...

Cited by 8 publications

References 97 publications

Improved Resistive and Synaptic Characteristics in Neuromorphic Systems Achieved Using the Double-Forming Process

Improved Resistive and Synaptic Characteristics in Neuromorphic Systems Achieved Using the Double-Forming Process

Measuring Electrical Resistivity at the Nanoscale in Phase-Change Materials

Operando Spectroscopic Investigation of the Valence Change Mechanism in La₂NiO_4+δ‐Based Memristive Devices

Contact Info

Product

Resources

About

Review of electrical stimulus methods ofin situtransmission electron microscope to study resistive random access memory

Abstract: Resistive random access memory (RRAM) has been demonstrated to be a promising solution for the implementation of a neuromorphic system with high-density synapses due to the simple device structure, nanoscale...

Cited by 8 publications

References 97 publications

Improved Resistive and Synaptic Characteristics in Neuromorphic Systems Achieved Using the Double-Forming Process

Improved Resistive and Synaptic Characteristics in Neuromorphic Systems Achieved Using the Double-Forming Process

Measuring Electrical Resistivity at the Nanoscale in Phase-Change Materials

Operando Spectroscopic Investigation of the Valence Change Mechanism in La2NiO4+δ‐Based Memristive Devices

Contact Info

Product

Resources

About

Operando Spectroscopic Investigation of the Valence Change Mechanism in La₂NiO_4+δ‐Based Memristive Devices