EUV Reflector Blocking Structure for Tin-Contaminated Mirror Slits

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Solution Overview

Problem

The challenge of reducing EUV light contamination and improving throughput in EUV scanners due to tin buildup on mirrors, leading to reduced power output and increased downtime for cleaning and recalibration.

Innovation Solution

Implementing a blocking structure that blocks individual mirror slits on a reflector associated with positions of tin contamination, reducing reflectivity impact and minimizing the need for cleaning and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If cleaning and recalibration of mirrors are performed to remove tin contamination, then reflectivity and power output are improved, but downtime and productivity are reduced

Engineering Contradiction:

Improvepower outputVSAvoidwafer per day throughput

Core Design Contradiction:

PowerVSProductivity

Solution Approach 1:

The system performs preliminary actions by blocking individual mirror slits before tin contamination significantly degrades performance. The blocking structure is positioned in advance to prevent contamination from affecting critical reflectivity, thereby avoiding the need for frequent cleaning interruptions and maintaining continuous productivity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The mirror surface is segmented into multiple individual slits that can be independently blocked. This segmentation allows the system to address contamination at specific locations without affecting the entire mirror surface, enabling localized maintenance that minimizes downtime and maintains overall power output.

Inventive Principle:

Principle #1Segmentation

2Power

If individual mirror slits are blocked to mitigate tin contamination, then reflectivity impact is reduced, but device complexity increases

Engineering Contradiction:

Improvepower outputVSAvoidblocking structure complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The blocking structure implements local quality by providing individualized blocking elements for each mirror slit only where contamination occurs. Rather than uniformly complicating the entire mirror system, the blocking elements are selectively positioned at specific slit locations affected by tin buildup, maintaining simplicity where the mirror surface is clean.

Inventive Principle:

Principle #3Local quality

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

Enhances EUV scanner power output and reduces downtime by mitigating the effects of tin contamination on mirrors, thereby improving wafer per day throughput.

Implementation Method 1

blocking a portion of the radiation by a blocking structure, the blocking structure being attached to a reflector

Methodology Applied

Scientific EffectLight blocking: Absorption (EM radiation)

Implementation Method 2

directing radiation reflected from a collector of the lithography system toward the mask layer

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS12572080B2Lithography system and methods

Publication Date: 2026.03.10 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method includes: depositing a mask layer over a substrate; directing radiation reflected from a collector of a lithography system toward the mask layer according to a pattern; blocking a portion of the radiation by a blocking structure, the blocking structure being attached to a reflector of the lithography system; forming openings in the mask layer by removing regions of the mask layer exposed to the radiation; and removing material of a layer underlying the mask layer exposed by the openings.