This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-...This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-and(222)-oriented ITO BEs deposited under pure argon and argon–oxygen(20%O_(2))sputtering atmospheres,as well as SrRuO_(3)(SRO),show distinct RS behaviors.The Al/ZrO_(2)/(400)-ITO and Al/ZrO_(2)/SRO devices demonstrate stable bipolar RS performance,with(400)-ITO enabling an abrupt reset process,a wider memory window(>10^(4)),and superior stability,while SRO devices exhibit gradual reset transitions with lower power consumption.Furthermore,the crystallographic orientation control applied to ITO BE significantly affects the V_(O) dynamics and RS performance,with(222)-ITO devices exhibiting irreversible RS behavior.It is irrefutable that BE material and its orientation can strongly influence RS performance by modulating the V_(O) dynamics,electric field distribution,and conductive filament behavior.These findings underscore the importance of BE properties in optimizing ReRAM performance and provide valuable guidance for the development of high-efficiency memory devices.展开更多
As artificial intelligence and big data become increasingly prevalent, resistive random-access memory (RRAM) has become one of the most promising alternatives for storing massive amounts of data. In this study, we emp...As artificial intelligence and big data become increasingly prevalent, resistive random-access memory (RRAM) has become one of the most promising alternatives for storing massive amounts of data. In this study, we employed high-quality crystalline TiN/Al_(2)O_(3)/BaTiO_(3)/Pt RRAM with an optimized thin Al_(2)O_(3) interlayer around 12 nm thick prepared using atomic layer deposition since the thickness of the interlayer affects the memory window size. After insertion of the Al_(2)O_(3) interlayer, the novel RRAM exhibited outstanding uniform resistive switching voltage and the ON/OFF memory window drastically increased from 10 to 103 without any discernible decline in performance. Moreover, the low-resistance state and high-resistance state operating current values decreased by almost one order and three orders of magnitude, respectively, thereby decreasing the power consumption for the RESET and SET processes by more than three and almost one order of magnitude, respectively. The device also exhibits multilevel resistive switching behavior when varying the applied voltage. Finally, we also developed a 6 6 crossbar array which demonstrated consistent and reliable resistive switching behavior with minimal variation. Hence, our approach holds great promise for producing state-of-the-art non-volatile resistive switching devices.展开更多
A CMOS compatible RRAM device with TaN/Ta/TaOx/Ta N structure was proposed for nonvolatile memory applications.Excellent resistive switching characteristics,including low operation voltages(<1 V),low operation curr...A CMOS compatible RRAM device with TaN/Ta/TaOx/Ta N structure was proposed for nonvolatile memory applications.Excellent resistive switching characteristics,including low operation voltages(<1 V),low operation current(<100μA),good programming/erasing endurance(>10^(6) cycles),satisfactory uniformity,and reliable data retention,have been demonstrated.Furthermore,all of the elements in the fabricated Ta N/Ta/Ta Ox/Ta N devices are highly compatible with modern CMOS manufacturing process,showing promising application in the next generation of nonvolatile memory.展开更多
Transient electronics has attracted interest as an emerging technology to solve electronic-waste problem,due to its physically vanishing ability in solution.Here in this work,we demonstrate a flexible and degradable t...Transient electronics has attracted interest as an emerging technology to solve electronic-waste problem,due to its physically vanishing ability in solution.Here in this work,we demonstrate a flexible and degradable transient resistive switching(RS) memory device with simple structure of Cu/sodium alginate(SA)/ITO.The device presents excellent RS characteristics as well as high flexibility,including low operating voltage(<1.5 V) and multilevel RS behavior.No performance degradation occurs after bending the device 50 times.Moreover,our device can be absolutely dissolved in deionized water.The proposed SA-based transient memory device has great potential for the development of green and security memory devices.展开更多
Resistive switching(RS)devices have great application prospects in the emerging memory field and neuromorphic field,but their stability and unclear RS mechanism limit their relevant applications.In this work,we constr...Resistive switching(RS)devices have great application prospects in the emerging memory field and neuromorphic field,but their stability and unclear RS mechanism limit their relevant applications.In this work,we construct a hydrogenated Au/SnO_(2)nanowire(NW)/Au device with two back-to-back Schottky diodes and investigate the RS characteristics in air and vacuum.We find that the Ion/Io ff ratio increases from 20 to 10^(4)when the read voltage decreases from 3.1 V to^(-1)V under the condition of electric field.Moreover,the rectification ratio can reach as high as 10^4owing to oxygen ion migration modulated by the electric field.The nanodevice also shows non-volatile resistive memory characteristic.The RS mechanism is clarified based on the changes of the Schottky barrier width and height at the interface of Au/SnO_(2)NW/Au device.Our results provide a strategy for designing high-performance memristive devices based on SnO_(2)NWs.展开更多
The resistive switching characteristics of TiO_2 nanowire networks directly grown on Ti foil by a single-step hydrothermal technique are discussed in this paper. The Ti foil serves as the supply of Ti atoms for growth...The resistive switching characteristics of TiO_2 nanowire networks directly grown on Ti foil by a single-step hydrothermal technique are discussed in this paper. The Ti foil serves as the supply of Ti atoms for growth of the TiO_2 nanowires, making the preparation straightforward. It also acts as a bottom electrode for the device. A top Al electrode was fabricated by e-beam evaporation process. The Al/TiO_2 nanowire networks/Ti device fabricated in this way displayed a highly repeatable and electroforming-free bipolar resistive behavior with retention for more than 10~4 s and an OFF/ON ratio of approximately 70. The switching mechanism of this Al/TiO_2 nanowire networks/Ti device is suggested to arise from the migration of oxygen vacancies under applied electric field. This provides a facile way to obtain metal oxide nanowire-based Re RAM device in the future.展开更多
