EUV Light Source Radical Transport Conduit for In-Situ Debris Cleaning

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Solution Overview

Problem

In extreme ultraviolet (EUV) light sources, debris accumulation on collector mirrors and other elements within the vacuum chamber reduces system performance, and traditional cleaning methods require removing these elements from their operating environment, leading to system downtime.

Innovation Solution

A free radical transport system that delivers reactive free radicals through a conduit with strategically positioned openings to the debris-covered elements within the vacuum chamber, allowing for in-situ cleaning without removing the elements, using a conduit material that minimizes radical recombination and employing a pressure differential to direct radicals effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional cleaning methods are used to remove debris from collector mirrors and elements, then cleaning effectiveness is improved, but system downtime increases due to element removal

Engineering Contradiction:

Improvecleaning effectivenessVSAvoidsystem downtime

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces free radicals as an intermediary cleaning agent that can be delivered through a conduit to the element surface. The free radicals chemically react with and remove debris without requiring physical access or removal of the element, thus maintaining cleaning effectiveness while eliminating system downtime associated with element removal

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical cleaning methods (which require physical access and element removal) with a chemical cleaning mechanism using free radicals. The free radicals are delivered through a conduit and react chemically with debris on the element surface, substituting mechanical intervention with a chemical process that can occur in-situ

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of time

If free radicals are delivered through a conduit to clean elements in-situ, then system downtime is reduced, but radical recombination losses increase

Engineering Contradiction:

Improvesystem downtimeVSAvoidradical recombination losses

Core Design Contradiction:

Loss of timeVSLoss of substance

Solution Approach 1:

The patent employs a porous conduit material that allows free radicals to pass through while minimizing recombination losses. The porous structure provides a controlled environment for radical transport, reducing unwanted reactions with the conduit walls while maintaining efficient delivery to the element surface

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent optimizes parameters such as conduit material composition, pore size, and radical generation rate to minimize recombination losses. By carefully controlling these parameters, the system maintains high radical delivery efficiency while reducing waste through recombination reactions

Inventive Principle:

Principle #35Parameter changes

3Reliability

If multiple openings are positioned in the conduit sidewall, then uniform debris removal is achieved, but conduit complexity increases

Engineering Contradiction:

Improveuniform debris removalVSAvoidconduit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the conduit into multiple sections with openings positioned at different locations along its length. Each opening delivers free radicals to a specific region of the element surface, ensuring uniform coverage and debris removal across the entire surface area through segmented radical delivery zones

Inventive Principle:

Principle #1Segmentation

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 effectively removes debris from the elements at a uniform rate, maintaining system performance without the need for element removal, thus reducing downtime and ensuring continuous operation.

Implementation Method 1

receiving, at a first opening defined by a first end of a conduit, free radicals that combine with debris that is created by converting a target mixture to plasma

Methodology Applied

Scientific EffectFree radical reaction: Oxidation

Implementation Method 2

The free radicals in the conduit can be directed toward the at least one other opening by creating a pressure differential between a source of the free radicals and the at least one other opening

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

the conduit including a material that passes the free radicals

Methodology Applied

Scientific EffectRadical transport through permeable material: Permeation

Data Source

PatentUS9560730B2Transport system for an extreme ultraviolet light source

Publication Date: 2017.01.31 ASML NETHERLANDS BV

AI summary

Free radicals that combine with debris that is created by converting a target mixture to plasma that emits EUV light are received at a first opening defined by a first end of a conduit, the conduit including a material that passes the free radicals and the conduit including a sidewall that extends away from the first opening and defines at least one other opening, the at least one other positioned to release the free radicals toward an element that accumulates the debris on a surface. The free radicals in the conduit are directed toward the at least one other opening. The free radicals are passed through the at least one other opening and to the surface of the element to remove the debris from the surface of the element without removing the element from the EUV light source.