激光转镜扫描系统中自由曲面f-物镜的设计

为了满足扫描系统高分辨率、大工作面、小型化的需要,设计了一款具有衍射受限聚焦能力的超广角f-物镜。在此基础上,针对五面转镜引起f-物镜入瞳偏移从而导致系统分辨率降低、线性畸变增大的问题进行了分析,计算得到光瞳偏移量与扫描转角存在非对称分布的非线性关系。采用在系统中引入含有奇次高阶项自由曲面校正光瞳漂移的方法,在ZEMAX软件中利用多重结构对f-转镜扫描系统建模优化设计,并给出了设计实例。该物镜采用远摄型结构,有效减小了扫描系统总体长度及透镜尺寸。结果表明,经优化校正后,f-物镜性能得到显著改善,在其扫描角度115范围内,线性畸变小于0.5%,60%以上能量集中在半径30m圆内。该f-扫描系统具有结构紧凑、分辨率高、线性畸变小等优点,有良好的适用性。     

共轭距可变的光刻投影物镜光学设计

一种用于印刷电路板(PCB)的激光直接成像(LDI)光刻设备,需要加工高密度互连(HDI)基板的厚度变化范围为0.025~3mm,为此设计了一种共轭距可变的光刻投影物镜。采用双远心光路结构,通过压缩物方和像方远心度误差的办法,可以有效地实现共轭距变化范围达3mm。采用正负光焦度合理匹配,可以有效地在共轭距变化范围内很好地校正波像差、畸变等像差,实现良好的成像质量。以光刻投影物镜光学设计的具体实例,证实了通过压缩物方和像方远心度误差的办法,可以有效地获得共轭距变化一定范围的光刻投影物镜,并在该变化范围内保证实际光刻设备所要求投影物镜的成像质量。     

DVD光学头读出物镜设计

DVD光学读数头是新一代的高密度光盘系统的核心部件。本文在分析并确定DVD光学头读出物镜的参数后,设计出了满足这种特殊要求的双面非球面读出物镜,并对系统的各元素误差的影响进行了分析。     

自由曲面底板的LED 光学设计

提出了一种基于自由曲面底板的LED 配光新方法,采用TracePro 软件设计自由曲面并进行仿真分析。结果表明:将LED 芯片直接贴装在带有自由曲面的底板上,可以获得较大的出光角度,半光强角达到60,比传统反光杯的配光方式获得的半光强角增大25。此外,通过这种新方法可获得高光效和高均匀照度的照明模式,在实现相同的目标平面平均照度时,总光通量比传统配光方式减少25%,照度的衰减减少了60%。通过调节自由曲面底板的形状进行配光,可根据需要获得不同的照明效果,实现高品质的LED 照明。     

自由曲面光学的超精密加工技术及其应用

突破传统光学成像系统设计理论和方法,将自由曲面引入光学成像系统中,极大地提高了系统的成像质量和能量的传输效率;采用先进数控超精密制造技术加工自由曲面光学元件,解决了自由曲面光学元件加工的技术瓶颈.开发了自由曲面控制网格的节点矢量的精确计算方法,以及多轴超精密数控加工光学自由曲面的自动编程及其刀具轨迹仿真系统,建立了自由曲面三维拓扑预测模型与优化系统,研发了多个自由曲面测量及评估方法,并搭建了自由曲面光学设计、加工、测试一体化的集成平台.上述核心技术有助解决国际上对复杂自由曲面光学元件在超精密加工及纳米级表面测量中的关键技术难题.研究成果推动了超精密加工及纳米测量领域内的技术进步.     

近红外大数值孔径平场显微物镜设计

为满足飞秒激光微纳加工系统对高加工精度和大加工范围的需求,首先确定了该系统的重要组成部分-无限共轭距显微物镜所需具备的特性及设计指标。依据薄透镜组的初级像差理论,针对飞秒激光波长推导出光学系统为校正匹兹凡场曲和二级光谱所需满足的条件。该镜头由11片球面透镜构成,所选用材料皆为国产玻璃,同时避免三胶合结构的使用。设计了一套工作波长为785~815 nm,数值孔径为0.9,像方视场为22.5 mm,放大倍率为40的近红外平场复消色差显微物镜。设计结果表明:该镜头的MTF良好,全视场波像差均小于0.08,各种几何像差均远小于公差且满足平场和复消色差条件,能量集中度高。使用补偿器放松材料公差、加工公差和装调公差,公差分配后全视场RMS波像差小于0.09,满足实际应用要求。     

