The wafer pre-aligner is a crucial component in the lithography process to correct the wafer center and notch orientation. To improve the precision and the efficiency of pre-alignment, a new method to calibrate the center and the orientation of a wafer based on the weighted Fourier series fitting of circles (WFC) method and the least squares fitting of circles (LSC) method, respectively, is proposed. The WFC method effectively suppressed the influence of the outliers and had high stability compared with the LSC method when fitted to the center of the circle. While the weight matrix degenerated to the identity matrix, the WFC method degenerated into the Fourier series fitting of circles (FC) method. The fitting efficiency of the FC method is 28% higher than that of the LSC method, and the fitting accuracy of the center of the FC method is the same as that of the LSC method. In addition, the WFC method and the FC method perform better than the LSC method in radius fitting. The pre-alignment simulation results showed that the absolute position accuracy of the wafer was ±2 µm, the absolute direction accuracy was 0.01°, and the total calculation time was less than 3.3 s in our platform.
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http://dx.doi.org/10.3390/mi14050956 | DOI Listing |
The Circle of Willis (CW) is a critical cerebrovascular structure that supports collateral blood flow to maintain brain perfusion and compensate for eventual occlusions. Increased tortuosity of highrisk vessels within the CW has been implicated as a marker in the progression of cerebrovascular diseases especially in structures like the internal carotid artery (ICA). This is partly due to age-related plaque deposition or arterial stiffening.
View Article and Find Full Text PDFSci Rep
December 2024
School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan, 430070, China.
Urban rail transit systems, represented by subways, have significantly alleviated the traffic pressure brought by urbanization and have addressed issues such as traffic congestion. However, as a commonly used construction method for subway tunnels, shield tunneling inevitably disturbs the surrounding soil, leading to uneven ground surface settlement, which can impact the safety of nearby buildings. Therefore, it is crucial to promptly obtain and predict the ground surface settlement induced by shield tunneling construction to enable safety warnings and evaluations.
View Article and Find Full Text PDFACS Meas Sci Au
December 2024
Department of Bioengineering and Nano-Bioengineering, Research Center for Bio Materials and Process Development, Incheon National University, Incheon 22012, Republic of Korea.
Thermal cycling-based quantitative polymerase chain reaction (qPCR) represents the gold standard method for accurate and sensitive nucleic acid quantification in laboratory settings. However, its reliance on costly thermal cyclers limits the implementation of this technique for rapid point-of-care (POC) diagnostics. To address this, isothermal amplification techniques such as rolling circle amplification (RCA) have been developed, offering a simpler alternative that can operate without the need for sophisticated instrumentation.
View Article and Find Full Text PDFHealth Sci Rep
December 2024
Department of Research The Medical Research Circle Goma Congo.
Background: Lennox-Gastaut syndrome (LGS) poses significant challenges in diagnosis, management, and treatment due to its rare nature, diverse presentation, and drug-resistant seizures. While classical features aid diagnosis, challenges persist, impacting patient care and outcomes. Understanding the syndrome's burden is essential for improving healthcare policies and interventions.
View Article and Find Full Text PDFAnn Med Surg (Lond)
December 2024
Medical Research Circle (MedReC), Goma, DR Congo.
Introduction And Importance: This case report is a clinical diagnosis walk through of a rare subtype of multiple sclerosis (MS). It gives an overview of how tumefactive multiple sclerosis (TMS) is systematically narrowed down as the definitive diagnosis.
Case Presentation: This 29-year-old male patient presented to the emergency department.
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