RF磁控溅射法制备ZnO薄膜的XRD分析

采用RF磁控溅射法，在玻璃村底上制备多晶ZnO薄膜，并对所制备的ZnO薄膜在空气气氛中进行了不同温度（350～600℃）的退火处理和600℃时N2气氛中的退火处理。利用X射线衍射分析了溅射参数如溅射功率、溅射氧分压、衬底温度以及退火处理对ZnO薄膜结晶性能的影响。结果表明，合适的衬底温度和退火处理能够提高ZnO薄膜的结晶质量。     

ZnO缓冲层上低温生长Al掺杂的ZnO薄膜

采用射频磁控溅射法在ZnO缓冲层上制备了不同Al掺杂量的ZnO（AZO）薄膜。利用X射线衍射（XRD）、扫描电子显微镜（SEM）和光致发光（PL）等表征技术,研究了AZO薄膜的微观结构、表面形貌和发光特性。结果表明,随着Al掺杂量的增加,ZnO薄膜的择优取向性发生了改变,且当Al的掺杂量为0.81%（原子分数）时,（002）衍射峰与其它衍射峰强度的比值达到最大,表明适合的Al掺杂使ZnO薄膜的择优取向性得到了改善。在可见光范围内薄膜的平均透过率超过70%。通过对样品光致发光（PL）谱的研究,发现所有样品出现了3个发光峰,分别对应于以444nm（2.80eV）、483nm（2.57eV）为中心的蓝光发光峰和以521nm（2.38eV）为中心较弱的绿光峰。并对样品的发光机理进行了详细的探讨。     

AlN/Si衬底上ZnO薄膜的择优取向生长

当ZnO薄膜直接沉积在Si衬底上时,由于ZnO与Si的晶格失配度大,不易于获得高质量的ZnO薄膜.因此,选择合适的衬底材料沉积ZnO薄膜,对提高其质量非常重要.本文采用射频磁控溅射法,通过在Si(100)衬底上预沉积AlN作为ZnO薄膜生长的缓冲层,获得了择优取向的ZnO薄膜.我们还讨论了ZnO薄膜在AlN/Si衬底上的取向生长机理.     

在p-Si(100)上溅射法生长ZnO的结构和光学特性

室温下在ｐ－Ｓｉ（１００）上采用直流反应磁控溅射法外延生长了ＺｎＯ薄膜。ＸＲＤ测量表明了ＺｎＯ是高度ｃ轴单一取向生长的,ＸＲＣ测量则表明了ＺｎＯ的高质量在室温下的ＰＬ测量中见到了带边发射,其强度与晶体质量有关。     

ZnO薄膜生长技术的最新研究进展

ZnO是一种新型的Ⅱ-Ⅳ族半导体材料，目前已研究了开发了许多ZnO薄膜的生长技术，其中，磁控溅射，喷雾热分解，分子束外延，激光脉冲沉积，金属有机物化学气相外延等沉积技术得到了有效应用；而一些新的工艺方法，如溶胶－凝胶，原子层外延，化学浴沉积，离子吸附成膜，离子束辅助沉积，薄膜氧化等也进行了深入研究，详细阐述了ZnO薄膜生长技术的最新研究进展。     

掺杂ZnO薄膜研究

采用电子束蒸发方法在玻璃衬底上制备ZnO薄膜和掺杂ZnO薄膜.通过X射线衍射、台阶仪及Hall效应等测试研究了衬底温度和掺杂对晶体质量和电学性能的影响,发现原位生长的ZnO薄沿c轴择优生长,且掺杂ZnO薄膜具有低达3.029×10-4Ω·cm的电阻率.     

反应磁控溅射ZnO薄膜的高温退火研究

ZnO薄膜是一种新型的Ⅱ-Ⅵ族直接能带化合物半导体材料，有可能实现短波长的探测器，LED和LD等光电子器件，用磁控溅射法在硅衬底上生长ZnO薄膜,，由于薄膜与衬底之间较大的应力失配，以及由于较快的生长速率，薄膜中存在较多的Zn间隙原子和O空位，在薄膜中存在应力。通过高温退火，可以使应力得到驰豫，降低O空位和Zn空隙原子的浓度，提高薄膜的化学计量比和改善薄膜的结晶质量，本实验用XRD和AFM研究了高温退火对ZnO薄膜的晶体性能和表面的影响。对ZnO薄膜在退火处理后c轴方向的应力性质的转变作了机理上的探讨。     

磁控溅射制备大面积ZnO薄膜性能的研究

通过磁控溅射氧化锌陶瓷靶材的方法在玻璃基片上制备ZnO薄膜,研究了溅射功率、溅射气压以及基片温度对ZnO薄膜相结构、禁带宽度及光学性能的影响.使用X射线衍射仪(XRD)分析了薄膜相结构,使用台阶仪测试薄膜厚度,采用薄膜测试仪测试薄膜的透过率,采用扫描电镜(SEM)观察薄膜表面形貌.结果表明:不同制备条件下均形成具有(0...     

