Tilt metrology on rough dielectric surfaces using low coherence scanning interferometry
Autor: | Joonho You, Yunseok Kim, Chang-Yun Lee |
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Rok vydání: | 2019 |
Předmět: |
Materials science
business.industry Centroid Angle gauge 02 engineering and technology Surface finish Dielectric 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics Metrology 010309 optics Optics Tilt (optics) 0103 physical sciences Coherence scanning interferometry 0210 nano-technology business Camera module |
Zdroj: | Optics express. 27(24) |
ISSN: | 1094-4087 |
Popis: | In this investigation, we propose a technique to obtain not only the dimensional surface profile but also tilt information of the rough dielectric surface having a few microns root-mean-square roughness. This technique is based on low coherence scanning interferometry (LCSI) using a compound light source by combining a superluminescent light-emitting diode with ytterbium-doped fiber amplifier. Tilt angle and direction of the measured surface is extracted by the principal component analysis (PCA) from the measurement surface data and the centroid peak detection algorithm. To verify the performance of the proposed tilt measurement method, standard angle gauge block and certified step height sample were used as specimens. LCSI tilt measurement was about 3 times superior to the conventional auto-collimator in terms of the measurement precision in the practical camera module manufacturing process of smartphones. The proposed method was also discussed the dynamic tilt evaluation for the moving object. |
Databáze: | OpenAIRE |
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