Effects of substrate temperature and substrate material on the structure of reactively sputtered TiN films

Stoichiometric TiN films were reactively magnetron sputtered in an Ar-N₂ atmosphere. The films were deposited at various substrate temperatures in the range 200–650°C onto two types of substrate material, high speed steel and stainless steel. The microstructure of the films obtained was investigated by the use of a transmission electron microscope and the morphology was studied in a scanning electron microscope. Measurements of the hardness were also performed. The analysis of the microstructure shows that the growth of the film is markedly influenced by the substrate material. In particular, the high speed steel substrates were found to have a considerable influence on the microstructure. The vanadium carbide particles in these steels, which have a good lattice match to TiN, stimulate a localized epitaxial growth to occur on these carbide particles. This results in a microstructure consisting of large grains surrounded by small grains. The shape of the large grains is influenced by the temperature. In the development of these large grains cracks and/or voids occur in and around the grains at substrate temperatures above 400°C and the hardness drops by about 20%. No large grains were found on films deposited onto stainless steel and their hardness increases slightly with temperature. High hardness for films deposited onto the high speed steel substrate at temperatures above 400°C can also be obtained if a substrate bias is used. Ion bombardment during film growth suppresses the formation of the large grains with voided or cracked boundaries because of a continuous renucleation process. The formation of the different microstructures is discussed in terms of surface energy minimization and thermally activated processes as surface and grain boundary migration.     

Influence of substrate temperature and film thickness on the structure of reactively evaporated In2O3 films

Indium oxide films 25–550 Å thick were reactively evaporated at an oxygen pressure of about 0.27 Pa and at a substrate temperature between room temperature and 400°C. The dependence of the structure of the films on the substrate temperature and on the film thickness was studied using transmission electron microscopy and electron diffraction. It was found that thick films (about 550 Å) were amorphous at room temperature, partially crystallized at 50–125°C and crystalline at 150–400°C. The crystallinity of the films deposited at 150–250°C also depended markedly on the film thickness. Very thin films about 25 Å thick were quasi-amorphous, but with increasing film thickness the amorphous phase transformed into a crystalline phase.The thermal transformation of the amorphous films after deposition was also studied. Amorphous films about 550 Å thick deposited at room temperature and 100°C crystallized at 230°C and 210°C respectively.     

塑料基TiO2电致变色薄膜制备及性能研究

采用溶胶-凝胶法分别在镀有ITO透明电极的玻璃和塑料基体上制备了TiO2电致变色薄膜,对比研究了不同基体上溶胶的成膜性及薄膜的电致变色性能.结果表明:在相对湿度低于15%的环境中,采用0.4mol/L的溶胶可以通过多次提拉制得表面光洁的较厚透明TiO2薄膜;随热处理温度的升高,薄膜的电色可逆性变好,循环寿命变大,但离子储存能力下降;塑料基TiO2薄膜与相同条件下制备的玻璃基薄膜具有相似的性能,呈现出较弱的阴极电致变色效应和较强的Li 储存能力,有望用作柔性电致变色器件的对电极.     

Structural and resistivity studies of ion plated metal films on plastics

The comparison of conventionally evaporated and ion plated metal films on plastic substrates that was reported previously has now been extended to include structural and resistivity studies. The problems encountered with d.c. are eliminated with r.f. biasing but in both bias conditions a superior adhesion and more fine grain structure is achieved than for conventional evaporation. Preliminary resistivity measurements on d.c. diode and triode ion plated copper films on polyethersulphone show that resistivities comparable to the bulk value can be achieved.     

