改善CVD金刚石薄膜涂层刀具性能的工艺研究

用热丝CVD法,以丙酮和氢气为碳源,在WC-Co硬质合金衬底上沉积金刚石薄膜,在分析了工艺条件(衬底温度、碳源浓度、反应压力)对金刚石薄膜性能的影响的基础上,提出了分步沉积法改善金刚石薄膜涂层刀具性能的新工艺.结果表明,合理控制工艺条件的新工艺对涂层薄膜质量、形貌和粗糙度、薄膜与衬底间的附着力、刀具的耐用度及切削性能有显著影响,对获取实用化的在硬质合金刀具基体上沉积高附着强度、低粗糙度金刚石薄膜的新技术具有重要的意义.     

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.     

Multifractal analysis of Mg-doped ZnO thin films deposited by sol–gel spin coating method

A multifractal analysis has been performed on the 3D (three-dimensional) surface microtexture of magnesium-doped zinc oxide (ZnO:Mg) thin films with doping concentration of 0, 2, 4, and 5%. Thin films were deposited onto the glass substrates via the sol–gel spin coating method. The effect of magnesium doping, on the crystal structure, morphology, and band gap for ZnO:Mg thin films has been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and UV–Vis spectroscopy. It has been observed that the surface of ZnO thin films is multifractal in nature. However, multifractality and complexity observed to decrease with increasing content of Mg in ZnO thin films due to formation of islands on the surface in accordance with Volmer–Weber growth mechanism. The investigations revealed that crystallinity, microtexture, morphology, and optical properties of the thin films can be tuned by controlling the Mg content within the ZnO lattice. In particular, their optical band gap energies were 3.27, 3.31, 3.34, and 3.33 eV at 0, 2, 4, and 5%, respectively. The prepared thin films of ZnO:Mg with tuned characteristics would have promising applications in optoelectronic devices.     

Color cathodoluminescence-scanning electron microscopy study of the 4H-SiC heteroepitaxial layers grown by sublimation “sandwich method”

The color cathodoluminescence scanning electron microscopy (CCL-SEM) technique was used for the study of the 4H-SiC epitaxial layers grown by sublimation “sandwich method” on the 6H- or 21R substrates. Elements of the BIY group were introduced for polytype transformations. The method makes it possible to control the polytype in thin layers (0.1–2 μam). The effect of supersaturation and the growth rate on 4H polytype formation have been studied. It was shown that the probability of polytype transformation depends on the configuration of the substrate surface. At low supersaturation, 4H polytype nuclei arise predominantly on projected areas of the (0001)C substrate surface, which had no growth centers such as screw dislocations.     

Study on the effect of DIC deformation sensor on mechanical property of substrate

The thin epoxy film with micro-scale speckle pattern as a digital image correlation (DIC) deformation sensor has been fabricated or transferred on the surface of sample in the previous study. When the thickness of the film cannot be ignored, it may have an influence on the validity of measurement results. And thus, the influence of the thin epoxy film on mechanical properties of substrates should be investigated. In this study, the mechanical behavior of thin film itself and surface strain of composite structure of thin film and substrate were measured using micro digital image correlation (MDIC) method. And theoretical and simulative results were also analyzed. From the comparison analysis of theoretical, simulative and experimental results, it is concluded that when the ratios of Young’s modulus and thickness between the film and substrate are smaller than 13 and 0.5 respectively, the influence from the thin film can be ignored, and thin epoxy film as DIC sensor can be used to measure the deformation of substrate.     

Mechanical and tribological properties of nanostructured coatings based on multicomponent oxides

The mechanical and tribological properties of thin (up to 300 nm) oxide coatings that are produced by the carboxylate method and have various chemical compositions and thicknesses and are deposited on substrates from different materials (steel or quartz glass) have been assessed. The study involves the surface examination and the determination of the surface roughness of specimens using optical and atomic force microscopes, the determination of the elastic properties of the coatings based on indentation results, as well as the study of their tribological behavior during dry and lubricated sliding.     

