Influence of substrate orientation on the morphologyand orientation of LaNiO3 thin films

LaNiO₃ thin films were successfully prepared by a chemical method from citrate precursors. The LNO precursor solution was spin‐coated onto Si (100) and Si (111) substrates. To obtain epitaxial or highly oriented films, the deposited layers were slowly heated in a gradient thermal field, with a heating rate of 1° min^?1, and annealed at 700°C. The influence of different substrate orientations on the thin film morphology was investigated using atomic force microscopy and X‐ray diffraction analysis. Well‐crystallized films with grains aligned along a certain direction were obtained on both substrates. Films deposited on both substrates were very smooth, but with a different grain size and shape depending on the crystal orientation. Films deposited on Si (100) grew in the (110) direction and had elongated grains, whereas those on Si (111) grew in the (211) direction and had a quasi‐square grain shape.     

沉积温度对脉冲真空弧源沉积类金刚石薄膜性能的影响

利用脉冲真空弧源沉积技术在Cr17Ni14Cu4不锈钢和Si(100)基体上制备了类金刚石(DLC)薄膜,研究了基体沉积温度对DLC薄膜的性能和结构的影响。研究表明,随着沉积温度由100 ℃提高到400 ℃,DLC薄膜中sp3 键质量分数减少,sp2键质量分数增多,薄膜复合硬度逐渐降低。当DLC薄膜沉积温度达到400 ℃时,薄膜中C原子主要以sp2键形式存在,与沉积温度为100 ℃时制备的DLC薄膜相比,薄膜复合硬度降低50%。DLC薄膜具有优异的耐磨性,摩擦因数低,随着沉积温度由100 ℃提高到400 ℃,Cr17Ni14Cu4不锈钢表面沉积的DLC薄膜耐磨性降低。沉积温度为100 ℃时,Cr17Ni14Cu4不锈钢表面沉积的DLC薄膜后,耐磨性大幅度提高。DLC薄膜与不锈钢基体结合牢固。     

光纤持气率测井仪响应规律的实验研究

为考察现有光纤持气率计在油气水三相流中的响应特性,采用多相流标定装置对其进行测定,系统研究光纤持气率计在油量固定不变含水量不同条件下的持气率响应规律。实验结果表明,当油量为5m3/d、气量小于10m3/d时,持气率随含气量的增大而增大,二者线性变化程度较低;而气量在10～35m3/d之间变化时,持气率随含气量的增大而线性增大。     

Electron cryo-microscopy of biological specimens on conductive titanium-silicon metal glass films

Thin films of the metal glass Ti88Si12 were produced by evaporation and characterized by AFM and conductivity measurements. Thin Ti88Si12 support films for electron microscopy were prepared by coating standard EM grids with evaporated films floated off mica, and characterized by electron imaging and electron diffraction. At room temperature, the specific resistance of a thin TiSi film was 10(6) times lower than that of an amorphous carbon film. At 77K, the specific resistance of TiSi films decreased, whereas that of carbon became immeasurably high. The effective scattering cross-section of TiSi and amorphous carbon for 120 kV electrons is roughly equal, but TiSi films for routine use can be approximately 10 times thinner due to their high mechanical strength, so that they would contribute less background noise to the image. Electron diffraction of purple membrane on a TiSi substrate confirmed that the support film was amorphous, and indicated that the high-resolution order of the biological sample was preserved. Electron micrographs of TiSi films tilted by 45 degrees relative to the electron beam recorded at approximately 4 K indicated that the incidence of beam-induced movements was reduced by 50% compared to amorphous carbon film under the same conditions. The success rate of recording high-resolution images of purple membranes on TiSi films was close to 100%. We conclude that TiSi support films are ideal for high-resolution electron cryo-microscopy (cryo-EM) of biological specimens, as they reduce beam-induced movement significantly, due to their high electrical conductivity at low temperature and their favorable mechanical properties.     

