Chuck Leveling Control for Exposure Apparatus
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Solution Overview
Problem
Large chucks used in exposure and optical inspection apparatuses face challenges in maintaining flatness and balance due to increased size, leading to difficulties in ensuring the entire plate is within the depth of focus range, which can result in exposure failures.
Innovation Solution
A method is introduced to detect and adjust the tilt component of the chuck, and if residual tilt is present, further tune scaling and coordinate parameters to ensure accurate leveling and focus, utilizing a multi-point support configuration and a controller to irradiate light and adjust the chuck's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the chuck size is increased to accommodate larger LCD panels, then the processing capability is improved, but the flatness and balance of the chuck deteriorate due to buckling and limited mechanical accuracy
Solution Approach 1:
The chuck is divided into multiple independent support points (at least three) that can be individually adjusted. This segmentation allows each support point to be precisely controlled to maintain overall chuck flatness despite the large chuck size, preventing buckling and maintaining manufacturing precision across the entire surface.
Solution Approach 2:
The vertical positions of multiple support points are independently adjusted to change the geometric parameters of the chuck surface. By controlling the Z-coordinates of each support point, the system maintains chuck flatness and eliminates tilt components even as the chuck size increases to accommodate larger panels.
2Area of stationary object
If the chuck size is increased, then the processing capability is improved, but the difficulty in ensuring the entire plate is within the depth of focus range increases
Solution Approach 1:
The chuck surface is segmented into multiple adjustable support points that can be independently positioned. This allows precise control over the entire chuck surface geometry, ensuring that the whole plate remains within the depth of focus range during exposure, thereby maintaining exposure accuracy despite the larger chuck size.
Solution Approach 2:
The system uses focus sensors to detect tilt components and height variations across the chuck surface. Based on this feedback, the controller automatically adjusts the support point positions to eliminate tilt and ensure the entire plate is within the depth of focus range, improving exposure reliability.
3Device complexity
If manual leveling methods are used for large chucks, then the setup process is simple, but the time required for leveling increases significantly
Solution Approach 1:
The system performs automatic self-leveling by using focus sensors to detect tilt components and automatically adjusting the support point positions through actuators. This eliminates the need for complex manual leveling operations, significantly reducing the time required while maintaining simplicity in the overall process.
Solution Approach 2:
Manual mechanical leveling operations are replaced with an automated optical-mechanical system. Focus sensors optically detect tilt components, and electronic controllers automatically drive actuators to adjust support point positions, substituting manual mechanical adjustment with an automated sensing and actuation system that is both faster and more precise.
4Measurement precision
If the chuck is leveled with respect to a focus sensor, then the focusing accuracy is improved, but it becomes necessary to minimize change of focus throughout the plate
Solution Approach 1:
Instead of relying on a single focus sensor measurement, the system segments the measurement across multiple support points. By detecting and adjusting each support point's position individually, the system achieves accurate focus measurement while minimizing focus variation across the entire plate, reducing the complexity of maintaining uniform focus.
Solution Approach 2:
The system changes the vertical position parameters of multiple support points to eliminate tilt components and minimize focus variation across the plate. By independently adjusting each support point's Z-coordinate, the system achieves both accurate focus measurement and uniform focus across the entire plate surface.
Data Source
AI summary
Exemplary embodiments of the invention disclose an exposure apparatus and a method of tuning parameters of a chuck, which may reduce a time taken to level the chuck by previously tuning parameters of the chuck. The method of tuning parameters of a chuck includes detecting a tilt component of the chuck, performing chuck tilt adjustment to minimize the tilt component of the chuck, and tuning the parameters of the chuck if a residual tilt component is present after performing the chuck tilt adjustment.