A method for preparing cross sections of films on wear surfaces for transmission electron microscopy study

A method for preparing cross sections of surface layers which exist on bulk metal substrates for transmission electron microscopy (TEM) study is described. The surface layer or film is protected by a vacuum-deposited or sputtered coating of a suitable metal. A mask is placed over the surface and non-masked areas are subjected to ion beam etching until the substrate is exposed. A thick electroplated layer is then applied to the surface. This layer adheres well to the ion-etched substrate and seals the coated surface film against damage during the usual slicing and grinding steps which are required for the preparation from bulk materials of thin foils for TEM study. The method was developed specifically for the analysis of boundary and extreme pressure lubrication films on wear surfaces together with the near-surface region of the substrate. However, it is also applicable to the investigation of oxide, corrosion and other surface films.     

Imaging analysis of the interface between osteoblasts and microrough surfaces of laser‐sintered titanium alloy constructs

Previous work using focused ion beam (FIB) analysis of osteoblasts on smooth and microrough Ti surfaces showed that the average cell aspect ratio and distance from the surface are greater on the rough surface. In order to better interrogate the relationship between individual cells and their substrate using multiple imaging modalities, we developed a method that tracks the same cell across confocal laser scanning microscopy (CLSM) to correlate surface microroughness with cell morphology and cytoskeleton; scanning electron microscopy (SEM) to provide higher resolution for observation of nanoroughness as well as chemical mapping via energy dispersive X‐ray spectroscopy; and transmission electron microscopy (TEM) for high‐resolution imaging. FIB was used to prepare thin sections of the cell‐material interface for TEM, or for three‐dimensional electron tomography. Cells were cultured on laser‐sintered Ti‐6Al‐4V substrates with polished or etched surfaces. Direct cell to surface attachments were observed across surfaces, though bridging across macroscale surface features occurred on rough substrates. Our results show that surface roughness, cell cytoskeleton and gross morphology can be correlated with the cell‐material cross‐sectional interface at the single cell level across multiple high‐resolution imaging modalities. This work provides a platform method for further investigating mechanisms of the cell‐material interface.     

微波等离子体CVD法在非平面基体上生长金刚石膜

介绍了在微波等离子体CVD装置中,用甲烷和氢气作为原料,在非平面基体(如钨丝、钻头、铣刀等)上生长金刚石薄膜的研究。在金刚石沉积过程中,由于"尖端效应",在基体的尖端很难沉积出金刚石膜。在采用金属丝屏蔽后,克服了"尖端效应",成功地在非平面基体上沉积出了金刚石膜。用扫描电镜(SEM)和激光拉曼光谱(Raman)分析了金刚石膜的形貌和质量。结果表明:非平面基体不同位置金刚石的晶形不同,晶粒比较细小,膜的质量较高。     

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。     

Thin optic constraint

The success of using thin substrates in various fields has urged researchers to further study the possibilities of improving the technology for future applications. For example, the high surface-area-to-weight ratio and strength of sheet glass allow flat-panel display technology to result in high-definition televisions that can be hung on walls like paintings. Sheet glass is also the prime candidate for grazing-incidence foil-optic X-ray telescopes, such as the segmented mirror approach considered for the NASA C onstellation X mission, where cost limitations necessitate lightweight substrates.The effects of different parameters present during the metrology of thin optics, such as gravity, frictional and thermal forces, are identified and analyzed. These forces alter the optic’s surface topography by tens of microns depending on how the optics are manipulated and constrained. This renders metrology and thus surface shaping process results inconclusive.A metrology truss utilizing monolithic flexures to kinematically constrain thin optics during metrology is designed. This device mitigates the effects of the forces mentioned above that are induced on the thin sheet while being mechanically constrained, thus significantly improving the repeatability of the optic surface map measurements.     

