Browsing by Author "Chen, Kai-Huang"

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Bipolar Resistive RAM Characteristics Induced by Nickel Incorporated Into Silicon Oxide Dielectrics for IC Applications
(2012-12-01)
Tsai, Tsung-Ming
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Syu, Yong-En
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Chuang, Siang-Lan
In this letter, we successfully produced resistive switching behaviors by nickel doped into silicon oxide at room temperature. The nickel element was doped into silicon oxide, which is a useful dielectric material in integrated circuit (IC) industries by cosputtering technology. Based on the proposed method, satisfactory reliability of the resistance switching device can be demonstrated by endurance and retention evaluation. We believe that the silicon oxide doped with nickel at room temperature is a promising method for resistive random access memory nonvolatile memory applications due to its compatibility with the IC processes.
Characteristics of hafnium oxide resistance random access memory with different setting compliance current
(2013-10-14)
Su, Yu-Ting
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Zhang, Rui
In this Letter, the characteristics of set process of hafnium oxide based resistance random access memory are investigated by different set processes with increasing compliance current. Through current fitting, carrier conduction mechanism of low resistance state changes from hopping to surface scattering and finally to ohmic conduction with the increase of setting compliance current. Experimental data of current-voltage measurement under successive increasing temperature confirms the conduction mechanism transition. A model of filament growth is eventually proposed in a way by merging discrete metal precipitates and electrical field simulation by COMSOL Multiphysics further clarifies the properties of filament growth process. (C) 2013 AIP Publishing LLC.
Characterization of Oxygen Accumulation in Indium-Tin-Oxide for Resistance Random Access Memory
(2014-06-01)
Zhang, Rui
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Huang, Syuan-Yong
In this letter, we report the oxygen accumulation effect and its influence on resistive switching for gadolinium-doped silicon dioxide (Gd:SiO2) resistance random access memory (RRAM). We find that oxygen absorbance by indium-tin-oxide electrode affects the conduction current mechanism, and remarkably modifies the device performance of RRAM devices. By current fitting, Schottky emission can be observed in both low and high resistance states, from which conduction model is proposed to clarify the oxygen accumulation phenomenon. Reliability tests, including endurance and high temperature retention are further carried out, evaluating the significance of oxygen accumulation effect in redox reaction for RRAM devices.
Effect of different constant compliance current for hopping conduction distance properties of the Sn:SiOx thin film RRAM devices
(2016-03)
Chen, Kai-Huang
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Liao, Kuo-Hsiao
To effectively lower the power consumption effect of Sn:SiO2 RRAM devices, the electrical hopping conduction mechanism for set/reset state was effectively used and achieved by different constant compliance current forming process. To assume and discuss the tin metal clustered reaction and electron transport behaviors in metallic filament path-forming model, the various electrical switching current and conduction mechanism model of the Sn:SiO2 RRAM devices for different constant compliance current were also investigated and described. Finally, the switching current relationship between hopping conduction energy and average inter-trap distance properties of the RRAM devices was also simulated and demonstrated in this study.
Electrical conduction mechanism of Zn:SiOx resistance random access memory with supercritical CO2 fluid process
(2013-08-19)
Chang, Kuan-Chang
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Tsai, Tsung-Ming
;
Zhang, Rui
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Chang, Ting-Chang
;
Chen, Kai-Huang
In this study, the electrical conduction mechanism of Zn:SiOx resistance random access memory (RRAM) treated with supercritical CO2 fluid (SCCO2) process was investigated by low temperature measurement. The current of low resistance state for current-voltage curves in SCCO2-treated and untreated Zn:SiOx RRAM were measured and compared under a low temperature range from 100K to 298 K. The electrical conduction mechanisms of hopping conduction and metal-like behaviors in SCCO2-treated and untreated Zn:SiOx RRAM were discussed, respectively. Finally, the electrical conduction mechanism was analyzed and verified by the chemical composition and bonding intensity of XPS analyses. (C) 2013 AIP Publishing LLC.
High performance of graphene oxide-doped silicon oxide-based resistance random access memory
(2013-11-21)
Zhang, Rui
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Chen, Kai-Huang
In this letter, a double active layer (Zr:SiO (x) /C:SiO (x) ) resistive switching memory device with outstanding performance is presented. Through current fitting, hopping conduction mechanism is found in both high-resistance state (HRS) and low-resistance state (LRS) of double active layer RRAM devices. By analyzing Raman and FTIR spectra, we observed that graphene oxide exists in C:SiO (x) layer. Compared with single Zr:SiO (x) layer structure, Zr:SiO (x) /C:SiO (x) structure has superior performance, including low operating current, improved uniformity in both set and reset processes, and satisfactory endurance characteristics, all of which are attributed to the double-layer structure and the existence of graphene oxide flakes formed by the sputter process.
