Nanoscale Focusing and Leveling Measurement Technology Based on Optical Spatial Split

Yuwen, 孙裕文 Sun; Shiguang, 李世光 Li; Mingcheng, 宗明成 Zong

doi:10.3788/aos201636.0512002

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Conventional focusing techniques from ASML, Cannon, Nikon, etc., are based on focus and level sensors, combined with optical trigonometry to accomplish the measurement, where the measurement light is obliquely incident onto the surface of the substrate from the lateral direction of the lithography objective at a large angle of incidence , and the offset of the wafer surface relative to the focal plane is computed by capturing the reflected light that carries the height information. [10][11][12] As DOF continues to shrink, the distance between the objective lens and the wafer is extremely short, and this method is no longer applicable. 13 The coaxial focusing method 14 can effectively solve this problem, but its optical focusing system, including multiple lenses and complex optical components, is relatively complex, making installation and adjustment difficult.…”

Section: Introductionmentioning

confidence: 99%

Research on high precision and large range automatic focusing method for digital lithography

Liu,

Luo,

Chen

et al. 2024

Advanced Fiber Laser Conference (AFL2023)

View full text Add to dashboard Cite

At present, the resolution of digital lithography based on digital micromirror devices is constantly improving. The assembly and debugging of traditional autofocusing devices are complicated, and the focus detection precision and range are difficult to meet the requirements of high precision digital lithography. Therefore, it has become an important research topic to explore the matching digital lithography autofocusing method. In this paper, a set of high resolution digital lithography system is established, which integrates digital lithography autofocus algorithm with variable step size peak search autofocus algorithm. Various common image sharpness evaluation functions and objectives at a variety of magnifications are used to realize the autofocus algorithm, and the performance of the image sharpness function is analyzed comprehensively. The experimental results show that by using algorithm fused with the autofocusing device in this paper, focus detection ranges of 10x, 20x and 40x objective lenses can reach 280µm, 160µm and 105µm, respectively, and the autofocusing accuracy can reach 0.625µm, achieving the submicron precision and large range autofocus at various magnifications. The experimental results of this paper can provide important reference value for autofocus of submicron scale digital lithography.

show abstract

Section: Introductionmentioning

confidence: 99%