A study of titanium thin films in transmission laser micro-joining of titanium-coated glass to polyimide

Electron beam evaporation (EB-PVD) and cathodic arc physical vapor deposition (CA-PVD) techniques were used for the preparation of titanium (Ti) thin films onto Pyrex borosilicate 7740 glass wafers and the deposited films were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) techniques. The microstructure and surface morphology of the films were studied as a function of the film deposition techniques. Film properties such as, adherence, microstructure and roughness were interconnected to the laser joint strength between Ti coated glass wafers and polyimide films. Ti thin films on glass had a natural oxide layer on the surface as found from XPS. AFM study showed the formation of a uniform Ti coating consisted of packed crystallites with average size of 35 nm by EB-PVD. The root-mean-square surface roughness of the films was 1-2 nm. Whereas, films prepared by CA-PVD had crystallites with an average size of 120 nm and defects in the form of macro-particles which is a common attribute of this deposition system. The surface roughness of the film was 125 nm. The laser joint strength was found to be influenced by the Ti film quality on the glass substrate.     

Microstructural characteristics and mechanical properties of magnetron sputtered nanocrystalline TiN films on glass substrate

Nanocrystalline TiN thin films were deposited on glass substrate by d.c. magnetron sputtering. The microstructural characteristics of the thin films were characterized by XRD, FE-SEM and AFM. XRD analysis of the thin films, with increasing thickness, showed the (200) preferred orientation up to 1·26 μm thickness and then it transformed into (220) and (200) peaks with further increase in thickness up to 2·83 μm. The variation in preferred orientation was due to the competition between surface energy and strain energy during film growth. The deposited films were found to be very dense nanocrystalline film with less porosity as evident from their FE-SEM and AFM images. The surface roughness of the TiN films has increased slightly with the film thickness as observed from its AFM images. The mechanical properties of TiN films such as hardness and modulus of elasticity (E) were investigated by nanoindentation technique. The hardness of TiN thin film was found to be thickness dependent. The highest hardness value (24 GPa) was observed for the TiN thin films with less positive micro strain.     

The role of the Zn buffer layers in the structural and photoluminescence properties of ZnO films on Zn buffer layers deposited by RF magnetron sputtering

Highly c-axis oriented ZnO thin films were grown on Si (100) substrates with Zn buffer layers. Effects of the Zn buffer layer thickness on the structural and optical qualities of ZnO thin films were investigated for the ZnO films with the buffer layers 90, 110, and 130 nm thick using X-ray diffraction (XRD), photoluminescence (PL) and atomic force microscopy (AFM) analysis techniques. It was confirmed that the quality of a ZnO thin film deposited by RF magnetron sputtering was substantially improved by using a Zn buffer layer. The highest ZnO film quality was obtained with a Zn buffer layer 110 nm thick. The surface roughness of the ZnO thin film increases as the Zn buffer layer thickness increases.     

Quantitative analysis of electrodeposited tin film morphologies by atomic force microscopy

This study of the electrodeposition of tin on steel substrates demonstrates that it is possible to obtain quantitative information on the thin film growth at industrially relevant substrates using atomic force microscopy (AFM) to monitor the film morphology and X-ray fluorescence (XRF) to measure the average film thickness. The effects of current density and electrolyte temperature on the film morphology, surface roughness, and grain size distribution (GSD) are reported. While the roughness of the substrates used in this study can vary by several hundred nanometers to a micrometer, we are interested in quantitative characterization of the tin films with thickness varying from a few tens of nanometers to several hundred nanometers. This study shows that for the range of film thickness and length scale studied, analysis of the AFM images can provide quantitative characterization of the thin film roughness and grain size distribution at various stages of growth with little interference from the substrate morphological inhomogeneities.     

脉冲激光沉积ZrW2O8薄膜的制备和性能

采用脉冲激光沉积法在石英基片上沉积制备了ZrW2O8薄膜.用X射线衍射仪(XRD)、原子力显微镜(AFM)研究了不同衬底温度对薄膜结构组分、表面粗糙度和形貌的影响,用台阶仪和分光光度计测量薄膜的厚度和不同衬底温度下制备薄膜的透射曲线,用变温XRD分析了ZrW2O8薄膜的负热膨胀特性.实验结果表明:在衬底温度为室温、550℃和650℃下脉冲激光沉积的ZrW2O8薄膜均为非晶态,非晶膜在1200℃保温3min后淬火得到立方相ZrW2O8薄膜;随着衬底温度的升高,ZrW2O8薄膜的表面粗糙度明显降低;透光率均约为80%,在20～600℃温度区间内,脉冲激光沉积制备的ZrW2O8薄膜的负热膨胀系数为-11.378×10-6 K-1.     

