Lithography Drive System Coordinate Velocity Transformation
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Solution Overview
Problem
In immersion-type lithographic apparatuses, the simultaneous operation of x and y direction drive motors at their maximum velocities can result in a resultant velocity vector exceeding the maximum immersion velocity, leading to liquid contamination and loss, as the current control systems do not effectively manage the combined velocities to prevent this excess.
Innovation Solution
The implementation of a coordinate transformation method that limits the velocities in the x and y directions using specific formulas to transform set-point and motion coordinates, ensuring the resultant velocity vector does not exceed the maximum immersion velocity, by using first and second coordinate transformers and set-point generators to adjust the motion data for the drive motors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If x and y direction drive motors operate simultaneously at their maximum velocities to maximize substrate throughput, then productivity is improved, but the resultant velocity vector exceeds the maximum immersion velocity causing liquid contamination and loss
Solution Approach 1:
The system dynamically adjusts the velocity parameters of the x and y direction drive motors based on their operational timing. When both motors operate simultaneously, their velocity commands are scaled down from maximum values to ensure the resultant velocity vector does not exceed the maximum immersion velocity. This parameter adjustment resolves the contradiction by modifying the velocity parameters adaptively.
Solution Approach 2:
The control system monitors the operational state of the x and y direction drive motors and adjusts their velocity commands accordingly. When both motors are active, the system applies velocity reduction factors to prevent the resultant velocity from exceeding the immersion velocity limit. This feedback mechanism ensures liquid containment while maintaining efficient substrate processing.
2Ease of operation
If the maximum velocity of x and y direction drive motors is set to the maximum immersion velocity, then ease of operation is improved, but the combined velocity vector exceeds the maximum immersion velocity
Solution Approach 1:
The system transitions from static velocity limits to dynamic velocity adjustment. The maximum velocity settings for x and y direction motors are no longer fixed at the maximum immersion velocity but are dynamically adjusted based on the operational state. When both motors run simultaneously, the velocity commands are scaled using reduction factors that ensure the resultant velocity vector remains within the maximum immersion velocity limit.
Solution Approach 2:
The velocity parameters of the drive motors are changed adaptively based on operational conditions. The system modifies the velocity commands in real-time, applying reduction factors when both x and y motors operate simultaneously, ensuring reliability compliance while maintaining ease of operation through automated control.
3Device complexity
If independent control of x and y direction drive motors is used, then device complexity is reduced, but the combined velocity effect cannot be controlled to prevent liquid loss
Solution Approach 1:
The control systems of the x and y direction drive motors are merged at the velocity command level. When both motors operate simultaneously, the system combines their velocity commands and applies a reduction factor to ensure the resultant velocity vector does not exceed the maximum immersion velocity. This merging approach prevents liquid loss while maintaining relatively simple independent motor structures.
Solution Approach 2:
An intermediary velocity adjustment mechanism is introduced between the independent x and y direction control systems. This intermediary applies velocity reduction factors to the commands of both motors when they operate simultaneously, mediating their combined effect to prevent the resultant velocity from exceeding the immersion velocity limit, thereby preventing liquid loss.
Data Source
AI summary
A lithographic apparatus includes a projection system to project a patterned beam of radiation onto a substrate, which is held on a substrate support and a drive system to move the substrate support along a trajectory. In the drive system, set-point data, including set-point coordinates, are generated for moving the substrate support relative to the projection system in a first and second directions. The set-point coordinates of the first and second directions are transformed into set-point coordinates of third and fourth directions. Motion data, including motion coordinates, are generated for moving the substrate support relative to the projection system in the third and fourth directions, limiting the velocity in the third and fourth directions to a maximum velocity. The motion coordinates of the third and fourth directions are transformed into motion coordinates of the first and second directions for driving the first and second drive motors.