共查询到20条相似文献,搜索用时 390 毫秒
1.
Dielectric-breakdown-like forming process in the unipolar resistance switching of Ta2O5−x thin films
Moon Jee YoonShin Buhm Lee Hyang Keun YooSoobin Sinn Bo Soo Kang 《Current Applied Physics》2012,12(3):846-848
We report unipolar resistance switching (URS) in Ta2O5−x thin films. The current increased suddenly when we applied voltages up to 5-7 V to the pristine state of Pt/Ta2O5−x/Pt, Ni/Ta2O5−x/Pt, and Ti/Ta2O5−x/Pt cells. Just after this forming process, we observed a repetitive URS occurring independently of the electrodes. We found that the required voltages for the forming process did not depend on the top electrode type, but on the film thickness. These results suggest that the forming process is driven by a dielectric-breakdown-like phenomenon, and that URS occurs due to the formation and rupture of conducting channels inside the Ta2O5−x thin film. 相似文献
2.
Thickness‐dependent electroforming behavior of ultra‐thin Ta2O5 resistance switching layer
下载免费PDF全文
![点击此处可从《固体物理学:研究快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tae Hyung Park Seul Ji Song Hae Jin Kim Soo Gil Kim Suock Chung Beom Yong Kim Kee Jeung Lee Kyung Min Kim Byung Joon Choi Cheol Seong Hwang 《固体物理学:研究快报》2015,9(6):362-365
Electroforming behaviours of Ta2O5 resistance switching memory cell with a diameter of 28 nm and different thickness (0.5–2.0 nm) of Ta2O5 layer have been examined. The devices showed a constant forming electric field of 0.54 V/nm regardless of Ta2O5 thickness. The electroforming with negative bias to top TiN electrode was ascribed to electric field‐ driven migration of oxygen vacancies, originally residing near the bottom interface, toward the top electrode interface and formation of conducting filaments. The estimated electroforming energy (0.094–0.14 eV) was favourably compared with the hopping energy of electrons from the VO site to a nearby Ta site. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
3.
《Current Applied Physics》2020,20(3):431-437
Based on the bipolar resistive switching (RS) characteristics of SnO2 films, we have fabricated a new prototypical device with sandwiched structure of Metal/SnO2/fluorine-doped tin oxide (FTO). The SnO2 microspheres film was grown on FTO glass by template-free hydrothermal synthesis, which was evaporated with various commonly used electrodes such as aluminium (Al), silver (Ag), and gold (Au), respectively. Typical self-rectifying resistance switching behaviors were observed for the RS devices with Al and Au electrodes. However, no obvious rectifying resistance switching behavior was observed for the RS device with Ag electrode. Above results were interpreted by considering the different interface barriers between SnO2 and top metal electrodes. Our current studies pave the ways for modulating the self-rectifying resistance switching properties of resistive memory devices by choosing suitable metal electrodes. 相似文献
4.
Xiliang He Xiaomin Li Xiangdong Gao Weidong Yu Rui Yang Xinjun Liu Xun Cao 《Applied Physics A: Materials Science & Processing》2012,108(1):177-183
Unipolar reversible resistance switching effects were found in 5 at% Ti-doped polycrystalline Ta2O5 films with the device structure of Pt/Ti–Ta2O5/Pt. Results suggest that the recovery/rupture of the conductive filaments which are involved in the participation of oxygen vacancies and electrons leads to the resistance switching process. Ti-doped Ta2O5 thin films possess higher resistance whether in low-resistance state or high-resistance state and higher resistance switching ratio than Ta2O5 thin films, where Ti addition plays an important role in the resistance switching process by suppressing the migration of oxygen vacancies via forming an electrically inactive Ti/O–vacancy complex. Excellent retention properties of the high and low resistances under constant stress of applied voltage were obtained. 相似文献
5.
D. Wu A.D. Li H.Q. Ling T. Yu Z.G. Liu N.B. Ming 《Applied Physics A: Materials Science & Processing》2000,71(5):597-600
Voltage shifts of hysteresis loops of metalorganic decomposition (MOD)-derived SrBi2Ta2O9 (SBT) thin films, known as imprint, have been observed after exposing the thin-film capacitors to unipolar pulses. The voltage
shift changes with cumulative total time at maximum voltage, following a relationship with no pulse-width dependence. The
origin of the voltage shift is briefly discussed in terms of an internal bias field induced by injected electrons trapped
at positive polarity. The pulse-measurement responses are greatly affected by the internal bias field, even though no imprint
failure was observed up to 1010 unipolar pulses. The voltage shift and asymmetric properties can be removed easily by applying bipolar pulses of saturation
amplitude.
