【作者】 陈华；

【导师】 吴清文； 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） ， 机械制造及其自动化， 2011， 博士

【摘要】 半导体光刻机的发展一直是推动精密光学元件加工和检测水平不断提高的动力。目前193nm光刻机投影物镜的光学元件面形精度要求达到了1~2nm rms,部分元件的要求更高。为了达到这么高的元件面形加工精度,首先需要解决的是面形检测问题,因为元件加工的去除量是以测试结果为参考的。高精度面形检测首先要保证的是测试的重复性和复现性,在此基础上才能实现较小的测试不确定度。而环境扰动却会引入较大的、不稳定的测试误差。为此,本论文针对环境条件对面形检测的影响展开研究,分析环境条件如何作用于面形检测过程,从而为精密环境控制设定合适的目标,并研究如何评价环境条件引入的测量不确定度,从而了解不同环境条件引入的测试误差。论文的主要工作如下:(1)针对环境温度引起的机械结构变形,采用仿真分析的办法研究环境温度的空间分布不均匀性、时间上的不稳定性及镜子内外温度不一致导致的镜面面形变化,并设计相应实验验证,从保证机械结构稳定性的方面提出环境控制的目标;(2)针对环境条件对参考面和测试面间光腔折射率的影响,建立流体仿真分析模型,分析存在空间热源/热沉时不同气流状态下光腔温度、压强的分布情况,并建立光线追迹模型计算由此引入的波前面形偏差。分析了在不引起湍流情况下提高送风速度以减小光腔温度分布不均匀性、降低光腔的引入的面形偏差的可行性。(3)在已有的环境条件下,针对实际测试过程,引入不确定度矩阵和波前重复性的指标来衡量单次测量中环境扰动引入的面形误差,并分析了多次测量均值的误差范围。对比分析了不同环境条件引入的测量不确定度大小,为环境条件建设的进一步完善提供参考。(4)建立了高精度的温度测量系统,分析了温度测量系统及温度传感器的误差来源,设计试验测试了Fluke 5611珠状热敏电阻温度传感器在小温区范围内的测温误差特点,以验证提高其在小温区范围测温准确度的可行性,从而保证了高精度环控实验室温度测量的正确性。更多还原

【Abstract】 The demands of semiconductor lithography optics provide a significant driver for continuous improvement of optical manufacturing and metrology. At present, the 193nm lithography requires optical surfaces to 1~2nm rms or more accuracy. For such accuracy to be achieved, highly accurate figure metrology is essential, because the optics are polished according to the error ditribution which is measured from an interferometer. Repeatability and reproducabiligy of a measurement are essential to low measurement uncertainty. The enviromental disturbance will introduce large radomly chaning errors, to reduce the enviromental disturbance effects, we should control the enviroment to some level. For this purpose, this thesis analyzes the enviromental disturbance effects to optical figure measurements and evaluates the figure error caused by envrioment. The major works of this thesis are summarized as follows:(1) Analysed the thermal deformation of the lens with simulation models. According to temperature distribution characteristics in a real laboratory, the ununiformity in space, unstability with time of air temperature and because of insufficiently stablization of lens itself, will cause figure deformation error. Then the goals of enviromet control are provided from the aspects of guaranting enough mechanical stability. (2) Aiming at the influence of environmental condition on the optical cavity between the refrence surface and test surface, the flow simulational analysis model is established and the temerature, pressure distributions of the optical cavity under different flow state when there are heat source/heat sink exsting in the room is analysed. At the same time the raytracing model is established to calculate the resulting wavefront deviation. The feasibility of reducing the nonuniform distribution temperature of the optical cavity and depressing the resulting wavefront deviation by increasing flow speed is analyzed, too.(3) According to practical figure measurement process, the uncertainty matrix and wavefront repeatability are introduced to describe the figure mesurement uncertainty caused by environment turbulence in a single measurement. The distribution of uncertainty after many mesurements being averaged is analyzed. Measurement uncertainties under different environment conditions are compared to provide a reference for improvement of environment conditions. (4) A high precise air temperature testing system is established. The error sources of a temperature sensor are analyzed. The feature of a Silicone-Bead thermistor probe Fluke 5611s in a narrow temperature range are tested to verify the measurement accuracy of the probe. Thus, we have assured the high accurate measurement of the air temperature in a highly controlled laboratory environment.更多还原