scholarly journals Multi-Level Resistive Switching of Pt/HfO2/TaN Memory Device

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1885
Author(s):  
Hojeong Ryu ◽  
Hoeje Jung ◽  
Kisong Lee ◽  
Sungjun Kim
Keyword(s):  
Resistive Switching ◽  
Recognition Accuracy ◽  
Memory Device ◽  
Ohmic Conduction ◽  
Bipolar Resistive Switching ◽  
Switching Operation ◽  
Practical Operation ◽  
Frenkel Emission ◽  
Neuromorphic System ◽  
Multi Level

This work characterizes resistive switching and neuromorphic simulation of Pt/HfO2/TaN stack as an artificial synaptic device. A stable bipolar resistive switching operation is performed by repetitive DC sweep cycles. Furthermore, endurance (DC 100 cycles) and retention (5000 s) are demonstrated for reliable resistive operation. Low-resistance and high-resistance states follow the Ohmic conduction and Poole–Frenkel emission, respectively, which is verified through the fitting process. For practical operation, the set and reset processes are performed through pulses. Further, potentiation and depression are demonstrated for neuromorphic application. Finally, neuromorphic system simulation is performed through a neural network for pattern recognition accuracy of the Fashion Modified National Institute of Standards and Technology dataset.

scholarly journals Gradually Modified Conductance in the Self-Compliance Region of an Atomic-Layer-Deposited Pt/TiO2/HfAlOx/TiN RRAM Device

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1199
Author(s):  
Hojeong Ryu ◽  
Sungjun Kim
Keyword(s):  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Atomic Layer ◽  
High Resistance State ◽  
Long Term Potentiation ◽  
Memory Device ◽  
Bipolar Resistive Switching ◽  
Term Potentiation ◽  
Resistance State ◽  
Neuromorphic System

This study presents conductance modulation in a Pt/TiO2/HfAlOx/TiN resistive memory device in the compliance region for neuromorphic system applications. First, the chemical and material characteristics of the atomic-layer-deposited films were verified by X-ray photoelectron spectroscopy depth profiling. The low-resistance state was effectively controlled by the compliance current, and the high-resistance state was adjusted by the reset stop voltage. Stable endurance and retention in bipolar resistive switching were achieved. When a compliance current of 1 mA was imposed, only gradual switching was observed in the reset process. Self-compliance was used after an abrupt set transition to achieve a gradual set process. Finally, 10 cycles of long-term potentiation and depression were obtained in the compliance current region for neuromorphic system applications.

scholarly journals Improved Stability and Controllability in ZrN-Based Resistive Memory Device by Inserting TiO2 Layer

Micromachines ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 905
Author(s):  
Junhyeok Choi ◽  
Sungjun Kim
Keyword(s):  
Data Storage ◽  
Resistive Switching ◽  
Memory Device ◽  
Comparison Study ◽  
Tio2 Layer ◽  
Bipolar Resistive Switching ◽  
Resistive Switching Memory ◽  
Current Voltage ◽  
Improved Stability ◽  
Switching Characteristics

In this work, the enhanced resistive switching of ZrN-based resistive switching memory is demonstrated by embedding TiO2 layer between Ag top electrode and ZrN switching layer. The Ag/ZrN/n-Si device exhibits unstable resistive switching as a result of the uncontrollable Ag migration. Both unipolar and bipolar resistive switching with high RESET current were observed. Negative-SET behavior in the Ag/ZrN/n-Si device makes set-stuck, causing permanent resistive switching failure. On the other hand, the analogue switching in the Ag/TiO2/ZrN/n-Si device, which could be adopted for the multi-bit data storage applications, is obtained. The gradual switching in Ag/TiO2/ZrN/n-Si device is achieved, possibly due to the suppressed Ag diffusion caused by TiO2 inserting layer. The current–voltage (I–V) switching characteristics of Ag/ZrN/n-Si and Ag/TiO2/ZrN/n-Si devices can be well verified by pulse transient. Finally, we established that the Ag/TiO2/ZrN/n-Si device is suitable for neuromorphic application through a comparison study of conductance update. This paper paves the way for neuromorphic application in nitride-based memristor devices.

Effect of conductance linearity and multi-level cell characteristics of TaOx-based synapse device on pattern recognition accuracy of neuromorphic system

2018 ◽  
Vol 29 (11) ◽  
pp. 115203 ◽  
Author(s):  
Changhyuck Sung ◽  
Seokjae Lim ◽  
Hyungjun Kim ◽  
Taesu Kim ◽  
Kibong Moon ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Recognition Accuracy ◽  
Neuromorphic System ◽  
Multi Level

Eliminating failure behavior by introducing CdS inter-layer in Cu2O-based memory cell

2018 ◽  
Vol 81 (2) ◽  
pp. 20101 ◽  
Author(s):  
Weijie Duan ◽  
Zhenxing Liu ◽  
Yang Zhang
Keyword(s):  
Resistive Switching ◽  
Random Access ◽  
Memory Cell ◽  
Memory Device ◽  
Failure Behavior ◽  
Access Memory ◽  
Bipolar Resistive Switching ◽  
Non Volatile Memory ◽  
Switching Characteristics ◽  
High Set

Resistive switching random access memory (RRAM) has attracted great attention due to its outstanding performance for the next generation non-volatile memory. However, the unexpected failure behaviors seriously hinder the further studies and applications of this new memory device. In this work, the bipolar resistive switching characteristics in Pt/CdS/Cu2O/FTO cells are investigated. The CdS inter-layer is used to suppress the failure behavior in set process. Comparing to the Pt/Cu2O/FTO cell, the switching process in Pt/CdS/Cu2O/FTO cell is not affected even at a high set voltage and the failure behavior is eliminated effectively. Therefore, this work proposes a feasible approach to solve the failure problem in RRAM.

scholarly journals Bipolar and Complementary Resistive Switching Characteristics and Neuromorphic System Simulation in a Pt/ZnO/TiN Synaptic Device

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 315 ◽  
Author(s):  
Sobia Ali Khan ◽  
Geun Ho Lee ◽  
Chandreswar Mahata ◽  
Muhammad Ismail ◽  
Hyungjin Kim ◽  
...  
Keyword(s):  
Resistive Switching ◽  
Photoelectron Spectroscopy ◽  
Recognition Rate ◽  
Long Term Potentiation ◽  
Memory Device ◽  
Chemical Information ◽  
Bipolar Resistive Switching ◽  
Cross Point ◽  
Pulse Input

In this work, a ZnO-based resistive switching memory device is characterized by using simplified electrical conduction models. The conventional bipolar resistive switching and complementary resistive switching modes are accomplished by tuning the bias voltage condition. The material and chemical information of the device stack including the interfacial layer of TiON is well confirmed by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analysis. The device exhibits uniform gradual bipolar resistive switching (BRS) with good endurance and self-compliance characteristics. Moreover, complementary resistive switching (CRS) is achieved by applying the compliance current at negative bias and increasing the voltage at positive bias. The synaptic behaviors such as long-term potentiation and long-term depression are emulated by applying consecutive pulse input to the device. The CRS mode has a higher array size in the cross-point array structure than the BRS mode due to more nonlinear I–V characteristics in the CRS mode. However, we reveal that the BRS mode shows a better pattern recognition rate than the CRS mode due to more uniform conductance update.

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