Combination Stop for EUV Projection Arrangement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Microlithography with extreme ultraviolet light (EUVL) requires optical projection arrangements with reflective elements that effectively manage stray light and provide flexible imaging parameters, but existing systems face challenges in efficiently combining aperture and stray light stops within limited installation space.
Innovation Solution
An optical projection arrangement with an exchangeable combination stop featuring aperture and field stops that can be positioned transversely to the meridional plane, allowing for adjustable openings to manage stray light while minimizing installation space, and a segmented design for easy exchange and adjustment of imaging conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a combination stop with multiple openings is used to manage stray light and provide flexible imaging parameters, then imaging flexibility and stray light obscuration are improved, but device complexity increases
Solution Approach 1:
The patent combines multiple stops (aperture stop and stray light stop) into a single combination stop component. The stop features multiple openings (first opening for aperture control, second opening for stray light management) integrated in one piece, eliminating the need for separate stop components and reducing overall device complexity while maintaining imaging flexibility.
Solution Approach 2:
The combination stop serves multiple functions simultaneously: it acts as an aperture stop to control the ray bundle, a stray light stop to block unwanted light paths, and provides flexibility for different imaging parameters through its multiple openings. This multi-functionality reduces the number of components needed in the optical projection arrangement.
2Volume of moving object
If the combination stop is positioned transversely to the meridional plane to reduce installation space, then installation space is reduced, but alignment precision becomes more difficult
Solution Approach 1:
The combination stop is positioned at an angle (80° to 100°) to the meridional plane rather than strictly parallel or perpendicular, utilizing a intermediate angular dimension. This angled positioning optimizes the balance between minimizing installation space and maintaining adequate alignment precision, allowing the stop to fit in limited space while still being alignable with the optical axis.
3Adaptability or versatility
If the second opening is given a certain minimum size to allow adjacent ray bundles, then ray path flexibility is improved, but stray light shielding effectiveness decreases
Solution Approach 1:
The combination stop employs different opening sizes and positions for different functions: the first opening (aperture stop) has a specific size for controlling the main ray bundle, while the second opening (stray light stop) has a minimum size optimized for allowing adjacent ray bundles while still effectively blocking stray light. Each opening is locally optimized for its specific function, achieving both ray path flexibility and stray light shielding.
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 enables effective stray light obscuration, flexible imaging capabilities, and reduced installation space requirements, allowing for simple replacement and adjustment of stops to accommodate various imaging parameters without the need for extensive reconfiguration.
Implementation Method 1
The projection arrangement includes mirrors or other reflective elements, by which a ray path is defined
Data Source
AI summary
The disclosure relates to an optical projection arrangement that can be used to image a reticle onto a substrate. The projection arrangement includes reflective elements, by which a ray path is defined. A combination stop is in a pupil of the ray path. The combination stop has a first opening (aperture opening) for use as an aperture stop. The combination stop also has a second opening for allowing passage of a ray bundle of the ray path, such that the combination stop acts as a combined aperture stop and stray light stop. In addition, the disclosure relates to a corresponding combination stop for optical arrangements, as well as related systems, components and methods.