Papers by Keyword: Magnetron Sputtering

Abstract: In this work, carbon films were deposited by magnetron sputtering on silicon substrate. The effect of sputtering time on the surface wettability and mechanical properties of carbon films was investigated. Contact angle measurement was used to analyse surface wettability, and the nanomechanical properties were characterized by nanoindentation. In experiments, the sputtering time was 45 min, 60 min, 75 min and 90 min. The measurement results show that the maximum film hardness was achieved for sputtering time 90 min, with a value of 2.34 GPa. Longer sputtering time resulted in preferable mechanical properties. It was analyzed that the size of the crystal grains on the substrate surface and thickness of the films were increased with the increment of sputtering time. The surface roughness decreased with the increase of sputtering time. Moreover, Youngs modulus increased with sputtering time and the maximum value was 16.94 GPa. The contact angle measurement results show that the prepared films take on the hydrophilicity. The minimum contact angle was achieved for sputtering time 45 min with a value of 54o.

Abstract: In this paper, ZnO thin films were prepared on ITO conductive glass by direct current magnetron sputtering and the Cu electrodes were evaporated on ZnO/ITO by electric beam evaporation to get transparent Cu/ZnO/ITO resistive random access memory. The crystal structure and surface morphology were investigated by X-ray diffraction and atomic force microscopy, respectively. The transmittance spectra of ZnO/ITO in the visible region were measured by UV-VIS spectroscopy. The resistive switching characteristics of the fabricated devices were investigated by the voltage sweeping method, which showed that the transparent Cu/ZnO/ITO device had good resistive switching characteristics.

Abstract: Direct current (DC) magnetron sputtering method was used to deposit vanadium oxide thin films on ordinary glass substrates from a vanadium metal target and a five factors four levels orthogonal experimental method was used to find the best combination of sputtering pressure, sputtering power, oxygen/argon flow ratio, substrate temperature and deposition time for fabricating high temperature coefficient of resistance (TCR) vanadium oxide film. The results indicate that a good combination of these parameters should be 1Pa, 160W, 1.5/25, 280°C and 60 minutes. And the film fabricated using this parameters combination is mainly composed of V₂O₅ and has a resistance range of 80.3kΩ to 40kΩ while its temperature changed from 20°C to 80°C.

Abstract: Zinc Oxide (ZnO) is a wide bandgap semiconductor material which can be successfully used for wide variety of potential applications such as biosensors or acoustic resonator devices. ZnO normally crystallizes in the wurtzite structure with c-axis (001) preferred orientation. However, for bio-sensing in liquids, it is necessary to generate a shear horizontal mode wave, where the wave displacement is within the plane of the crystal surface. For generation of such a shear horizontal wave, a-axis film textures such as the (110) or (100) is necessary. This work is focused on the preferred orientation control of ZnO film prepared by RF magnetron sputtering. It is found that preferred orientation can be controlled by substrate bias and substrate temperature during deposition without the use of expensive crystalline substrates. There are three areas of operating parameters when the structure of the ZnO films is dominated by different preferred orientation. Moreover, the film annealing was performed to enhance the film structure.

Abstract: Titanium dioxide gas sensors are typically employing metastable anatase nanocrystalline phase. Operation at high temperature can thus negatively affect their long term stability. Employment of rutile phase with strong texture and larger grain size may ensure better reliability and longer lifetime. Therefore in this work we study the possibility to utilize stable rutile phase thin films prepared at relatively low temperature on c-cut sapphire substrates. Technological conditions have been chosen in order to obtain highly oriented titanium dioxide rutile thin films using reactive DC magnetron sputtering on unheated substrates. Subsequent ex-situ annealing in temperature range from 500°C to 800°C leads to increase of crystallite size and improvement of in-plane preferential orientation. Surface topography has been characterized by atomic force microscopy. Structure, texture and the strain evolution has been investigated using x-ray diffraction measurements. All investigated thin films showed epitaxial relationship with respect to the substrate: rutile-TiO₂(100)[00 || Al₂O₃(0001)[10. Sensitivity of such rutile films to hydrogen has been measured and compared with our previous results on anatase thin films.

Abstract: Transparent conducting gallium doped zinc oxide (GaZnO) films were prepared by magnetron sputtering technique. The influence of growth temperature on the microstructural and optical properties of the films were investigated by means of X-ray diffraction (XRD), spectrophotometer and optical characterization method, respectively. The results show that all the samples are polycrystalline in nature having a hexagonal wurtzite type crystal structure with a preferred grain orientation in the (002) direction. The growth temperature significantly affects the crystal structure and optical properties of the samples. The film deposited at the growth temperature of 670 K possesses the largest grain grain, the minimum dislocation density and the lowest microstrain. The average visible transmittance and optical energy gap of the samples increase gradually with the increment of growth temperature.

Abstract: Normal 0 7.8 磅 0 2 false false false MicrosoftInternetExplorer4 It is necessary to prepare compressive films on sapphire window for preventing its high-temperature failure. In this study, the yttrium oxide (Y₂O₃) thin films were deposited on the sapphire substrates by RF reactive magnetron sputtering with varying sputtering pressure. The as-deposited Y₂O₃ films were also annealed. The composition, structure, refractive index and mechanical properties of the films were systematically analyzed by XPS, XRD, ellipsometry and nanoindention method, respectively. The influences of sputtering pressure on the deposition velocity and the refractive index were investigated. It can obtain desirable Y₂O₃ thin films for the preparation conditions (sputtering pressure: 10Pa, substrate temperature: 500°C, RF power: 200W) after annealing in O₂ at 500°C for 1h. The refractive index and hardness both have the maximum value (1.8337 and 3.98 GPa), respectively. The elastic module has the minimum value (109.24 GPa). It is promising for the Y₂O₃ film as the underlayer of protective coating of sapphire windows.