Received: 27 June 2000 / Accepted: 16 August 2000 / Published online: 5 October 2000 相似文献
6.
The resistive switching effect in metal–oxide–metal (MOM) structures has been investigated, where the 10% Li-doped ZnO layer was used as an oxide layer, as well as Pt and 20% fluorine doped SnO2 (SnO2:F) were used as a bottom electrodes. The current–voltage (I–V) and switching (I–t) characteristics of Ag/ZnO:Li/Pt and Ag/ZnO:Li/SnO2:F structures were investigated. The unipolar resistive switching is detected in the structures with the Pt, while the use of transparent conductive SnO2:F electrode instead of Pt, results to the bipolar memory effect. 相似文献
7.
Shin Buhm Lee Seo Hyoung Chang Hyang Keun Yoo Moon Jee Yoon Sang Mo Yang Bo Soo Kang 《Current Applied Physics》2012,12(6):1515-1517
We find that resistance switching (RS) phenomena change reversibly between bipolar RS (BRS) and unipolar RS (URS) in a Pt/SrTiOx/Pt cell. For an asymmetric electrode configuration of Ti/SrTiOx/Pt cells whose top and bottom interfaces are Ohmic and Schottky-like rectifying, we determine that BRS only occurs when a positive voltage is applied to the bottom Pt electrode at the forming process. During the set process of BRS in a Pt/SrTiOx/Pt cell, O2 bubbles develop on the top Pt electrode. From the experimental results for a single sample in which both BRS and URS occur, O2? ion movement and consequent interfacial resistance modification might play an important role in BRS but not URS. 相似文献
8.
We investigated the film-thickness and ambient oxygen-pressure dependence of the electric field, EF, required to initiate unipolar resistance switching (URS) in Ta2O5?x thin films. We measured the dependence of EF by applying a triangular-waveform voltage signal to the film over a wide sweep-rate range (v = 20 mV s?1 to 5 MV s?1). Our results showed that the URS-EF was not influenced by the Ta2O5?x film thickness nor ambient oxygen-pressure. This suggested that the URS-forming process in Ta2O5?x thin films should be governed by thermally assisted dielectric breakdown in our measurement range. 相似文献
9.
Amorphous TaOx thin films were deposited at different temperatures, and the resistance switching properties of the Pt/TaOx/Pt structure were investigated. X‐ray photoelectron spectroscopy showed that the amount of Ta2O5 in the film decreased and the content of Ta suboxides increased substantially when the growth temperature was increased. Unipolar resistance switching near the anode was stable only for TaOx film grown at room temperature. The experimental results revealed the critical effect of the film composition on the resistance switching behavior of TaOx films. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
10.
《Current Applied Physics》2019,19(12):1421-1426
The resistive random access memory (RRAM) based on resistive switching effect has considered to be the most advanced next generation memory, in which the switching direction determines the order of reading-writing. In this work, the rare-earth metal Er2O3 was used as functional layer, and Ag and indium-tin-oxide (ITO) are selected as top and bottom electrode to fabricate resistive switching device. Further, it is observed that the switching direction and memory window of resistive switching device can be regulated by exchanging top and bottom electrode. Moreover, the complementary switching memory behavior in Ag/Er2O3/ITO/Er2O3/Ag structure was also observed. Through mechanism analysis, it is expected that the barrier changes and metal-ions oxidation-reduction should be responsible for the conversion of switching direction and regulation of memory window. This work opens up a way to the development of next generation new concept memory. 相似文献
11.
