Papers by Keyword: DC Magnetron Sputtering

Abstract: This study investigated the correlation between the oxygen-argon ratio and crystal phase, the surface flatness and electrical properties of ZrO₂ thin films The films were deposited on transparent conductive indium tin oxide (ITO) substrates by DC magnetron sputtering. ZrO₂ films exhibit ZrO cubic and ZrO₂ monoclinic mixed phases when deposited with a low oxygen-argon ratio of 5:45. As the oxygen-argon ratio increases, a gradual phase transition ZrO to orthorhombic ZrO₂ occurs. Besides, the ZrO₂ film deposited with an oxygen-argon ratio of 10:40 exhibits highest resistance to electric field strength, and lowest leakage current.

Abstract: Shape memory alloy film-based micro-actuators have their behaviour controlled by a change in the thermomechanical stress that occurs in the bimorph - shape memory alloy film plus substrate assembly. The modification of the composition of the shape memory alloy leads to a change of the transformation temperature and implicitly of the temperature at which the stress change takes place in the bimorph. The design of micro-actuator blocks in which the composition and/or the temperature control mode of each micro-actuator in the block allows to obtain successive or sequential transformation sequences. The paper analyses the case of cantilever actuator modules with films of different compositions, deposited on the same substrate. It is highlighted how the composition of the alloy film with shape memory influences the modification of the curvature of bimorph cantilever type actuators in the studied block.

Abstract: Ti doped Cu₂O thin films were prepared at distinct Argon/Oxygen gas flow ratio of 34/1, 33/2,32/3 and 31/4 with net flow (Ar+O₂) of 35 sccm by using DC magnetron sputtering system on glass substrates at room temperature. The gas mixture influence on the film properties studied by using X-ray diffraction, Field emission scanning electron microscopy and UV-Visible spectroscopy. From XRD results, it is evident that, with a decrease in oxygen content, the amplitude of (111) peak increased, peak at a 35.67^o scattering angle and the films shows a simple cubic structure. The FESEM images indicated the granularity of thin films was distributed uniformly in a homogenous model and also includes especially pores and cracks. The film deposited at 31/4 showed a 98% higher transmittance in the visible region.

Abstract: The DC reactive magnetron sputtering method was employed to deposit Titanium Chromium Nitride (TiCrN) thin film on silicon (100) substrates. The coatings were annealed at different temperature from 700°C to 1000°C with increase step of 100 °C in air for 2 h. The crystal structure, surface morphologies, microstructure and chemical compositions were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). The x-ray patterns confirmed the TiO₂ rutile structure with strong preferred orientation of (101) plane was appeared from 700°C. The crystallinity of film increased with the annealing temperatures. The lattice constant (a and c) were in the range of 4.565 – 4.607 Å and 2.946 – 2.956 Å. The void between grain boundaries was confirmed by FE-SEM micrograph. The cross-sectional analysis revealed that the porous structure with enhancement of thickness from 1.64 - 1.95 μm were obtained as increase annealing temperatures. The EDX results indicated that the O content increase from 0 – 60.67 At% whereas the Ti, Cr, and N contents were decreased from 43.26 - 22.40 At%, 20.65 – 2.57 At% and 51.19 – 14.36 At% through the annealing temperatures.

Abstract: W-doped VO₂ films were prepared by DC reactive magnetron sputtering with various substrate bias. The microstructure, surface morphology, electrical and optical performances of the films were characterized by x-ray diffraction, scanning electron microscope, four-point probe method and spectrophotometer, respectively. The effect of substrate bias on microstructure, electrical and optical properties of sputtered W-doped VO₂ films was studied. The XRD results reveal that all samples exhibit preferential VO₂ (011) lattice orientation except the as-grown sample in our experiment. All the samples applied substrate bias show some degree optical switching performance in IR range, while the thermochromic phenomena was observed from resistance-temperature dependence plot only for the samples of substrate bias varied from-100V to-200V. This indicate that the optical and electrical properties of W-doped VO₂ films have different sensitivity to substrate bias. Optimal substrate bias of-200V sample shows fine semiconductor-metal-transition performance.