Hopping conduction distance dependent activation energy characteristics of Zn:SiO2 resistance random access memory devices
(2013-04-01)
Chen, Kai-Huang
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Zhang, Rui
;
Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Chang, Kuan-Chang
In this study, the hopping conduction distance variation of Zn:SiO2 resistance random access memory (RRAM) devices with different operating compliance currents was discussed and verified. To investigate and determine the hopping conduction distance dependent activation energy characteristics, the Arrhenius plot of low resistance state of Zn:SiO2 RRAM devices was applied, from which we proposed carrier conduction model. With the increase of current compliance, more metal ions would accumulate to form precipitates with larger diameter, which in turn resulted in the shortening of hopping distance. Because of shorter hopping distance, activation energy for carrier hopping would decrease. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4799655]
Hopping conduction properties of the Sn:SiO (X) thin-film resistance random access memory devices induced by rapid temperature annealing procedure
(2015-06-01)
Chen, Kai-Huang
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Liao, Kuo-Hsiao
Bipolar switching properties and electrical conduction mechanism in Sn:SiO (X) thin-film RRAM devices were investigated and discussed. To complete the resistive switching properties of the stannum doped into silicon oxide thin films, the RTA-treated Sn:SiO (X) thin-film RRAM devices were investigated and discussed. In addition, the improvement qualities and electrical switching properties of the RTA-treated Sn:SiO (X) thin-film RRAM devices were carried out XPS, FT-IR, and IV measurement. The ohmic conduction with metal-like behavior and hopping conduction dependent activation energy properties by the Arrhenius plot equation in LRS of the Sn:SiO (X) thin films was investigated. The activation energy and hopping distance for the RTA-treated thin films were found to be 0.018 eV and 1.1 nm, respectively. For the compatibility with the IC processes, the RTA treatment was a promising method for the Sn:SiO (X) thin-film RRAM nonvolatile memory applications.
Hopping Effect of Hydrogen-Doped Silicon Oxide Insert RRAM by Supercritical CO2 Fluid Treatment
(2013-05-01)
Chang, Kuan-Chang
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Pan, Chih-Hung
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Zhang, Rui
In this letter, we introduced hydrogen ions into titanium metal doped into SiO2 thin film as the insulator of resistive random access memory (RRAM) by supercritical carbon dioxide (SCCO)(2) fluid treatment. After treatment, low resistance state split in to two states, we find the insert RRAM, which means it has an operating polarity opposite from normal RRAM. The difference of the insert RRAM is owing to the resistive switching dominated by hydrogen ions, dissociated from OH bond, which was not by oxygen ions as usual. The current conduction mechanism of insert RRAM was hopping conduction due to the metal titanium reduction reaction through SCCO2.
Illumination Effect on Bipolar Switching Properties of Gd:SiO2 RRAM Devices Using Transparent Indium Tin Oxide Electrode
(2016-04-27)
Chen, Kai-Huang
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Liang, Shu-Ping
To discuss the optoelectronic effect on resistive random access memory (RRAM) devices, the bipolar switching properties and electron-hole pair generation behavior in the transparent indium tin oxide (ITO) electrode of Gd:SiO2 thin films under the ultraviolet (lambda = 400 nm) and red-light (lambda = 770 nm) illumination for high resistance state (HRS)/low resistance state (LRS) was observed and investigated. In dark environment, the Gd:SiO2 RRAM devices exhibited the ohmic conduction mechanism for LRS, exhibited the Schottky emission conduction and Poole-Frankel conduction mechanism for HRS. For light illumination effect, the operation current of the Gd:SiO2 RRAM devices for HRS/LRS was slightly increased. Finally, the electron-hole pair transport mechanism, switching conduction diagram, and energy band of the RRAM devices will be clearly demonstrated and explained.
Improvement mechanism of resistance random access memory with supercritical CO2 fluid treatment
(2014-01-01)
Chang, Kuan-Chang
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Chen, Jung-Hui
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Tsai, Tsung-Ming
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Chang, Ting-Chang
;
Huang, Syuan-Yong
We demonstrated that the supercritical CO2 fluid treatment was a new concept to efficiently reduce the operation current of resistance random access memory. The dangling bonds of tin-doped silicon oxide (Sn:SiOx) thin film were passivated by the hydration-dehydration reaction through supercritical CO2 fluid treatment, which was verified by the XPS and FTIR analyses. The current conduction mechanism of low resistance state in post-treated Sn:SiOx thin film was transferred to hopping conduction from Ohmic conduction. Furthermore, the current conduction mechanism of high resistance state in the memory device was transferred to Schottky emission from Frenkel-Poole conduction. The phenomena were attributed to the discontinuous metal filament formed by hydration-dehydration reaction in Sn:SiOx thin film through supercritical fluid treatment. Finally, a reaction model was proposed to explain the mechanism of current reduction in Sn:SiOx thin film with supercritical CO2 fluid treatment. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.
