High-NA and low-residual-aberration projection lens for DUV scanner

Matsuyama, Tomoyuki; Shibazaki, Yuichi; Ohmura, Yasuhiro; Suzuki, Takeshi

doi:10.1117/12.474617

Cited by 9 publications

(5 citation statements)

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“…With the increasing demand of finer optical resolution, higher imaging quality, and larger field of view, largeaperture lenses are widely used in many applications, such as semiconductor lithography apparatus, solidstate laser facilities, and space telescopes. [1][2][3] These lens systems must be very accurate and must minimize distortion of each lens after assembly. However, large aperture usually results in large gravitational sag of a lens under its own weight, which induces wave front errors into the lens system and further deteriorates its optical performance.…”

Section: Introductionmentioning

confidence: 99%

A Monte Carlo analysis of uncertainty in supporting assembly of large-aperture optical lenses

Shen

Luo

Liu

et al. 2013

Proceedings of the Institution of Mechanical Engineers, Part B:

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Large-aperture lenses are widely used to improve optical resolution and enlarge field of view of a precision optical system, and reasonable mounting can result in higher optical performance. Flexure mounts are usually utilized to minimize distortion of the lens under its own weight and must be accurately assembled so as to provide uniform support loads for the lens. The supporting loads produced by flexure mounts are difficult to be identical because of various uncertainties during assembly process, such as human operation and tool resolution. These nonuniform supporting loads may generate asymmetric deformation of the lens and deteriorate its performance. It is essential to explore the influence of uncertainty supporting loads on the optical performance. A Monte Carlo analysis method is proposed to investigate the optical performance of a lens under uncertainty supporting loads at different load levels. Patran Command Language is used for repetitive calculation of finite element model with random sample of supporting loads. The optical performance responses, such as the surface peak-to-valley and root-mean-square errors and Zernike coefficients, are calculated by fitting the surface deformation data, and their stochastic properties are researched by statistical testing. Consequently, the critical variation range of uncertainty supporting loads considering assembly process can be determined based on Three Sigma theorem with specific optical performance requirement. The results can be used to assign appropriate tolerance of flexure mounts during assembly and to optimize the supporting system of a high-precision optical system.

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Section: Introductionmentioning

confidence: 99%

A Monte Carlo analysis of uncertainty in supporting assembly of large-aperture optical lenses

Shen

Luo

Liu

et al. 2013

Proceedings of the Institution of Mechanical Engineers, Part B:

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show abstract

“…The residual stress affects the performance, life and structural integrity of a given material. Whether minimizing the stress during optical annealing, polishing and other processes [2], or carefully controlling it during material manufacturing [3], measurement procedures are indispensable. Some popular NDT methods used to estimate residual stress are X-ray, neutron diffraction, wafer curvature, ultrasonic method, electrical-magnetic methods, and photoelastic methods [1].…”

mentioning

confidence: 99%

Detecting residual stress on toughened glass surface by two complementary interferometers

Jia¹,

Liu²,

Wan³

et al. 2021

EPL

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Taking advantage of the birefringence of crystal, this paper proposes an effective optical system to detect the residual stress at the surface of toughened glass. A theoretical model based on matrix optics is built to describe the optical distribution of a probe light in the system, and the simulation outputs two complementary images whose mode patterns are determined by the phase delay arising from the surface-stress–induced birefringence. The experimental results confirm the simulation results that the mode pattern varies accordingly while the phase delay varies in 2 period. Features of interference fringes are extracted by dedicated image recognition algorithm and form their own feature data sets. Comparing the experimental data sets with the simulation ones, the phase delay of each experimental pattern can be deduced, so the stress of the sample point can be calculated. Our device's surface stress scanning results of toughened glass are very close to the commercial instrument SCALP-04's ones, with the relative deviation between them below 6%. Our system provides an efficient and simple way to measure present stress distribution on the surface of transparent materials, and owing to its fewer instruments involvement, broad detecting distance, and high signal-to-noise ratio, our system can be developed into integrated products. This method can also be applied in different materials such as high polymer, silicide, etc., where only the wavelength of the laser needs to be modified.

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“…Therefore, to achieve better compensation, it is advisable to measure the surface figures of optical components coupled in the lens seat and to include them in the optimization of figure-error balancing. For high-precision optical systems, such as a lithographic projection lens, lens-mounting seats 10 are designed to be stress-free such that stress-related index changes and surface deformations can be neglected. It is generally advisable to measure surface figures in their proper setting within the optical system, so that disturbances due to stress and temperature are appropriately considered in figure-error balancing.…”

Section: Relationship Between Figure Error Andmentioning

confidence: 99%

Clocking-optimization method for figure-error balancing in complex optical systems

Liu

2015

Opt. Eng

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Abstract. Figure errors of optical surfaces degrade the performance of optical systems. When predicting the performance and performing system assembly, compensation by clocking of optical components around the optical axis is a conventional but user-dependent method. Commercial optical software cannot optimize this clocking, and existing automatic figure-error balancing methods have limitations. To overcome these limitations, a global and general optimization method based on analyzing the precise relationships between the figure errors and the wavefront error (WFE) is proposed. Using the footprint data of each optical surface, the resulting WFE is calculated. Direct map operation is used for intercepting and rotating the figure-error maps. The simulated annealing algorithm is used to seek the optimal combination of clocking angles for the optical components. This method can be applied to most coaxial optics systems, including dioptric, catoptrics, and catadioptric complex lenses. It is successfully implemented for a catadioptric immersion lithographic optics system with artificial figure errors, and for an experimental lithographic optics system with actual manufacturing figure errors. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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High-NA and low-residual-aberration projection lens for DUV scanner

Cited by 9 publications

References 0 publications

A Monte Carlo analysis of uncertainty in supporting assembly of large-aperture optical lenses

A Monte Carlo analysis of uncertainty in supporting assembly of large-aperture optical lenses

Detecting residual stress on toughened glass surface by two complementary interferometers

Clocking-optimization method for figure-error balancing in complex optical systems

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