Optimum film thickness of thin metallic coatings on silicon substrates for low load sliding applications

The frictional behaviour of thin metallic films on silicon substrates sliding against 52100 steel balls is presented. The motivation of this work is to identify an optimum film thickness that will result in low friction under relatively low loads for various metallic films. Dry sliding friction experiments on silicon substrates with soft metallic coatings (silver, copper, tin and zinc) of various thickness (1–2000 nm) were conducted using a reciprocating pin-on-flat type apparatus under a controlled environment. A thermal vapour deposition technique was used to produce pure and smooth coatings. The morphology of the films was examined using an atomic force microscope, a non-contact optical profilometer and a scanning electron microscope. Following the sliding tests, the sliding tracks were examined by various surface characterization techniques and tools. The results indicate that the frictional characteristics of silicon are improved by coating the surface with a thin metallic film, and furthermore, an optimum film thickness can be identified for silver, copper and zinc coatings. In most cases ploughing marks could be found on the film which suggests that plastic deformation of the film is the dominant mode by which frictional energy dissipation occurred. Based on this observation, the frictional behaviour of thin metallic coatings under low loads is discussed and friction coefficients are correlated with an energy based friction model.     

氩气与氮气流量比对磁控溅射法制备TiN薄膜的影响

用直流反应磁控溅射法在Si(100)基底上制备了TiN薄膜,采用X射线衍射仪和原子力显微镜对其结构和形貌进行了表征,利用四探针测试仪测量了TiN薄膜的方块电阻,使用紫外可见分光光度计测定了薄膜反射率;研究了溅射沉积过程中氩气与氮气流量比对TiN薄膜结构及性能的影响.结果表明:在不同氩气与氮气流量比下,所制备薄膜的主要组成相是(200)择优取向的立方相TiN;随着氩气与氮气流量比的增加,薄膜厚度逐渐增大,而表面粗糙度与电阻率先减小后增大;当氩气与氮气流量比为15:1时,薄膜表面粗糙度和电阻率均达到最小值;TiN薄膜的反射率与氩气与氮气流量比的关系不大.     

Adhesion Force Measurements of Polymer Particles by Detachment Field Method

The adhesion force distributions of polymer particles to aluminum substrates were measured by the detachment field method. Polymer particles with conducting surface treatment were used for the measurements.Further the conventional detachment field method was modified to be applicable to the adhesion force measurements of a single particle. The adhesion force of the polymer particles increased with an increase in relative humidity. The surface roughness of the substrate influenced the adhesion forces of particles significantly. The influence of the CF4 plasma treatment of the polymer particles and thin layer coating of the substrate surface on the adhesion forces of the polymer particles was also studied, and factors affecting adhesion forces of polymer particles are discussed.     

The evaluation of surface topography changes in nanoscaled 2,6‐diphenyl anthracene thin films by atomic force microscopy

The physical properties of electronic devices made by 2,6‐diphenyl anthracene (DPA) are influenced by the microtexture of DPA surfaces. This work focused on the experimental investigation of the 3‐D surface microtexture of DPA thin films deposited on OTS (octadecyltrichlorosilane), HMDS (Hexamethyldisilasane), OTMS (octadecyltrimethoxysilane), and Si/SiO₂ (300 nm SiO₂ thickness) substrates with 5 and 50 nm thicknesses and 5 and 10 μm scan size. The thin film surfaces were recorded using atomic force microscopy (AFM) and their images were stereometrically analyzed to obtain statistical parameters, in accordance with ASME B46.1‐2009 and ISO 25178‐2: 2012. The results showed the effect of different manufacturing parameters on microtexture values where the granular structure is confirmed in all films. In addition, root mean square is increased by increasing the thickness from 5 to 50 nm for all types of substrates.     

