EUV Mirror Multi-Layer Diffraction for Radiation Purity
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Solution Overview
Problem
Existing semiconductor exposure devices face challenges in achieving high-purity extreme ultra-violet (EUV) radiation for semiconductor processing due to the need for multiple layers and low transmission efficiency, which affects the accuracy and reliability of patterning, and the difficulty in separating EUV radiation from other wavelengths.
Innovation Solution
A semiconductor exposure device utilizing a mirror with a laminated structure of multiple regions, where the number and shape of multi-layers differ, enhances EUV radiation purity through beneficial diffraction effects, and includes a radiation shield to separate EUV radiation from other wavelengths, reducing the number of layers required and improving transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a multi layer structure is used to reflect EUV radiation, then reflectivity is improved, but the number of reflections increases causing output to gradually decrease
Solution Approach 1:
The patent changes the physical parameters of the multi-layer structure by optimizing the thickness of individual layers (e.g., Mo and Si layers) to achieve constructive interference and maximize reflectivity at the EUV wavelength, thereby improving illumination intensity while minimizing energy loss through careful parameter selection
Solution Approach 2:
The patent employs composite multi-layer structures combining different materials (such as molybdenum and silicon) with complementary properties to achieve high reflectivity for EUV radiation, where each material layer contributes to the overall optical performance and minimizes energy loss
2Manufacturing precision
If radiation of other wavelengths is present in the EUV radiation, then exposure contrast deteriorates, but separating EUV radiation requires additional components
Solution Approach 1:
The patent designs optical components that serve multiple functions: the multi-layer mirrors not only reflect EUV radiation but also inherently filter out other wavelengths through their selective reflectivity properties, eliminating the need for separate filtering components while maintaining exposure contrast
Solution Approach 2:
The patent applies local quality by designing the multi-layer structure with specific layer thicknesses and material compositions that are optimized for EUV wavelength reflection, creating a localized spectral filtering effect that separates EUV radiation from other wavelengths without requiring additional components
3Reliability
If the number of multi layers is increased to improve EUV radiation purity, then transmission efficiency decreases, but reducing layers affects radiation purity
Solution Approach 1:
The patent optimizes the parameters of the multi-layer structure by precisely controlling layer thicknesses and material properties to achieve the desired EUV radiation purity with a minimized number of layers, thereby maintaining transmission efficiency while ensuring radiation purity through parameter optimization
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 provides high-purity EUV radiation with improved transmission efficiency and reduced layer stress, enhancing the accuracy and reliability of semiconductor patterning while reducing manufacturing costs and maintaining long-term device performance.
Implementation Method 1
enhances EUV radiation purity through beneficial diffraction effects
Implementation Method 2
a plurality of mirrors for extreme ultra violet radiation which reflect the extreme ultra violet radiation
Data Source
AI summary
The exposure device is able to supply only EUV radiation to a mask, while eliminating radiation other than the EUV radiation. A multi layer made from a plurality of Mo/Si pair layers is provided upon the front surface of a mirror, and blazed grooves are formed in this multi layer. Radiation which is incident from a light source device is incident upon this mirror, and is reflected or diffracted. Since the reflected EUV radiation (including diffracted EUV radiation) and the radiation of other wavelengths are reflected or diffracted at different angles, accordingly their directions of progression are different. By eliminating the radiation of other wavelengths with an aperture and/or a dumper, it is possible to irradiate a mask only with EUV radiation of high purity.