Temperature dependence dynamical permeability characterization of magnetic thin film using near-field microwave microscopy

A temperature dependence characterization system of microwave permeability of magnetic thin film up to 5 GHz in the temperature range from room temperature up to 423 K is designed and fabricated as a prototype measurement fixture. It is based on the near field microwave microscopy technique (NFMM). The scaling coefficient of the fixture can be determined by (i) calibrating the NFMM with a standard sample whose permeability is known; (ii) by calibrating the NFMM with an established dynamic permeability measurement technique such as shorted microstrip transmission line perturbation method; (iii) adjusting the real part of the complex permeability at low frequency to fit the value of initial permeability. The algorithms for calculating the complex permeability of magnetic thin films are analyzed. A 100 nm thick FeTaN thin film deposited on Si substrate by sputtering method is characterized using the fixture. The room temperature permeability results of the FeTaN film agree well with results obtained from the established short-circuited microstrip perturbation method. Temperature dependence permeability results fit well with the Landau-Lifshitz-Gilbert equation. The temperature dependence of the static magnetic anisotropy H(K)(sta), the dynamic magnetic anisotropy H(K)(dyn), the rotational anisotropy H(rot), together with the effective damping coefficient α(eff), ferromagnetic resonance f(FMR), and frequency linewidth Δf of the thin film are investigated. These temperature dependent magnetic properties of the magnetic thin film are important to the high frequency applications of magnetic devices at high temperatures.     

Grain size distribution analysis in polycrystalline LiF thin films by mathematical morphology techniques on AFM images and X-ray diffraction data

The influence of the deposition temperature on the grain size of polycrystalline lithium fluoride (LiF) thin films is studied using a mathematical morphology method. On atomic force microscopy images of the LiF surface, the grain sizes and shapes are determined by applying the watershed technique, together with a shape factor algorithm. Also, the domain size of the film structure, determined by an X-ray diffraction data analysis, is compared and correlated with the mean grain size as a function of the deposition temperature. In both cases a linear increase with temperature and a very good agreement among the two structural parameters (grain and domain size) was found.     

Reducing Friction Force of Si Material by Means of Atomic Layer-Deposited ZnO Films

With excellent lubricating property, zinc oxide (ZnO) films are promising candidates to act as protective coatings in Si-based microelectromechanical system devices for the purpose of decreasing friction forces of silicon (Si) material. In this paper, the nanotribological behavior of ZnO films prepared by atomic layer deposition on a Si (100) substrate is investigated by an atomic force microscope. The ZnO films have various thicknesses ranging from 10.0 to 182.1 nm. With the increase of film thickness, the root-mean-square roughness of the films increases, while the ratio of hardness to Young’s modulus (H/E) decreases. Due to their large surface roughness, the thick ZnO films are low in adhesion force. The friction force of the ZnO films is smaller than that of the Si (100) substrate and is greatly influenced by their adhesion force and mechanical property. In a low-load condition, the friction force is dominated by the adhesion force, and thus, the friction force of the ZnO films decreases as film thickness increases. While in a high-load condition, the friction force is dominated by plowing. Films with higher H/E possess smaller friction force, and thus, the friction force increases with the decreasing film thickness.     

Tribological properties of anatase TiO<Subscript>2</Subscript> sol–gel films controlled by mutually soluble dopants

Tribological properties of TiO2 sol–gel thin films with mutually soluble dopants were studied on a glass substrate. The results showed that the formation of mutually soluble solid solution played a very important role in the growth of titania grains. The fine-grained TiO₂ films controlled by SiO₂ dopant were superior to pure TiO₂ film in wear resistance and endurance life, although both films greatly improve the surface characteristics of glass substrate, enhancing its tribological characteristics. High resistance to microfracture because of the very small grain size as well as a good adhesion of the film to the substrate is believed to be the determining factors influencing the tribological properties of SiO₂ doped TiO₂ films. However, excessive SiO₂ seriously deteriorates wear resistance of film due to phase separation. The wear mechanisms were also discussed based on the observation of the surface morphologies by scanning electron microscope (SEM).     

