轴向调节机构中调节力对光学元件面形的影响  

Effect of Adjusting Force on Surface Figure of Optical Element in Axial Adjustment Mechanism

作　　者：郭抗[1] 巩岩[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室,吉林长春130033

出　　处：《光学学报》2013年第11期222-229,共8页Acta Optica Sinica

基　　金：国家重大科技专项(2009ZX02005)

摘　　要：深紫外光刻投影物镜光学系统对光学元件的面形精度要求极高,物镜中轴向调节机构调节力对光学元件面形的影响不可忽略。针对一种一体化结构的光学元件轴向调节机构,研究了调节力对光学元件面形的影响规律。采用有限元计算的方法分析了调节力与光学元件面形均方根(RMS)值、Code V标准Zernike系数之间的关系,并进一步提出了通过隔离调节力和吸收调节力以减小调节力对元件面形影响的方法。计算结果表明:光学元件面形的RMS值和Zernike系数随调节力线性变化,调节力不会导致已有像差转变为其他类型的像差,也不会导致新像差的产生;在光学元件与轴向调节机构的支撑镜框之间采用具有吸收调节力功能的柔性结构后,调节前后光学元件面形RMS值的变化幅度由187%降低到了8%以内,调节力对元件面形的影响得到了有效控制。Axial adjustment mechanism is applied in deep ultraviolet photolithography objective lens for aberration compensation. Since the surface accuracy of the optical element in the objective lens is rigorous, effect of the adjusting force on the surface figure of optical element in the axial adjustment mechanism cannot be ignored. Regularity between the adjusting force and the surface figure of the optical element is investigated aiming at an axial adjustment mechanism with monolithic configuration. Finite element method is adopted to analyze the relationship between the adjusting force and the root-mean-square （RMS） value, Code V standard Zernike coefficients for the surface figure evaluation of the optical element. Methods for reducing the effect of the adjusting force on the surface figure of optical element are further proposed, which is adjusting force isolation and adjusting force absorption. The calculation results show that the RMS value and the Zernike coefficients linearly change with the adjusting force, and the adjusting force does not cause the existing aberration to transform into other types of aberrations, nor lead to a new generation of aberration. After flexible structure is introduced and set between the optical element and the support mount of the axial adjustment mechanism, the variation amplitude of RMS value reduces from 187% to less than 8%, which indicates that the effect of the adjusting force on the surface figure of optical element is effectively controlled.

关 键 词：光学器件 调节机构 有限元分析 调节力 面形精度 

分 类 号：TN305.7[电子电信—物理电子学]