Improvement of Bipolar Switching Properties of Gd:SiOx RRAM Devices on Indium Tin Oxide Electrode by Low-Temperature Supercritical CO2 Treatment
(2016-02-01)
Chen, Kai-Huang
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Liang, Shu-Ping
Bipolar switching resistance behaviors of the Gd:SiO2 resistive random access memory (RRAM) devices on indium tin oxide electrode by the low-temperature supercritical CO2-treated technology were investigated. For physical and electrical measurement results obtained, the improvement on oxygen qualities, properties of indium tin oxide electrode, and operation current of the Gd:SiO2 RRAM devices were also observed. In addition, the initial metallic filament-forming model analyses and conduction transferred mechanism in switching resistance properties of the RRAM devices were verified and explained. Finally, the electrical reliability and retention properties of the Gd:SiO2 RRAM devices for low-resistance state (LRS)/high-resistance state (HRS) in different switching cycles were also measured for applications in nonvolatile random memory devices.
Improvement of Resistive Switching Characteristic in Silicon Oxide-Based RRAM Through Hydride-Oxidation on Indium Tin Oxide Electrode by Supercritical CO2 Fluid
(2015-06-01)
Chang, Kuan-Chang
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Tsai, Tsung-Ming
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Chang, Ting-Chang
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Zhang, Rui
;
Chen, Kai-Huang
Supercritical carbon dioxide (SCCO2) fluid technology was applied to indium-tin-oxide (ITO) electrode to improve the resistive switching characteristic of silicon oxide RRAM through hydride oxidation for the first time. We found device power consumption can be effectively reduced so that side effects can be also restricted under device operation. By applying SCCO2 fluid, more oxygen ions will be introduced into the ITO electrode and thus the participation of net oxygen ions in the RRAM redox reaction will increase. Fourier transform spectroscopy and X-ray photoelectron spectroscopy were used to confirm hydride oxidation on ITO electrode. Combined with the current fitting results, we proposed a reaction model to explain the improvement of resistive switching in RRAM by SCCO2 fluids.
Low Temperature Improvement Method on Zn:SiOx Resistive Random Access Memory Devices
(2013-04-01)
Chang, Kuan-Chang
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Tsai, Tsung-Ming
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Chang, Ting-Chang
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Wu, Hsing-Hua
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Chen, Kai-Huang
To improve the resistive switching properties of the resistive random access memory (RRAM), the supercritical carbon dioxide (SCCO2) fluid is used as a low temperature treatment. In this letter, the Zn:SiOx thin films are treated by SCCO2 fluid mixed with pure water. After SCCO2 fluid treatment, the resistive switching qualities of the Zn:SiOx thin films are carried out by XPS, fourier transform infrared spectroscopy, and IV measurement. We believe that the SCCO2-treated Zn:SiOx thin film is a promising material for RRAM applications due to its compatibility with portable flat panel display.
Mechanism of power consumption inhibitive multi-layer Zn:SiO2/SiO2 structure resistance random access memory
(2013-12-21)
Zhang, Rui
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Tsai, Tsung-Ming
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Chang, Ting-Chang
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Chang, Kuan-Chang
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Chen, Kai-Huang
In this paper, multi-layer Zn:SiO2/SiO2 structure is introduced to reduce the operation power consumption of resistive random access memory (RRAM) device by modifying the filament formation process. And the configuration of multi-layer Zn:SiO2/SiO2 structure is confirmed and demonstrated by auger electron spectrum. Material analysis together with conduction current fitting is applied to qualitatively evaluate the carrier conduction mechanism on both low resistance state and high resistance state. Finally, single layer and multilayer conduction models are proposed, respectively, to clarify the corresponding conduction characteristics of two types of RRAM devices. (C) 2013 AIP Publishing LLC.
