超高真空磁控溅射Co／Si多层膜的X射线衍射分析

采用Ｘ射线衍射分析表征了磁控溅射方法制备的Ｃｏ／Ｓｉ周期多层膜,由带折射修正的布喇格衍射定律导出多层膜周期厚度,对两组折射修正公式的计算结果进行对比,讨论了平均折射率修正值为负的原因,并应用薄膜光学理论分析小角Ｘ射线衍射谱中出现的一系列现象。     

一种用于极紫外多层膜反射率测量的平台

一种用于紫外多层膜反射率那0量的样品台，由步进电机驱动．其构成由三个部分：机械系统，计算机控制系统，单片机控制系统．最后对极紫外多层膜进行了测量，结果显示该系统满足使用要求，运行可靠．     

衍射频谱法测光栅膜层厚度

根据傅立叶光学理论从光栅的衍射频谱中可以反推光栅本身的多种信息,包括其形貌特征。 利用矩形相位光栅的傅立叶变换,推导出零级和一级衍射光强和矩形相位光栅膜层厚度之间的函数关系,据此可在测得零级和一级次光强后,推算出光栅膜层厚度。以台阶仪作为标准,该方法的测量误差在4%以内。     

X射线光学多层膜的研究

介绍X射线光学多层膜的构成原理、制作、测量方法及在超高真空系统中的研制技术。     

磁控溅射法制备Mo/B4C软X射线多层膜

用DC和RF磁控溅射法制备出了波长小于 10nm波段的Mo/B4 C软X射线多层膜反射镜。掠入射X射线衍射仪的测量结果表明 ,磁控溅射法有很高的控制精度 ,制备出的Mo/B4 C软X射线多层膜周期结构非常好 ,表 (界 )面粗糙度非常小 ,约为 0 4nm。     

波长小于10nm的软X射线多层膜制备技术

软X射线短波段区域(1～10nm)高反射率多层膜的制备对软X射线光学的研究具有十分重要的意义.该波段要求镀膜过程中能减小界面扩散,实现膜厚控制,从而严格限制了制备技术的应用.介绍了软X射线短波段多层膜的发展现状和制备技术,主要包括蒸发沉积、溅射沉积、脉冲激光沉积技术和激光分子束外延,对这些方法进行了比较并提出了今后的研究方向.     

Mo/Si和Mo/B_4C软X射线多层膜的界面热稳定性研究

用磁控溅射法制备Mo／Si多层膜（周期为25nm，20层）和Mo／B4C多层膜（周期为3．9nm，121层），并在真空中加热30min，温度为200，400，600，800和1000℃。用小角X射线衍射法和透射电镜研究不同温度下（保温0．5h）加热的样品。实验结果表明，当加热温度达600℃时，Mo／Si多层膜周期被破坏。而Mo／B4C多层膜在800℃加热温度下仍保持周期性层状结构。说明Mo／B4C多层膜不仅周期只有3．9nm，而且具有很好的热稳定性，可以作为较短波长的软X射线多层膜推广应用。     

磁控溅射法制备Mo／B4C软X射线多层膜

用ＤＣ和ＲＦ磁控溅射法制备出了波长小于１０ｎｍ的波段的Ｍｏ／Ｂ４Ｃ软Ｘ射线多层膜反射镜。掠入射Ｘ射线衍射仪的测量结果表明，磁控溅射法有很高的控制精度，制备出的Ｍｏ／Ｂ４Ｃ软Ｘ射线多层膜周期结构非常好，表（界）面粗糙度非常小，约为０．４ｎｍ。     

In-situ ellipsometric monitor with layer-by-layer analysis for precise thickness control of EUV multilayer optics

Ion beam sputtering fabrications of Mo/Si multilayers for soft X-ray mirrors were studied using an automatic null ellipsometer. The ellipsometric growth curves plotted on the complex plane showed island structure formation for every Mo layer grown on Si when deposition was performed with a 1400 V Ar ion beam. The ellipsometric growth curves indicated that the multilayers fabricated with 900 V ions had sharper and smoother interfaces compared to those fabricated with 1400 V ions. Quantitative layer-by-layer analysis showed that the Si layers deposited at 1400 V became optically isotropic as thin as 1 nm. These data depict the usefulness of our in-situ ellipsometer in controlling layer thickness and also optimizing the deposition condition to form homogeneous and optically isotropic layer structures.     

Cleaning technology for EUV multilayer mirror using atomic hydrogen generated with hot wire

A method of removing contaminants from Ru-capped Mo/Si multilayer mirrors for extreme ultraviolet lithography has been developed. It employs atomic hydrogen generated by a heated catalyzer consisting of a W wire. A new experimental system was designed and constructed to examine the cleaning capability of atomic hydrogen transported through a quartz tube. The chemical state of an oxidized Ru surface was investigated by X-ray photoelectron spectroscopy before and after cleaning; and it was found that transported hydrogen radicals deoxidized the surface and reduced the amount of oxide to the level before oxidation. Although the time needed was longer, transported atomic hydrogen was found to be capable of deoxidizing an oxidized Ru surface. The dependence of the density of atomic hydrogen on W catalyzer temperature and hydrogen gas pressure was measured by a vacuum ultraviolet absorption technique; and the potential to increase the density, and thereby to reduce the treatment time, was demonstrated.     

