Carbon films deposited by MCECR plasma sputtering

The mirror-confinement-type electron cyclotron resonance (MCECR) plasma source has high plasma density and high electron temperature, and it is quite useful in many plasma processing, and has been used for etching and thin-film deposition. In this paper, the carbon films about 50 nm thickness were deposited on Si (1 0 0) by MCECR plasma sputtering the sintered carbon target with the argon plasma, and its properties were studied. The bonding structure of the film was analyzed by using the X-ray photoelectron spectropscopy (XPS) and the nanostructure was evaluated with the high-resolution transmission electron microscopy (HRTEM). The tribological properties (friction coefficient, wear rate, and wear life) of the film was investigated by using the pin-on-disk tribometer under the conditions that the normal load is 1 N and the sliding velocity is 0.05 m/s. The nanohardness of the films was measured by using the nanoindenter under conditions that the maximum displacement is 30 nm and the maximum load is 500 μN. The optical properties were measured by using the ellipsometer. The residual stress was measured with a surface profilometer. The surface morphology was studied by using the atomic force microscope (AFM).     

Influence of oxygen flow rate on photocatalytic TiO2 films deposited by rf magnetron sputtering

Titanium dioxide (TiO₂) thin films having anatase (1 0 1) crystal structure were prepared on non-alkali glass substrates by rf (13.56 MHz) magnetron sputtering using a TiO₂ ceramic target under various oxygen partial pressures. At a fixed substrate temperature of 400 °C and total gas pressure of 1 Pa after 3 h deposition. Effects of oxygen partial pressure on the structural, surface morphology, and photocatalytic activities of the TiO₂ thin films were investigated. We performed both photoinduced decomposition of methylene blue (MB) and photoinduced hydrophilicity under UV light illumination. The XRD patterns exhibited a broad-hump shape indicating the amorphous structure of TiO₂ thin films. The results showed that when the [O₂/(Ar + O₂)] flow rate increased to 50%, the photoinduced decomposition of MB and photoinduced hydrophilicity were enhanced. The water contact angle after 9 min UV illumination was approximately 4.5°, and the methylene blue (MB) solution decomposition from 12 down to 3.34 μ mol/L for 240 min UV irradiation.     

Electron and Atomic Force Microscopy studies of photocatalytic titanium dioxide thin films deposited by DC magnetron sputtering

Titanium dioxide thin films were deposited on glass substrates and on fluorine doped tin oxides at room temperature by DC magnetron sputtering at different working gas pressures and were evaluated using photocatalytic degradation of an organic compound. The structural properties of the films were studied by electron microscopy techniques and Atomic Force Microscopy. Numerous structural defects were detected for samples deposited at 16 mTorr and it was associated with the highest photo-degradation rate. Also small band gap shift in titanium dioxide films was detected for different gas pressures. These behaviors are related with structural details derived from the synthesis conditions and the influence of structural defects on the photocatalytic activity is discussed.     

Preferentially oriented vanadium nitride films deposited by magnetron sputtering

Because of solid state lubricious properties of vanadium oxides, wear resistant coatings based on nitrides and carbides of that metal are still of interest for research teams. The aim of this report is to show phase composition evolution from metallic vanadium through intermediate phases up to δ-VN phase supersaturated with nitrogen in thin films deposited by reactive, pulsed magnetron sputtering from vanadium target. This analysis is completed by remarks on preferential orientation, lattice constant and crystallite size. Presented work is a part of research on composite hard coatings for woodworking tools where vanadium nitrides and carbides are considered as a component reducing friction.     

