EUV Light Generation Conductive Shielding for Target Stability

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Solution Overview

Problem

In EUV light generation systems, positional stability of charged targets is compromised due to fluctuations in potential distribution caused by charged particles adhering to non-conductive structural elements, leading to contamination and damage to optical components.

Innovation Solution

An electrically conductive shielding member is connected to the chamber, reducing fluctuations in potential distribution by shielding non-conductive members and maintaining a reference potential, thereby improving the positional stability of charged targets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrical insulators are used to hold electrodes in the target generator, then electrical insulation is provided, but charged particles from plasma cause potential distribution fluctuations that reduce target positional stability

Engineering Contradiction:

Improvetarget positional stabilityVSAvoidcharged particle scattering

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A conductive shielding member is introduced as an intermediary between the plasma generation region and the electrical insulator. This shielding member intercepts charged particles before they reach the insulator, preventing potential distribution fluctuations while allowing the insulator to maintain its electrical insulation function. The shielding member acts as a mediator that protects the insulator from charged particle damage.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrical properties of the shielding member are specifically designed to be conductive, contrasting with the insulating properties of the electrical insulator. This parameter change (from insulating to conductive) allows the shielding member to effectively intercept and redirect charged particles, solving the positional stability problem while maintaining electrical insulation where needed.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a conductive shielding member is added to protect against charged particles, then target positional stability improves, but device complexity increases

Engineering Contradiction:

Improvetarget positional stabilityVSAvoidshielding member integration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The conductive shielding member serves multiple functions: it shields against charged particles, provides a reference potential to reduce potential distribution fluctuations, and can be integrated with existing chamber structures. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The shielding member is electrically connected to the chamber structure, merging its function with the existing conductive elements of the system. This integration approach allows the shielding function to be added without creating entirely separate, independent components, thus reducing the overall complexity increase.

Inventive Principle:

Principle #5Merging (Combining)

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 enhances the positional stability of charged targets within the chamber, reducing contamination and damage to optical components by preventing charged particles from affecting the potential distribution.

Implementation Method 1

irradiating a target material by a laser beam from a laser apparatus to turn the target material into plasma

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

an electrically conductive shielding member being connected electrically to an electrically conductive structural member of the chamber... reducing fluctuations in potential distribution by shielding non-conductive structural elements

Methodology Applied

Scientific EffectElectrostatic shielding: Faraday Cage

Data Source

PatentUS8698112B2Extreme ultraviolet light generation apparatus

Publication Date: 2014.04.15 GIGAPHOTON INC

AI summary

An apparatus, configured to generate extreme ultraviolet light by irradiating a target material by a laser beam from a laser apparatus to turn the target material into plasma, includes a chamber with an inlet for introducing the laser beam into the chamber, the chamber including an electrically conductive structural member; and a target generator including an electrode having a first through-hole through which a charged target passes, an electrical insulator for holding the electrode, and a shielding member having a second through-hole, through which the charged target passes, the shielding member being positioned between a plasma generation region and at least the electrical insulator. The target generator generates the charged target of a liquid target material and output the charged target toward the plasma generation region inside the chamber, and the shielding member has electrically conductive properties and is connected electrically to the electrically conductive structural member of the chamber.