Resilient Wall Cooling for Lithographic Detector Vibration Isolation

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Solution Overview

Problem

Lithographic apparatuses face challenges in accurately measuring and minimizing wavefront aberrations in projection systems, particularly due to vibrations caused by cooling liquid flow in vacuum environments, which affect the stability and positioning of detectors.

Innovation Solution

A cooling arrangement with a heat sink and a resilient wall that maintains a pressure difference, allowing for efficient heat transfer using a gas in the gap between the heat sink and the detector, while decoupling vibrations, and utilizing a bellows for flexible mounting to accommodate movement and maintain precise positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a cooling liquid is used to cool the detector in a vacuum environment, then heat transfer efficiency is improved, but vibrations are generated affecting detector stability and positioning

Engineering Contradiction:

Improvedetector temperatureVSAvoiddetector positioning stability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

A resilient wall is introduced as an intermediary element between the cooling liquid and the detector. The resilient wall is in contact with the cooling liquid but mechanically decoupled from the detector, allowing heat transfer while blocking vibration transmission. This mediator resolves the contradiction by enabling thermal coupling while preventing mechanical coupling of vibrations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical contact cooling with a indirect cooling method using a resilient wall. Instead of mechanically attaching the detector to a cold plate (which transmits vibrations), the system uses a vibration-isolating resilient wall that allows thermal energy transfer while blocking mechanical vibration transmission to the detector.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of energy

If direct thermal contact is made between the heat sink and the detector, then heat transfer efficiency is improved, but vibrations from the heat sink are transmitted to the detector

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidvibration isolation

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The resilient wall serves as a mediator between the heat sink and detector. It maintains thermal contact for efficient heat transfer while mechanically isolating the detector from vibrations generated by the cooling liquid flow in the heat sink. The resilient material properties allow it to conduct heat while dampening mechanical vibrations.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If the detector is rigidly mounted to maintain precise positioning, then positioning accuracy is improved, but vibration transmission and thermal management are compromised

Engineering Contradiction:

Improvepositioning accuracyVSAvoidmounting structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs a resilient wall with flexible properties to mount the detector. This flexible mounting structure accommodates thermal expansion and contraction while maintaining precise detector positioning. The resilient wall absorbs vibrations and allows for thermal management without requiring complex rigid mounting structures, thereby achieving positioning accuracy with simpler design.

Inventive Principle:

Principle #30Flexible shells and thin films

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 effectively cools detectors in vacuum environments, reducing vibrations and maintaining accurate positioning, thereby improving the measurement and minimization of wavefront aberrations, enhancing the precision and reliability of lithographic processes.

Implementation Method 1

The gap mechanically decouples the object from the heat sink so that transmission of possible vibrations from the heat sink to the detector module, e.g. caused by the flow of a cooling liquid, is mitigated.

Methodology Applied

Scientific EffectVibration isolation: Damping

Implementation Method 2

The gap filled with the gas allows for an efficient transport of heat from the detector module to the heat sink

Methodology Applied

Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 3

The gap filled with the gas allows for an efficient transport of heat from the detector module to the heat sink

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentUS8817228B2Cooling arrangement and lithographic apparatus comprising a resilient wall creating a gap between a detector module housing and a heat sink of the cooling arrangement

Publication Date: 2014.08.26 ASML NETHERLANDS BV

AI summary

A cooling arrangement is described and includes a heat sink having a first thermal contact surface, an object having a second thermal contact surface and a resilient wall. The first thermal contact surface and the second thermal contact surface face each other and define a gap. The resilient wall is part of an enclosure that surrounds a space at least comprising the gap, and the cooling arrangement includes a facility to maintain a pressure difference between the space and an environment of the cooling arrangement. Additionally, a lithographic apparatus comprising such a cooling arrangement is described.