Piezoresistive response of ITO films deposited at room temperature by magnetron sputtering

Indium tin oxide (ITO) thin films have been deposited on (100) Si substrates by RF magnetron sputtering from a compact target (90% In₂O₃–10% SnO₂ in weight) with 6 in. in diameter. In order to perform electromechanical characterizations of these films, strain gauges were fabricated. An experimental set-up based on bending beam theory was developed to determine the longitudinal piezoresistive coefficient (π_l) of the strain gauges fabricated. It has been confirmed that electrical resistance of the strain gauges decreases with load increases which results a negative gauge factor. A model based on the activation energy was used to explain the origin of this negative signal. The influence of the temperature on piezoresistive properties of ITO films was also evaluated.     

Properties of Ce-doped ITO films deposited on polymer substrate by DC magnetron sputtering

Ce-doped indium tin oxide (ITO:Ce) films were deposited on flexible polyimide substrates by DC magnetron sputtering using ITO targets containing various CeO₂ contents (CeO₂ : 0, 0.5, 3.0, 4.0, 6.0 wt.%) at room temperature and post-annealed at 200 °C. The crystallinity of the ITO films decreased with increasing Ce content, and it led to a decrease in surface roughness. In addition, a relatively small change in resistance in dynamic stress mode was obtained for ITO:Ce films even after the annealing at high temperature (200 °C). The minimum resistivity of the amorphous ITO:Ce films was 3.96 × 10^− 4 Ωcm, which was deposited using a 3.0 wt.% CeO₂ doped ITO target. The amorphous ITO:Ce films not only have comparable electrical properties to the polycrystalline films but also have a crystallization temperature > 200 °C. In addition, the amorphous ITO:Ce film showed stable mechanical properties in the bended state.     

Enhanced characterization of ITO films deposited on PET by RF superimposed DC magnetron sputtering

Tin-doped indium oxide (ITO) films were deposited on polyethylene terephthalate substrates by RF superimposed DC magnetron sputtering using an ITO target composed of In₂O₃ (90 wt.%):SnO₂ (10 wt.%). The total sputtering power was maintained at 70 W and the power ratio of RF/(RF + DC) was varied from 0 to 100% in steps of 25%. The discharge voltage and deposition rate decreased with increasing RF/(RF + DC) power ratio. The ITO film deposited at a 50% RF portion of the total power showed the lowest resistivity (3.18 × 10^− 4 Ωcm), high transmittance (87.5%) and relatively good mechanical durability, which was evaluated using bending and scratch tests.     

High quality ZnO films deposited by radio-frequency magnetron sputtering using layer by layer growth method

Three-layered ZnO films were deposited on Si substrates by radio-frequency magnetron sputtering using layer by layer growth method. The Raman scattering confocal analysis confirms that ZnO film quality is improving at increasing the number of ZnO layers at film deposition.Applied method of deposition was used to realize homoepitaxial growth of ZnO films on c-Al₂O₃, Si, SiN_x/Si, glass and ITO/glass substrates. In order to improve the film quality we increased the number of deposition stages up to 5. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmittance measurements were used to testify the quality of grown five-layered ZnO films. XRD results showed that all five-layered ZnO films have (002) texture. The second order diffraction peak (004) on XRD spectra additionally testifies to the high quality of all five-layered ZnO films. SEM results demonstrated that no defects such as cracks and dislocations caused by interruption of deposition ZnO films were observed. Transmittance measurement results showed that ZnO films deposited on transparent substrates have abrupt absorption edge and high optical transmission in the visible region of the spectrum.     

Microstructures of ITO films deposited by d.c. magnetron sputtering with H2O introduction

ITO films were deposited by d.c. magnetron sputtering with/without H₂O introduction. The structural and optoelectrical properties of the films were analyzed in detail. The films deposited with H₂O introduction exhibited an entirely amorphous structure, whereas the as-deposited films deposited without H₂O introduction exhibited a polycrystalline In₂O₃ structure. The amorphous ITO films deposited under the high H₂O partial pressure were confirmed to contain a much higher concentration of hydrogen inside the films by secondary ion mass spectroscopy, which remained after post-annealing at 350 °C. The crystallization temperature of the films subjected to post-annealing was increased to higher than 220 °C. These stable amorphous ITO films had a wet-etching rate in oxalic acid solution two orders of magnitude higher than that of the films deposited without H₂O introduction.     

室温直流磁控溅射制备ITO膜及光电性能研究

室温条件下,在玻璃衬底上,采用直流磁控溅射法制备了ITO膜.研究了溅射压强,氧流量和溅射功率等工艺参数对薄膜光电性能的影响.结果表明当Ar流量为44.2 sccm和溅射时间20 min等参数不变时,溅射气压0.7 Pa,氧流量0.62 sccm和溅射功率130 W为最佳工艺条件.并得到了电阻率5.02×10-4 Ω·cm,在可见光区平均透过率80%以上ITO薄膜.     

非织造基磁控溅射纳米银薄膜导电性能的研究

在室温条件下采用射频磁控溅射在丙纶(PP)、聚乳酸(PLA)熔喷非织造布表面生长纳米银(Ag)薄膜,并且用等离子体预处理样品进行对比。采用扫描电子显微镜(SEM)对其形貌进行表征,采用四探针测试仪对所制备的纳米薄膜的导电性能进行表征。研究溅射时间、孔隙率及孔径分布和等离子处理对非织造基纳米银薄膜的导电性能的影响。实验表明:随着反应溅射时间的增加,薄膜的方块电阻值下降,导电性能增加;孔径大小也影响薄膜的导电性能,随着孔径的增大,薄膜的导电性能降低;等离子体处理对织物表面进行刻蚀,增加了纤维的比表面积,提高了纤维的润湿性能,改善了织物的导电性能。     

磁控溅射ITO薄膜的退火处理

采用直流磁控溅射方法在室温下玻璃基板上制备ITO(Indium tin oxide)薄膜,并在真空中不同温度(100℃~400℃)下退火处理.研究了退火对薄膜表面形貌、电光特性的影响.XRD测试发现薄膜在200℃退火后结晶,优选晶向为(222).随退火温度升高,方块电阻迅速下降,表面更加平整,薄膜在可见光范围平均透过率提高到85%.     