宽光谱、长焦距准直物镜光学设计

介绍了大视场、宽光谱、长焦距微光准直物镜的光学设计.重点讨论了宽谱段准直物镜的二级光谱校正及像差平衡问题,并用Zemax软件,进行了光学设计.设计结果:系统的二级光谱为0.1 mm,其他像差也达到了像质要求.     

反射式自由曲面头盔显示器光学系统设计

头盔显示器（HMD）作为一种头戴目视设备,具有小型化、轻量化的特点,同时为了获得良好的佩戴体验,要求合理的出瞳距、出瞳直径以及视场。为了同时满足头盔显示器的上述要求,采用紧凑的双反射镜结构来满足头盔显示器对体积和重量的要求,应用自由曲面增加设计自由度来校正大视场和非旋转对称结构引入的像差,并阐述了自由曲面补偿非旋转对称光学系统像差的基本原理以及该光学系统的设计方法与过程。该光学系统无色差,视场为5025,出瞳大小为8 mm,出瞳距大于27 mm。在奈奎斯特频率处全视场的调制传递函数大于0.4,可应用于新一代头盔显示技术。     

0.85数值孔径双非球面单片物镜的设计

设计了超高密度光盘存储的核心元器件——0.85数值孔径的单片物镜。设计中采用了3种方法,即两种商业软件Zemax和CodeV以及新型的CEDDA(离散定义非球面)算法。设计采用国际最新的单片双非球面的物镜形式,在考虑了偏心误差、视场倾斜角等实际制造工艺与使用条件的情况下,在合理的结构范围内,设计出的透镜波像差的RMS值可控制在1/30λ以下,达到了实际应用的技术要求。     

采用双自由曲面整形的无掩模光刻照明系统

为了实现无掩模光刻系统所需求的矩形准直平顶激光光束照明,提高照明系统的能量利用率,提出了一种利用双自由曲面整形的照明系统设计方法。根据光程守恒原理和折射定律,推导了积分形式的双自由曲面面形方程;采用数值解法求解积分方程,分别设计了含有双自由曲面的双透镜整形单元和单透镜整形单元的照明系统,使用光学设计软件对两种照明系统进行模拟,得到两种照明系统的照明均匀性在93%以上,能量利用率大于91%。结果表明,两种照明系统均能实现无掩模光刻系统的高均匀性、高能量利用率照明。     

Broad-band extreme ultraviolet lithography with a wet-silylated and dry-developed resist

Broad-band extreme ultraviolet (1340nm) lithography (EUVL) has been examined. Exposure intensity at the broad-band of 1340nm was 20 times larger than at the conventional narrow-band of 13nm. Moreover, broad-band EUVL with a wet-silylated and dry-developed resist process has been investigated in order to obtain a high resolution of 0.1μm with high-aspect-ratio. Imaging experiments were performed using 32:1 reduction Schwarzschild optics illuminated with a synchrotron radiation light source from SORTEC ring. The exposure was done through a 0.1μm-thick SiN vacuum window, Mo/Si multilayer coated optics and without a Be filter. Silylation characterization and determination of optimum composition of the silylation solution have been performed using Fourier transform infrared spectroscopy (FTIR). Using broad band EUVL with the optimal wet-silylated and dry-developed resist, 0.1μm lines and spaces of 0.55μm-thick resist (aspect RATIO = 5.5) can be successfully delineated.     

Laser-produced plasma light source for extreme ultraviolet lithography

Pulsed Nd:YAG lasers have been developed to achieve high peak power and high pulse repetition rate. These systems are being used as drivers for laser-produced plasmas which efficiently convert the 1064-nm laser output to extreme ultraviolet (EUV) light at 13.5 nm for future microlithography systems. The requirements for laser-produced plasma EUV light sources and their integration in lithography tools for high-volume manufacturing are reviewed to establish the key design issues for high-power lasers and plasma targets. Xenon has been identified as a leading target material to realize the goals of intense EUV emission and clean operation. Recent progress in high-power diode-pumped Nd:YAG lasers and xenon targets for EUV generation is reviewed, showing that laser-produced plasma sources meet the needs for current EUV lithography development tools. Future directions to meet EUV source requirements for high-volume manufacturing tools are discussed.     

