Laser Beam Alignment Using Fiducial Marker Correlation
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Solution Overview
Problem
Optimal laser beam alignment and diagnostic in photolithography systems are challenging due to the need for precise alignment of laser beams with multiple optical components and the requirement for accurate characterization of laser beam characteristics.
Innovation Solution
A method involving rasterization of the laser beam across sensors using optical components, forming correlations between the physical disposition of these components and the laser beam impact points, and aligning the laser beam by adjusting the physical disposition of the optical components to achieve desired impact points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional alignment methods are used for laser beam alignment with multiple optical components, then the alignment process becomes complex and time-consuming, but the system requires high precision alignment for optimal laser operation
Solution Approach 1:
A fiducial marker is introduced as an intermediary element between the laser beam and the sensor. The fiducial marker provides a known reference point that simplifies the alignment process by enabling direct correlation between sensor position and laser beam impact point, eliminating the need for complex iterative alignment procedures while maintaining high precision
Solution Approach 2:
The system creates a positional copy or mapping relationship between the sensor location and the laser beam impact point on the workpiece through the fiducial marker. This copying approach allows the alignment information to be transferred and used for subsequent laser operations without requiring repeated complex alignment procedures
2Measurement precision
If traditional diagnostic approaches are used for laser beam characterization, then the diagnostic process lacks comprehensive data, but accurate characterization of laser beam characteristics is required for optimal operation
Solution Approach 1:
The sensor provides real-time feedback on the laser beam impact position by detecting the fiducial marker. This feedback mechanism enables continuous monitoring and characterization of laser beam characteristics, allowing for accurate measurement of beam position, focus, and other parameters while simplifying the diagnostic process through automated data collection
Data Source
AI summary
Methods and apparatuses for aligning and diagnosing the laser beam traversing an optical train in a highly space-efficient, lower cost and/or retrofit-friendly manner are disclosed. The optical components of the optical train are mounted such that one or more optical components can direct their exit laser beam to partially or wholly scan across one or more downstream sensors. Correlation data between physical disposition of optical components and the points of impact data and/or beam quality data are employed to, among others, align and/or diagnose the laser beam and/or localize failure sites and/or optimize maintenance schedule.