基于AZ5214光致保护层的As2S3硫系脊型波导制备

实验研究发现AZ5214光刻胶在一定曝光剂量下显影后会留存一定厚度的底膜，该底膜可以在干法刻蚀过程中避免As-S薄膜与碱性显影液直接接触，减轻薄膜表面损伤，起到保护作用。基于此，采用该底膜作为保护层制备As₂S₃脊型波导，研究结果表明，在AZ5214光刻胶匀胶厚度为2.1μm、紫外曝光剂量为200 mJ/cm²、显影时间为45 s的条件下会留存约为220 nm厚的光致保护层，该条件下保护层均匀性较好，且在刻蚀阶段可以完全去除。实验表明利用此保护层制备的As₂S₃脊型波导具有良好的形貌特征，波导脊宽约为3μm、脊高约为800 nm的As₂S₃脊型波导的传输损耗约为0.74 dB/cm@1 550 nm。     

弯月面涂胶均匀性改进

针对大面积衍射光学元件制作过程中对光刻胶均匀涂覆的困难,研究弯月面均匀涂胶方法。利用沟槽型弯月面涂胶机,分析影响光刻胶厚度和厚度均匀性的因素。从实验上验证了光刻胶的胶厚和涂覆扫描速率的正相关关系。分析了光刻胶的浓度、基片与涂覆器刀口间隙、供胶速率等因素对胶厚及胶厚均匀性的影响。利用非接触式的激光微位移传感器监测基片和涂覆器刀口间隙,控制此间隙的抖动小于15 m,优化系统运行的稳定性,提升了弯月面涂覆胶厚的均匀性,实现了胶厚峰谷值偏差3%和标准偏差0.5%的均匀光刻胶涂覆,能够满足脉宽压缩光栅等制作过程中对光刻胶均匀涂覆的需求。     

凹球面涂布光刻胶均匀性研究

通过对离心法在凹球面上涂布光刻胶过程进行分析,阐明了离心状态下光刻胶在凹球面基底上的流动机理,结合试验提出影响凹球面涂布光刻胶膜厚均匀性的主要因素有胶液粘度、旋涂速度、旋涂时间,列举了以上因素引起的各种现象,并进行了理论分析。引用凹球面旋涂光刻胶的膜厚公式,建立了膜厚与速度关系数学模型;利用流体力学原理解释了有限圆形空间中流体速度对膜层均匀性的影响,从而解决了大曲率凹球面上制备微细图形结构的关键工艺问题,对非球面上制备微细图形具有借鉴作用。     

建筑节能薄膜的设计与制备

对介质－金属组合的建筑节能薄膜进行了理论设计，给出双导和三层膜的理论参数，用计算机模拟了大面积薄膜的膜厚均匀性分布，获得了最佳的蒸发源配置，实验上达到了满足实际使用的均匀性要求，最后给出了实际样品的光谱特性。     

TE0导模干涉刻写周期可调亚波长光栅理论研究

通过棱镜耦合激发非对称金属包覆介质波导结构中的TE₀导波模式, 利用两束TE₀模的干涉从理论上实现了周期可调的亚波长光栅刻写. 分析了TE₀模式的色散关系, 刻写亚波长光栅的周期与激发光源、棱镜折射率、光刻胶薄膜厚度及折射率之间的关系. 用有限元方法数值模拟了金属薄膜、光刻胶薄膜和空气多层结构中TE₀导模的干涉场分布. 研究发现, 激发光源波长越短, TE₀ 模干涉刻写的亚波长光栅周期越小; 光刻胶越厚, 刻写的亚波长光栅周期越小; 高折射率光刻胶有利于更小周期亚波长光栅的刻写. 相较于表面等离子体干涉光刻, 基于TE₀ 模的干涉可在厚光刻胶条件下通过改变激发光源、棱镜折射率、光刻胶材料折射率、特别是光刻胶薄膜的厚度等多种方式实现对亚波长光栅周期的有效调控.     

铁电高分子共聚物薄膜样品真空制膜仪的设计与制作

设计与制作了铁电高分子共聚物薄膜样品真空制膜仪，该制膜仪操作简单，制膜方便，制备出的薄膜样品厚度均匀，膜厚可控制在30－40μm，可替代昂贵的机械静热压式或旋转悬浮式制膜仪。     

干涉高斯光诱导的表面等离子激元驻波场的分析

考虑到实际入射光强的空间分布不均匀,基于Kretschmann模型并采用角谱方法分析模拟了两束高斯光干涉诱导表面等离子激元(SPP)驻波场。与理想平面波不同,高斯光诱导的SPP干涉条纹幅值大小不等,分布复杂,这表明光强空间非均匀程度会严重地影响到曝光深度的分布。还分析了金属薄膜的厚度、损耗以及光刻胶的介电常数对SPP驻波场的影响,并得出不恰当的金属板厚和细微损耗都会极大削弱SPP驻波场,而如果光刻胶的介电常数过大则有可能产生不了表面等离子体共振的结论。     