电子束退火法制备ZnO薄膜

利用溶胶-凝胶法制备出ZnO的凝胶前驱膜,用电子束退火取代传统炉子退火,对前驱膜进行后处理,退火时固定电子束加速电压为10kV,退火时间为5min,调节聚焦束流和电子束束流,使退火温度在600~900℃范围内变化。扫描电镜(SEM)、X射线衍射(XRD)、原子力显微镜(AFM)和压电力显微镜(PFM)的测试结果表明,运用电子束退火法可制备出晶粒尺寸小于30nm、沿(002)择优取向、具有压电效应的六方ZnO薄膜,且随着退火温度的升高,晶粒尺寸逐渐变大,薄膜的结晶性和取向变好,压电效应越来越明显。     

RF sputtered piezoelectric zinc oxide thin film for transducer applications

This paper demonstrates the substrate dependency of the c-axis zinc oxide growth in radio-frequency sputtering system. Different deposition conditions were designed to study the influences of Si, SiO₂/Si, Au/Ti/Si, and Au/Ti/SiO₂/Si substrates on the piezoelectric and crystalline qualities of the ZnO thin films. Experimental results showed that the multilayer of Au/Ti/SiO₂/Si-coated silicon substrate provided a surface that facilitated the growth of ZnO thin film with the most preferred crystalline orientation. The 1.5 μm-thick thermally grown amorphous silicon dioxide layer effectively masked the crystalline surface of the silicon substrate, thus allowing the depositions of high-quality 20 nm-thick titanium adhesion layer followed by 150 nm-thick of gold thin film. The gold-coated surface allowed deposition of highly columnar ZnO polycrystalline structures. It was also demonstrated that by lowering the deposition rate at the start of sputtering by lowering RF power to less than one-third of the targeted RF power, a fine ZnO seed layer could be created for subsequent higher-rate deposition. This two-step deposition method resulted in substantially enhanced ZnO film quality compared to single-step approach. The influence of stress relaxation by annealing was also investigated and was found to be effective in releasing most of the residual stress in this layered structure.     

Fabrication of piezoelectric thin film of zinc oxide in composite membrane of ultrasonic microsensors

The fabrication of the thin piezoelectric layers on the silicon substrate by means of the pulse dc and the dc magnetron sputtering methods is discussed. The influences of the different kind of the surface, the conditions of deposition as well as the process of the thermal stabilising on the properties of the piezoelectric layer were investigated. The results of the investigations of the diffraction spectrum for the thin ZnO films are presented and discussed. The selection of the technological process parameters for the production of the thin ZnO layers in the sensor membranes with the ultrasonic wave generated was analysed.     

Chemically deposited zinc oxide thin film gas sensor

Zinc oxide (ZnO) thin films were prepared by a low cost chemical deposition technique using sodium zincate bath. Structural characterizations by X-ray diffraction technique (XRD) and scanning electron microscopy (SEM) indicate the formation of ZnO films, containing 0.05–0.50 m size crystallites, with preferred c-axis orientation. The electrical conductance of the ZnO films became stable and reproducible in the 300–450 K temperature range after repeated thermal cyclings in air. Palladium sensitised ZnO films were exposed to toxic and combustible gases e.g., hydrogen (H₂), liquid petroleum gas (LPG), methane (CH₄) and hydrogen sulphide (H₂S) at a minimum operating temperature of 150 °C; which was well below the normal operating temperature range of 200–400 °C, typically reported in literature for ceramic gas sensors. The response of the ZnO thin film sensors at 150 °C, was found to be significant, even for parts per million level concentrations of CH₄ (50 ppm) and H₂S (15 ppm).     

Growth and characterization of electrosynthesised zinc oxide thin films

Zinc oxide (ZnO) films have been electrodeposited from an aqueous solution containing 0.1 M zinc nitrate as the electrolyte with pH around 5±0.1. The deposition was carried out by galvanostatic reduction with an applied cathodic current density in the range between 5 and 20 mA cm⁻². The influence of bath composition on the preparation of ZnO films is studied. The effects of zinc nitrate concentration and cathodic current density on the deposition rate of ZnO films were also studied. An optimum current density of 10 mA cm⁻² is identified for the growth of ZnO film with improved crystallinity and optical transmittance. The crystalline structure of the deposits studied by X-ray diffraction reveals the possibility of growing hexagonal ZnO films under suitable electrochemical conditions. The surface morphological studies by scanning electron micrographs revealed the presence of nodular appearance for films deposited at 800 °C bath temperatures.     

