The rapid advancement of semiconductor manufacturing and precision medicine demands imaging tools capable of capturing nanometer-scale details across large areas. Quantitative Phase Imaging (QPI) has emerged as a premier solution for observing transparent biological cells and measuring the 3D topography of silicon wafers. However, conventional QPI systems face a fundamental "bottleneck": high-magnification objectives provide high resolution but only a tiny field of view. To image a whole wafer or a large tissue sample, researchers must use "step-and-repeat" stitching, a process prone to mechanical misalignments and phase discontinuities that compromise data integrity.
In a new paper published in Light: Advanced Manufacturing, a team of scientists led by Professor Jinlong Zhu from the School of Mechanical Science and Engineering at Huazhong University of Science and Technology, China, has developed a novel computational imaging architecture called Lateral Line-scan Computational Phase Imaging (L2-CPI). This system extends the conventional limits of optical microscopy by enabling continuous, high-resolution phase imaging across an arbitrarily large field of view, limited only by the travel range of the scanning stage.
The L2-CPI system is centered around a Linnik-type interferometric configuration that utilizes the sample's lateral motion to generate phase shifts. Unlike traditional methods that require the sample to stop for every frame, L2-CPI captures data "on the fly." The team integrated a Dynamic Compensation System (DCS) to suppress mechanical vibrations in real time and employed a robust three-parameter cosine-fitting algorithm to retrieve phase information with high precision. These scientists summarize the operational principle of their system:
"We designed a lateral scanning architecture that serves three purposes in one: (1) to achieve diffraction-limited resolution across an arbitrary field of view without the need for image stitching; (2) to eliminate 'proximal errors' typically found in step-scan systems through a continuous pixelated acquisition strategy; and (3) to ensure high-fidelity 3D reconstruction even in the presence of industrial-level mechanical vibrations."
"Because our method retrieves phase information from a massive number of data points during the scan, it is significantly more robust against noise and environmental disturbances than traditional phase-shifting techniques," they added.
The researchers demonstrated the power of L2-CPI by inspecting patterned defect array wafer and microlens arrays. The system successfully identified sub-wavelength defects—such as bridge and cutting defects — in an intentionally fabricated defect array on a wafer with a 60 nm critical dimension, which are typically invisible to conventional intensity-based imaging systems. Based on our simulations, L²-CPI is expected to retain detectability even when the critical dimension is scaled down to 15 nm.
"The presented technique provides a high-throughput, non-destructive solution for large-scale nanometrology. It will be particularly transformative for the semiconductor industry, where rapid and accurate defect detection is critical for yield enhancement. Beyond the cleanroom, we foresee L2-CPI opening new avenues in digital pathology and automated biological screening, allowing researchers to 'see' large-scale life processes with unprecedented detail," the scientists forecast.
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References
DOI
10.37188/lam.2026.020
Original Source URL
https://doi.org/10.37188/lam.2026.020
Funding information
This work was funded by the National Nature Science Foundation of China (Grant No. 52175509 and 52450158), the National Key Research and Development Program of China (2023YFF1500900), the Shenzhen Fundamental Research Program (JCYJ20220818100412027), the Shenzhen Science and Technology Program (SGDX20230116093543005), and the Innovation Project of Optics Valley Laboratory (Grant No. OVL2023PY003).
About Light: Advanced Manufacturing
The Light: Advanced Manufacturing is a new, highly selective, open-access, and free of charge international sister journal of the Nature Journal Light: Science & Applications. It will primarily publish innovative research in all modern areas of preferred light-based manufacturing, including fundamental and applied research as well as industrial innovations.