DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based Alignment
Alignment systems are core subsystems of lithography, which directly affect the overlay accuracy of the lithography process. The Moiré fringe-based alignment method has the advantages of high precision and low complexity. However, the precision of this method is highly sensitive to variations in the...
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| Language: | English |
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MDPI AG
2025-03-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/16/3/356 |
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| author | Kairui Zhang Haifeng Sun Dajie Yu Song Hu Junbo Liu Ji Zhou |
| author_facet | Kairui Zhang Haifeng Sun Dajie Yu Song Hu Junbo Liu Ji Zhou |
| author_sort | Kairui Zhang |
| collection | DOAJ |
| description | Alignment systems are core subsystems of lithography, which directly affect the overlay accuracy of the lithography process. The Moiré fringe-based alignment method has the advantages of high precision and low complexity. However, the precision of this method is highly sensitive to variations in the gap between the wafer and the mask. To enhance the performance of Moiré fringe-based alignment, this paper proposes a novel method in which the multi-wavelength approach is used to enhance the imaging depth of focus (DOF). We use a multi-wavelength light to illuminate the alignment marks on the wafer and mask, which is combined with different sources. Then, we use the improved phase analysis algorithm to analyze the contrast of the Moiré fringe and calculate the Moiré fringe displacement. Experiments show that, in an alignment range of 1000 μm, the effective DOF can exceed 400 μm. It is evidenced that the accuracy of the Moiré fringe alignment is unaffected and remains at the nanometer level. Otherwise, with parameter optimization, the alignment DOF is expected to be further extended. |
| format | Article |
| id | doaj-art-b59b517b897c4ff69182ad7cdb97ff83 |
| institution | Kabale University |
| issn | 2072-666X |
| language | English |
| publishDate | 2025-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj-art-b59b517b897c4ff69182ad7cdb97ff832025-08-20T03:43:14ZengMDPI AGMicromachines2072-666X2025-03-0116335610.3390/mi16030356DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based AlignmentKairui Zhang0Haifeng Sun1Dajie Yu2Song Hu3Junbo Liu4Ji Zhou5National Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences, Chengdu 610209, ChinaNational Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences, Chengdu 610209, ChinaNational Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences, Chengdu 610209, ChinaNational Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences, Chengdu 610209, ChinaNational Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences, Chengdu 610209, ChinaNational Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences, Chengdu 610209, ChinaAlignment systems are core subsystems of lithography, which directly affect the overlay accuracy of the lithography process. The Moiré fringe-based alignment method has the advantages of high precision and low complexity. However, the precision of this method is highly sensitive to variations in the gap between the wafer and the mask. To enhance the performance of Moiré fringe-based alignment, this paper proposes a novel method in which the multi-wavelength approach is used to enhance the imaging depth of focus (DOF). We use a multi-wavelength light to illuminate the alignment marks on the wafer and mask, which is combined with different sources. Then, we use the improved phase analysis algorithm to analyze the contrast of the Moiré fringe and calculate the Moiré fringe displacement. Experiments show that, in an alignment range of 1000 μm, the effective DOF can exceed 400 μm. It is evidenced that the accuracy of the Moiré fringe alignment is unaffected and remains at the nanometer level. Otherwise, with parameter optimization, the alignment DOF is expected to be further extended.https://www.mdpi.com/2072-666X/16/3/356lithographyalignmentMoiré fringe technologymulti wavelength measurement |
| spellingShingle | Kairui Zhang Haifeng Sun Dajie Yu Song Hu Junbo Liu Ji Zhou DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based Alignment Micromachines lithography alignment Moiré fringe technology multi wavelength measurement |
| title | DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based Alignment |
| title_full | DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based Alignment |
| title_fullStr | DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based Alignment |
| title_full_unstemmed | DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based Alignment |
| title_short | DOF Enhanced via the Multi-Wavelength Method for the Moiré Fringe-Based Alignment |
| title_sort | dof enhanced via the multi wavelength method for the moire fringe based alignment |
| topic | lithography alignment Moiré fringe technology multi wavelength measurement |
| url | https://www.mdpi.com/2072-666X/16/3/356 |
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