scholarly journals Resistive Switching Characteristics of Li-Doped ZnO Thin Films Based on Magnetron Sputtering

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1282 ◽  
Author(s):  
Zhao ◽  
Li ◽  
Ai ◽  
Wen
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Resistive Switching ◽  
Photoelectron Spectroscopy ◽  
Lattice Structure ◽  
Zno Thin Films ◽  
Bipolar Resistive Switching ◽  
X Ray ◽  
Doped Zno ◽  
Switching Characteristics

A kind of devices Pt/Ag/ZnO:Li/Pt/Ti with high resistive switching behaviors were prepared on a SiO2/Si substrate by using magnetron sputtering method and mask technology, composed of a bottom electrode (BE) of Pt/Ti, a resistive switching layer of ZnO:Li thin film and a top electrode (TE) of Pt/Ag. To determine the crystal lattice structure and the Li-doped concentration in the resulted ZnO thin films, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) tests were carried out. Resistive switching behaviors of the devices with different thicknesses of Li-doped ZnO thin films were studied at different set and reset voltages based on analog and digital resistive switching characteristics. At room temperature, the fabricated devices represent stable bipolar resistive switching behaviors with a low set voltage, a high switching current ratio and a long retention up to 104 s. In addition, the device can sustain an excellent endurance more than 103 cycles at an applied pulse voltage. The mechanism on how the thicknesses of the Li-doped ZnO thin films affect the resistive switching behaviors was investigated by installing conduction mechanism models. This study provides a new strategy for fabricating the resistive random access memory (ReRAM) device used in practice.

scholarly journals Comparative Study of ZnO Thin Films Grown on Quartz Glass and Sapphire (001) Substrates by Means of Magnetron Sputtering and High-Temperature Annealing

2019 ◽  
Vol 9 (21) ◽  
pp. 4509
Author(s):  
Weijia Yang ◽  
Fengming Wang ◽  
Zeyi Guan ◽  
Pengyu He ◽  
Zhihao Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Magnetron Sputtering ◽  
Comparative Study ◽  
Quartz Glass ◽  
Photoelectron Spectroscopy ◽  
Zno Thin Films ◽  
High Temperature Annealing ◽  
X Ray ◽  
Glass Substrates

In this work, we reported a comparative study of ZnO thin films grown on quartz glass and sapphire (001) substrates through magnetron sputtering and high-temperature annealing. Firstly, the ZnO thin films were deposited on the quartz glass and sapphire (001) substrates in the same conditions by magnetron sputtering. Afterwards, the sputtered ZnO thin films underwent an annealing process at 600 °C for 1 h in an air atmosphere to improve the quality of the films. X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectra, photoluminescence spectra, and Raman spectra were used to investigate the structural, morphological, electrical, and optical properties of the both as-received ZnO thin films. The ZnO thin films grown on the quartz glass substrates possess a full width of half maximum value of 0.271° for the (002) plane, a surface root mean square value of 0.50 nm and O vacancies/defects of 4.40% in the total XPS O 1s peak. The comparative investigation reveals that the whole properties of the ZnO thin films grown on the quartz glass substrates are comparable to those grown on the sapphire (001) substrates. Consequently, ZnO thin films with high quality grown on the quartz glass substrates can be achieved by means of magnetron sputtering and high-temperature annealing at 600 °C.

scholarly journals Coexistence of unipolar and bipolar resistive switching characteristics in ZnO thin films

2010 ◽  
Vol 108 (7) ◽  
pp. 076101 ◽  
Author(s):  
Seunghyup Lee ◽  
Heejin Kim ◽  
Jinjoo Park ◽  
Kijung Yong
Keyword(s):  
Thin Films ◽  
Resistive Switching ◽  
Zno Thin Films ◽  
Bipolar Resistive Switching ◽  
Switching Characteristics

scholarly journals X-RAY PHOTOELECTRON SPECTROSCOPIC STUDY ON HIGH-ELECTRON-MOBILITY GALLIUM AND HYDROGEN CO-DOPED ZINC OXIDE THIN FILMS