Abstract: We prepare Lead Telluride (PbTe) thin film by DC magnetron sputtering method. The powder precursors of Pb and Te purity 99.99 % ratio 1:1 were mixed. PbTe Powder was pressed using as sputtering target. DC magnetron sputtering condition, the base pressure is 3.2×10⁻³ Torr, applied the argon gas (purity 99.99%) in vacuum chamber to obtained working pressure at 50×10⁻³ Torr. The sputtering power is 25 W and sputtering time is 30 minutes. Phase identification, morphology and film thickness have been investigated by X−ray diffraction and scanning electron microscope. Electrical resistivity and Seebeck coefficient of the PbTe thin films have been investigated by four probe steady state method. The results demonstrated that the crystal phase of PbTe is face center cubic (FCC) structure. The average PbTe films yielded film thickness is around 460 nm, the average electrical resistivity is 17 Ω m and seebeck coefficient is 8.0×10⁻⁵ V K^─1.

Abstract: The effect of continuous and discontinuous deposition time on the properties of TiO₂ thin films deposited by reactive direct current magnetron sputtering (DCMS) on glass substrates was investigated. The deposition processes were designed for a condition of continuous deposition time D1 (60 min) and three conditions of discontinuous deposition time D2 (30 min × 2 times), D3 (15 min × 4 times), and D4 (1 min × 60 times). The crystal structure, surface morphology, and hydrophilicity of TiO₂ thin films were characterized by X-ray diffraction, atomic force microscope, and water contact angle method, respectively. It was found that the increasing of discontinuous deposition time (conditions from D1 to D4) shows the changing of grain size from big grain size with spherical shape to small grain size with oval shape. The crystallinity of TiO₂ films decrease with increasing the discontinuous deposition time. The water contact angles also decrease as a function of increasing discontinuous deposition time. These results may be explained from the accumulation of heat on the substrate which affected the phase composition and surface morphology of TiO₂ thin films.

Abstract: The effects of residual stresses in thin W-C based coatings were investigated with the aim to find their influence on nanohardness and indentation modulus. Ten samples of W-C based coatings were deposited on microslide glass substrates using DC magnetron sputtering at the identical deposition parameters. Their thickness was in the range from 500 to 600 nm. The residual stresses in the coatings varied from 1.5 GPa up to 4.4 GPa. Increase of residual stress caused linear increase of H_IT from 16 to 19.5 GPa. This increase was only the result of the compressive stresses. E_IT of the studied coatings was not sensitive to residual stresses and corresponded to 185 GPa ± 15 GPa.

Abstract: In this paper it has been deposited films of titanium oxide (TiO₂), on a support of glass, by a D.C. magnetron sputtering system, by varying the working pressure (p = 2∙10^-3 - 6.5∙10^-3mbar) of the substrate temperature on three levels. The obtained layers were investigated and characterized by optical microscopy, Scanning Electron Microscopy SEM, X-ray diffraction and Atomic Force Microscopy. It was observed that, by modifying technological parameters of the process (working pressure and substrate temperature) it is changing the initial orientation of the compounds ((100) turns into (101) or (002)). The AFM analysis has allowed the observation of the fact that the average roughness of deposited films, expressed as RMS, has increased over 98% at the increasing of sputtering pressure from 2 10^-3mbar to 6.5 10^-3mbar. SEM analysis showed that the density of the deposit increases with substrate temperature. The granulation of the films obtained, presents an increasing trend with the variation of process parameters.

Abstract: Transparent conductive oxides such as Impurity doped indium oxides, tin oxides, zinc oxide systems are widely used in the field of optoelectronics such as Photo voltaic solar cells, Flat panel displays. Recently in case of the ZnO / Ag Multilayer thin films, doping Ag films on the ZnO layer and ZnO deposited on top of it a way that has been used. However, if thin film applied to the semiconductor, because of lamination of various forms, characteristics of stacking sequence and thin film layer is a need for research. In this study, using DC magnetron sputteirng how the stacking sequence of the film and the transparent operation of various process variables, the possibility of the application to electronic devices was confirmed.