Papers by Keyword: Magnetron Sputtering

Abstract: The purpose of this work is to establish a deposition process of Ti-Ni-Cu films showing shape memory effect in the as-deposited state. 5-µm-thick Ti₅₀Ni₃₅Cu₁₅ films have been deposited onto thermally oxidized (001) Si wafer by triple-source dc magnetron sputtering at various substrate temperatures. Their shape memory behavior were characterized by XRD, DSC measurements and thermal cycling tests under various constant tensile stresses. We have confirmed that crystalline films can be grown directly when the substrate temperature exceeds 400°C. The films deposited at higher than 450°C showed thermoelastic martensitic transformation and their M_s temperature slightly increased with increasing substrate temperature. Since their M_s temperature were found to be higher than 30°C, they can be used as an actuator at RT. These films were also found to have higher critical stress against plastic deformation than the post-deposition crystallized films. We have also tried to fabricate a prototype of micro-actuator and to characterize their actuation behavior and have confirmed that TiNiCu/SiO₂ double layered diaphragm showed an actuation response to a pulsed current of more than 100Hz.

Abstract: A new type of multi-site magnetron sputtering system has been researched, which has more than one workbench. Based on the operating principle of the magnetron sputtering system which with a circular plane target, a mathematical model has been developed to simulate and discuss the influencing factors on the film thickness uniformity. The results showed that when the substrates were rotating axially and eccentrically, the film thickness distribution were affected by both the target-substrate distance and the eccentricity. If the eccentricity was constant, the film thickness would become thinner when the target-substrate distance increased, and the thickness uniformity tended to be improved. If the target-substrate distance was constant, the thickness uniformity would become better when the eccentricity increased. Moreover, if the substrate rotated axially and revolved around the target simultaneously, the thickness uniformity would become better when velocity ratio of axial rotation to revolution increased. And the effect of the thickness uniformity became small gradually if the ratio increases to a certain degree. In addition, increasing the etching area properly not only could conduct the film distribution to better, and improve the substrate film thickness uniformity also. Finally, taking a series of experiments, and analyzing the experimental data, the conclusion of the study results in the paper had been verified.

Abstract: Polycrystalline TiO₂ nano-films were prepared by DC magnetron sputtering at different Ar/O₂ flow ratios. The thicknesses of all the prepared films were about 200 nm. The prepared films consist of a mixture of anatase and rutile phase. The TiO₂ nano-films deposited at Ar/O₂ flow ratio (1:1) have the best crystallinity and the mixture phase of anatase and rutile. SEM images show that the film surface composed of polygonal particles about 100 nm in diameter. UV–Vis transmission measurements reveal that the band gap of the deposited TiO₂ nano-films changed from 3.01 to 3.12 eV. The photocatalytic activities of the TiO₂ films were investigated by the decomposition of IPA under UV irradiation. The IPA can be oxidized to acetone and further to CO₂. The maximal acetone concentration and CO₂ concentration can reach to 29.2 ppm and 4 ppm after 120 min.

Abstract: Aluminium doped ZnO (ZnO:Al) films were deposited on polymer substrates by RF magnetron sputtering. The effects of deposition temperatures on structure and properties of films were investigated by X-ray diffractometery, Scanning electronic microscopy, UV-visible spectrophotometer, as well as Four-point Probes System. The results revealed that moderate deposition temperature was helpful to improve the crystal quality and optoelectronic properties of ZnO:Al films. The lowest resistivity of 9.5×10^-3Ω•cm and the average transmittance of 76% in the visible region was obtained for the film deposited from ZnO:2wt% Al₂O₃ target at 75°C.

Abstract: Abstract. Using the radio frequency reactive magnetron sputtering technique, ZnO and Al-dopped ZnO thin films were fabricated on glass substrate by changing the Ar/O₂ ratio and substrate temperature. The film crystallinity、optical properties and surface morphology were investigated by X-ray diffraction、 UV - visible spectrophotometer and scanning electron microscopy (SEM). The XRD results showed that by changing the argon oxygen ratio, Al-dopped ZnO films deposited at sputtering power of 40W and room temperature for 1 hour sputtering time showed no significant peaks, suggesting that the film growth was amorphous. UV-Vis spectrophotometer at 400nm wavelength test showed less than 90% light transmission rate. When substrate temperature was increased to 200 ° C, significant (002) diffraction peak and transmittance of 88% or more in the 400 ~ 800nm wavelength range appeared. A minimum XRD diffraction peak FWHM was found at substrate temperature of 300 ° C. TEM showed well crystal growth with maximum grain size at 300 ° C, XRD showed that there are only (101) peaks ,no (002) peaks in Al- doped ZnO.