Protective YSZ-based thin films deposited by RF magnetron sputtering

Protective Zr(Y)O_2−δ-based films sputter-deposited onto apatite-type lanthanum silicate ceramics were appraised for potential applications in solid oxide fuel cells with silicate-based solid electrolytes, where the performance may suffer from surface decomposition processes in reducing atmospheres. Dense and crystalline coatings were deposited using radio-frequency magnetron sputtering from an yttria-stabilized zirconia target. On the basis of microstructural analysis and profile measurements, a sputtering power of 300 W was selected in order to achieve deposition rates in the range 0.50-0.75 μm/h. The surface morphology studies using an atomic force microscope revealed typical film structures with small (<50 nm) grains. The polarization of model electrochemical cells with cermet anodes comprising Ni, yttria-stabilized zirconia and Ce_0.8Gd_0.2O_2−δ (50:30:20 wt.%), deposited onto the protective zirconia films, was found quite similar to that of copper-zirconia cermets without interlayers, suggesting that the electrochemical reaction is essentially governed by the oxygen anion transfer from zirconia phase and/or hydrogen oxidation in the vicinity of zirconia film surface.     

Microstructure analysis of Ag films deposited by low-voltage sputtering

The microstructure of Ag films was investigated as a function of the cathode voltage during sputter deposition. It was found that the resistivity of the Ag films decreased when the Ag film was deposited at low cathode voltage using a magnetron cathode with high-magnetic flux density. X-ray diffraction measurement revealed that the Ag films deposited at low cathode voltages exhibited higher crystallization degree and larger crystallites. Besides, it was confirmed from glancing incident X-ray reflectivity measurement that the density of the Ag films increased with decreasing in the cathode voltage. It can be concluded from these results that the improvements in the resistivity and microstructure of Ag films result from the low-voltage sputtering. It can be concluded that the kinetic energy of the Ar gas particles decreased with decreasing the cathode voltage; as a result, the microstructure of Ag films should be improved.     

Copper nitride films deposited by dc reactive magnetron sputtering

Copper nitride (Cu₃N) films were deposited on glass substrates by sputtering of copper target under various substrate temperatures in the range 303–523 K using dc reactive magnetron sputtering. The substrate temperature highly influenced the structural, mechanical, electrical and optical properties of the deposited films. The X-ray diffraction measurements showed that the films were of polycrystalline nature and exhibit preferred orientation of (111) phase of Cu₃N. The microhardness of the films increased from 2.7 to 4.4 GPa with the increase of substrate temperature from 303 to 473 K thereafter decreased to 4.1 GPa at higher temperature of 523 K. The electrical resistivity of the films decreased from 8.7 × 10⁻¹ to 1.1 × 10⁻³ Ωcm and the optical band gap decreased from 1.89 to 1.54 eV with the increase of substrate temperature from 303 to 523 K respectively.     

双离子束溅射法制备铁氮薄膜

使用双离子束溅射法制得了铁氮薄膜,随着基片温度的变化,薄膜的成分是ε－Fe2-3N,γ′－Fe4N或是二相的混合物,薄膜的晶粒尺寸随基片温度的升高而增大。以振动样品磁强计（VSM）测定了薄膜的磁性能。另外,研究了在基片温度为160℃时,改变主源中通入N2／Ar的比例对薄膜成分的影响。     

Thin films of tetragonal zirconia (3Y-TZ) deposited by reactive sputtering

Thin films of tetragonal zirconia (TZ), comprised of 3 mol% Y₂O₃ (3Y-TZ), were deposited onto silicon, oxide-coated silicon, slide glass and aluminum oxide substrates by reactive sputtering of metallic targets in mixtures of oxygen and argon. The texture of deposited films varied with oxygen-to-argon flow ratios with which the target surface altered between metal and oxide compound constituents. Thin films of TZP with (2 0 0) preferred orientation were obtained from sputter deposition in the metallic mode whereas (1 1 1) texture was obtained in the compound mode at ambient temperature. The film texture tends to align along the 〈1 1 1〉 direction while the substrate was heated to 300 °C during the deposition. The texture of all these films was stable upon annealing at 900 °C in air. The reasons for the texture development are discussed.     