2018 ◽  
Vol 56 (1A) ◽  
pp. 93
Author(s):  
Anh Thanh Tuan Pham
Keyword(s):  
Thin Films ◽  
Electron Mobility ◽  
Photoelectron Spectroscopy ◽  
Lattice Structure ◽  
Hydrogen Plasma ◽  
Crystalline Lattice ◽  
High Electron ◽  
X Ray ◽  
Doped Zno ◽  
Co Doped

In this study, gallium and hydrogen co-doped ZnO (HGZO) thin films were investigated. The films were deposited by sputtering from Ga-doped ZnO (GZO) ceramic target in hydrogen and argon plasma. The as-deposited HGZO films possess enhanced electron mobility of 48.6 cm2/Vs as compared to that of 39.4 cm2/Vs of GZO films, sputtered from the same target. Because of insignificant variation in crystallinity, this improvement is attributed to roles of hydrogen in crystalline lattice structure of the films. X-ray photoelectron spectroscopy (XPS) is employed as an essential technique for quantitative analyses and chemical binding states of films constituent elements. The roles of hydrogen are clarified through the binding states of Zn 2p, O 1s and Ga 3d. Obtained results suggest that the films are deposited more effectively in hydrogen plasma. Some point defects such as oxygen vacancies (VO), dangling bonds can be passivated in form of H+VOHO and O–H bonds. As a result, the reduction of scattering centers is indicated as a reason for the mobility improvement of the HGZO films.

scholarly journals Switching Characteristics and Mechanism Using Al2O3 Interfacial Layer in Al/Cu/GdOx/Al2O3/TiN Memristor

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1466
Author(s):  
Chiao-Fan Chiu ◽  
Sreekanth Ginnaram ◽  
Asim Senapati ◽  
Yi-Pin Chen ◽  
Siddheswar Maikap
Keyword(s):  
Resistive Switching ◽  
Photoelectron Spectroscopy ◽  
Interfacial Layer ◽  
Stable State ◽  
Schematic Model ◽  
Bipolar Resistive Switching ◽  
Al2o3 Layer ◽  
X Ray ◽  
Resistance State ◽  
Switching Characteristics

Resistive switching characteristics by using the Al2O3 interfacial layer in an Al/Cu/GdOx/Al2O3/TiN memristor have been enhanced as compared to the Al/Cu/GdOx/TiN structure owing to the insertion of Al2O3 layer for the first time. Polycrystalline grain, chemical composition, and surface roughness of defective GdOx film have been investigated by transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and atomic force microscopy (AFM). For bipolar resistive switching (BRS) characteristics, the conduction mechanism of high resistance state (HRS) is a space-charge limited current for the Al/Cu/GdOx/TiN device while the Al/Cu/GdOx/Al2O3/TiN device shows Schottky emission. However, both devices show Ohmic at a low resistance state (LRS). After the device has been SET, the Cu filament evidences by both TEM and elemental mapping. Oxygen-rich at the Cu/GdOx interface and Al2O3 layer are confirmed by energy dispersive X-ray spectroscopy (EDS) line profile. The Al/Cu/GdOx/Al2O3/TiN memristor has lower RESET current, higher speed operation of 100 ns, long read pulse endurance of >109 cycles, good data retention, and the memristor with a large resistance ratio of >105 is operated at a low current of 1.5 µA. The complementary resistive switching (CRS) characteristics of the Al/Cu/GdOx/Al2O3/TiN memristor show also a low current operation as compared to the Al/Cu/GdOx/TiN device (300 µA vs. 3.1 mA). The transport mechanism is the Cu ion migration and it shows Ohmic at low field and hopping at high field regions. A larger hopping distance of 1.82 nm at the Cu/GdOx interface is obtained as compared to a hopping distance of 1.14 nm in the Al2O3 layer owing to a larger Cu filament length at the Cu/GdOx interface than the Al2O3 layer. Similarly, the CRS mechanism is explained by using the schematic model. The CRS characteristics show a stable state with long endurance of >1000 cycles at a pulse width of 1 µs owing to the insertion of Al2O3 interfacial layer in the Al/Cu/GdOx/Al2O3/TiN structure.

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