In this study,resistive random-access memory(RRAM)-based crossbar arrays with a memristor W/TiO_(2)/HfO_(2)/TaN structure were fabricated through atomic layer deposition(ALD)to investigate synaptic plasticity and resi...In this study,resistive random-access memory(RRAM)-based crossbar arrays with a memristor W/TiO_(2)/HfO_(2)/TaN structure were fabricated through atomic layer deposition(ALD)to investigate synaptic plasticity and resistive switching(RS)characteristics for bioinspired neuromorphic computing.X-ray photoelectron spectroscopy(XPS)was employed to explore oxygen vacancy concentrations in bilayer TiO_(2)/HfO_(2)films.Gaussian fitting for O1s peaks confirmed that the HfO_(2)layer contained a larger number of oxygen vacancies than the TiO_(2)layer.In addition,HfO_(2)had lower Gibbs free energy(ΔG°=-1010.8 kJ/mol)than the TiO_(2)layer(ΔG°=-924.0 kJ/mol),resulting in more oxygen vacancies in the HfO_(2)layer.XPS results andΔG°magnitudes confirmed that formation/disruption of oxygen-based conductive filaments took place in the TiO_(2)layer.The W/TiO_(2)/HfO_(2)/TaN memristive device exhibited excellent and repeatable RS characteristics,including superb 10^(3) dc switching cycles,outstanding 107 pulse endurance,and high-thermal stability(10^(4) s at 125℃)important for digital computing systems.Furthermore,some essential biological synaptic characteristics such as potentiation-depression plasticity,paired-pulse facilitation(PPF),and spike-timing-dependent plasticity(STDP,asymmetric Hebbian and asymmetric anti-Hebbian)were successfully mimicked herein using the crossbar-array memristive device.Based on experimental results,a migration and diffusion of oxygen vacancy based physical model is proposed to describe the synaptic plasticity and RS mechanism.This study demonstrates that the proposed W/TiO_(2)/HfO_(2)/TaN memristor crossbar-array has a significant potential for applications in non-volatile memory(NVM)and bioinspired neuromorphic systems.展开更多
This review summarizes the mechanism and performance of metal oxide based resistive switching memory. The origin of resistive switching （RS） behavior can be roughly classified into the conducting filament type and t...This review summarizes the mechanism and performance of metal oxide based resistive switching memory. The origin of resistive switching （RS） behavior can be roughly classified into the conducting filament type and the interface type. Here, we adopt the filament type to study the metal oxide based resistive switch- ing memory, which considers the migration of metallic cations and oxygen vacancies, as well as discuss two main mechanisms including the electrochemical metallization effect （ECM） and valence change memory effect （VCM）. At the light of the influence of the electrode materials and switching layers on the RS char- acteristics, an overview has also been given on the performance parameters including the uniformity, endurance, the retention, and the multi-layer storage. Especially, we mentioned ITO （indium tin oxide） electrode and discussed the novel RS characteristics related with ITO. Finally, the challenges resistive random access memory （RRAM） device is facing, as well as the future development trend, are expressed.展开更多
Organic semiconducting/ferroelectric blend films attracted much attention due to their electrical bistability and rectification properties and thereof the potential in resistive memory devices. Blend films were usuall...Organic semiconducting/ferroelectric blend films attracted much attention due to their electrical bistability and rectification properties and thereof the potential in resistive memory devices. Blend films were usually deposited from solution, during which phase separation oc- curred, resulting in discrete semiconducting phase whose electrical property was modulated by surrounding ferroelectric phase. However, phase separation resulted in rough surface and thus large leakage current. To further improve electrical properties of such blend films, poly（methyl metacrylate） （PMMA） was introduced as additive into P3HT/P（VDF-TrFE） semiconducting/ferroelectric blend films in this work. It indicated that small amount of PMMA addition could effectively enhance the electrical stability to both large electrical stress and electrical fatigue and further improve retention performance. Overmuch PMMA addition tended to result in the loss of resistive switching property. A model on the configuration of three components was also put forward to well understand our experimental observations.展开更多
Resistive switching （RS） behaviors of Dy2O3- based memory devices with and without Pt nanocrystals （Pt-nc） layer were investigated for nonvolatile memory applications. The Cu/Pt-nc/Dy2O3/Pt memory exhibits excelle...Resistive switching （RS） behaviors of Dy2O3- based memory devices with and without Pt nanocrystals （Pt-nc） layer were investigated for nonvolatile memory applications. The Cu/Pt-nc/Dy2O3/Pt memory exhibits excellent unipolar RS characteristics, including highly uniform switching parameters, lower switching voltage （〈1.2 V）, high resistance ratio （〉1 × 104）, a large number of switching cycles, as well as long retention time （〉1 × 105 s）, owing to the local electric field confined and strengthened near the nanocrystals＇ location.展开更多