Electrical properties and morphology of obliquely deposited electrochromic WO3 films

A thin film of WO₃ deposited obliquely (θ≈50°) improves the electro-optical response times of an electrochromic display device based on a proton insertion-extraction mechanism. The difference in the response times is attributed to morphological differences as revealed by electron microscope observations. WO₃ films were deposited normally and obliquely, by electron beam gun deposition technique so as to have comparable resistivities in vacuum of about 10^-4 Torr. The resistivity of these films was varied in different ways by exposure to atmospheric air in a controlled manner. Systematic and comparative investigations of the variation in resistivity of these films showed that the resistivity increased in the first stage (10^-4 Torr to atmospheric pressure), attained a maximum value and decreased thereafter in the second stage on long exposure to the atmosphere. The initial increase was explained as the result of oxidation leading to better stoichiometry, limited by the process of uptake of water vapour (hydration). The latter effect was much less for normally deposited film; however, for obliquely deposited film it was much greater and resulted in a decrease in resistivity by three orders of magnitude more than for normally deposited film. The large degree of hydration in an obliquely deposited film was ascribed to its more porous nature, leading to faster electro-optical response times. It was concluded that the microstructure, the stoichiometry and the water content control the electro-optical response of WO₃ films.     

Crystallinity and photocatalytic activity of TiO2 films deposited by reactive sputtering with radio frequency substrate bias

TiO₂ films with thicknesses of 400-460 nm were deposited on the unheated non-alkali glass by radio frequency (rf) reactive magnetron sputtering using a Ti metal target. Depositions were carried out using a 3-in. 1000 G magnetron cathode with various rf substrate bias voltages (V_sb, dc component of self bias) of 10-80 V under total gas pressure of 1.0 or 3.0 Pa. The oxygen flow ratio [O₂/(O₂ + Ar)] and rf sputtering power were kept constant at 60% and 200 W, respectively. Photocatalytic activity on photoinduced oxidative decomposition of acetaldehyde (CH₃CHO) of the TiO₂ films showed a clear tendency to decrease with the increase in the V_sb during the deposition. Most of the films consisted of the mixture of anatase and rutile polycrystalline portions. It was confirmed that the rutile phase content increased and anatase phase content decreased markedly with increasing V_sb, where the crystallinity of anatase phase was much higher than that of rutile phase.     

射频磁控溅射法制备Bi2O3薄膜的电致变色性能研究

采用射频磁控溅射技术在ITO导电玻璃上沉积了Bi_2O_3薄膜,利用X射线衍射仪、原子力显微镜、X射线光电子谱对薄膜的微结构、表面形貌、成分和价态进行了表征。分析表明在空气气氛中350℃热处理的Bi_2O_3薄膜具有四方结构,属β-Bi_2O_3,该薄膜在-1.8-+3V的直流电压驱动下具有在透明和暗棕色之间转换的电致变色性能,着色和漂白过程中均没有其他价态(+3价以外)的Bi生成。研究发现Bi_2O_3薄膜在400-800nm的可见光波段平均透射率调制幅度可达44%,550nm处着色系数为9.6cm~2/C,该材料具有优良的电致变色性能。     

Titanium oxide thin films deposited by high-power impulse magnetron sputtering

Ionized physical vapor deposition processes are of great interest for surface modification because the flexibility of the thin film deposition process can be increased by ionizing the metallic vapor. Recently, high-power impulse magnetron discharges have been implemented to achieve high ionization rates.Thin films of titanium oxide have been deposited on glass and steel substrates using 450 × 150 mm rectangular titanium target in argon-oxygen atmosphere. The average power delivered to the plasma is ranging between 1.5 and 2 kW and peak current and voltage are respectively 200 A and 900 V.Films are characterized using Scanning Electron Microscopy, Grazing Incidence X-ray Diffraction and Optical Transmission Spectroscopy. One of the major findings is the presence of rutile deposited on steel substrate (even for 0 V bias grounded substrate) and the significant increase of the refractive index of the films deposited on glass compared to thin films deposited via conventional direct current bipolar pulsed magnetron sputtering. Films synthesized by high-power impulse magnetron sputtering are denser.     

