Lithography Original Holder Control via Misalignment Convergence
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Solution Overview
Problem
Current lithography apparatuses face challenges in reducing mounting errors and improving throughput due to misalignment between the original and the holder, which varies with scan driving conditions and is not effectively controlled by existing techniques.
Innovation Solution
A lithography apparatus with a controller that performs preliminary driving of the original holder to stabilize the coupling state, measuring misalignment and adjusting the number of preliminary scan driving cycles based on convergence values to minimize mounting errors while optimizing throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If preliminary driving is repeatedly performed to reduce misalignment, then manufacturing precision is improved, but productivity deteriorates due to increased processing time
Solution Approach 1:
The patent implements feedback control by measuring the misalignment amount after preliminary driving and using this measurement to determine whether to continue or terminate the preliminary driving process. The controller monitors the misalignment amount and compares it against a predetermined threshold to make real-time decisions about process continuation, thereby optimizing both precision and productivity.
Solution Approach 2:
The patent applies dynamics by making the number of preliminary driving cycles variable rather than fixed. The process adapts the driving count based on actual misalignment measurements, allowing the system to perform fewer cycles when misalignment is already small and more cycles when misalignment is large, thus dynamically optimizing the balance between precision and throughput.
2Manufacturing precision
If the number of preliminary scan driving cycles is increased to reduce mounting error, then manufacturing precision is improved, but loss of time increases
Solution Approach 1:
The measurement unit provides feedback on the misalignment amount after each preliminary driving cycle, enabling the controller to make informed decisions about whether to continue driving. This feedback mechanism prevents unnecessary preliminary driving cycles, reducing time loss while ensuring sufficient precision is achieved.
Solution Approach 2:
The patent applies partial action by performing only the necessary number of preliminary driving cycles required to reduce misalignment to an acceptable level, rather than performing a fixed excessive number of cycles. The process stops as soon as the misalignment amount satisfies the predetermined condition, avoiding unnecessary time consumption.
3Reliability
If preliminary driving is performed to stabilize coupling state, then reliability is improved, but productivity deteriorates due to reduced throughput
Solution Approach 1:
The system uses feedback from the measurement unit to monitor coupling stability through misalignment measurements. The controller adjusts the preliminary driving count based on this feedback, ensuring reliable coupling stabilization while minimizing the time spent on preliminary operations, thus maintaining higher throughput.
Solution Approach 2:
The patent makes the preliminary driving process dynamic by adapting the number of cycles to the actual coupling state. When coupling is already stable (indicated by small misalignment), fewer preliminary cycles are performed, preserving throughput. When coupling is unstable, more cycles are performed to ensure reliability, creating a dynamic balance between reliability and productivity.
Data Source
AI summary
A lithography apparatus includes an original holder configured to hold and move an original, a measurement unit configured to measure a misalignment amount of the original with respect to the original holder, and a controller configured to control movement of the original holder. The controller repeatedly performs preliminary driving for moving the original holder before performing the pattern formation. At this time, if the misalignment amount measured by the measurement unit converges to a predetermined convergence value while the preliminary driving is repeatedly performed, the controller ends the preliminary driving.