We investigate the resistive switching characteristics of a Cu/VOx/W structure. The VOx film is deposited by radio- frequency magnetron sputtering on the Cu electrode as a dielectric layer. The prepared VOx sample str...We investigate the resistive switching characteristics of a Cu/VOx/W structure. The VOx film is deposited by radio- frequency magnetron sputtering on the Cu electrode as a dielectric layer. The prepared VOx sample structure shows reproducible bipolar resistive switching characteristics with ultra-low switching voltage and good cycling endurance. A modified physical model is proposed to elucidate the typical switching behavior of the vanadium oxide-based resistive switching memory with a sudden resistance transition, and the self-saturation of reset current as a function of compliance current is observed in the test, which is attributed to the conducting mechanism is discussed in detail. growth pattern of the conducting filaments. Additionally, the related展开更多
The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/Cr Ox/Ti Ox/Ti N structure for the first time.Transmission electron microscope image confir...The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/Cr Ox/Ti Ox/Ti N structure for the first time.Transmission electron microscope image confirmed a viahole size of 0.4 lm.A 3-nm-thick amorphous Ti Oxwith 4-nm-thick polycrystalline Cr Oxlayer was observed.A small 0.4-lm device shows reversible resistive switching at a current compliance of 300 l A as compared to other larger size devices(1–8 lm)owing to reduction of leakage current through the Ti Oxlayer.Good device-to-device uniformity with a yield of[85%has been clarified by weibull distribution owing to higher slope/shape factor.The switching mechanism is based on oxygen vacancy migration from the Cr Oxlayer and filament formation/rupture in the Ti Oxlayer.Long read pulse endurance of[105cycles,good data retention of 6 h,and a program/erase speed of 1 ls pulse width have been obtained.展开更多
Resistive random-access memory(RRAM)is a promising technology to develop nonvolatile memory and artificial synaptic devices for brain-inspired neuromorphic computing.Here,we have developed a STO:Ag/SiO_(2) bilayer bas...Resistive random-access memory(RRAM)is a promising technology to develop nonvolatile memory and artificial synaptic devices for brain-inspired neuromorphic computing.Here,we have developed a STO:Ag/SiO_(2) bilayer based memristor that has exhibited a filamentary resistive switching with stable endurance and long-term data retention ability.The memristor also exhibits a tunable resistance modulation under positive and negative pulse trains,which could fully mimic the potentiation and depression behavior like a bio-synapse.Several synaptic plasticity functions,including long-term potentiation(LTP)and long-term depression(LTD),paired-pulsed facilitation(PPF),spike-rate-dependent-plasticity(SRDP),and post-tetanic potentiation(PTP),are faithfully implemented with the fabricated memristor.Moreover,to demonstrate the feasibility of our memristor synapse for neuromorphic applications,spike-timedependent plasticity(STDP)is also investigated.Based on conductive atomic force microscopy observations and electrical transport model analyses,it can be concluded that it is the controlled formation and rupture of Ag filaments that are responsible for the resistive switching while exhibiting a switching ratio of~10;along with a good endurance and stability suitable for nonvolatile memory applications.Before fully electroforming,the gradual conductance modulation of Ag/STO:Ag/SiO_(2)/p^(++)-Si memristor can be realized,and the working mechanism could be explained by the succeeding growth and contraction of Ag filaments promoted by a redox reaction.This newly fabricated memristor may enable the development of nonvolatile memory and realize controllable resistance/weight modulation when applied as an artificial synapse for neuromorphic computing.展开更多
In this paper, the bipolar resistive switching characteristic is reported in Ti/ZrO2/Pt resistive switching memory de- vices. The dominant mechanism of resistive switching is the formation and rupture of the conductiv...In this paper, the bipolar resistive switching characteristic is reported in Ti/ZrO2/Pt resistive switching memory de- vices. The dominant mechanism of resistive switching is the formation and rupture of the conductive filament composed of oxygen vacancies. The conduction mechanisms for low and high resistance states are dominated by the ohmic conduc- tion and the trap-controlled space charge limited current （SCLC） mechanism, respectively. The effect of a set compliance current on the switching parameters is also studied： the low resistance and reset current are linearly dependent on the set compliance current in the log-log scale coordinate; and the set and reset voltage increase slightly with the increase of the set compliance current. A series circuit model is proposed to explain the effect of the set compliance current on the resistive switching behaviors.展开更多
In this study, the unipolar resistive switching （URS） and bipolar resistive switching （BRS） are demonstrated to be coexistent in the Ag/ZnO/Pt memory device, and both modes are observed to strongly depend on the p...In this study, the unipolar resistive switching （URS） and bipolar resistive switching （BRS） are demonstrated to be coexistent in the Ag/ZnO/Pt memory device, and both modes are observed to strongly depend on the polarity of forming voltage. The mechanisms of the URS and BRS behaviors could be attributed to the electric-field-induced migration of oxygen vacancies （Vo） and metal-Ag conducting filaments （CFs） respectively, which are confirmed by investigating the temperature dependences of low resistance states in both modes. Furthermore, we compare the resistive switching （RS） characteristics （e.g., forming and switching voltages, reset current and resistance states） between these two modes based on Vo- and Ag-CFs. The BRS mode shows better switching uniformity and lower power than the URS mode. Both of these modes exhibit good RS performances, including good retention, reliable cycling and high-speed switching. The result indicates that the coexistence of URS and BRS behaviors in a single device has great potential applications in future nonvolatile multi-level memory.展开更多
