EUV Beam Homogenization via Reflective Etendue Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current radiation systems for lithographic applications face challenges in achieving sufficient etendue and spatial homogeneity of EUV radiation beams, leading to limitations in feature size and pattern precision due to non-homogeneous intensity profiles and potential interference patterns.
Innovation Solution
A radiation system incorporating a radiation alteration device that increases the etendue of EUV radiation beams by multiple successive reflections within a tube with a reflective internal surface, and optionally using diffusing elements or reflective facets to scramble and homogenize the radiation, thereby enhancing the spatial homogeneity and reducing coherence to prevent interference patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple successive reflections within a tube with reflective internal surface are used to increase etendue, then the etendue of EUV radiation beams is significantly increased, but the device complexity increases due to the need for precise alignment and maintenance of reflective surfaces
Solution Approach 1:
The radiation alteration device is divided into multiple reflective facets or segments arranged in a sequence. Each facet contributes to the successive reflections, allowing the etendue to be increased through modular additions rather than requiring a single complex reflective structure. This segmentation makes the system more manageable and easier to align.
Solution Approach 2:
The patent transforms the radiation beam propagation from a simple linear path to a multi-dimensional path involving successive reflections at different angles and positions within the tube. By utilizing the three-dimensional space within the tube and arranging reflective surfaces at various orientations, the system achieves significant etendue multiplication without proportionally increasing the physical footprint of the device.
2Stability of the object's composition
If diffusing elements or reflective facets are used to scramble and homogenize the radiation, then the spatial homogeneity is enhanced, but the manufacturing precision requirements increase for the diffusing elements
Solution Approach 1:
The patent employs diffusing elements with controlled surface roughness parameters and reflective facets with specific angular distributions. By carefully selecting and controlling these geometric parameters during manufacturing, the system achieves the desired radiation homogenization while keeping manufacturing tolerances within achievable limits. The diffusing elements are designed with surface characteristics that scatter radiation in a controlled manner to achieve uniform intensity profiles.
3Stability of the object's composition
If the radiation alteration device increases etendue by multiple successive reflections, then the intensity profile becomes more homogeneous, but the loss of energy increases due to multiple reflections
Solution Approach 1:
The patent employs sacrificial or replaceable diffusing elements and reflective coatings that can be replaced when their reflectivity degrades. Rather than designing for indefinite service life with extremely high precision, the system uses materials and coatings that provide sufficient performance for a defined operational period, after which they can be replaced. This approach reduces the initial manufacturing cost and energy loss while maintaining acceptable performance levels.
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 significantly increases the etendue of EUV radiation beams, achieving more homogeneous intensity profiles and reducing interference patterns, which improves the precision and effectiveness of EUV radiation in lithographic applications by providing a more uniform and coherent beam.
Implementation Method 1
multiple successive reflections within a tube with a reflective internal surface
Implementation Method 2
optionally using diffusing elements or reflective facets to scramble and homogenize the radiation
Data Source
AI summary
A radiation system includes a beam splitting apparatus configured to split a main radiation beam into a plurality of branch radiation beams and a radiation alteration device arranged to receive an input radiation beam and output a modified radiation beam, wherein the radiation alteration device is configured to provide an output modified radiation beam which has an increased etendue, when compared to the received input radiation beam, wherein the radiation alteration device is arranged such that the input radiation beam which is received by the radiation alteration device is a main radiation beam and the radiation alteration device is configured to provide a modified main radiation beam to the beam splitting apparatus, or wherein the radiation alteration device is arranged such that the input radiation beam which is received by the radiation alteration device is a branch radiation beam output from the beam splitting apparatus.