Frequency-resolved optical gating measurement of ultrashort pulsespassing through a high numerical aperture objective

We investigate using collinear type II second harmonic generation frequency-resolved optical gating (SHG FROG) to measure the pulse intensity and phase at the focus of high numerical aperture (NA) oil objectives. Because of the strong focusing for such objectives, it is not clear theoretically that such a measurement should work. Such objectives can produce severe distortions of the pulse as a function of radius in the objective. In addition, the standard SHG FROG algorithms are based on the assumption that the fundamental and second harmonic fields are plane waves that can be described by the paraxial approximation, and for high NA objectives, such assumptions are suspect. We show that such measurements work remarkably well. The tight focus, while a theoretical difficulty, eliminates many of the problems traditionally associated with SHG FROG including the difficulty of phase matching and walkoff of different polarizations in the crystal. Specifically, we use collinear type II SHG FROG to measure the intensity and phase at the focus of a Zeiss CP-Achromat 100x, 1.25 NA, infinity-corrected oil objective, and accurately retrieve 20 fs pulses     

高数值孔径光刻中衬底反射率的控制

高数值孔径（NA）光刻中,需要控制衬底反射率以减小薄膜干涉对光刻性能的影响。采用薄膜光学方法研究了高NA光刻中底层抗反膜（BARC）对衬底反射率的控制。针对硅基底对单层和双层BARC进行优化以探索满足高NA光刻要求的BARC材料光学参数容限。结果表明,当NA超过0.8时,单层BARC无法控制衬底反射率而有必要采用双层BARC。横电（TE）比横磁（TM）偏振光的衬底反射率更难以控制。NA越大,单层BARC折射系数的优化值越大。双层BARC中的顶层膜应采用低吸收率材料而底层膜应采用高吸收率材料。本研究可为高NA光刻中的BARC材料研制及衬底反射率控制提供理论依据。     

Multicomponent glass fibres with high numerical aperture

Multicomponent glass is suited for the preparation of high numerical aperture (n.a.) fibres which may be used in short-distance applications. Low loss of 20dB/km fibres have been produced with a n.a. of 0.53. Core glass having high refractive index has been prepared by using the additives of BaO and GeO2 which are hardly harmful to the intrinsic absorption loss.     

从极紫外光刻发展看全球范围内的技术合作

在针对芯片的"卡脖子"技术中, 极紫外(EUV)光刻是最重要的一环。EUV光刻技术已经被广泛应用于最先进工艺节点的集成电路芯片制造之中。它的研发交叉融合了光学、机械、电子、控制、软件、材料、数学、物理等多个学科的知识。EUV光刻的发展反映了世界范围内联合研发的演变过程, 开放和合作是发展过程中的主旋律。回顾了EUV光刻的发展历史及所涉及的重大项目和机构, 讨论了全球唯一的EUV光刻机制造商——ASML公司的灵活多变的国际化合作路线, 分析了自1997年以来世界各代表性研发机构的研发趋势以及与EUV光刻发展的关系, 详叙了各参与机构在世界范围内的合作对EUV光刻发展的影响。该研究为研发先进光刻机等类似高端装备提供了一些启示和参考。     

An ion-assisted Mo-Si deposition process for planarizing reticlesubstrates for extreme ultraviolet lithography

Substrate particles are a serious concern in the fabrication of reticles for extreme ultraviolet lithography (EUVL) because they nucleate defects in the reflective multilayer films that can print in the lithographic image. We have developed a strategy for planarizing reticle substrates with smoothing-layers and, in this letter, we investigate the smoothing properties of an ion-assisted Mo-Si deposition process. We have observed that ion-assistance can significantly improve the particle-smoothing properties of Mo-Si multilayer films and can do so without a significant increase in the high-spatial frequency roughness of the multilayer film. An ion-assisted Mo-Si smoothing-layer approach to reticle substrate planarization, therefore, shows significant promise for defect mitigation in EUVL reticles