非平衡磁控溅射类金刚石碳膜的性能

用非平衡磁控溅射的方法在室温下制备了光滑、均匀、致密的类金刚石(DLC)薄膜,分析和研究了DLC膜的形貌、结构和摩擦特性.结果表明,靶工作电流对DLC膜的沉积有重要的影响.随着工作电流的增大,薄膜的沉积速率增大,薄膜中sp3键的含量增加.薄膜的摩擦系数随着工作电流的增加略有增大,在摩擦的初始阶段,摩擦系数较高,随着摩擦循环次数的增加,摩擦系数逐渐减小,并逐渐趋于稳定.     

Transparent conductive ZnO:B films deposited by magnetron sputtering

This paper focuses on the preparation of boron doped ZnO (ZnO:B) films prepared by nonreactive mid-frequency magnetron sputtering from ceramic target with 2 wt.% doping source. Adjusting power density, ZnO:B film with low resistivity (1.54 × 10^− 3 Ω cm) and high transparency (average transparency from 400 to 1100 nm over 85%) was obtained. Different deposition conditions were introduced as substrate fixed in the target center and hydrogen mediation. Hall mobility increased from 11 to above 26 cm²/V·s, while carrier concentration maintained almost the same, leading to low resistivity of 6.45 × 10^− 4 Ω cm. Transmission spectra of ZnO:B films grown at various growth conditions were determined using a UV-visible-NIR spectrophotometer. An obvious blue-shift of absorption edge was obtained while transmittances between 600 nm and 1100 nm remained almost the same. Optical band baps extracted from transmission spectra showed irregular enhancement due to the Burstein-Moss effect and band gap renormalization. Photoluminescence spectra also showed a gradual increase at UV emission peak due to free exciton transition near band gap. We contributed this enhancement in both optical band gap and UV photoluminescence emission to the lattice structure quality melioration.     

磁控溅射WS2薄膜的制备工艺及其性能

采用孪生中频磁控溅射的方法在低温条件下制备了WS2薄膜,利用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)、能谱仪(EDX)、显微硬度仪、划痕仪和球盘式摩擦磨损试验机对薄膜的物相结构、微观形貌以及摩擦学性能进行了研究。结果表明:所制备的WS2薄膜呈现出明显的(002)晶面择优生长,S/W原子比1.52,在大气环境中摩擦系数可低于0.01,载荷与转速对薄膜的摩擦系数影响显著,在一定范围内加大载荷和提高转速都会增大其摩擦系数。     

Mn-doped ZnO transparent conducting films deposited by DC magnetron sputtering

Mn-doped zinc oxide (ZnO:Mn) thin films with low resistivity and relatively high transparency were firstly prepared on glass substrate by direct current (DC) magnetron sputtering at room temperature. Influence of film thickness on the properties of ZnO:Mn films was investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. As the thickness increases from 144 to 479 nm, the crystallite size increases while the electrical resistivity decreases. However, as the thickness increases from 479 to 783 nm, the crystallite size decreases and the electrical resistivity increases. When film thickness is 479 nm, the deposited films have the lowest resistivity of 2.1 × 10^− 4 Ω cm and a relatively high transmittance of above 84% in the visible range.     

Dielectric oxynitride LaTiOxNy thin films deposited by reactive radio-frequency sputtering

LaTiO_xN_y thin films have been deposited by RF sputtering on (001) Nb-doped SrTiO₃ and (001) MgO single-crystalline substrates at high temperature (T_S = 800 °C) under different nitrogen ratios in the plasma (vol.% N₂ = 0, 25, 71). The band gaps ranged from E_g = 3.30 eV for the epitaxial transparent film containing no nitrogen to E_g = 2.65 eV for the textured coloured film containing a moderate amount of nitrogen. Dielectric characterization in the frequency range [100 Hz-1 MHz], using a metal-insulator-metal structure, has shown a stable permittivity and loss tangent of the epitaxial low-nitrided LaTiO_xN_y film with values of ε′ = 135 and tanδ = 1.2 10^− 2 at 100 kHz (RT).