Ellipsometric study of thermally evaporated germanium thin film

The optical properties of thermally evaporated germanium thin films in the spectral range 0.3-1.7 mum were studied with spectroscopic ellipsometry. The microstructure of these films, including their crystallinity, density, surface morphology, and surface oxidation, was analyzed with x-ray diffraction, Rutherford backscattering spectrometry, atomic force microscopy (AFM), and Auger electron spectrometry (AES). Parameters such as the surface roughness and surface-oxidation-layer thickness, derived from AFM and AES measurements, were incorporated into our optical model. The complex index of refraction (n and k) of the films was determined throughout the above spectral range and compared with that of single-crystal germanium.     

In-situ investigations of magnetron sputtering processes with laboratory X-ray equipment

An Fe-Al duplex film was prepared on a Si(111)-wafer by sputter deposition in a vacuum chamber with two integrated small magnetron sources. The chamber allows the in-situ investigation of such sputtering processes using grazing incidence X-ray reflectivity, X-ray scattering measurements and X-ray diffraction. We will present details of the new cell and present the first results obtained using reflectivity measurements of the Fe-Al thin films. Here we will focus on the detailed evaluation of the specular reflectivity data of the iron films only, which clearly indicates the presence of an iron oxide, the density and roughness of which were determined and their changes with the film thickness were discussed in the framework of thin film growth models.     

Characterization on pulsed laser deposited nanocrystalline ZnO thin films

Nanocrystalline zinc oxide thin films were deposited on glass and silicon substrates by using pulsed laser deposition at different laser energy densities (1.5, 2, and 3 J/cm²). The film thickness, surface roughness, composition, optical and structural properties of the deposited films were studied using an α-step surface profilometer, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), optical transmittance, and X-ray diffraction (XRD), respectively. The film thickness was calculated as 244 nm. AFM analysis shows that the root-mean-square roughness increases with increasing laser energy density. XPS analysis shows that the interaction of zinc with oxygen atoms is greatly increased at high laser energy density. In the optical transmittance spectra, a shift of the absorption edge towards higher wavelength region confirms that the optical band gap increases with an increase in laser energy density. The particle size of the deposited films was measured by XRD, it is found to be in the range from 7.87 to 11.81 nm. It reveals that the particle size increases with an increase in laser energy density.     

X射线反射法分析ZnO基薄膜的厚度、密度和表面粗糙度

采用X射线反射法(XRR)测试了在SiO_2玻璃衬底上磁控溅射沉积的单层ZnO基薄膜的反射强度,得到了反射强度随掠入射角变化的曲线;讨论了薄膜厚度、密度和表面粗糙度与反射曲线的关系,最后通过拟合XRR曲线获得了所制备薄膜的厚度、密度和表面粗糙度分别为55.8 nm,5.5 g·cm~(-3)和1.7 nm,与利用XRR数据直接计算出的薄膜厚度56.2 nm仅相差0.4 nm,表面粗糙度也与AFM测试的结果基本相符。可见XRR能无损伤、精确且快速地测试薄膜试样的厚度、密度和表面粗糙度等参数。     

快速热处理对(Ba,Sr)TiO3薄膜晶化行为的影响

采用射频溅射法在Si(111)基片上制备了(Ba,Sr)TiO3(BST)薄膜,并对制备的薄膜进行了快速退火热处理.采用X射线衍射和原子力显微镜分析了退火温度、退火时间和加热速度对BST薄膜晶化行为的影响.研究结果表明,BST薄膜的晶化行为强烈依赖于退火温度、退火时间和加热速度.BST薄膜的结晶度随退火温度的升高而提高.适当的热处理可降低BST薄膜的表面粗糙度,BST薄膜的表面粗糙度随退火温度的升高经历了一个先降低后增大的过程,但退火后BST薄膜的表面粗糙度都小于制备态薄膜的表面粗糙度.BST薄膜的晶粒尺寸随退火温度的升高经历了一个先增大后减小的过程.随退火时间的延长,BST薄膜的特征衍射峰越来越强,薄膜的晶化程度越来越高.随退火时问的延长,BST薄膜的晶粒尺寸和表面粗糙度也经历了一个先增大后减小的过程.BST薄膜的晶粒大小主要由退火温度决定.高的升温速率可获得较小的晶粒.     