氨等离子体离子注入改性Ti-O薄膜表面

在Ti-O薄膜表面固定粘连可以使其内皮化。然而欲在Ti-O薄膜表面实现生物分子固定，必须对Ti-O薄膜表面进行活化改性，比如引入具有反应性的官能团。采用非平衡磁控溅射设备制备了Ti-O薄膜，随后用等离子体浸没离子注入（PⅢ）技术对Ti-O薄膜表面进行等离子体活化改性，处理气体为氨气。并分别用扫描电子显微镜（SEM）、X射线光电子能谱（XPS）对注入后的样品表面形貌、表面成分进行分析。结果表明，有一定量的氨基被引入到材料表面。     

Influence of substrate temperature on the growth and properties of reactively sputtered In-rich InAlN films

Indium-rich InAlN films were prepared on Si (111) substrates by using reactive co-sputtering in a mixed Ar-N₂ atmosphere. The substrate temperature was varied from room temperature to 300 °C to investigate the film’s growth and properties at different temperatures. Structural and optical properties of the films were evaluated through high resolution XRD and Raman spectroscopy respectively, surface morphology and roughness analysis was performed by using FE-SEM and AFM respectively, whereas the electrical characterizations were made through resistivity and current–voltage (I–V) measurements respectively. Highly c-axis oriented nanocrystalline InAlN films with wurtzite structure were obtained at a substrate temperature of 100 °C and above. Structural quality of the films was improved with increase of the substrate temperature. The Raman spectroscopy revealed A₁ (LO) modes which became more intense by the increasing the substrate temperature. The electrical studies indicated n-type nature of InAlN film having electron concentration in the range 3 × 10¹⁹–20 × 10¹⁹ cm^?3. The electrical resistivity exhibited a decreasing trend with increase of the deposition temperature. The I–V measurements showed a noticeable increase in the value of current by increasing the substrate temperature to 300 °C.     

Structural and electronic impact of SrTiO3 substrate on TiO2 thin films

We demonstrate that the atomic structures, electronic states, and bonding nature of the interface between SrTiO₃ substrate and anatase TiO₂ thin films could be related and technologically manipulated at the atomic level. Applying advanced transmission electron microscopy, the grown anatase TiO₂ thin films are found to make a clean and direct contact to the SrTiO₃ substrates in an epitaxial, coherent, and atomically abrupt way. The atomic-resolution microscopic images reveal that the interface comprises SrO-terminated SrTiO₃ and Ti-terminated TiO₂ with the interfacial Ti of TiO₂ sitting above the hollow site, which is confirmed theoretically to be the most energetically favorable. Quantitatively, the first-principles calculations predict that the oxygen sublattice at the interface undergoes a notable reconstruction, i.e., the interfacial O atoms of TiO₂ are displaced largely toward the SrO plane of the SrTiO₃, flattening the originally zigzag TiO₂ atomic chains. Consequently, the interfacial layers suffer a remarkable modification in the charge accumulation and also a deviation in the density of states from their bulk counterparts, indicating that the substrate can have an impact on the deposited thin films electronically. Using several analytic methods, the SrTiO₃/TiO₂ interface is found to take on a metallic nature, and the interfacial bonding is determined to be of a mixed covalent and ionic character. This combined experimental and theoretical investigation gains insight into the complex atomic and electronic structures of the buried interface, which are fundamental for relating the atomic-scale structures to their properties on a quantum level.     

Electrical studies of reactively sputtered Fe-doped VO2 thin films

Thin films of V_1−xFe_xO₂ (O<-x≤0.12) were prepared by r.f. reactive sputtering, and the resistivity of these films was measured from 25°C to 100°C. The semiconductor-metal transition temperature decreases as the iron content is increased at a rate of −6C°/at %Fe up to 1.4 %Fe. Beyond this concentration, the transition temperature then begins to increase slowly, remaining unchanged beyond 3% Fe. The apparent activation energy increases rapidly from 0.23 eV to a plateau of 0.33 eV, which then remains independent of the Fe concentration. This overall behavior is in contrast to previous reports and suggests that the iron has been incorporated into the VO₂ lattice in a fashion previously unobserved.     