Modifying Indium-Tin-Oxide by Gas Cosputtering for Use as an Insulator in Resistive Random Access Memory
(2016-11)
Chen, Po-Hsun
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Pan, Chih-Hung
In this paper, indium-tin-oxide (ITO) was used to act as both insulator and top electrode in resistive random access memory (RRAM) on identical bottom substrates. This is achieved by cosputtering an ITO target with nitride (N-2) or oxygen (O-2) gas as the insulator; then capping by an ITO electrode, such that both the rectifier and RRAM characteristics can be achieved before and after a forming process, respectively. In contrast, using pure ITO as an insulator does not exhibit RRAM behavior. To verify the rectifier and RRAM characteristics, material analyses and electrical measurements at various temperatures were conducted. Reliability tests including retention and endurance were also applied to verify the resistance switching stability. Finally, the rectifier and RRAM conduction models were proposed to examine the resistance switching behaviors. By applying the ITO material as both electrode and insulator, the resistance switching characteristic with high reliability is thus obtained.
Obtaining Lower Forming Voltage and Self-Compliance Current by Using a Nitride Gas/Indium-Tin Oxide Insulator in Resistive Random Access Memory
(2016-12)
Chen, Po-Hsun
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Chang, Ting-Chang
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Chang, Kuan-Chang
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Tsai, Tsung-Ming
;
Pan, Chih-Hung
This paper investigates the characteristics of applying indium-tin oxide (ITO) with and without nitride gas (N-2) as the insulator in resistive random access memory (RRAM). After cosputtering an ITO target with N-2 as the insulator and capping the same ITO material as the top electrode, the device exhibits rectifier and resistance switching characteristics before and after the forming process, respectively. The Schottky diodelike rectifier mechanism was also verified by various temperature measurements. Furthermore, robust resistance switching at a positive forming voltage, smaller than that required during negative bias forming, can be achieved. Both positive and negative forming processes are examined with current fitting results, which show different dominant mechanisms when using positive or negative biases. All these mechanisms have also been verified by temperature effect experiments, which confirmed the dominant conduction mechanisms. This, in combination with the fact that the positive forming voltage itself is smaller than the negative forming voltage, and decreases with device scale down, provides two highly beneficial results. This good performance achieved by using ITO with N-2 suggests significant progress of RRAM and remarkable potential applications.
Resistive Switching Mechanism of Oxygen-Rich Indium Tin Oxide Resistance Random Access Memory
(2016-04)
Tsai, Tsung-Ming
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Zhang, Rui
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Wang, Tong
DThis letter investigates the double-ended resistive switching characteristics of indium tin oxide (ITO) resistance random access memory (RRAM). Resistive switching can be achieved around both the active TiN electrode and the inert Pt electrode. In addition, complementary resistance switching (CRS) characteristics can be observed without current compliance during dc voltage sweep operations. Electrical measurement data fitting results indicate that the oxygen-rich ITO near top and bottom electrodes works as a double-ended resistive switching layer. Based on the analysis of the current conduction mechanism, we propose a physical model to interpret the CRS behaviors in ITO RRAM devices.
Space electric field concentrated effect for Zr:SiO2 RRAM devices using porous SiO2 buffer layer
(2013-12-11)
Chang, Kuan-
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Huang, Jen-wei
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Chen, Kai-Huang
To improve the operation current lowing of the Zr:SiO2 RRAM devices, a space electric field concentrated effect established by the porous SiO2 buffer layer was investigated and found in this study. The resistive switching properties of the low-resistance state (LRS) and high-resistance state (HRS) in resistive random access memory (RRAM) devices for the single-layer Zr:SiO2 and bilayer Zr:SiO2/porous SiO2 thin films were analyzed and discussed. In addition, the original space charge limited current (SCLC) conduction mechanism in LRS and HRS of the RRAM devices using bilayer Zr:SiO2/porous SiO2 thin films was found. Finally, a space electric field concentrated effect in the bilayer Zr:SiO2/porous SiO2 RRAM devices was also explained and verified by the COMSOL Multiphysics simulation model.
Tri-Resistive Switching Behavior of Hydrogen Induced Resistance Random Access Memory
(2014-02-01)
Chu, Tian-Jian
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Tsai, Tsung-Ming
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Chang, Ting-Chang
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Chang, Kuan-Chang
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Zhang, Rui
In this letter, the special role of hydrogen ions in hafnium doped silicon oxide resistive random access memory (RRAM) is presented. In addition to the more typical oxygen ion-dominated resistive switching, hydrogen ions were also observed to trigger a resistance transformation phenomenon, producing a tri-resistive device. Unlike a normal RRAM device, a hydrogen plasma-treated device is operated with a reversed voltage polarity, and the direction of hydrogen ion migration results in the chemical bonds breaking and repairing. By changing the voltage polarity and stop voltage, this tri-resistive behavior can be achieved. This particular hydrogen-induced switching behavior suggests a different RRAM switching mechanism and is finally explained by our model.