Magnetic Device Stray Field Reduction in Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnetic devices in lithographic apparatuses suffer from high magnetic stray fields and position-dependent motor constant variations, which affect the accuracy and efficiency of force compensation and pattern transfer.
Innovation Solution
Incorporating an additional magnetic part with a magnetic polarization angle of 90° to 270° relative to the existing magnetic parts, reducing magnetic stray fields and increasing flux density, allowing for a smaller and lighter magnetic device design while enhancing force compensation and motor constant stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional magnetic devices are used in lithographic apparatuses, then the device structure is simple, but the magnetic stray fields are high and motor constant varies with position
Solution Approach 1:
The magnetic device is divided into multiple magnetic parts (first magnetic part, second magnetic part, third magnetic part, fourth magnetic part) with different polarization directions. Each magnetic part generates a specific magnetic field component, and their combined effect produces the desired force while canceling out stray fields. This segmentation allows independent optimization of each part's contribution to reduce harmful magnetic stray fields.
Solution Approach 2:
The magnetic parts are arranged asymmetrically with specific polarization directions (first and third parts have first polarization direction, second and fourth parts have second polarization direction perpendicular to the first). This asymmetric configuration creates a balanced magnetic field distribution that reduces stray fields extending outside the device while maintaining the required force generation capability.
2Productivity
If conventional magnetic devices are used, then the device size is larger, but the force efficiency and motor constant stability are lower
Solution Approach 1:
The invention changes the magnetic field parameters by introducing multiple magnetic parts with different polarization directions (first polarization direction for force generation, second perpendicular polarization direction for flux density enhancement). This parameter optimization increases the motor constant and force efficiency, allowing a smaller and lighter device design while maintaining or improving productivity.
Solution Approach 2:
The magnetic device structure serves multiple functions simultaneously: the first and third magnetic parts generate primary force, while the second and fourth magnetic parts enhance flux density and reduce stray fields. This multi-functional design achieves both force efficiency improvement and device compactness without requiring separate components for each function.
3Measurement precision
If conventional magnetic devices are used, then the device is simpler to manufacture, but the position-dependent motor constant variations affect accuracy
Solution Approach 1:
Different magnetic parts are assigned different local qualities (polarization directions) to address specific local requirements. The first and third magnetic parts with first polarization direction provide force generation, while the second and fourth parts with perpendicular polarization direction provide flux enhancement and stray field reduction at their respective locations. This local quality differentiation ensures uniform motor constant across different positions, improving measurement precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution reduces magnetic stray fields, increases force efficiency, and allows for a more compact design with improved force compensation and stability, enhancing the overall performance of the magnetic device as a gravity compensator and Lorentz actuator.
Implementation Method 1
The first magnetic part and the second magnetic part are configured to magnetically interact with each other. The first magnetic part exerts a first force on the second magnetic part and the second magnetic part exerts a second force on the first magnetic part.
Implementation Method 2
The force between the first magnetic part MP1 and the second magnetic part MP2 may be used to compensate for a gravitational force.
Data Source
AI summary
A magnetic device includes first and second parts, a first magnetic part, with a first magnetic polarization, coupled to the first part, a second magnetic part, with a second magnetic polarization, coupled to the second part and an additional magnetic part coupled to the first part and having an additional magnetic polarization. The first and second magnetic parts magnetically interact with each other. The first magnetic part exerts a first force on the second magnetic part, the second magnetic part exerts a second force on the first magnetic part and the first and second forces have opposite directions that are parallel to a reference direction. The first magnetic polarization is substantially parallel to the reference direction, the second magnetic polarization is substantially perpendicular to the reference direction, the additional magnetic polarization makes an angle with the first magnetic polarization and has a magnitude in a range of about 90°-270°.