Modular Carrier Structure for EUV Lithography

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

EUV lithography projection exposure apparatuses face challenges due to contaminant adhesion on optical elements and temperature-related issues, which affect the optical properties and require complex and space-consuming solutions for contamination reduction and heat management.

Innovation Solution

A modular carrier structure for optical elements with varying geometry and fluid-tight sealing, integrating 'mini-environments' and heat shields, allowing for space-saving and flexible implementation of functionalities like contamination protection and heat management within the optical system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate vacuum housings and contamination reduction units are provided for each optical element, then contamination protection is improved, but device complexity and space consumption increase

Engineering Contradiction:
Improvecontamination protectionVSAvoidnumber of separate components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate vacuum housings and contamination reduction units into a single integrated carrier structure that houses multiple optical elements. This merging approach maintains contamination protection for each element while reducing the overall number of separate components and simplifying the system architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The carrier structure serves multiple functions simultaneously: it provides mechanical support for optical elements, creates vacuum-sealed environments, and integrates contamination reduction units. This multi-functionality eliminates the need for separate dedicated structures for each function, reducing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If separate vacuum housings surround each optical surface, then contamination protection is improved, but structural space is consumed

Engineering Contradiction:
Improvecontamination protectionVSAvoidstructural space
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent implements a nested structure where optical elements are positioned within the carrier structure, and contamination reduction units are integrated within the same carrier structure. This nesting allows multiple protective environments to coexist in a compact arrangement, reducing the overall volume required compared to separate housings for each element.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Multiple vacuum-sealed environments are merged into a single carrier structure, allowing contamination protection for multiple optical elements to be achieved within a shared structural volume rather than requiring separate housings for each element.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If measurement structures are provided outside the carrier structure, then thermal stability is improved, but spacing requirements increase

Engineering Contradiction:
Improvethermal stabilityVSAvoidspacing between sensors and mirrors
Core Design Contradiction:
Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The carrier structure is segmented into functionally distinct regions: some areas house optical elements while other areas are designated for measurement structures. This segmentation allows measurement structures to be positioned in thermally favorable locations within the carrier structure, achieving thermal stability without requiring excessive spacing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes three-dimensional space within the carrier structure to position measurement structures in locations that are thermally stable yet close to the optical elements. By exploiting spatial arrangement in multiple dimensions rather than simple linear spacing, thermal stability is achieved with minimal distance requirements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 modular design enhances flexibility and reduces the need for additional components, providing effective contamination protection and heat management while optimizing structural space, thus improving the optical system's performance and reliability.

Implementation Method 1

at least two carrier structure subelements are fluid-tightly sealed off relative to each other by way of at least one sealing element

Methodology Applied
Scientific EffectFluid-tight sealing:

Data Source

PatentEP2483747B1Optical arrangement in a projection exposure apparatus for EUV lithography
Publication Date: 2019.06.26 CARL ZEISS SMT GMBH
  • EP2483747B1 patent drawingFigure 1
  • EP2483747B1 patent drawingFigure 2~4
  • EP2483747B1 patent drawingFigure 3

AI summary

An optical arrangement includes a multiplicity of optical elements and a carrier structure which carries the optical elements. The carrier structure is composed of at least two releasably interconnected modules. Each module is composed of at least one carrier structure subelement. A subhousing is produced by a multiplicity of carrier structure subelements and/or modules. The subhousing has a geometry that varies, at least in regions, in correspondence to a usable beam path in the projection exposure apparatus, the usable beam path being defined as an envelope of all light bundles which can propagate from all field points in a field plane to an image plane of the projection exposure apparatus. A projection exposure apparatus for EUV lithography includes such an optical arrangement.