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.     

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.     

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.     

硅靶中频反应磁控溅射二氧化硅薄膜的特性研究

报道了中频双靶反应磁控溅射制备二氧化硅（SiO2)薄膜的装置、工艺及薄膜特性。对制备的SiO2薄膜的化学配比和元素化学态进行了SAM和XPS分析，测试了膜层对钠离子（Na^ )阻挡性能、光学折射率和可见光的透过率。研究表明作者开发的中频双靶反应磁控溅射沉积SiO2薄膜的设备和工艺可以高速率、大面积制备高质量的SiO2膜。     

Oxidation behavior of Ti-B-C-N coatings deposited by reactive magnetron sputtering

Quaternary Ti-B-C-N coatings with different carbon concentrations are deposited on high-speed steel substrates by reactive magnetron sputtering. The oxidation behavior between 300 and 800 °C under ambient conditions is studied by scanning electron microscopy, high-resolution transmission electron microscopy, Vickers micro-hardness, and X-ray diffraction. The Ti-B-C-N coatings with smaller carbon contents have better oxidation resistance and the oxidation process can be divided into two stages: low-speed oxidation below 700 °C and high-speed oxidation above 700 °C. An oxidation mechanism is proposed to explain the relationship between the reaction with oxygen and observed oxidation behavior.     

磁控溅射技术制备硅纳米晶多层膜及微观结构表征

在室温下,分别利用常规磁控溅射和反应磁控溅射技术交替沉积Si薄膜和Si1-xNx薄膜在单晶硅基体上制备了Si/Si1-xNx纳米多层膜。接下来,在高温下对Si/Si1-xNx多层膜进行退火诱发各层中形成硅纳米晶。研究了Si1-xNx层厚度和N2流量沉积对Si/Si1-xNx多层膜中Si量子点形成的影响。TEM检测结果表明,N2流量为2.5mL/min时沉积的多层膜退火后形成了尺寸为20～30nm的等轴Si3N4纳米晶;N2流量为5.0mL/min时沉积的多层膜退火后在Si层和Si1-xNx多层中均形成了硅纳米晶,而在7.5mL/min N2流量下沉积的Si/Si1-xNx多层膜退火后仅在Si层中形成了硅纳米晶。     

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.     

磁控溅射法制备低电阻率Ta薄膜研究

在无匹配层、常温、溅射气体为纯Ar的条件下,利用直流磁控溅射法在Si表面制备了Ta薄膜,系统研究了工作气压及直流功率对薄膜电阻率及微观结构的影响。分别用四探针测试仪、X射线衍射仪、原子力显微镜对不同条件下制备的Ta薄膜电阻率、相结构及表面形貌进行表征。结果发现,随溅射气压升高,高阻β相出现,薄膜电阻率随之增大;在相同溅射气压下,随着溅射功率的增加,薄膜电阻率先降低后升高。优化溅射工艺后制得的Ta薄膜的电阻率低至29.7μΩ·cm。     

Topography and microstructure of Cu-Sn coatings deposited by magnetron sputtering

The topographical and microstructural features of Cu-Sn coatings deposited by magnetron sputtering using alloy target of Cu-7.8%Sn and Cu-74%Sn onto ferritic stainless steel substrates with a temperature gradient were investigated by means of optical and scanning electron microscopy.Depending on the substrate temperature the alloy film forms by a vapour → solid process or a vapour → liquid process with solidification after substrate cooling. In between a mixed mechanism of vapour → liquid → solid occurs during condensation in the temperature ranges 990–1170 K and 460–790 K for coatings deposited by sputtering of Cu-7.8%Sn and Cu-74%Sn targets respectively.The copper-rich condensate formed in the temperature range 370–1220 K consists of a single-phase α solid solution of tin in copper. Its lattice parameter decreases with increasing temperature mainly because of the decreasing tin content.The film obtained by sputtering a Cu-74%Sn target has a two-phase η′-Cu₆Sn₅ plus tin structure independently of the deposition temperature.     

Influence of Au underlayer thickness on the electro-optical properties of ITO/Au layered films deposited by magnetron sputtering on unheated polycarbonate substrates

Transparent and conducting tin-doped indium oxide (ITO) and ITO/Au multilayered films were prepared on polycarbonate (PC) substrates by magnetron sputtering without intentional substrate heating. In order to consider the influence of the Au thickness on the optoelectrical properties and structure of ITO/Au films, the thickness of the Au underlayer was varied from 5 to 20 nm. The optoelectrical properties of the films were quite dependent on the Au film thickness. The lowest sheet resistance of 11 Ω/sq. and an optical transmittance of 61% with respect to air was obtained from ITO (95 nm)/Au (5 nm) films. Thin film crystallinity was also affected by the presence of the Au underlayer and varied with the thickness of the Au films. In X-ray diffraction (XRD) spectra, ITO films did not show any characteristic diffraction peak, while ITO/Au films with a 5-nm Au underlayer showed a characteristic diffraction peak. From the figure of merit, it can be concluded that the most effective Au thickness in ITO/Au films is 5 nm.     

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.