Laser Beam Guiding Device With Thermally Isolated Stray-Light Sleeve
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Solution Overview
Problem
Stray light absorption in optical beam guiding elements of drive lasers for EUV lithography causes inhomogeneous heating, leading to thermo-mechanical deformations and laser beam drift.
Innovation Solution
A beam guiding device with a sleeve inside the beam channel, thermally decoupled from the body via a gap, to absorb stray light and minimize heat transfer, using materials like aluminum for the body and sleeves, and optionally filled with a low-conductivity gas or solid material, and incorporating cooling fluid channels to further reduce heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the body of the beam guiding device absorbs stray light, then the stray light is removed from the optical path, but inhomogeneous heating occurs causing thermo-mechanical deformations and beam drift
Solution Approach 1:
The beam guiding device is segmented into a body and a sleeve, with the sleeve being a separate component that can be thermally decoupled from the body through a gap or thermal isolation structure. This segmentation allows the sleeve to absorb stray light while preventing heat transfer to the body, thereby avoiding thermo-mechanical deformations that would affect beam position stability.
Solution Approach 2:
A sleeve is introduced as an intermediary component between the stray light source and the body. The sleeve serves as a heat barrier, absorbing stray light and blocking heat transfer to the body through thermal isolation measures (gap, low thermal conductivity materials). This intermediary protects the body from thermal effects while maintaining the stray light absorption function.
2Stability of the object's composition
If a sleeve is added to absorb stray light, then beam drift is suppressed, but device complexity increases
Solution Approach 1:
The device is divided into modular components (body and sleeve) that can be independently manufactured and assembled. The sleeve is a simple cylindrical component that fits into the beam channel, requiring minimal additional manufacturing steps. The modular design allows for easy assembly and maintenance while achieving the thermal isolation function.
Solution Approach 2:
The sleeve can be designed as a thin-walled cylindrical structure that provides sufficient thermal isolation while minimizing material usage and structural complexity. The simple geometric form (cylinder) is easy to manufacture and integrate into the existing beam channel design, adding minimal complexity to the overall device.
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
Stabilizes the position of optical beam guiding elements by reducing thermo-mechanical deformations, thereby suppressing laser beam drift and maintaining beam stability.
Implementation Method 1
at least one sleeve is arranged inside the beam channel such that a gap exists between an outer surface of the sleeve and an inner surface of the body for thermally decoupling the sleeve from the body
Implementation Method 2
incorporating cooling fluid channels to further reduce heat transfer
Implementation Method 3
The stray light may be absorbed by the sleeve which consequently heats up
Data Source
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AI summary
The present invention concerns a beam guiding device (200) for guiding laser radiation, comprising a body (201) with an inner beam channel (202) and an optical beam guiding element (205), in particular a mirror, that is arranged inside the beam channel (202), wherein at least one sleeve (210, 211) is arranged inside the beam channel (202) such that a gap (207) exists between an outer surface of the sleeve (210, 211) and an inner surface of the body (201) for thermally decoupling the sleeve (210, 211) from the body (201). The present invention further concerns a lithography system (101), in particular extreme ultraviolet lithography system, comprising a drive laser (100) with a beam guiding device (200) as mentioned before.