氧化钒薄膜在玻璃基片上的生长研究

采用直流反应磁控溅射法, 在平整光滑的普通玻璃基片表面沉积了厚度分别为80nm、440nm和1μm的氧化钒薄膜. 采用原子力显微镜(AFM)、扫描电镜(SEM)和X射线衍射仪(XRD)对薄膜的表面形貌、结构和结晶化的分析表明, 厚度影响着薄膜的颗粒大小和结晶状态, 随着薄膜厚度的增加, 薄膜的颗粒增大, 晶化增强; 薄膜具有明显的垂直于衬底表面的“柱”状择优生长特征. 对薄膜的方阻和方阻随温度的变化进行了相关分析, 证实了厚度对氧化钒薄膜的电学性能存在明显的影响, 随着薄膜厚度的增加, 薄膜的方阻减小, 方阻温度系数升高, 薄膜的方阻随温度变化的回线滞宽逐渐增大, 薄膜的金属-半导体相变逐渐趋于明显.     

Microstructure and surface roughness study of highly crystallized μc-Si:H Films

We have deposited hydrogenated microcrystalline silicon films by standard rf glow discharge plasma CVD technique using a mixture of SiF₄, Ar and H₂ at low substrate temperatures. Although fully crystalline from the beginning of the growth, our films show a significant variation in the ratio of large (LG) and small grain (SG) with further growth, for any H₂ dilution case, though the trend changes for each case. The mean sizes of the LG and SG do not vary much with growth, but a marked variation occurs in the size of the conglomerate grains, as shown by atomic force microscopy (AFM) studies. Notably, a change in the H₂ dilution is found to affect not only the film microstructure, but also the crystalline orientation. We have shown the lateral and longitudinal growth of conglomerate grains to be highly dependent on the crystalline orientation. In studying the effect of film growth on film roughness, we have observed a linear correlation between the rms roughness as measured by AFM and the top surface layer as measured by spectroscopic ellipsometry. We have also succeeded in elucidating the growth mechanisms involved, apropos of surface roughness findings.     

新型工艺制备ZnO薄膜的结构与形貌研究

采用了一种新型工艺制备ZnO薄膜。新工艺采用二步法,首先在N型Si(100)衬底上用离子束沉积溅射一层金属Zn膜,然后通过热氧化金属Zn膜制备ZnO薄膜。通过X射线衍射、原子力显微镜对不同制备工艺下的ZnO薄膜进行结构与形貌的分析比较。研究表明,Zn膜的离子束溅射沉积时间、热氧化时间和辅助枪的离子束对热氧化后的ZnO薄膜再轰击处理对ZnO薄膜的结构与形貌都会产生影响。     

Effect of thickness on nanostructured SnO2 thin films by spray pyrolysis as highly sensitive H2S gas sensor

Nanostructured SnO2 thin films were prepared by spray pyrolysis technique onto glass substrates with different thickness by varying quantity of precursor solution. The structural, optical and electrical properties of these films have been studied. The crystallographic structure of the films was studied by X-ray diffraction (XRD). It is found that the films are tetragonal with (110) orientation. The grain size increases with thickness. Atomic Force Microscopy (AFM) showed that the nanocrystalline nature of the films with porous nature. The grain size increased 14 to 29 nm with increase in film thickness. The studies on the optical properties show that the direct band gap value decreases from 3.75 to 3.50 eV. The temperature dependence of the electrical conductivity was studied. The activation energies of the films are calculated from the conductance temperature characteristics. The nanostructured SnO2 thin films were used as sensing layers for resistive gas sensors. The dependence of gas sensing properties on the thickness of SnO2 thin films was investigated. The gas response of the SnO2 thin films towards the H2S gas was determined at an operating temperature of 150 degrees C. The sensitivity towards H2S gas is strongly depending on surface morphology of the SnO2 thin films.     

