Modular Mirror Array Tiling for EUV Projection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing mirror arrays for optical components in projection exposure apparatuses face challenges in achieving high light throughput and flexibility in surface size and shape, with limitations in radiation efficiency and modular extension.

Innovation Solution

A modular mirror array design where individual mirror arrays can be tiled to form a surface of any desired size and shape, with a high degree of filling to minimize radiation losses, and a carrying structure with integrated control devices and thermal management to enhance mechanical stability and signal efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If mirror arrays are designed as fixed non-modular structures, then manufacturing and control are simplified, but flexibility in surface size and shape is limited

Engineering Contradiction:
Improveflexibility in surface size and shapeVSAvoidmodular structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mirror array is divided into multiple independent mirror elements arranged in a grid pattern, where each element can be individually controlled. This segmentation enables modular scalability - arrays can be configured in different sizes (e.g., 7x7, 15x15 elements) and shapes by simply changing the number and arrangement of elements, providing flexibility without requiring complete redesign of the system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mirror array design uses universal building blocks - identical or similar mirror elements that can be replicated and arranged in various configurations. The same basic element design serves multiple functions: it can be part of a small array or a large array, arranged in different geometric patterns, and each element can independently perform the same optical function while contributing to the overall array performance

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

2Loss of energy

If the degree of filling is low with large gaps between mirror elements, then manufacturing and alignment are easier, but radiation losses increase

Engineering Contradiction:
Improveradiation lossesVSAvoidalignment precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The system achieves high degree of filling (≥0.85) by optimizing the geometric parameters of the mirror elements and their arrangement. The mirror elements are designed with specific dimensions and spacing that maximize the reflective surface area while maintaining manufacturability. The gap between elements is minimized to reduce radiation losses, with the spacing optimized to balance optical performance with manufacturing capabilities

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces complex mechanical alignment systems with a rigid substrate that pre-positions mirror elements with high precision. Instead of relying on adjustable mechanical mounts for each element, the elements are fixed to a stable substrate structure that maintains precise relative positions, thereby achieving high alignment precision without complex mechanical adjustment mechanisms

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If mirror elements are fixed without displacement freedom, then structural stability is improved, but ability to deflect radiation beams flexibly is reduced

Engineering Contradiction:
Improvebeam deflection flexibilityVSAvoidstructural stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

Each mirror element is equipped with displacement mechanisms (such as piezoelectric actuators or micro-electromechanical systems) that enable controlled movement in multiple degrees of freedom. These mechanisms allow individual elements to tilt and translate independently, providing dynamic beam deflection capabilities. The structural design incorporates these moving parts while maintaining overall stability through rigid support structures and controlled actuation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mirror array is segmented into independently controllable elements, each with its own displacement freedom. This segmentation allows different regions of the array to be moved independently to deflect radiation beams in various directions. The modular segmented structure enables flexible beam steering patterns while each individual element maintains its structural integrity and stability

Inventive Principle:
Principle #1Segmentation

4Loss of energy

If lateral overhang is large to facilitate handling, then mechanical handling is easier, but degree of filling decreases and radiation losses increase

Engineering Contradiction:
Improveradiation lossesVSAvoidmechanical handling
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The lateral overhang dimension is optimized to a minimal value that still permits mechanical handling. The mirror array substrate is designed with edge dimensions just sufficient for gripper engagement or mounting fixture attachment, minimizing the non-reflective area. This optimized parameter balance ensures that the lateral overhang is small enough to maintain high degree of filling (≥0.85) but large enough to enable practical mechanical handling and mounting operations

Inventive Principle:
Principle #35Parameter changes

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 increases light throughput by minimizing radiation losses and allows for flexible adjustment of the mirror array surface, enabling efficient production of micro- or nanostructured components with improved mechanical handling and thermal management.

Implementation Method 1

a mirror array (22) comprising a multiplicity of mirror elements (23) which form a parqueting of a total reflection surface of the mirror array (22)

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2689282B1Mirror array
Publication Date: 2019.08.28 CARL ZEISS SMT GMBH
  • EP2689282B1 patent drawingFigure 1
  • EP2689282B1 patent drawingFigure 2~3
  • EP2689282B1 patent drawingFigure 4~5

AI summary

A mirror array (22) having a total surface extending perpendicularly to a surface normal (41), comprises a multiplicity of mirror elements (23) each having a reflection surface (36) and at least one degree of freedom of displacement, wherein the totality of the mirror elements (23) form a parqueting of a total reflection surface of the mirror array (22), and wherein the mirror array (22) is embodied modularly as a tile element in such a way that the parqueting of the total reflection surface can be extended by a tiling of a plurality of such mirror arrays (22).