Resistive switching of HfO2 based flexible memories fabricated by low temperature atomic layer depositiona)
22 Mar 2012-Journal of Vacuum Science & Technology B (American Vacuum Society)-Vol. 30, Iss: 2, pp 020602
TL;DR: In this article, a low temperature atomic layer deposition (LTALD) process was used to examine resistive switching performance of HfO2-based flexible memories and the endurance and retention behaviors were investigated.
Abstract: HfO2-based flexible memories were fabricated using a low temperature atomic layer deposition (LTALD) process to examine resistive switching performance. The devices exhibit typical bipolar resistive switching. The endurance and retention behaviors were also investigated. No significant degradation of the device was noted at either room temperature or 85 °C, and the current transport mechanism of the high- and low-resistance states are estimated to be Ohmic and trap-assisted current, respectively. The authors propose that this LTALD process will significantly improve fabrication of flexible memories.
Citations
More filters
TL;DR: Considering the excellent performance of the device fabricated by low-temperature atomic layer deposition, the process may promote the potential applications of oxide-based resistive random access memory in flexible integrated circuits.
Abstract: We demonstrated a flexible resistive random access memory device through a low-temperature atomic layer deposition process. The device is composed of an HfO2/Al2O3-based functional stack on an indium tin oxide-coated polyethylene terephthalate substrate. After the initial reset operation, the device exhibits a typical bipolar, reliable, and reproducible resistive switching behavior. After a 104-s retention time, the memory window of the device is still in accordance with excellent thermal stability, and a 10-year usage is still possible with the resistance ratio larger than 10 at room temperature and at 85°C. In addition, the operation speed of the device was estimated to be 500 ns for the reset operation and 800 ns for the set operation, which is fast enough for the usage of the memories in flexible circuits. Considering the excellent performance of the device fabricated by low-temperature atomic layer deposition, the process may promote the potential applications of oxide-based resistive random access memory in flexible integrated circuits.
60 citations
Cites background or methods from "Resistive switching of HfO2 based f..."
...This is either incorporated by residue water precursors during the process because of the high desorption energy of water at low temperatures or exposing the film to the atmosphere (CO2 and moisture) before XPS measurement [23]....
[...]
...The deposition method of HfO2 was derived from our previous work [23]....
[...]
TL;DR: The Ru/Lu2O3/ITO flexible memory device shows promising RS behavior with low-voltage operation and small distribution of switching parameters, and the memory reliability characteristics of switching endurance, data retention, good flexibility, and mechanical endurance show promising applications in future advanced memory.
Abstract: In this article, the resistive switching (RS) behaviors in Lu2O3 thin film for advanced flexible nonvolatile memory applications are investigated. Amorphous Lu2O3 thin films with a thickness of 20 nm were deposited at room temperature by radio-frequency magnetron sputtering on flexible polyethylene terephthalate substrate. The structural and morphological changes of the Lu2O3 thin film were characterized by x-ray diffraction, atomic force microscopy, and x-ray photoelectron spectroscopy analyses. The Ru/Lu2O3/ITO flexible memory device shows promising RS behavior with low-voltage operation and small distribution of switching parameters. The dominant switching current conduction mechanism in the Lu2O3 thin film was determined as bulk-controlled space-charge-limited-current with activation energy of traps of 0.33 eV. The oxygen vacancies assisted filament conduction model was described for RS behavior in Lu2O3 thin film. The memory reliability characteristics of switching endurance, data retention, good flexibility, and mechanical endurance show promising applications in future advanced memory.
24 citations
Cites background from "Resistive switching of HfO2 based f..."
...Walczyk C, Walczyk D, Schroeder T, Bertaud T, Sowinska M, Lukosius M, Fraschke M, Wolansky D, Tillack B, Miranda E, Wenger C: Impact of temperature on the resistive switching behavior of embedded HfO2based RRAM devices....
[...]
...Fang RC, Wang LH, Yang W, Sun QQ, Zhou P, Wang PF, Ding SJ, Zhang DW: Resistive switching of HfO2 based flexible memories fabricated by low temperature atomic layer deposition....
[...]
...Recently, flexible resistive memories have been reported in various oxides including graphene oxide (GO) [13], HfO2 [14], NiO [15], and single-component polymer [16] thin films....
[...]
TL;DR: In this article, the implementation of inkjet-printed high-performance ReRAM devices based on the high-k HfO2 dielectric was demonstrated for the first time.
Abstract: In this letter we demonstrate for the first time, the implementation of inkjet-printed high-performance ReRAM devices based on the high-k HfO2 dielectric. Features such as high on/off current ratio and low switching voltages pave the way for low power applications. These characteristics, along with the known flexible properties of the inkjet-printed dielectric layer, make this kind of ReRAMs suitable for portable devices that do not require large integration density i.e. low density nonvolatile memories or reconfigurable analog circuits.