Effects of substrate temperature on the microstructure and photocatalytic reactivity of TiO2 films

Transmission electronic microscopy is used to study the structure, morphology and orientation of thin TiO2 films prepared by reactive magnetron sputtering on glass slides at different substrate temperatures (100 to 400 °C). The TiO2 films are used to purify a dye in waste water. The microstructure and photocatalytic reactivity of TiO2 films have been shown to be functions of deposition temperature. In the temperature range examined, all film samples have a porous nanostructure and the dimension of particles grown with increasing deposition temperature. Films are amorphous at temperatures of 100 °C and only anatase phase forms at 200 °C and above. Films deposited between 200 to 300 °C show a preferred orientation, while films at 400 °C change into complete random orientation. Deposition at 250 °C yields high efficiency in photocatalytic degradation owing to the high degree of preferred orientation and nanocrystalline/nanoporous anatase phase. © 1998 Kluwer Academic Publishers     

Interface between Sn-Sb-Cu solder and copper substrate

Influence of antimony and copper in Sn-Sb-Cu solder on the melting and solidification temperatures and on the microstructure of the interface between the solder and copper substrate after wetting the substrate at 623 K for 1800 s were studied. Microstructure of the interface between the solder and copper substrates in Cu-solder-Cu joints prepared at the same temperature for 1800 s was observed and shear strength of the joints was measured. Influence of the atmosphere - air with the flux and deoxidising N₂ + 10H₂ gas - was taken into account. Thermal stability and microstructure were studied by differential scanning calorimetry (DSC), light microscopy, scanning electron microscopy (SEM) with energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD). Melting and solidification temperatures of the solders were determined. An interfacial transition zone was formed by diffusion reaction between solid copper and liquid solder. At the interface Cu₃Sn and Cu₆Sn₅ phases arise. Cu₃Sn is adjacent to the Cu substrate and its thickness decreases with increasing the amount of copper in solder. Scallop Cu₆Sn₅ phase is formed also inside the solder drop. The solid solution Sn(Sb) and SbSn phase compose the interior of the solder drop. Shear strength of the joints measured by push-off method decreases with increasing Sb concentration. Copper in the solder shows even bigger negative effect on the strength.     

衬底对溶胶凝胶法制备TiO2薄膜性能的影响

以钛酸丁酯为前驱体,经浸渍拉膜法在不锈钢以及表面预镀一层非晶态SiO2薄膜的不锈钢表面镀TiO2薄膜.利用XRD、FE-SEM研究了薄膜晶体结构与表面形貌,同时研究了不同衬底上薄膜光催化活性和亲水性,并与以玻璃为衬底的作比较.结果表明,衬底对TiO2薄膜表面形貌及性能的影响很大.以不锈钢为衬底的TiO2薄膜性能光催化活性较弱,但在表面预镀一层非晶态SiO2后TiO2薄膜的光催化活性有所改善.     

沉积条件对RF反应溅射多晶ZnO薄膜结构的影响

采用ＲＦ反应溅射法在Ｓｉ（１１１）、玻璃衬底上制备了具有良好Ｃ轴承向的多晶ＺｎＯ薄膜。用ＸＲＤ分析了沉积条件（衬底温度、工作气体中的氧与氩气压比和衬底种类）对样品结构的影响,发现（１）薄膜的取向性随着衬底温或高而增强,超过４００℃后薄膜质量开始变差;（２）工作气体中氧与氩气压比（Ｐｏ２／ＰＡｒ）为２：３时,薄膜取向性最好;（３）薄膜晶粒尺寸１１－３４ｎｍ,相同沉积条件下,单晶硅衬底样品（００２）衍     

离子束后处理对TiO2薄膜光学性质影响的实验研究

采用中频反应磁控溅射方法和线性阳极层离子源实现了TiO2薄膜在线制备和在线离子束后处理。通过对薄膜光学性质的研究,发现氧离子束后处理对提高薄膜折射率,降低薄膜吸收率具有明显效果。为工业生产中,薄膜的在线制备及后处理提供了切实可行的手段。     

The effect of the substrate temperature on the optical properties of reactively evaporated silicon oxide films

SiO was evaporated simultaneously onto substrates held at different temperatures in the range 25–300°C. The evaporations were carried out in an oxygen atmosphere or in high vacuum. The refractive index, the absorption constant and the thickness of the films were evaluated, and their dependence on substrate temperature, oxygen pressure and evaporation rate was determined. In addition, the packing density and the infrared transmission of the films were investigated. The influence of the substrate temperature is most pronounced under oxidizing conditions.