近地空间下X/EUV透射光栅的热力学有限元分析

为了实现极紫外透射光栅光谱仪在近地空间的应用,针对其核心色散元件2000线/毫米X/EUV透射光栅,本文采用有限元方法建立了机械模型并对其热学性能和耦合特性进行计算机模拟计算,通过模拟热膨胀系数不同的材料构成的薄膜光栅在近地空间受到太阳辐照后的温度场,得到该光栅表面的热形变分布.结果表明,在高真空热环境下,该透射光栅表面形变量平均可达0.56μm,而影响光栅周期的纵向形变平均值则为71.5 nm.由于热形变会对光栅衍射效率产生重要影响并导致光谱仪精度和性能的下降,利用有限元分析模拟的结果,进一步优化光栅的封装和设计制作,使其栅线处纵向热形变趋近于零,为2000线/毫米X/EUV透射光栅在太阳极紫外辐射探测器上得到应用提供了科学依据和有效支持.     

衍射光学元件分析和设计中标量理论的局限性

以衍射光栅为例,用标量理论和严格耦合波理论的对比,分析衍射光学元件各参数对标量理论适用范围的影响。结果表明在光栅周期减小,刻蚀深度增加,光栅折射率增加,光束入射角度增加以及填充因子偏离 50%等情况下,标量理论的误差将逐渐增大,其中光栅周期和刻蚀深度对标量理论的影响较大,光栅周期小到 5 倍波长或者刻蚀深度大到 5 倍波长时,标量理论将不再适用。     

折/衍混合透视型头盔显示器光学系统设计

为满足头盔显示器(HMD)对大视场、高像质和彩色显示的要求,提出了改进型 HMD 光学系统。该系统以彩色 LCD 为图像源实现彩色显示;以折/衍混合单透镜代替双胶合,利用其负色散和波面任意整形特性消除系统色差及改善波前像差。图像源发出的光束在分束器附近成中间像,可增大系统视场;出瞳在中继光学组元中间成像,可减小系统口径,增大出瞳直径;球面耦合器将分束器反射过来的光束准直后投射到人眼,能消除人眼反复观察不同焦距的视频图像和外界图像所造成的疲劳。该系统垂轴色差小于 42μm,视场扩大为 40°(水平)×30°(垂直),分辨力接近人眼的最小分辨能力;口径小于 46mm,重量比现有 HMD 光学系统下降 47%。     

5 × 5 Spot array based on two crossed single-groove gratings

Compared to the reported 5?×?5 spot arrays, we propose a way of generating a 5?×?5 spot array with much higher efficiency and better uniformity by using two crossed single-groove gratings. Normally, a single-groove grating cannot generate a 1?×?5 equal-intensity array by employing traditional Fourier optics theory. In this letter, we will show by vector diffraction theory that when the period of a single-groove grating is more than twice that of the incident wavelength, it may generate a 1?×?5 equal-intensity array. Based on this discovery, we expand the 1?×?5 array into a 5?×?5 spot array straightforwardly by using two crossed single-groove gratings. The dependence on the refractive index for producing a 1?×?5 equal-intensity array is interesting and we explain the phenomenon from the perspective of energy distribution by the simplified modal method.     

The superconducting transition temperature of multilayer superconductors: The frustratedXY-Josephson model

The superconducting transition temperature of multilayered superconducting structures of the S-N(D)-S type in the RVB theory is defined taking into account the resonance pair tunneling between superconducting layers. The Josephson array defectivity is considered with the frustration parameters.     

遗传算法用于衍射光学元件的优化设计

提出了一种基于遗传算法的衍射光学元件优化设计方法;在衍射光学元件设计中遗传算法运行参数对遗传算法性能有一定的影响:采用较大的群体规模,遗传算法越容易获得最优解;交叉算子越大,遗传算法全局搜索能力越强;选择算子对遗传算法的影响不是太大;如果要进一步提高解的精度,可选取较大的终止代数。数值计算结果表明,用遗传算法优化设计的衍射光学元件,其误差小于 5.2%,衍射效率达到 91.2%。遗传算法很适合衍射光学元件的优化设计。     

High quality transparent conductive ZnO/Ag/ZnO multilayer films deposited at room temperature

We have fabricated, by simultaneous DC and RF magnetron sputtering, multilayer transparent electrodes having much lower electrical resistance than the widely used transparent conductive oxide electrodes. The multilayer structure consists of three layers (ZnO/Ag/ZnO). Ag films with different film thickness were used as metallic layers. Optimum thicknesses of Ag and ZnO films were determined for high optical transmittance and good electrical conductivity. Several analytical tools such as spectrophotometer, atomic force microscopy, scanning electron microscopy and four-point probe were used to explore the possible changes in electrical and optical properties. A high quality transparent electrode, having resistance as low as 3 Ω/sq and high optical transmittance of 90% was obtained at room temperature and could be reproduced by controlling the preparation process parameters. The electrical and optical properties of ZnO/Ag/ZnO multilayers were determined mainly by the Ag film properties. The performance of the multilayers as transparent conducting materials was also compared using a figure of merit.