The Ti-doped Ta2O5 thin films (<10 nm) obtained by rf sputtering are studied with respect to their composition, dielectric and electrical properties. The incorporation of Ti is performed by two methods - a surface doping, where a thin Ti layer is deposited on the top of Ta2O5 and a bulk doping where the Ti layer is sandwiched between two layers of Ta2O5. The effect of the process parameters (the method and level of doping) on the elemental distribution in-depth of the films is investigated by the time of flight secondary ion mass spectroscopy (ToF-SIMS). The Ti and Ta2O5 are intermixed throughout the whole thickness but the layers are very inhomogeneous. Two sub-layers exist in all the samples — a near interfacial region which is a mixture of Ta-, Ti-, Si-oxides as well as TaSiO, and an upper Ti-doped Ta2O5 sub-layer. For both methods of doping, Ti tends to pile-up at the Si interface. The electrical characterisation is performed on capacitors with Al- and Ru-gate electrodes. The two types of MIS structures exhibit distinctly different electrical behavior: the Ru gate provides higher dielectric permittivity while the stacks with Al electrode are better in terms of leakage currents. The specific metal-dielectric reactions and metal-induced electrically active defects for each metal electrode/high-k dielectric stack define its particular electrical behavior. It is demonstrated that the Ti doping of Ta2O5 is a way of remarkable improvement of leakage characteristics (the current reduction with more than four orders of magnitude as compared with undoped Ta2O5) of Ru-gated capacitors which originates from Ti induced suppression of the oxygen vacancy related defects. 相似文献
12.
《Current Applied Physics》2007,7(2):124-134
Thermal stabilities of various metal bottom electrodes were examined by using a Ta2O5 metal-oxide-metal (MOM) capacitor structure. After depositing 10-nm thick Ta2O5 on metal-electrode/poly-Si, we performed rapid thermal oxidation (RTO) at 850 °C for 60 s in an O2 ambient. A chemical-vapor-deposition (CVD) WSi2 electrode showed satisfactory thermal stability after the RTO, while other examined electrode materials exhibited thermal degradation caused by oxidation failure or interfacial reaction between the substrate poly-Si and the Ta2O5. After post-annealing at 650 °C for 30 min (in N2 condition) with CVD TiN top electrode, an effective oxide thickness (Tox) of ∼32 Å and a leakage current density of ∼107 A/cm2 at 1.25 V were obtained from the MOM capacitor with the WSi2 bottom electrode. Other electrode materials, such as TiN, TiSix, WNx, W, and Ta, were severely oxidized during the RTO in the MOM structures, and very poor capacitor properties were obtained in terms of Tox and leakage current. 相似文献
13.
The evolution of the gate voltage during the constant current stress of Ta2O5 films grown on silicon exhibits an additional decreasing region, compared to the case of SiO2 films. That phenomenon has been previously attributed to the thickness lowering of the ultrathin SiO2 interfacial layer naturally grown during the Ta2O5 deposition. Based on the previously proposed method of the evolution of the capacity in accumulation with the stress time, a simplified phenomenological model of capacitors in series was developed and employed as a tool for monitoring the degradation of the insulating film. In some cases breakdown events manifested by abrupt changes of the capacity in accumulation were observed, e.g., the case with the voltage on the silicon dioxide films. In other cases, saturation of the capacity in accumulation was detected, indicating continuous degradation of the SiO2 layer till its final destruction. The above effect was not observed in SiO2 films and can be peculiar for Ta2O5/SiO2 or similar stacked layers. PACS 73.61.-r; 77.22.Jp; 77.55.+f 相似文献
14.
在室温条件下利用溅射Ta2O5靶材的方法制备了Ta2O5薄膜,并采用将薄膜两侧的反射率光谱进行比较的简便方法分析评估薄膜的光吸收,发现溅射制备薄膜的额外光吸收源是溅射引起的缺氧形成的,选择适当的溅射功率和含氧比例的工作气体能有效地消除这些缺陷、不用任何加温处理就可制备得到表面平坦和高致密度的高品质Ta2O5薄膜.
关键词:
2O5薄膜')" href="#">Ta2O5薄膜
光吸收
表面形貌
磁控溅射 相似文献
15.