大口径超薄基板双面溅射膜厚均匀性研究

可见光高透射近红外高截止滤光片采用大口径超薄尺寸的玻璃作为基板,在两面同时沉积制备而成,因此对薄膜均匀性及成膜后基板面型有着较高的要求。以Nb/Si作为薄膜靶材,采用反应溅射镀膜的方法,从靶材磁场强度分布、公-自转系统、基板夹具遮挡角度三个方面分析膜厚均匀性的差异,采用对称膜系结构,实现红外截止滤光片上下表面薄膜应力平衡。最终制备的薄膜均匀性在300 mm范围内达到0.13%,基板翘曲度为0.085 mm,满足使用需求。     

化学溶液法制备Bi-2212超导厚膜及表征

在柔性衬底上制备的Bi-2212(Bi2Sr2CaCu2O8+x)超导厚膜在高场低温下有高的临界电流密度、可塑性好、易加工成材等特点,因而有广阔的应用前景.所以制备低成本、高性能的Bi-2212厚膜技术已经成为此类高温超导材料实用化的关键.本文系统的研究了采用Bi系超导粉前驱化学溶液的方法进行Bi-2212超导厚膜的制备和表征.对制备超导厚膜过程中的关键步骤做了系统的研究,主要包括局部熔融烧结温度、固相烧结温度、匀胶机最高转速、涂层的厚度等对超导转变温度和转变宽度的影响.我们得出最佳的烧结温度和固相温度分别是888℃、845℃,并发现随着匀胶机转速和涂层厚度的增加,超导膜的转变温度逐步提高,当最高转速为4000r/min,涂层厚度设定为七层,制备出的超导膜R～T曲线的第二个相转变点消失了.制备出的超导膜的转变温度在90K左右.与此同时还进行了XRD、SEM测试表征.最终可以得到均匀平整无裂纹的高质量Bi-2212超导厚膜.     

采用溶胶凝胶协同自组装与光刻相结合的方法在反蛋白石结构薄膜中引入二维缺陷

采用溶胶凝胶协同自组装与光刻相结合的方法,在光子晶体反蛋白石结构中引入缺陷,通过溶胶凝胶协同自组装方法在硅片上垂直沉积胶体晶体复合薄膜,把BP212正性光刻胶均匀旋涂在复合薄膜上,通过曝光、显影等光刻工艺,把掩膜版图案复制在复合薄膜上,用此样品再次垂直沉积一层复合薄膜,使图案被复合薄膜覆盖.最后去除胶体微球与光刻胶图案,从而在反蛋白石结构中引入缺陷,用扫描电子显微镜对样品进行表征.分析了光刻胶图案对胶体微球排列的影响.     

ECR-PECVD制备Si3N4薄膜沉积工艺的研究

由偏心静电单探针诊断了电子回旋共振等离子体增强化学汽相沉积(ECR-PECVD)反应室内等离子体密度的空间分布规律．结果表明在轴向位置Z=50cm处,直径Φ12cm范围内等离子体密度分布非常均匀．分析了等离子体密度径向均匀性对沉积速率均匀性和薄膜厚度均匀性的影响．讨论了沉积制备一定薄膜厚度的Si₃N₄薄膜的工艺重复性．研究了各种沉积工艺参数与Si₃N₄薄膜沉积速率的相互关系．得到了ECR-PECVD技术在沉积薄膜时的工 关键词：     

Effect of substrate curvature on thickness distribution of polydimethylsiloxane thin film in spin coating process

The polymer spin coating is critical in flexible electronic manufaction and micro-electro-mechanical system(MEMS)devices due to its simple operation, and uniformly coated layers. Some researchers focus on the effects of spin coating parameters such as wafer rotating speed, the viscosity of the coating liquid and solvent evaporation on final film thickness.In this work, the influence of substrate curvature on film thickness distribution is considered. A new parameter which represents the edge bead effect ratio(re) is proposed to investigate the influence factor of edge bead effect. Several operation parameters including the curvature of the substrate and the wafer-spin speed are taken into account to study the effects on the film thickness uniformity and edge-bead ratio. The morphologies and film thickness values of the spin-coated PDMS films under various substrate curvatures and coating speeds are measured with laser confocal microscopy. According to the results, both the convex and concave substrate will help to reduce the edge-bead effect significantly and thin film with better surface morphology can be obtained at high spin speed. Additionally, the relationship between the edge-bead ratio and the thin film thickness is like parabolic curve instead of linear dependence. This work may contribute to the mass production of flexible electronic devices.     

