Lithography Positioning Control for X-Beam Yaw Suppression
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Solution Overview
Problem
Existing lithography apparatuses face challenges in achieving high positioning accuracy and throughput due to yawing vibration of the X beam, which is not effectively suppressed by existing techniques, especially with weight reduction and manufacturing tolerances leading to vibration transmission across axes.
Innovation Solution
A positioning apparatus with a control unit that applies different correction operation amounts to YL and YR actuators to offset moments generated during X-axis movement, performing feedforward control to reduce yawing vibration of the X beam without the need for rotation measurement, using a configuration of YL and YR actuators parallel to each other and an X actuator within the X beam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If weight reduction is implemented in the positioning apparatus, then productivity and speed are improved, but manufacturing precision deteriorates due to inability to make center of mass and effort coincide, causing vibration transmission
Solution Approach 1:
The control unit calculates correction operation amounts in advance based on the operation amount of the third actuator, and applies these corrections to the first and second actuators before the vibration occurs. This preliminary counter-action compensates for the moment generated by the displacement between center of mass and effort, preventing vibration transmission to other axes while maintaining weight reduction for high productivity
2Manufacturing precision
If feedback control is used to suppress yawing vibration by measuring rotation displacement, then positioning accuracy is improved, but response time increases causing delay
Solution Approach 1:
Instead of measuring rotation displacement and applying feedback control, the control unit performs preliminary calculation of correction operation amounts based on the operation amount of the third actuator, and applies these corrections in advance. This eliminates the need for rotation measurement and feedback processing, achieving high positioning accuracy without response delay
3Object-affected harmful factors
If the center of mass and effort are made to coincide, then vibration transmission is reduced, but device complexity increases due to strict arrangement requirements and manufacturing tolerances
Solution Approach 1:
Instead of mechanically aligning the center of mass and effort through strict arrangement and manufacturing tolerances, the invention substitutes this mechanical requirement with a control system. The control unit calculates and applies correction operation amounts to compensate for the moment generated by the displacement, achieving vibration suppression without complex mechanical constraints
Data Source
AI summary
The present invention provides a positioning apparatus for positioning of an object, the positioning apparatus including a first actuator and a second actuator configured to be arranged along a first direction so as to be parallel to each other, and to cause a beam to move in the first direction, a third actuator configured to be built in the beam, and to cause the object to move in a second direction relative to the beam, the second direction intersecting with the first direction, and a control unit configured to control the first actuator, the second actuator, and the third actuator.