Structural, optical and mechanical properties of nanostructure diamond synthesized by chemical vapor deposition

Nanostructure diamond (NSD) films on Si substrate are prepared by microwave plasma enhanced chemical vapor deposition (MPECVD) using methane and hydrogen as the reactants with two-step negative substrate bias (SB). The dependencies of the NSD film morphology, grains, surface roughness, crystal and bonding structures and hardness on the negative SB at the bias-enhanced growth (BEG) step and substrate temperature during growth have been investigated by conducting atomic force microscopy (CAFM), X-ray diffraction (XRD), Raman spectroscopy and nanoindentation. The hardness of the NSD film is found to be as high as 80 GPa with CAFM average and root mean square roughness of 7 and 9 nm, respectively, under optimal negative SB at the BEG step. From the studies of substrate temperature effect, the hardness of the NSD film is as high as 70 GPa, with average and root mean square CAFM roughness of 9 and 11 nm, respectively, which were obtained at a substrate temperature of 500 °C. In both cases, the film hardness was found to be affected by the size of clusters, which are composed of many small NSD particles, the amount of NSD in an amorphous matrix as well as surface roughness. We also synthesized transparent NSD films by MPECVD under optimized single-step growth conditions on quartz substrates, which are scratched with several micrometers diamond powder. A hardness as high as 60 GPa and a maximum transmittance of 60% in the visible light region are achieved for an NSD coating of 1.0 μm thickness with small surface roughness.     

硅基微机械表面粘附及摩擦性能的AFM试验研究

在Si（100）基片上制备了十八烷基三氯硅烷（OTS）分子润滑膜，并用原子力显微镜（AFM）对比研究了施加OTS膜前后的硅表面的粘附、摩擦磨损性能。试验考虑了相对湿度和扫描速度对粘附、摩擦性能的影响。结果表明，相对于硅构件来讲，OTS膜表面粘附力较小，具有较小的摩擦因数，呈现较好的润滑性能；硅构件受湿度变化的影响比OTS膜明显。微构件的摩擦性能由于水合化学作用生成Si（OH）。润滑膜，使得其受相互间运动速度影响很大。OTS膜不仅是一种耐磨性较好的润滑膜，而且有良好的稳定性。     

INFLUENCE OF RARE EARTH DOPING ON MECHANICAL PROPERTY AND MICRO-STRUCTURE OF CHROMIA OXIDE FILM

The isothermal oxidizing kinetics of Co-40Cr alloy and its yttrium ion-implanted samples are studied at 1 000 ℃ in air by thermal-gravity analysis （TGA）. Scanning electronic microscopy （SEM） is used to examine the Cr2O3 oxide film＇s morphology after oxidation. Acoustic emission （AE） method is used in situ for monitoring the cracking and spalling of oxide films formed on both samples during oxidizing and subsequent air-cooling stages. Theoretical model is proposed relating to the film fracture process and is used for analyzing the acoustic emission spectrum both on time domain and on AE-event number domain. It is found that yttrium implantation remarkably reduces the isothermal oxidizing rate of Co-40Cr and improves the anti-cracking and anti-spalling properties of Cr2O3 oxide film. The reasons for the improvement are mainly that the implanted yttrium reduced the grain size of Cr2O3 oxide, increased the high temperature plasticity of oxide film, and remarkably reduced the number and size of Cr2O3/Co-40Cr inteffacial defects.     

刀具表面CVD法金刚石薄膜剥离及其结合性能

在硬质合金和Si3N4陶瓷刀具表面采用热丝CVD法合成金刚石薄膜的结合性能具有明显差异。在沉积金刚石过程中，根据碳源通入系统中的时机不同，硬质合金表面容易形成石墨、WC等松散层，膜的结合性能变差，由于热应力大，在无外力作用下膜有时发生自动剥落现象；而Si3N4陶瓷表面上金刚石膜具有良好结合性能。在压应力作用下，两衬底上的金刚石薄膜剥离过程也不同，硬质合金上膜支接以剥落形式失效，而Si3N4上膜以产生裂纹及其扩展失效。     