High performance low temperature solution-processed zinc oxide thin film transistor

Amorphous zinc oxide thin films have been processed out of an aqueous solution applying a one step synthesis procedure. For this, zinc oxide containing crystalline water (ZnO⋅ × H₂O) is dissolved in aqueous ammonia (NH₃), making use of the higher solubility of ZnO⋅ × H₂O compared with the commonly used zinc oxide. Characteristically, as-produced layers have a thickness of below 10 nm. The films have been probed in standard thin film transistor devices, using silicon dioxide as dielectric layer. Keeping the maximum process temperature at 125 °C, a device mobility of 0.25 cm²V^− 1s^− 1 at an on/off ratio of 10⁶ was demonstrated. At an annealing temperature of 300 °C, the performance could be optimized up to a mobility of 0.8 cm²V^− 1s^− 1.     

PZT压电薄膜无阀微泵

介绍了一种基于PZT压电薄膜的无阀压电微泵.该微泵利用自制的压电圆型薄膜片作为驱动部件、聚二甲基硅氧烷(PDMS)作为泵膜.本文在对微豕制备工艺研究的基础上,对其性能进行了数值和实验研究.建立了基于扩张管/收缩管理论的无阀微泵的有限元模型.利用MFX-AN-SYS/CFX技术实现了对微泵的双向流固耦合分析.对微泵的锥形角、最小宽度、扩散管长度、泵腔高度进行数值计算,得到了优化参数.数值计算的结果与实际测量的数据进行了比较,验证了仿真的正确性.     

Growth and characterization of transparent conducting nanostructured zinc indium oxide thin films

Transparent conductive oxide (TCO) films have been widely used in various applications, such as for transparent electrodes in flat-panel displays, and in solar cells, optoelectronic devices, touch panels and IR reflectors. Among these, tin doped zinc oxide (ZTO) and indium doped zinc oxide (ZIO) have attracted considerable attention. Particularly, IZO thin film is the best candidate for high-quality transparent conducting electrodes in OLEDs and flexible displays. In this work zinc indium oxide (ZIO) thin films were deposited on glass substrate with varying concentration (ZnO:In₂O₃ — 100:0, 90:10, 70:30 and 50:50 wt.%) at room temperature by flash evaporation technique. These deposited ZIO films were annealed in vacuum to study the thermal stability and to see the effects on the physical properties. The XRF spectra revealed the presence of zinc and indium with varying concentration in ZIO thin films, while the surface composition and oxidation state were analyzed by X-ray photoelectron spectroscopy. The core level spectra were deconvoluted to see the effect of chemical changes, while the valance band spectra manifest the electronic transitions. The surface morphology studies of the films using atomic force microscopy (AFM) revealed the formation of nanostructured ZIO thin films. The optical band gap was also found to be decreased for both types of films with increasing concentration of In₂O₃.     

Transparent conducting zinc oxide thin film prepared by off-axis rf magnetron sputtering

Highly conducting and transparent ZnO : Al thin films were grown by off-axis rf magnetron sputtering on amorphous silica substrates without any post-deposition annealing. The electrical and optical properties of the films deposited at various substrate temperatures and target to substrate distances were investigated in detail. Optimized ZnO : Al films have conductivity of 2200 S cm^-1 and average transmission in the visible range is higher than 85%. The conductivity and mobility show very little temperature dependence.     

Uniformity of gallium doped zinc oxide thin film prepared by pulsed laser deposition

Recently, transparent conducting oxide thin films have attracted attention for the application to transparent conducting electrodes. In this work, we evaluated the uniformity of electrical, optical and structural properties for gallium doped zinc oxide thin films prepared on the 10 × 10 cm² silica glass substrate by pulsed laser deposition. The resistivity, carrier concentration, mobility, bonding state and atomic composition of the film were uniform along in-plane and depth direction over the 10 × 10 cm² area of the substrate. The film showed the average transmittance of 81-87%, resistivity of 1.4 × 10^− 3 Ω cm, carrier concentration of 9.7 × 10²⁰/cm³ and mobility of 5 cm²/Vs in spite of the amorphous X-ray diffraction pattern. The gradual thickness distribution was found, however, the potential for large-area and low temperature deposition of transparent conducting oxide thin film using pulsed laser deposition method was confirmed.