Imaging Trigger Timing Correction for Moving Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods fail to accurately image a predetermined position of a subject when the camera and subject are relatively moving, leading to timing delays and positional shifts during image capture, which affects the accuracy and efficiency of inspections in semiconductor manufacturing and other applications.
Innovation Solution
A method and apparatus that predict and correct the imaging trigger timing based on the relative speed and distance of the substrate and camera movement, ensuring the camera is positioned correctly before capturing the image, using a shift amount prediction unit and imaging trigger correction unit to adjust the trigger generation accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the wafer is moved at high speed to improve productivity, then inspection time is reduced, but imaging position accuracy deteriorates due to time lag between trigger generation and image capture
Solution Approach 1:
The patent applies preliminary action by predicting the shift amount before image capture and pre-adjusting the imaging trigger timing. The shift amount prediction unit calculates the expected positional displacement based on current movement speed and direction, and the imaging trigger generation unit advances the trigger timing by this predicted shift amount, ensuring the camera captures the intended position even during high-speed movement.
Solution Approach 2:
The patent implements feedback through a closed-loop system where the imaging trigger generation unit receives real-time position information from the position detection unit and movement speed information from the movement speed detection unit. The system continuously adjusts trigger timing based on actual movement conditions, creating a feedback mechanism that maintains imaging accuracy during dynamic movement.
2Measurement precision
If the imaging trigger is generated earlier to compensate for time lag, then imaging position accuracy is improved, but device complexity increases due to additional prediction and correction mechanisms
Solution Approach 1:
The patent applies self-service by having the system automatically calculate and apply position corrections without external intervention. The shift amount prediction unit uses the movement speed detection unit's output to self-determine the required timing adjustment, and the imaging trigger generation unit automatically incorporates this correction. This self-correcting mechanism improves accuracy while minimizing the need for complex external control systems.
3Manufacturing precision
If static deviation correction methods are used, then manufacturing precision is improved for stationary subjects, but productivity decreases when imaging moving substrates
Solution Approach 1:
The patent applies dynamics by transitioning from static correction methods to dynamic correction methods that adapt to real-time movement conditions. The shift amount prediction unit continuously updates its calculations based on current movement speed and direction, and the imaging trigger generation unit dynamically adjusts timing for each image capture. This dynamic approach enables accurate positioning during high-speed movement, significantly improving productivity while maintaining precision.
Data Source
AI summary
An imaging method for imaging an image on a substrate at an accurate position while relatively moving the substrate and the imaging unit. The imaging method includes the steps of taking an image while relatively moving the substrate and a camera, predicting a shift amount of the imaging position and the position of the actual imaging when generating an imaging trigger without a correction, based on the relative moving speed and moving distance of the substrate and camera, and correcting the imaging trigger for shifting the timing of generating the imaging trigger only for the time corresponding to the predicted shift amount.