A new device has been realized using flip-chip joining two printed circuit boards(PCBs) on which zinc oxide(ZnO) nanowires were synthesized. Energy dispersive X-ray measurement has been conducted for the ZnO nanowires...A new device has been realized using flip-chip joining two printed circuit boards(PCBs) on which zinc oxide(ZnO) nanowires were synthesized. Energy dispersive X-ray measurement has been conducted for the ZnO nanowires, confirming that Cu elements have been diffused into the nanowires during the chemical growth process. From I-V measurements, this Cu/ZnO nanowire/Cu structure exhibits a resistive tuning behaviour, which varies greatly with the frequency of the applied sinusoidal source.展开更多
Polycrystalline LaCrO3（LCO） thin films are deposited on Pt/Ti/SiO2/Si substrates by pulsed laser deposition and used as the switching material to construct resistive random access memory devices. The unipolar resist...Polycrystalline LaCrO3（LCO） thin films are deposited on Pt/Ti/SiO2/Si substrates by pulsed laser deposition and used as the switching material to construct resistive random access memory devices. The unipolar resistive switching（RS） behavior in the Au/LCO/Pt devices exhibits a high resistance ratio of ~104 between the high resistance state（HRS） and low resistance state（LRS） and exhibits excellent endurance/retention characteristics.The conduction mechanism of the HRS in the high voltage range is dominated by the Schottky emission, while the Ohmic conduction dictates the LRS and the low voltage range of HRS. The RS behavior in the Au/LCO/Pt devices can be understood by the formation and rupture of conducting filaments consisting of oxygen vacancies,which is validated by the temperature dependence of resistance and x-ray photoelectron spectroscopy results.Further analysis shows that the reset current IR and reset power PR in the reset processes exhibit a scaling law with the resistance in LRS（R0）, which indicates that the Joule heating effect plays an essential role in the RS behavior of the Au/LCO/Pt devices.展开更多
In this paper, a WO3-based resistive random access memory device composed of a thin film of WO3 sandwiched between a copper top and a platinum bottom electrodes is fabricated by electron beam evaporation at room tempe...In this paper, a WO3-based resistive random access memory device composed of a thin film of WO3 sandwiched between a copper top and a platinum bottom electrodes is fabricated by electron beam evaporation at room temperature. The reproducible resistive switching, low power consumption, multilevel storage possibility, and good data retention characteristics demonstrate that the Cu/WO3/Pt memory device is very promising for future nonvolatile memory applications. The formation and rupture of localised conductive filaments is suggested to be responsible for the observed resistive switching behaviours.展开更多
The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits s...The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits stable bipolar resistive switching characteristic, good retention performance, and reversal characteristic. Under different pulse voltages and light fields, four stable resistance states can also be realized. The analysis shows that the main conduction mechanism of the resistive switching characteristic of the heterojunction is space charge limited current(SCLC) effect. After the comprehensive analysis of the band diagram and the P–E ferroelectric property of the multilayer heterojunction, we can deduce that the SCLC is formed by the effect of the oxygen vacancy which is controlled by ferroelectric polarizationmodulated change of interfacial barrier. And the effective photo-generated carrier also plays a regulatory role in resistance state(RS), which is formed by the double ferroelectric layer Ba TiO3/BiFeO3 under different light fields. This research is of potential application values for developing the multi-state non-volatile resistance random access memory(RRAM) devices based on ferroelectric materials.展开更多
The(001)oriented BiFeO_(3)thin film was deposited on the Nb:SrTiO_(3)substrate by radio frequency magnetron sputtering technology,and the bipolar resistive switching effect was observed in the BiFeO_(3)/Nb:SrTiO_(3)he...The(001)oriented BiFeO_(3)thin film was deposited on the Nb:SrTiO_(3)substrate by radio frequency magnetron sputtering technology,and the bipolar resistive switching effect was observed in the BiFeO_(3)/Nb:SrTiO_(3)heterostructure.The results showed that the ratio between the high resistance and low resistance was more than two orders at a reading pulse of-0.5 V and it exhibited excellent retention over 3600 s.The current density-voltage characteristic was dominated by the space-charge-limited conduction.The resistive switching effect of the structure was attributed to the trapping/detrapping of the charge carriers.展开更多
基金supported in part by the National Natural Science Foundation of China(Grant Nos.51602160 and 61605086)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20150842)the Talent Project of Nanjing University of Posts and Telecommunications(NUPTSF)(Grant No.NY222127)。
文摘This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-and(222)-oriented ITO BEs deposited under pure argon and argon–oxygen(20%O_(2))sputtering atmospheres,as well as SrRuO_(3)(SRO),show distinct RS behaviors.The Al/ZrO_(2)/(400)-ITO and Al/ZrO_(2)/SRO devices demonstrate stable bipolar RS performance,with(400)-ITO enabling an abrupt reset process,a wider memory window(>10^(4)),and superior stability,while SRO devices exhibit gradual reset transitions with lower power consumption.Furthermore,the crystallographic orientation control applied to ITO BE significantly affects the V_(O) dynamics and RS performance,with(222)-ITO devices exhibiting irreversible RS behavior.It is irrefutable that BE material and its orientation can strongly influence RS performance by modulating the V_(O) dynamics,electric field distribution,and conductive filament behavior.These findings underscore the importance of BE properties in optimizing ReRAM performance and provide valuable guidance for the development of high-efficiency memory devices.