Development of interdigital transducer sensors for non-destructive characterization of thin films using high frequency Rayleigh waves

In this paper, Rayleigh waves were generated and studied over a broad frequency range (5-50 MHz) and from the dispersion phenomenon, two substrate on layer type-samples with thin layer thicknesses of 1 μm and 500 nm, respectively, were characterized. The originality in this paper is the use of surface acoustic wave interdigital transducers (IDT) to generate surface waves as well as the development of a measuring device enabling an accurate estimation of the phase velocity to be obtained, which is essential in order to characterize such thin layers. Considering the excitation frequencies (5-50 MHz) and therefore the widths necessary on the electrodes for these types of IDT sensors (20-200 μm), a lift-off procedure was chosen to deposit the electrodes on the lithium niobate (LiNbO(3)) piezoelectric substrates. The use of these IDT, first enabled problems of loss and attenuation linked to the high frequency of conventional sensors (wedge sensors) to be overcome and second to carry out quasi-monochromatic measurements in order to obtain an extremely accurate estimation of the phase velocity with rapid post-processing. An inverse method provided a very precise estimation of the thickness of the layers and the elastic constants of the substrate. The estimations of the thicknesses were then confirmed by measurements with a profilometer.     

Assessing conformal thin film growth under nonstochastic deposition conditions: application of a phenomenological model of roughness replication to synthetic topographic images

In this work, a simple method to follow the evolution of the surface of thin films during growth on substrates characterised by high roughness is detailed. To account for real cases as much as possible, the approach presented is based on the hypothesis that deposition takes place under nonstochastic conditions, such as those typical of many thin film processes in industry and technology. In this context, previous models for roughness replication, which are mainly based on idealised deposition conditions, cannot be applied and thus ad hoc approaches are required for achieving quantitative predictions. Here it is suggested that under nonstochastic conditions a phenomenological relation can be proposed, mainly based on local roughening of surface, to monitor the statistical similarity between the film and the substrate during growth or, in other words, to detect changes of the bare substrate morphological profile occurring during the film growth on top. Such approximation is based on surface representation in terms of power spectral density of surface heights, derived from topographic images; in this work, such method will be tested on two separate batches of synthetic images which simulate thin films growth onto a real rough substrate. In particular, two growth models will be implemented: the first reproduces the surface profile obtained during an atomic force microscopy measurement by using a simple geometrical envelope of surface, regardless the thin film growth mechanism; the second reproduces the columnar growth expected under nonstochastic deposition conditions. It will be shown that the approach introduced is capable to highlight differences between the two batches and, in the second case, to quantitatively account for the replication of the substrate roughness during growth. The results obtained here are potentially interesting in that they account essentially for the geometrical features of the surfaces, and as such they can be applied to synthetic depositions that reproduce different thin film depositions and experimental contexts.     

锑掺杂纳米SnO2透明导电薄膜的制备与性能研究

采用溶胶-凝胶法在Si片、已镀SiO2的钠钙硅玻璃和普通钠钙硅玻璃上镀Sb掺杂摩尔分数为8%的SnO2薄膜(ATO),在450℃热处理温度下对薄膜结构,电学、光学性能进行表征。结果表明:薄膜以四方金红石结构存在,结晶完全;方阻值随镀膜层数的增加而明显降低,12层时薄膜最低方阻值为129Ω/□,可见光平均透过率在75%以上。随着波长的增大,红外波段的反射率逐渐增大,从15%增加到55%左右。     

Surface characteristics and tribology study of metal oxide thin films

Abstract

Microcrystalline high quality undoped ZnO thin films were deposited on Si(100) and Corning 1737F glass substrates by a dc magnetron sputtering system. Surface and mechanical properties of ZnO thin films deposited under different deposition conditions (thickness, deposition rate and plasma composition) were investigated. Atomic force microscopy, nanoindentation techniques and scratch tests have been carried out. The lateral grain radius was between 50 and 160 nm. Surface roughness was found to vary from 1·3 to 10·3. In order to measure the real hardness of ZnO thin films grown on Si(100) and glass Continuous Stiffness Measurement technique was used. The hardness was found to be between 11 and 13 GPa for the polycrystalline ZnO almost five times larger than for the corresponding single crystalline material, while scratch tests verified a film structure, thickness, and surface morphology dependency on the mechanical properties for these metal oxide thin films.     

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.