EUV Illumination System Electron Beam Polarization Control
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Solution Overview
Problem
Conventional EUV radiation sources, such as LPP and GDP, face challenges in providing a resolution-optimized illumination with adjustable polarization, which is essential for precise object illumination in projection lithography.
Innovation Solution
An EUV illumination system utilizing an electron beam-based light source with a polarization setting device that adjusts the electron beam's polarization, allowing for linear, elliptical, or circular polarization, and a scanning device synchronized with the polarization setting device to achieve flexible illumination adjustments, avoiding the need for movable parts and compensating for polarization changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional EUV radiation sources (LPP or GDP) are used, then the illumination system can operate, but the resolution and polarization control are insufficient for precision lithography
Solution Approach 1:
The patent applies parameter changes by controlling the polarization state of the electron beam through adjustable deflecting effects. The polarization setting device modifies the electron beam parameters (polarization state) to generate EUV light with different polarization states, thereby achieving both high resolution and polarization adaptability in the illumination system
2Adaptability or versatility
If a polarization setting device with movable parts is used to adjust electron beam deflection, then polarization control is achieved, but the device complexity increases
Solution Approach 1:
The patent replaces mechanical systems with electromagnetic systems. Instead of using mechanical movable parts to adjust polarization, the invention uses electromagnetic deflecting effects applied to the electron beam. This substitution eliminates complex mechanical structures while achieving precise polarization control through electromagnetic field manipulation
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 system provides a high-resolution, adjustable polarization output beam that can be tailored to specific illumination requirements, enhancing the precision and flexibility of the illumination system, thereby improving the resolution and efficiency of the EUV projection lithographic exposure apparatus.
Implementation Method 1
an electron beam supply device (2a), an EUV generating device (2c) which is supplied with an electron beam (2b) by the electron beam supply device (2a)
Implementation Method 2
an EUV generating device (2c) which is supplied with an electron beam (2b) by the electron beam supply device (2a)
Implementation Method 3
a polarization setting device (25), which exerts an adjustable deflecting effect on the electron beam (2b) for setting the polarization of the output beam (3)
Data Source
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AI summary
An illumination system for an EUV projection lithographic projection exposure apparatus (1) comprises an EUV light source (2), which generates an output beam (3) of EUV illumination light with a predetermined polarization state. An illumination optical unit (5) guides the output beam (3) along an optical axis, as a result of which an illumination field (14) in a reticle plane (15) is illuminated by the output beam (3). The light source (2) comprises an electron beam supply device (2a), an EUV generating device (2c) and a polarization setting device (25). The EUV generating device (2c) is supplied with an electron beam (2b) by the electron beam supply device (2a). The polarization setting device (25) exerts an adjustable deflecting effect on the electron beam (2b) for setting the polarization of the output beam (3). This results in an illumination system, which operates on the basis of an electron beam-based EUV light source and provides an output beam, which is improved for a resolution-optimized illumination.