Sol-gel制备PLCT薄膜的结晶特性与电畴结构研究

运用sol-gel技术制备了(Pb,La,Ca)TiO3(简写为PLCT)铁电薄膜;利用XRD、SEM、AFM和EDAX分析了PLCT薄膜的结构、表面形貌和组分。XRD衍射结果表明,PLCT薄膜呈钙钛矿结构。随着退火时间的增加,PLCT薄膜的XRD衍射峰的强度也随之增加。SEM、AFM分析表明,PLCT铁电薄膜表面平整、致密、无裂缝。EDAX分析表明,PLCT薄膜的实际组分十分接近设计组分。利用PFM分析了PLCT薄膜的电畴结构,发现随着退火时间的增加,PLCT薄膜的电畴由细小圆点状逐渐增大并形成片状电畴。     

铝诱导晶化P型非晶硅薄膜实验研究

利用PECVD设备在普通玻璃基片上沉积硼掺杂P型非晶硅薄膜,采用铝诱导晶化法（AIC）在氮气气氛保护下进行退火处理制备出P型多晶硅薄膜,研究了不同厚度的金属铝膜和热处理温度对非晶硅薄膜的微观结构、表面形貌的影响。实验结果表明：铝膜相对厚度越厚,对a—Si的晶化诱导效果则越好,在一定温度条件下,相对较厚的铝膜可以缩短a—Si晶化为polv-Si的时间,并且能使a—Si的晶化更加完整,产生尺寸较大的硅晶颗粒。在铝膜厚度相同,退火温度相同的条件下,热处理的时间越长,则晶化发生的程度越深,晶化越为彻底。     

Micromorphology and nanomechanical characteristics of sputtered aluminum thin films

Micromorphology and nanoindentation properties of sputtered aluminum thin films are presented. The field emission scanning electron microscope, atomic force microscopy (AFM) and nanoindentation results are presented for films prepared at a substrate temperature ranging between 44.5 °C and 100 °C. A multifractal approach on the microstructure is presented to comprehend the micromorphology of the films. The roughness decreases, whereas fractal dimension increases as the temperature increases. The hardness and Young's modulus do not exhibit any predictable trend. Hardness and Young's modulus exhibit a linear relationship.     

Biomimetic formation of titania thin films: effect of amino acids on the deposition process

Different types of amino acids have been used as additives to control the aqueous deposition of titanium dioxide thin films on single-crystal Si wafers. Thin titania films can be obtained through a chemical bath deposition (CBD) process using TiCl? as a precursor in an aqueous solution at temperatures below 100 °C. The addition of amino acids to the deposition solution was shown to reduce the thickness and roughness of the films and to increase their density. These protein building blocks were employed to modify the deposition rate as well as the size of aggregates that form the film. The thickness, crystallinity, morphology and composition of the grown films were characterized by a variety of techniques, including XRD, XPS, AFM and SEM. The consequences of the type of the amino acid additive (and its concentration in the solution) on the microstructural evolutions of the deposed films are thus revealed and discussed on the basis of the organic-inorganic interactions in solution and at the film surface.     

Microstructure and Surface Topography Evolution of Ti and Ni Thin Structures

This paper presents the results of a study of microstructure and surface topography of electron-beam deposited nano-scale (10-500 nm thick) thin films of Ti and Ni. The films are deposited on substrates with different moduli (Ni, NaCl, and Si). The microstructure of each film is characterized using transmission electron microscopy. The surface topography is also studied using atomic force microscopy. The microscopic observations show that the grain size and film roughness increase with increasing film thickness. The grain coarsening observed in Ni films was greater than that observed in Ti films. Furthermore, the effects of coarsening amplitude on (001) oriented NaCl crystals were much greater than those on stiffer (001) oriented silicon substrates. The implications of the results are then discussed for applications of thin films in biomedical engineering, microelectronics, and micro-electro-mechanical systems (MEMS).     

偏压对直流磁控溅射Fe-N薄膜结构及性能的影响

为了揭示偏压对溅射态Fe-N薄膜磁学行为的影响规律及机理,采用直流磁控溅射工艺在不同偏压下制备了Fe-N薄膜.利用掠入射X射线衍射、小角X射线散射技术和振动样品磁强计研究了薄膜的相结构、厚度、表面粗糙度以及磁性能.结果表明,增加偏压有利于薄膜中非晶的形成,且随着偏压的增大,薄膜的厚度增加,表面粗糙度降低.Fe-N薄膜的磁性能表明,随着偏压的增加,薄膜的饱和磁化强度和矫顽力均有不同程度的减小.偏压的增加导致Fe-N薄膜由晶态向非晶态转变,从而引起磁性能的改变.