A. Paskaleva M. ?apajna E. Dobro?kaK. Hušeková E. AtanassovaK. Fröhlich 《Applied Surface Science》2011,257(17):7876-7880
Hf-doped Ta2O5 thin films are studied with respect to their composition, dielectric and electrical properties. The incorporation of Hf is performed by sputtering of a 0.7 nm thick Hf layer on top of Ta2O5 and subsequent annealing to stimulate diffusion of Hf into Ta2O5 and their intermixing. The elemental in-depth distribution of the films is investigated by the time of flight secondary ion mass spectroscopy (ToF-SIMS), which has revealed that Hf and Ta2O5 are intermixed throughout the whole thickness. Two sub-layers exist in all the samples - an upper homogeneous Hf-doped Ta2O5 sub-layer and a near interfacial region which is a mixture of Ta- and Si-oxides. The X-ray reflectivity (XRR) analysis shows existence of interfacial layer with a thickness of about 1.9-2 nm, irrespectively of the total thickness of the stacks. Metal-oxide-Si structures with Ru and RuO2 metal electrodes have been prepared and investigated in terms of dielectric constant, effective work function (EWF) and interfacial layer parameters. The influence of post-metallization annealing steps on these parameters was also studied. 相似文献
16.
N. Ghenzi P. Stoliar M.C. Fuertes F.G. Marlasca P. Levy 《Physica B: Condensed Matter》2012,407(16):3096-3098
We study the electric pulse induced resistance switching of TiO2–Ag contacts at room temperature, exploring both unipolar and bipolar switching modes. Initially we observed unipolar response. After hundred pulsing cycles the unipolar switching response vanishes but the device can still be operated in bipolar switching regime. The underlying mechanism for resistance switching is modeled in terms of formation and rupture of filament, and movement of oxygen vacancies. 相似文献
17.
Dong-Xu Zhang Yu-Xiang Zheng Qing-Yuan Cai Wei Lin Kang-Ning Wu Peng-Hui Mao Rong-Jun Zhang Hai-bin Zhao Liang-Yao Chen 《Applied Physics A: Materials Science & Processing》2012,108(4):975-979
An effective method for determining the optical constants of Ta2O5 thin films deposited on crystal silicon (c-Si) using spectroscopic ellipsometry (SE) measurement with a two-film model (ambient–oxide–interlayer–substrate) was presented. Ta2O5 thin films with thickness range of 1–400 nm have been prepared by the electron beam evaporation (EBE) method. We find that the refractive indices of Ta2O5 ultrathin films less than 40 nm drop with the decreasing thickness, while the other ones are close to those of bulk Ta2O5. This phenomenon was due to the existence of an interfacial oxide region and the surface roughness of the film, which was confirmed by the measurement of atomic force microscopy (AFM). Optical properties of ultrathin film varying with the thickness are useful for the design and manufacture of nano-scaled thin-film devices. 相似文献
18.
H. Bispinck O. Ganschow L. Wiedmann A. Benninghoven 《Applied Physics A: Materials Science & Processing》1979,18(2):113-117
Thick layers of tantalum oxide prepared by thermal and anodic oxidation have been studied by combined SIMS, AES, and XPS during
depth profiling by 3keV Ar+ ion sputtering. The chemical composition of these films is revealed by the OKLL and O 1s signals and by the “lattice valence” parameter determined from the TaO
n
±
intensities. Thus the anodic film consists of a contamination layer, an oxygen-rich reactive interface and a thick homogeneous
oxide layer followed by an interface to the Ta metal. The thermal oxide shows an oxygen concentration decreasing with depth
and a broad oxide-metal interface. In both cases, carbon contamination (carbide) prevents the application of the valence model
to the clean Ta substrate. The sputtering yield of the oxides was found to be 0.6 Ta2O5/ion. 相似文献
19.
20.
R. Yang X. M. Li W. D. Yu X. J. Liu X. D. Gao Q. Wang L. D. Chen 《Applied Physics A: Materials Science & Processing》2009,97(1):85-90
A novel Ag–Al alloy electrode has been prepared on the La0.67Ca0.33MnO3 (LCMO) film grown by pulsed laser deposition, with the aim to improve its resistance-switching properties. Nonlinear, asymmetric,
and hysteretic current–voltage characteristics and reversible polarity-dependent switching properties are achieved in the
Ag–Al alloy/LCMO/Pt structure. Detailed current–voltage characteristics analysis indicates that the resistance-switching behavior
can be well explained by the mechanism of trap-controlled space charge limited conduction at the Ag–Al alloy/LCMO interface.
The LCMO film with an Ag–Al alloy top electrode exhibits much better resistance-switching properties than that with an Al
top electrode, including the shorter switching time and more stable switching process, demonstrating that the Ag–Al alloy
electrode is a promising electrode materials of manganite films for resistance random access memory applications. 相似文献