【作者】 谷勇强；

【导师】 杨怀江；

【作者基本信息】 中国科学院研究生院（长春光学精密机械与物理研究所） ， 光学， 2013， 博士

【摘要】 随着大规模集成电路制造水平的发展，光刻机的地位日益突出。投影光刻物镜系统是光刻机的核心部分，为完成具有高NA、大视场投影光刻物镜的研制，对系统使用的光学元件的面形精度要求极高。本文主要研究利用离子束溅射技术，制造出面形精度达到纳米甚至亚纳米量级的平面、球面以及非球面光学元件，满足投影光刻物镜的使用需求；同时，光学检测水平制约着加工所能达到的最高精度,为此，针对光刻投影物镜光学元件检测的需要，就立式干涉检测和非球面检测中存在的问题也开展了一些研究。1.开展光学检测研究，提高光刻投影物镜光学元件的检测精度，为离子束高精度面形加工奠定基础。对Fizeau型相移干涉仪的检测原理、相移算法、绝对检测技术进行了调研，分析了影响检测精度的主要因素，掌握了相移精度、光源、振动以及干涉腔内温度、压强、湿度等环境变化等对检测精度的影响大小；利用双球面绝对检测技术，标定了立式工作时Fizeau型相移干涉仪标准镜参考面，并与卧式工作状态下的标定结果进行对比，明确了重力、夹持力等因素对检测精度的影响；利用计算全息技术标定了抛物面非球面面形，并与共焦小球法的实际检测结果进行对比，获得计算全息法检测抛物面的最终精度。2.阐述离子束溅射的机理，对离子束加工的稳定性等基本性能进行研究。通过测试，获得了离子束在十个小时的短期内和四个月内的稳定性，以及离子束溅射去除固定厚度时的均匀性和离子束单次加工的收敛速度；针对投影光刻物镜可能采用的利用补偿镜修正系统波象差的方案，对随机选取36项Zernike多项式系数生成的面形进行了加工，从加工方面证实了方案的可行性。3.研究影响离子束溅射加工低频面形精度的因素，对离子束在不同驻留时间下的去除速率进行了测试，分析并模拟计算了定位误差对加工精度的影响。在对各种误差进行严格控制下，测试离子束溅射加工平面和球面元件的极限精度，证实对平面和球面均能实现RMS值优于0.45nm的面形精修，达到国内领先水平；阐述离子束溅射对元件中高频误差影响的机理，通过与微射流超光滑加工的迭代实验，确保光学元件的低频和中高频精度能够同时满足投影光刻物镜的使用要求。4.对非球面光学元件的加工方法进行研究，通过两种不同的加工路线对非球面面形进行实际加工，即在铣磨和抛光阶段将光学元件加工成非球面后用离子束进行面形精修和直接利用离子束将最佳拟合球面加工成非球面。两种方式均实现了相对精度优于RMS值1.5nm的非球面面形加工，满足光刻投影物镜对非球面的面形要求。更多还原

【Abstract】 As the development of the integrated circuit, the lithographic plants arebecoming more and more important. To develop the projection lithographic objectivesystem with high NA value and large filed range, which is the heart part of thelithographic machine, surface errors of lenses used in the system must be controlledwithin a very low level. The purpose of the paper is to find out a way to fabricatelenses with surface errors less than root mean square value1nanometer, by the useof Ion Beam Figuring technic, to meet the requirement of projection lithographicobjective system. In the meantime, because the level of optical surface test willinfluence the final fabrication accuracy a lot, a serious of researches, includingproblems exist in the vertical interferometric testing and parabolic testing are done tomeet the surface test requirement of lenses used in projection lithographic objective.1. Carrying out researches on optical test, to improve the surface test accuracyand settle the foundation of ion beam figuring with high accuracy. Principles ofFiezau phase-shift interferometry, phase shift algorithms and absolute tests areintroduced, and then the main factors that will influence the final test accuracy areanalyzed, including the phase shift error, source error, vibration, temperature, airpressure and humidity in the interfering cavity. After that, two spheres absolute testis used to calibrate surface error of the transmission sphere when used in Fizeauinterferometer vertically, and compared with results tested when it is usedhorizontally, errors including gravity and mounting forces are analyzed. Finally, parabolic lens is tested by using computer generated holograph and focus ballmethod separately, and the test results are compared with each other, errors ofcomputer generated holograph method are analyzed.2. Principle of ion beam figuring is introduced and the basic characters of ionbeam figuring are researched. By a serious of experiments, the stability of ion beamin four months and ten hours, the uniformity when removing a constant thicknessand also the rapidity of convergence for one single polish are tested. To test thepossibility of using a single lens to correct the wavefront aberration of the wholeprojection lithographic objective system, a surface generated by random Zernikepolynomial is fabricated by ion beam and very good accuracy is achieved.3. Factors that will influence the final fabricate accuracy of ion beam figuringare analyzed. The ion beam removal rate is tested when the dwell time varies from5seconds to150seconds, also the influence of positioning error are calculatedsimulationaly. By control of these factors, surface error with root mean square valueof less than0.45nm is achieved on both sphere and flat. The principle of ion beamfiguring errors in middle and high spatial frequency range is introduced and by theiteration experiments with super smoothing technic, errors in low, middle and highspatial frequency range are all corrected to a perfect level and can meet therequirement of projection lithography objective.4. The way of fabricating aspheric surface is studied and two different methodsare used to polish aspheric surface by ion beam. The first one is to grind the lens toasphere and then to polish the surface error by ion beam, the second one is to grindthe lens to best-fit sphere and then polish to asphere by ion beam directly. Root meansquare value of less than1.5nm is achieved by both of the methods.更多还原