基金supported by the National Research Foundation of Korea funded by the Korean Government(grant No.RS-2023-00208801).
文摘As artificial intelligence and big data become increasingly prevalent, resistive random-access memory (RRAM) has become one of the most promising alternatives for storing massive amounts of data. In this study, we employed high-quality crystalline TiN/Al_(2)O_(3)/BaTiO_(3)/Pt RRAM with an optimized thin Al_(2)O_(3) interlayer around 12 nm thick prepared using atomic layer deposition since the thickness of the interlayer affects the memory window size. After insertion of the Al_(2)O_(3) interlayer, the novel RRAM exhibited outstanding uniform resistive switching voltage and the ON/OFF memory window drastically increased from 10 to 103 without any discernible decline in performance. Moreover, the low-resistance state and high-resistance state operating current values decreased by almost one order and three orders of magnitude, respectively, thereby decreasing the power consumption for the RESET and SET processes by more than three and almost one order of magnitude, respectively. The device also exhibits multilevel resistive switching behavior when varying the applied voltage. Finally, we also developed a 6 6 crossbar array which demonstrated consistent and reliable resistive switching behavior with minimal variation. Hence, our approach holds great promise for producing state-of-the-art non-volatile resistive switching devices.
基金Project supported by the Key Research and Development Program of Gansu Province-Industrial Project(Grant No.25YFGA005)。
文摘A CMOS compatible RRAM device with TaN/Ta/TaOx/Ta N structure was proposed for nonvolatile memory applications.Excellent resistive switching characteristics,including low operation voltages(<1 V),low operation current(<100μA),good programming/erasing endurance(>10^(6) cycles),satisfactory uniformity,and reliable data retention,have been demonstrated.Furthermore,all of the elements in the fabricated Ta N/Ta/Ta Ox/Ta N devices are highly compatible with modern CMOS manufacturing process,showing promising application in the next generation of nonvolatile memory.
基金Project supported by the Fund from the Ministry of Science and Technology of China(Grant No.2018YFE0118300)the National Natural Science Foundation of China(Grant Nos.11974072,51902048,61774031,and 61574031)+3 种基金the“111”Project,China(Grant No.B13013)the China Postdoctoral Science Foundation,China(Grant No.2019M661185)the Fundamental Research Funds for the Central Universities,China(Grant No.2412019QD015)Science Fund from the Jilin Province,China(Grant No.JJKH20201163KJ)。
文摘Transient electronics has attracted interest as an emerging technology to solve electronic-waste problem,due to its physically vanishing ability in solution.Here in this work,we demonstrate a flexible and degradable transient resistive switching(RS) memory device with simple structure of Cu/sodium alginate(SA)/ITO.The device presents excellent RS characteristics as well as high flexibility,including low operating voltage(<1.5 V) and multilevel RS behavior.No performance degradation occurs after bending the device 50 times.Moreover,our device can be absolutely dissolved in deionized water.The proposed SA-based transient memory device has great potential for the development of green and security memory devices.
基金Chenzhou Science and Technology Plan Project of China(Grant No.ZDYF2020159)Scientific Research Project of Hunan Provincial Department of Education(Grant No.21C0708)。
文摘Resistive switching(RS)devices have great application prospects in the emerging memory field and neuromorphic field,but their stability and unclear RS mechanism limit their relevant applications.In this work,we construct a hydrogenated Au/SnO_(2)nanowire(NW)/Au device with two back-to-back Schottky diodes and investigate the RS characteristics in air and vacuum.We find that the Ion/Io ff ratio increases from 20 to 10^(4)when the read voltage decreases from 3.1 V to^(-1)V under the condition of electric field.Moreover,the rectification ratio can reach as high as 10^4owing to oxygen ion migration modulated by the electric field.The nanodevice also shows non-volatile resistive memory characteristic.The RS mechanism is clarified based on the changes of the Schottky barrier width and height at the interface of Au/SnO_(2)NW/Au device.Our results provide a strategy for designing high-performance memristive devices based on SnO_(2)NWs.
基金supported by the Natural Sciences and Engineering Research Council(NSERC)of CanadaThe financial support of the State Scholarship Fund of China(No.201506160061)
文摘The resistive switching characteristics of TiO_2 nanowire networks directly grown on Ti foil by a single-step hydrothermal technique are discussed in this paper. The Ti foil serves as the supply of Ti atoms for growth of the TiO_2 nanowires, making the preparation straightforward. It also acts as a bottom electrode for the device. A top Al electrode was fabricated by e-beam evaporation process. The Al/TiO_2 nanowire networks/Ti device fabricated in this way displayed a highly repeatable and electroforming-free bipolar resistive behavior with retention for more than 10~4 s and an OFF/ON ratio of approximately 70. The switching mechanism of this Al/TiO_2 nanowire networks/Ti device is suggested to arise from the migration of oxygen vacancies under applied electric field. This provides a facile way to obtain metal oxide nanowire-based Re RAM device in the future.