24 citations
Cites background from "Resistive switching of HfO2 based f..."
...Among the metal oxides, HfO2 has been deeply studied and proved as good material for memory devices [10], [19]....
[...]
TL;DR: In this article, an Al-doped HfO x-based resistive memory device has been fabricated on indium tin oxide (ITO)-coated polyethylene terephthalate (PET) flexible substrate at room temperature.
Abstract: The Al-doped HfO x -based resistive memory devices have been fabricated on indium tin oxide (ITO)-coated polyethylene terephthalate (PET) flexible substrate at room temperature. X-ray photoelectron spectroscopy is used to extract the different doping percentage of Al which allows optimizing the switching performance. It improves the cycle-to-cycle and cell-to-cell uniformity of switching parameters by tuning the oxygen vacancies in HfO x layers. The 7.5% Al-doped HfO x -based flexible resistive memory device shows excellent switching characteristics such as resistance ratio ( $> 10^{3}$ ) and retention ( $\sim 10^{4}$ s). There is no degradation of memory window under the mechanical strain with bending radius ranging from 25 to 5 mm. The temperature-dependent resistive switching characteristics have also been studied. There is sufficient memory window ( $> 10^{2}$ ) till $\sim 10^{4}$ s at elevated temperature. The ${I}$ – ${V}$ curve fitting shows the ohmic (hopping) conduction in low resistance state (LRS) and the trap-controlled space charge limited conduction (SCLC) in high resistance state (HRS), supported by Arrhenius plot.
12 citations
01 Oct 2012
TL;DR: This paper demonstrated an Al-2-sub-O-3-based FRRAM fabricated under low temperature, and improved its performance by utilizing Al2O3
Abstract: Resistive random access memory (RRAM) has been widely investigated. However, for the applications in flexible electronics, this type of memory is not so widely investigated for its requirement of the low processing temperature. In this paper, we demonstrated an Al 2 O 3 -based FRRAM fabricated under low temperature, and improved its performance by utilizing Al 2 O 3 /HfO 2 functional stack.
1 citations
References
More filters
TL;DR: A coarse-grained classification into primarily thermal, electrical or ion-migration-induced switching mechanisms into metal-insulator-metal systems, and a brief look into molecular switching systems is taken.
Abstract: Many metal–insulator–metal systems show electrically induced resistive switching effects and have therefore been proposed as the basis for future non-volatile memories. They combine the advantages of Flash and DRAM (dynamic random access memories) while avoiding their drawbacks, and they might be highly scalable. Here we propose a coarse-grained classification into primarily thermal, electrical or ion-migration-induced switching mechanisms. The ion-migration effects are coupled to redox processes which cause the change in resistance. They are subdivided into cation-migration cells, based on the electrochemical growth and dissolution of metallic filaments, and anion-migration cells, typically realized with transition metal oxides as the insulator, in which electronically conducting paths of sub-oxides are formed and removed by local redox processes. From this insight, we take a brief look into molecular switching systems. Finally, we discuss chip architecture and scaling issues.
4,547 citations
4,540 citations
TL;DR: In this paper, the authors review the current status of one of the alternatives, resistance random access memory (ReRAM), which uses a resistive switching phenomenon found in transition metal oxides.
2,641 citations
TL;DR: In this article, the conduction mechanism of metal oxide resistive switching memory is investigated and an alternative viewpoint based on a trap-assisted-tunneling model is provided. But the model is not suitable for tunneling due to the fitted dielectric constant and trap energy.
Abstract: The conduction mechanism of metal oxide resistive switching memory is debated in the literature. We measured the I-V characteristics below the switching voltages through TiN/HfOx/Pt memory stack and found the conduction cannot be described by the commonly used Poole-Frenkel model, because the fitted dielectric constant and the trap energy are unreasonable as compared to their known values. Therefore, we provide an alternate viewpoint based on a trap-assisted-tunneling model. Agreement of the bias polarity/temperature/resistance state-dependent conduction behavior was achieved between this model and experimental data. And insights for the multilevel capability due to the control of tunneling distance were obtained.
335 citations
TL;DR: In this paper, a rewriteable low-power operation nonvolatile physically flexible memristor device is demonstrated, which is inexpensively fabricated at room temperature by spinning a TiO2 sol gel on a commercially available polymer sheet.
Abstract: A rewriteable low-power operation nonvolatile physically flexible memristor device is demonstrated. The active component of the device is inexpensively fabricated at room temperature by spinning a TiO2 sol gel on a commercially available polymer sheet. The device exhibits memory behavior consistent with a memristor, demonstrates an on/off ratio greater than 10 000 : 1, is nonvolatile for over 1.2 times 106 s, requires less than 10 V, and is still operational after being physically flexed more than 4000 times.
251 citations