Abstract: Magnetic materials have long been used for signal processing structures in the microwave range. High-frequency signal processing as for band-stop or notch filters, ferromagnetic resonance frequency can be adjusted or set by magnetic properties, such as saturation magnetization M_s. In this work, Fe-Co-N thin films have been synthesized using an improved facing-target magnetron sputtering system, where the sputtering current on Co and Fe targets can be regulated independently. During deposition of Fe-Co-N thin film, parameters on Fe target followed the one for synthesis of ε-Fe₃N, while changing the input current on Co target. It was found that on an unheated substrate, with the Co content of about 7 at.%, high value of M_s (265.08Am²kg^-1) could be obtained in the Fe-Co-N film, which contained α"-(Fe,Co)₁₆N₂ nanoparticles with the average size of 7 nm.

Abstract: The present research aims to synthesize a nanoscale multilayer CrTiAlMoN hard coating for the modification of wear and friction performance, as compare to CrTiAlN coatings. CrTiAlMoN coatings were deposited on 1045 carbon steel substrates by magnetron sputtering at different Mo target current. The wear and friction resistance were characterized by pin-on-disc test. When a WC-Co ball was used as the counterpart, the coefficients of friction of CrTiAlMoN coatings were found to decrease with the increase of Mo target current, with the lowest value (0.34) being only one half that of CrTiAlN coating (0.76). The combination of high hardness above 36GPa and low coefficients of friction reduces the specific wear rate of the CrTiAlMoN coatings to only 10% of CrTiAlN coatings. When tested against a bearing steel ball, results demonstrate that the effect of Mo on reducing friction of the CrTiAlMoN coatings is not significant and even negative due to adhesive wear.

Abstract: Thin Nano-CuInSi films have been prepared by multilayer synthesized method using magnetron sputtering technology, and followed by annealing in N2 atmosphere at different temperatures. The structures of CuInSi films were detected by X-ray diffraction(XRD); X-ray diffraction studies of the annealed films indicate the presence of CuInSi, the peak of main crystal phase is at 2θ=42.450°; the morphology of the film surface was studied by SEM. The SEM images show that the crystalline of the film prepared by multilayer synthesized method was granulated. The transmittance (T) spectra of the films were measured by Shimadzu UV-2450 double beam spectrophotometer. The calculated absorption coefficient is larger than 105 cm−1 when the wavelength is shorter than 750 nm. The band gap has been estimated from the optical absorption studies and found to be about 1.47 eV, but changes with purity of CuInSi. CuInSi thin film is a potential absorber layer material applied in solar cells and photoelectric automatic control.

Abstract: The SiO_x thin films for food packaging were deposited by RF magnetron sputtering physical vapor technology on the substrates of 20μm polyethylene terephthalate (PET) by using a pure SiO₂ target. The molecular structure of thin film surface composition were detected and analyzed by Fourier transform infrared spectroscopy (FTIR); and the barrier properties of the films were examined by MOCON water vapor permeability testing instrument, also，the relationship maps between permeability and process parameters were drew and the process parameters were optimized; The mechanical properties of thin films were tested by electronic tensile testing machine, and the curves of the relationship between the mechanical properties and process parameters depicted. The SiOx/PET thin films of the lowest water vapor permeability were prepared under the pressure of 7.5×10^-3 Pa, the sputtering pressure of 0.23 Pa, the deposition time of 30min and the sputtering power of 1500W. The yield strength increased 4 times and elastic modulus increased 3 times when the water vapor permeability of the SiO_x/PET thin films rose about 10 times of the blank.

Abstract: A physical model of magnetron sputtering process was built, the distribution of film thickness on the substrate was deduced, and the data were analysised by using the Mathematica and Matlab. The results show that the distribution of the film thickness on the substrate is uneven and it is also influenced by the radius as well as the distance between the target and substrate. The results of experiment correspond fairly well with the theory. The relational expression provides a theoretical basis for evaluation and estimation of the film thickness.