基金financially supported in part by a grant(2021R1C1C1004422)of the National Research Foundation(NRF)grant funded by the Korean government(MSIP)。
文摘In this study,resistive random-access memory(RRAM)-based crossbar arrays with a memristor W/TiO_(2)/HfO_(2)/TaN structure were fabricated through atomic layer deposition(ALD)to investigate synaptic plasticity and resistive switching(RS)characteristics for bioinspired neuromorphic computing.X-ray photoelectron spectroscopy(XPS)was employed to explore oxygen vacancy concentrations in bilayer TiO_(2)/HfO_(2)films.Gaussian fitting for O1s peaks confirmed that the HfO_(2)layer contained a larger number of oxygen vacancies than the TiO_(2)layer.In addition,HfO_(2)had lower Gibbs free energy(ΔG°=-1010.8 kJ/mol)than the TiO_(2)layer(ΔG°=-924.0 kJ/mol),resulting in more oxygen vacancies in the HfO_(2)layer.XPS results andΔG°magnitudes confirmed that formation/disruption of oxygen-based conductive filaments took place in the TiO_(2)layer.The W/TiO_(2)/HfO_(2)/TaN memristive device exhibited excellent and repeatable RS characteristics,including superb 10^(3) dc switching cycles,outstanding 107 pulse endurance,and high-thermal stability(10^(4) s at 125℃)important for digital computing systems.Furthermore,some essential biological synaptic characteristics such as potentiation-depression plasticity,paired-pulse facilitation(PPF),and spike-timing-dependent plasticity(STDP,asymmetric Hebbian and asymmetric anti-Hebbian)were successfully mimicked herein using the crossbar-array memristive device.Based on experimental results,a migration and diffusion of oxygen vacancy based physical model is proposed to describe the synaptic plasticity and RS mechanism.This study demonstrates that the proposed W/TiO_(2)/HfO_(2)/TaN memristor crossbar-array has a significant potential for applications in non-volatile memory(NVM)and bioinspired neuromorphic systems.
基金financial support from the National Natural Science Foundation of China(Nos.61474039 and 51572002)the Nature Science Foundation(Key Project) of Hubei Province (No.2015CFA052)
文摘This review summarizes the mechanism and performance of metal oxide based resistive switching memory. The origin of resistive switching （RS） behavior can be roughly classified into the conducting filament type and the interface type. Here, we adopt the filament type to study the metal oxide based resistive switch- ing memory, which considers the migration of metallic cations and oxygen vacancies, as well as discuss two main mechanisms including the electrochemical metallization effect （ECM） and valence change memory effect （VCM）. At the light of the influence of the electrode materials and switching layers on the RS char- acteristics, an overview has also been given on the performance parameters including the uniformity, endurance, the retention, and the multi-layer storage. Especially, we mentioned ITO （indium tin oxide） electrode and discussed the novel RS characteristics related with ITO. Finally, the challenges resistive random access memory （RRAM） device is facing, as well as the future development trend, are expressed.
基金This work was supported by the STCSM （No.13NMI400600） and the National Natural Science Foundation of China （No.U1430106）.
文摘Organic semiconducting/ferroelectric blend films attracted much attention due to their electrical bistability and rectification properties and thereof the potential in resistive memory devices. Blend films were usually deposited from solution, during which phase separation oc- curred, resulting in discrete semiconducting phase whose electrical property was modulated by surrounding ferroelectric phase. However, phase separation resulted in rough surface and thus large leakage current. To further improve electrical properties of such blend films, poly（methyl metacrylate） （PMMA） was introduced as additive into P3HT/P（VDF-TrFE） semiconducting/ferroelectric blend films in this work. It indicated that small amount of PMMA addition could effectively enhance the electrical stability to both large electrical stress and electrical fatigue and further improve retention performance. Overmuch PMMA addition tended to result in the loss of resistive switching property. A model on the configuration of three components was also put forward to well understand our experimental observations.
