Optical Diffraction Component for Stray Light Suppression
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Solution Overview
Problem
Current optical diffraction components are inadequate in effectively suppressing stray light wavelengths by destructive interference, particularly in EUV projection exposure apparatuses, as they often require complex designs and tight manufacturing tolerances to achieve optimal suppression efficiency.
Innovation Solution
An optical diffraction component with a periodic grating structure featuring three diffraction structure levels - a neutral, positive, and negative level - arranged to create destructive interference for target wavelengths, allowing for flexible suppression of multiple wavelengths within a defined bandwidth, including infrared, near-infrared, visible, ultraviolet, and deep ultraviolet ranges, by optimizing the grating period and structure depths to achieve improved suppression efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional optical diffraction components are used for suppressing stray light wavelengths, then suppression of target wavelengths can be achieved, but the design requires complex structures and tight manufacturing tolerances to achieve optimal suppression efficiency
Solution Approach 1:
The grating structure is segmented into three distinct diffraction structure levels (first level, second level, third level) with different depths relative to a reference plane. This segmentation allows each level to contribute differently to the diffraction pattern, enabling effective suppression of target wavelengths through destructive interference while maintaining simpler individual level geometries that are easier to manufacture with relaxed tolerances.
Solution Approach 2:
Different regions of the grating structure are assigned different local qualities through the three diffraction structure levels, where each level has a specific depth characteristic. The first level, second level, and third level are positioned at different depths to create specific phase relationships for different wavelength ranges, allowing optimized suppression performance across multiple wavelength bands without requiring uniform complex structures throughout.
2Adaptability or versatility
If conventional optical diffraction components are used, then suppression of stray light is achieved, but flexibility in suppressing multiple wavelengths within a defined bandwidth is limited
Solution Approach 1:
The optical diffraction component achieves multi-functionality by incorporating three diffraction structure levels that can simultaneously suppress multiple target wavelengths within a defined bandwidth. The different levels are designed to target different wavelength ranges (e.g., infrared, near-infrared, visible, ultraviolet, deep ultraviolet), allowing a single grating structure to perform multiple suppression functions that would otherwise require separate components, thereby enhancing versatility while maintaining reliable suppression efficiency across all targeted wavelengths.
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 proposed solution enhances the suppression of target wavelengths through destructive interference, offering improved flexibility and manufacturing tolerance relaxation, leading to enhanced stray light suppression and increased design freedom for optical diffraction components in EUV projection exposure systems.
Implementation Method 1
An optical diffraction component with a periodic grating structure featuring three diffraction structure levels - a neutral, positive, and negative level - arranged to create destructive interference for target wavelengths
Implementation Method 2
arranged to create destructive interference for target wavelengths, allowing for flexible suppression of multiple wavelengths within a defined bandwidth
Data Source
AI summary
An optical diffraction component is configured to suppress at least one target wavelength by destructive interference. The optical diffraction component includes at least three diffraction structure levels that are assignable to at least two diffraction structure groups. A first of the diffraction structure groups is configured to suppress a first target wavelength λ1. A second of the diffraction structure groups is configured to suppress a second target wavelength λ2, where (λ1−λ2)2/(λ1+λ2)2<20%. A topography of the diffraction structure levels can be described as a superimposition of two binary diffraction structure groups. Boundary regions between adjacent surface sections of each of the binary diffraction structure groups have a linear course and are superimposed on one another at most along sections of the linear course.