氮气反应溅射制备软X射线Co/Ti多层膜

针对"水窗"波段(280~540eV)对多层膜反射镜的应用需求,在Ti的L吸收边(452.5eV)附近,优化设计了Co/Ti多层膜的膜系结构。计算了不同界面粗糙度条件下的反射率,结果显示,界面粗糙度对多层膜反射率有较大影响。采用直流磁控溅射方法在超光滑硅基片上制备了Co/Ti多层膜,通过将氮气引入原有的溅射气体氩气中作为反应气体,明显减小了制备的多层膜的界面粗糙度。利用X射线掠入射反射实验和透射电子显微镜测试了多层膜结构,并在北京同步辐射装置(BSRF)3W1B实验站测量了不同氮气浓度下多层膜的反射率。结果显示,氮气含量为5%的溅射气体制备的多层膜样品反射率最高,即将纯氩气溅射制备得到的反射率9.5%提高到了12.0%。得到的结果表明,将氮气加入反应溅射气体可以有效改善Co/Ti多层膜的性能。     

Anti-oxidant mechanism of TiAlN/SiN decorative films on borosilicate glass by magnetron sputtering

The black TiAlN decorative film was prepared on the borosilicate glass by the magnetron sputtering in equipment with multiple vacuum chambers. The transparent SiN protective layer was deposited on the surface of the TiAlN film to keep the black color invariant at the high temperature. The structure of the TiAlN/SiN film was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM). The coating adhesion was measured by scratch tester. The TiAlN film has a columnar crystal structure with a thickness of 200 nm, and the top SiN layer is amorphous with a thickness of 100 nm. The coated borosilicate glass with the TiAlN/SiN films still retains the black color after oxidation at 600 °C in atmosphere. While the oxidation temperature elevates to 700 °C, the color of the TiAlN/SiN films begins to change. The top SiN layer plays a role as the barrier against oxygen diffusion into the inner TiAlN layer. The thin self-formed aluminum oxide layer was generated on the surface of the SiN layer and it contributes to the improvement of anti-oxidant property of the inner TiAlN layer. However, the thick self-formed aluminum oxide layer leads to the color change of the black TiAlN film. The thermal oxidation benefits the improvement of the adhesion for the TiAlN/SiN films with glass substrate.     

Fractal characteristics and microstructure evolution of magnetron sputtering Cu thin films

How to describe surface morphology characteristic and microstructure evolution are the hottest researches of current thin film researches.But in traditional characterization of surface morphology,the roughness parameters are scale related.And the microstructure evolution of thin film during post-treatment is usually not considered in detail.To give a better understanding of the roughness of thin films topography,fractal method is carried out.In addition,microstructure evolution of thin films is analyzed based on the crystallography and energy theory.Cu thin films are deposited on Si(100) substrates by magnetron sputtering,and then annealed at different temperatures.Surface topography is characterized by atomic force microscope(AFM).Triangular prism surface area(TPSA) algorithm is used to calculate the fractal dimension of the AFM images.Apparent scale effect exists between the surface morphology roughness and film thickness.Relationship between the fractal dimension and roughness is analyzed by linear regression method and linear relationship exists between fractal dimension and surface roughness root mean square(RMS).Fractal dimension can be characterized as a scale independence parameter to represent the complex degree and roughness level of surface.With the increase of annealing temperature,surface roughness and fractal dimension decrease.But when the annealing temperature exceeds the recrystallization temperature,due to the agglomeration and coalescence of Cu grain,surface roughness and fractal dimension increase.Scale effect and changing regularity of grain growth and shape evolution for different film thickness under different annealing temperatures are analyzed.Based on minimum total free energy,regularity of grain growth and changing is proposed.The proposed research has some theory significance and applicative value of Cu interconnect process and development of MEMS.     