基金financially supported by the National Natural Science Foundation of China(Nos.50932001,51102020,and 51202013)the Important National Science&Technology Specific Projects(No.2009ZX02039-005)
文摘Resistive switching （RS） behaviors of Dy2O3- based memory devices with and without Pt nanocrystals （Pt-nc） layer were investigated for nonvolatile memory applications. The Cu/Pt-nc/Dy2O3/Pt memory exhibits excellent unipolar RS characteristics, including highly uniform switching parameters, lower switching voltage （〈1.2 V）, high resistance ratio （〉1 × 104）, a large number of switching cycles, as well as long retention time （〉1 × 105 s）, owing to the local electric field confined and strengthened near the nanocrystals＇ location.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61274113 and 11204212)the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-11-1064)+1 种基金the Natural Science Foundation of Tianjin City, China (Grant Nos. 10SYSYJC27700, 13JCYBJC15700, and 10ZCKFGX01200)the Science and Technology Development Funds of Universities and Colleges of Tianjin City, China (Grant No. 20100703)
文摘We investigate the resistive switching characteristics of a Cu/VOx/W structure. The VOx film is deposited by radio- frequency magnetron sputtering on the Cu electrode as a dielectric layer. The prepared VOx sample structure shows reproducible bipolar resistive switching characteristics with ultra-low switching voltage and good cycling endurance. A modified physical model is proposed to elucidate the typical switching behavior of the vanadium oxide-based resistive switching memory with a sudden resistance transition, and the self-saturation of reset current as a function of compliance current is observed in the test, which is attributed to the conducting mechanism is discussed in detail. growth pattern of the conducting filaments. Additionally, the related
基金supported by Ministry of Sci ence and Technology(MOST)Taiwan,under Contract no.NSC-1022221-E-182-057-MY2grateful to EOL/ITRI Hsinchu,Taiwan for their experimental support
文摘The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/Cr Ox/Ti Ox/Ti N structure for the first time.Transmission electron microscope image confirmed a viahole size of 0.4 lm.A 3-nm-thick amorphous Ti Oxwith 4-nm-thick polycrystalline Cr Oxlayer was observed.A small 0.4-lm device shows reversible resistive switching at a current compliance of 300 l A as compared to other larger size devices(1–8 lm)owing to reduction of leakage current through the Ti Oxlayer.Good device-to-device uniformity with a yield of[85%has been clarified by weibull distribution owing to higher slope/shape factor.The switching mechanism is based on oxygen vacancy migration from the Cr Oxlayer and filament formation/rupture in the Ti Oxlayer.Long read pulse endurance of[105cycles,good data retention of 6 h,and a program/erase speed of 1 ls pulse width have been obtained.
基金financially supported by the National Science Funds for Excellent Young Scholars of China(no.61822106)the Natural Science Foundation of China(no.U19A2070)。
文摘Resistive random-access memory(RRAM)is a promising technology to develop nonvolatile memory and artificial synaptic devices for brain-inspired neuromorphic computing.Here,we have developed a STO:Ag/SiO_(2) bilayer based memristor that has exhibited a filamentary resistive switching with stable endurance and long-term data retention ability.The memristor also exhibits a tunable resistance modulation under positive and negative pulse trains,which could fully mimic the potentiation and depression behavior like a bio-synapse.Several synaptic plasticity functions,including long-term potentiation(LTP)and long-term depression(LTD),paired-pulsed facilitation(PPF),spike-rate-dependent-plasticity(SRDP),and post-tetanic potentiation(PTP),are faithfully implemented with the fabricated memristor.Moreover,to demonstrate the feasibility of our memristor synapse for neuromorphic applications,spike-timedependent plasticity(STDP)is also investigated.Based on conductive atomic force microscopy observations and electrical transport model analyses,it can be concluded that it is the controlled formation and rupture of Ag filaments that are responsible for the resistive switching while exhibiting a switching ratio of~10;along with a good endurance and stability suitable for nonvolatile memory applications.Before fully electroforming,the gradual conductance modulation of Ag/STO:Ag/SiO_(2)/p^(++)-Si memristor can be realized,and the working mechanism could be explained by the succeeding growth and contraction of Ag filaments promoted by a redox reaction.This newly fabricated memristor may enable the development of nonvolatile memory and realize controllable resistance/weight modulation when applied as an artificial synapse for neuromorphic computing.
基金supported by the National Basic Research Program of China(Grant No.2011CBA00606)the National Natural Science Foundation of China(Grant Nos.61106106,11304237,61376099,and 11235008)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant Nos.20130203130002 and 20110203110012)
文摘In this paper, the bipolar resistive switching characteristic is reported in Ti/ZrO2/Pt resistive switching memory de- vices. The dominant mechanism of resistive switching is the formation and rupture of the conductive filament composed of oxygen vacancies. The conduction mechanisms for low and high resistance states are dominated by the ohmic conduc- tion and the trap-controlled space charge limited current （SCLC） mechanism, respectively. The effect of a set compliance current on the switching parameters is also studied： the low resistance and reset current are linearly dependent on the set compliance current in the log-log scale coordinate; and the set and reset voltage increase slightly with the increase of the set compliance current. A series circuit model is proposed to explain the effect of the set compliance current on the resistive switching behaviors.
基金Project supported by the National Natural Science Foundation of China for Excellent Young Scholars(Grant No.51422201)the National Natural Science Foundation of China(Grant Nos.51172041,51372035,11304035,61574031,and 61404026)+4 种基金the National Basic Research Program of China(Grant No.2012CB933703)the"111"Project,China(Grant No.B13013)the Fund from Jilin Province,China(Grant Nos.20140520106JH and 20140201008GX)the Research Fund for the Doctoral Program of Higher Education,China(Grant No.20130043110004)the Fundamental Research Funds for the Central Universities,China(Grant Nos.2412015KJ008 and 2412016KJ003)
文摘In this study, the unipolar resistive switching （URS） and bipolar resistive switching （BRS） are demonstrated to be coexistent in the Ag/ZnO/Pt memory device, and both modes are observed to strongly depend on the polarity of forming voltage. The mechanisms of the URS and BRS behaviors could be attributed to the electric-field-induced migration of oxygen vacancies （Vo） and metal-Ag conducting filaments （CFs） respectively, which are confirmed by investigating the temperature dependences of low resistance states in both modes. Furthermore, we compare the resistive switching （RS） characteristics （e.g., forming and switching voltages, reset current and resistance states） between these two modes based on Vo- and Ag-CFs. The BRS mode shows better switching uniformity and lower power than the URS mode. Both of these modes exhibit good RS performances, including good retention, reliable cycling and high-speed switching. The result indicates that the coexistence of URS and BRS behaviors in a single device has great potential applications in future nonvolatile multi-level memory.