旋涂法制备氧化锆介质层及其在薄膜晶体管中的应用

采用旋涂法制备了氧化锆介质层薄膜,重点讨论了退火温度以及旋涂转速对薄膜性能的影响及作用机制。研究发现高温后退火一方面使得氧化锆水合物脱水形成氧化锆,另一方面促使氧化锆薄膜结晶。此外,转速较高时,其变化对薄膜厚度及粗糙度无显著影响。当转速为5 000 r/min、退火温度为300℃时,制备的绝缘层厚度具有良好的厚度均匀性,粗糙度为0.7 nm,漏电流为3.13×10^-5 A/cm²（电场强度1 MV/cm）。最终,利用ZrO₂薄膜作为栅极绝缘层,在玻璃基板上制备了铟镓锌氧化物-薄膜晶体管（IGZO-TFT）,其迁移率为6.5 cm²/（V·s）,开关比为2×10⁴。     

The plasma characteristics and film formation generated by theelectron cyclotron resonance mechanism

Silicon nitride thin film (SiN_x) is deposited onto the 3 inch silicon wafer using an electron cyclotron resonance (ECR) plasma apparatus. The plasma parameters from N₂-SiH₄ electron cyclotron resonance plasma are obtained. Radial distribution of radical atom density is determined by optical emission spectroscopy. From the comparison of the uniformities of deposited film thickness, electron density and radical atom density, it was concluded that the uniformity of film thickness is related to that of radical density rather than plasma density. The dependence of the uniformity film thickness on the waveguide mode was also examined     

A hybrid aerodynamic and electrostatic atomization system for enhanced uniformity of thin film

Droplet deposition processes by the mechanisms of either aerodynamics or electrostatic spray have been widely studied in various applications such as aerosol generators, thin film coatings, and nanoparticle formations. Among the current state-of-art methodologies, air spray deposition can produce small-sized droplets without fine control on their sizes and uniformity in deposited thin films. Conventional electrospray depositions, on the other hand, can fabricate thin films with good uniform with a relatively slow deposition speed. In this paper, a hybrid mechanism by means of aerodynamic and electrostatic deposition is investigated and demonstrated to allow high throughput and improved uniformity for thin film depositions. It utilizes both the electrostatic force and aerodynamic force to atomize the liquid and control the droplet spraying process with good stability/repeatability. A uniform thin TiO₂ film has been deposited as the demonstration example using this method. The velocities and trajectories of droplets during the deposition process have been characterized under different experimental parameters by using the technique of particle image velocimetry (PIV). This hybrid thin film fabrication method could be applicable in several industrial processes for better uniformity in making transparent electrodes, solar cells, displays, and automobiles.     

A study on the wet etching behavior of AZO (ZnO:Al) transparent conducting film

This paper studies the wet etching behavior of AZO (ZnO:Al) transparent conducting film with tetramethylammonium hydroxide (TMAH). The optimum optoelectronic film is prepared first using designated RF power, film thickness and controlled annealing heat treatment parameters. The AZO film is then etched using TMAH etchant and AZ4620 photoresist with controlled etchant concentration and temperature to examine the etching process effect on the AZO film optoelectronic properties. The experimental results show TMAH:H₂O = 2.38:97.62 under 45 °C at the average etch rate of 22 nm/min as the preferred parameters. The activation energy drops as the TMAH concentration rises, while the etch rate increases along with the increase in TMAH concentration and temperature. After lithography, etching and photoresist removal, the conductivity of AZO film dramatically drops from 2.4 × 10⁻³ Ω cm to 3.0 × 10⁻³ Ω cm, while its transmittance decreases from 89% to 83%. This is due to the poor chemical stability of AZO film against AZ4620 photoresist, leading to an increase in surface roughness. In the photoresist postbaking process, carbon atoms diffused within the AZO film produce poor crystallinity. The slight decreases in zinc and aluminum in the thin film causes a carrier concentration change, which affect the AZO film optoelectronic properties.     

光溅射镀膜均匀性的优化模拟

为了改善脉冲激光溅射沉积大面积薄膜的均匀性,发展了基片离轴旋转的扫描技术.根据基片离轴旋转的基本原理和等离子体羽空间余弦分布规律,建立了径向膜厚分布公式.数值模拟了各种因素对基片离轴旋转扫描沉积薄膜均匀性的影响.分析表明,优化粒子束中心与基片中心偏置距离、溅射点与基片的距离是改善基片离轴旋转扫描镀膜均匀性的主要途径.同时也考虑了电机转速、镀膜时间和激光重频的影响.通过参量优化,当均匀度要求在95％时,计算得到薄膜的最大半径超过40 mm.     

Thickness effect on stress,structural, electrical and sensing properties of (0 0 2) preferentially oriented undoped ZnO thin films

Preferentially oriented (0 0 2) ZnO thin films with c-axis-oriented wurtzite structure have been grown on Si (1 0 0) and glass substrates using radio frequency magnetron sputtering. The residual stresses have been determined and calculated via the Stoney formalism. The ZnO thin films have been also characterised by X-ray diffraction and scanning electron microscope, and their stoichiometry was verified by Rutherford backscattering spectroscopy. The evolution of the residual stress was studied as a function of film thickness in the 10–1200 nm range. A growth scenario is proposed and a possible correlation between the residual stress, film’s texture and crystallographic orientation is highlighted. The crystalline quality was found to improve, while the stress values decreased with increasing thickness, and as a ramification the thicker films developed better sensing response to gases. The mechanical (stress) and electrical properties of the films were also investigated as a function of the film thickness, which tended to manifestly improve in dependence on thickness as well. We attribute this to the fact that the thinner films are under vehement misfit stress that declines with increasing the film thickness further.