SiN_x和SiN_x/SiO_x薄膜的荧光和红外吸收光谱研究

采用射频磁控溅射法在Si(100)和含有SiOx缓冲层的Si(100)上制备SiNx薄膜。直接生长在Si(100)的SiNx薄膜几乎不发光;而SiNx/SiOx薄膜在650℃以上的高温热处理后有非常强的光致发光,当退火温度为800oC时发光强度达到最高。傅立叶红外吸收研究表明,直接生长在Si(100)的SiNx薄膜在退火后氧化程度略有增加;而SiNx/SiOx薄膜在高温热处理后氧化程度明显升高,但过高温度的退火会导致Si-N键显著减少。分析认为SiNx/SiOx薄膜的发光与Si-N键和Si-O键密切相关。     

Characterization of lead zirconate titanate--lanthanum ruthenate thin film structures prepared by chemical solution deposition

In this work, the results of compositional and microstructural analysis of lead zirconate titanate--lanthanum ruthenate thin film structures prepared by chemical solution deposition are discussed. The cross-section transmission electron microscope (TEM) micrographs of the La-Ru-O film deposited on a SiO2/Si substrate and annealed at 700 degrees C revealed RuO2 crystals embedded in a glassy silicate matrix. When the La-Ru-O film was deposited on a Pt/TiO2/SiO2/Si substrate, RuO2 and La4Ru6O19 crystallized after annealing at 700 degrees C. After firing at 550 degrees C randomly oriented lead zirconate titanate (PZT) thin films crystallized on the La-Ru-O/SiO2/Si substrate, while on La-Ru-O/Pt/TiO2/SiO2/Si substrates PZT thin films with (111) preferred orientation were obtained. No diffusion of the Ru atoms in the PZT film was found. Ferroelectric response of PZT thin films on these substrates is shown in comparison with the PZT film deposited directly on the Pt/TiO2/SiO2/Si substrate without a La-Ru-O layer.     

Effects of morphological control on the characteristics of vertical-type OTFTs using Alq3

We have fabricated vertical-type organic thin-film transistors (OTFTs) using tris-(8-hydroxyquinoline) aluminum (Alq(3)) as an n-type active material. Vertical-type OTFT using Alq(3) has a layered structure of Al(source electrode)/Alq(3)(active layer)/Al(gate electrode)/Alq(3)(active layer)/ITO glass(drain electrode). Alq(3) thin films containing various surface morphologies could be obtained by the control of evaporation rate and substrate temperature. The effects of the morphological control of Alq(3) thin layer on the grain size and the flatness of film surface were investigated. The characteristics of vertical-type OTFT significantly influenced the growth condition of Alq(3) layer.     

Mechanical property and dimensional stability of substrates for magnetic tapes

We have performed a comparative study on mechanical property and dimensional stability of substrates for magnetic tapes. The substrates include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and aromatic polyamide (ARAMID), which could be used for linear-type magnetic tapes for computer data storage. We have demonstrated that ARAMID is the most attractive substrate and that PET has the advantage of considerably smaller irreversible creep deformation and lateral contraction caused by tension as compared to PEN film. In this paper, we also introduce recently developed PET (Advanced PET) with higher glass transition temperature compared to conventional PET; moreover, we discuss the relationship between film properties and polymeric structures of these substrates.     

Influence of target grit count and sintering temperature on pulsed laser deposition of SiC thin films

A pulsed laser deposition (PLD) technique for depositing SiC on Si(100) substrates using Nd³⁺:YAG laser at 355 nm is studied. The influence of substrate temperature, ambient pressure, and SiC powder grit size on both structure and morphology of SiC thin film is investigated. Further, the influence of the target preparation on the reduction of droplet formation during Nd³⁺:YAG laser-assisted pulsed laser deposition of SiC thin films is investigated. Experimental studies show that multicrystalline SiC film can be obtained with temperature ranging from 600 to 700 °C and at an ambient pressure of about 5.5 × 10^?3 Pa. Further, droplet formation on the deposited film was reduced significantly by selecting the grit count of SiC powder 500 and the pressure of 2 × 10^?2 Pa. SiC target sintered at 1,600 °C showed a reduced wear during the laser ablation. The X-ray diffraction (XRD) and the Raman spectroscopy studies on deposited films clearly show the multicrystalline (combined 3C-SiC and 4H-SiC) nature of SiC films. I-V characteristics of deposited SiC film on n-type c-Si substrate also indicated that SiC thin film possesses P-type semiconductor properties.