基金the UK Leverhulme Trust, College of Engineering and Department of Research and Innovation of Swansea University for financial support
文摘A new device has been realized using flip-chip joining two printed circuit boards(PCBs) on which zinc oxide(ZnO) nanowires were synthesized. Energy dispersive X-ray measurement has been conducted for the ZnO nanowires, confirming that Cu elements have been diffused into the nanowires during the chemical growth process. From I-V measurements, this Cu/ZnO nanowire/Cu structure exhibits a resistive tuning behaviour, which varies greatly with the frequency of the applied sinusoidal source.
基金Supported by the Joint Funds of the National Natural Science Foundation of China and the Chinese Academy of Sciences’Large-Scale Scientific Facility under Grant No U1532149the National Basic Research Program of China under Grant No2014CB931704
文摘Polycrystalline LaCrO3（LCO） thin films are deposited on Pt/Ti/SiO2/Si substrates by pulsed laser deposition and used as the switching material to construct resistive random access memory devices. The unipolar resistive switching（RS） behavior in the Au/LCO/Pt devices exhibits a high resistance ratio of ~104 between the high resistance state（HRS） and low resistance state（LRS） and exhibits excellent endurance/retention characteristics.The conduction mechanism of the HRS in the high voltage range is dominated by the Schottky emission, while the Ohmic conduction dictates the LRS and the low voltage range of HRS. The RS behavior in the Au/LCO/Pt devices can be understood by the formation and rupture of conducting filaments consisting of oxygen vacancies,which is validated by the temperature dependence of resistance and x-ray photoelectron spectroscopy results.Further analysis shows that the reset current IR and reset power PR in the reset processes exhibit a scaling law with the resistance in LRS（R0）, which indicates that the Joule heating effect plays an essential role in the RS behavior of the Au/LCO/Pt devices.
基金Project supported by the National Basic Research Program of China(Grant Nos.2008CB925002 and 2010CB934200)the National Natural Science Foundation of China(Grant Nos.60825403 and 50972160)the National High Technology Research and Development Program of China(Grant No.2009AA03Z306)
文摘In this paper, a WO3-based resistive random access memory device composed of a thin film of WO3 sandwiched between a copper top and a platinum bottom electrodes is fabricated by electron beam evaporation at room temperature. The reproducible resistive switching, low power consumption, multilevel storage possibility, and good data retention characteristics demonstrate that the Cu/WO3/Pt memory device is very promising for future nonvolatile memory applications. The formation and rupture of localised conductive filaments is suggested to be responsible for the observed resistive switching behaviours.
基金Project supported by the Scientific Research Program of Hunan Provincial Education Department,China(Grant No.18C0232)the International Cooperative Extension Program of Changsha University of Science and Technology,China(Grant No.2019IC35)
文摘The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits stable bipolar resistive switching characteristic, good retention performance, and reversal characteristic. Under different pulse voltages and light fields, four stable resistance states can also be realized. The analysis shows that the main conduction mechanism of the resistive switching characteristic of the heterojunction is space charge limited current(SCLC) effect. After the comprehensive analysis of the band diagram and the P–E ferroelectric property of the multilayer heterojunction, we can deduce that the SCLC is formed by the effect of the oxygen vacancy which is controlled by ferroelectric polarizationmodulated change of interfacial barrier. And the effective photo-generated carrier also plays a regulatory role in resistance state(RS), which is formed by the double ferroelectric layer Ba TiO3/BiFeO3 under different light fields. This research is of potential application values for developing the multi-state non-volatile resistance random access memory(RRAM) devices based on ferroelectric materials.
基金Funded by the National Natural Science Foundation of China(Nos.61201046 and 61306057)the Beijing Natural Science Foundation of China(Nos.4162013,2132023 and 4164082)+2 种基金the Beijing Postdoctoral Research Foundation(No.2015ZZ-33)the Scientific Research Project of Beijing Educational Committee(No.KM201610005005)the Scientific Research Foundation for Returned Overseas Chinese Scholars,State Education Ministry
文摘The(001)oriented BiFeO_(3)thin film was deposited on the Nb:SrTiO_(3)substrate by radio frequency magnetron sputtering technology,and the bipolar resistive switching effect was observed in the BiFeO_(3)/Nb:SrTiO_(3)heterostructure.The results showed that the ratio between the high resistance and low resistance was more than two orders at a reading pulse of-0.5 V and it exhibited excellent retention over 3600 s.The current density-voltage characteristic was dominated by the space-charge-limited conduction.The resistive switching effect of the structure was attributed to the trapping/detrapping of the charge carriers.
