Active Wet Scrubbing Filtration for Semiconductor Cleanroom Air

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Solution Overview

Problem

Traditional air filtration systems for semiconductor processing tools face challenges such as increased pressure resistance, limited service life, introduction of particulate and chemical contamination, and difficulties in temperature and humidity control, particularly in photolithography tools, which affect tool availability and cost.

Innovation Solution

An active wet scrubbing filtration system using a vortexing apparatus and scrubbing fluid, such as de-ionized water, to remove contaminants through absorption, adsorption, and dissolution, integrated with a chemical filtration system that regenerates filtering media without downtime, ensuring precise temperature and humidity control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional filters are used to remove contaminants, then contaminant removal capability is improved, but pressure resistance increases and service life is limited

Engineering Contradiction:
Improvecontaminant removal capabilityVSAvoidpressure resistance
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The patent replaces traditional solid filters with a wet scrubbing system that uses liquid scrubbing fluid to remove contaminants from the gas stream. The scrubbing fluid flows through a packed bed and continuously removes molecular contaminants through absorption and adsorption mechanisms, eliminating the pressure drop issues associated with solid filters while maintaining effective contaminant removal.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the physical state of the filtration medium from solid to liquid, transforming the contamination removal mechanism from physical filtration to chemical absorption/adsorption. This parameter change allows for continuous operation without pressure buildup, as the liquid scrubbing fluid can be continuously circulated and regenerated rather than becoming clogged like solid filters.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If traditional filters are used to remove contaminants, then contaminant removal capability is improved, but device complexity increases due to multiple filters required

Engineering Contradiction:
Improvecontaminant removal capabilityVSAvoidnumber of filters
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple filtration functions into a single wet scrubbing system. The packed bed scrubbing column simultaneously removes particulates and molecular contaminants through the action of scrubbing fluid, eliminating the need for separate filter stages. The system integrates contaminant removal, humidity control, and temperature management in one unified apparatus.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The wet scrubbing system performs multiple functions simultaneously: it removes molecular contaminants through absorption/adsorption, removes particulates through impaction, controls humidity through condensation, and manages temperature through heat exchange. This multi-functionality replaces what would traditionally require multiple separate devices and filter media.

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

3Reliability

If filters are used to remove molecular contaminants, then contaminant removal is improved, but temperature and humidity control becomes difficult

Engineering Contradiction:
Improvemolecular contaminant removalVSAvoidtemperature control
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent uses liquid scrubbing fluid in a packed bed to remove molecular contaminants through absorption and adsorption mechanisms. The liquid phase allows for better thermal management and humidity control compared to solid filters, as the scrubbing fluid can be temperature-controlled and its phase change properties can be utilized for humidity regulation while maintaining effective molecular contaminant removal.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 reduces molecular and particulate contaminants, maintains stable temperature and humidity levels, and reduces operational costs by integrating air handling and filtration, enhancing tool availability and reducing capital and maintenance expenses.

Implementation Method 1

one or more contaminants are removed from the gas stream by sorption in the scrubbing fluid

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

one or more contaminants are removed from the gas stream by sorption in the scrubbing fluid

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

scrubbing fluid, such as de-ionized water, to remove contaminants through absorption, adsorption, and dissolution

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 4

the contaminant-bearing gas stream is induced to move in a helical flow around an axis parallel to a net motion of the gas stream

Methodology Applied
Scientific EffectVortex flow: Vortex Ring

Data Source

PatentEP3897924B1Active wet scrubbing filtration system
Publication Date: 2025.09.03 ENTEGRIS INC
  • EP3897924B1 patent drawingFigure 1
  • EP3897924B1 patent drawingFigure 2
  • EP3897924B1 patent drawingFigure 3

AI summary

An active wet scrubbing filtration system for decontamination of a gas stream comprises components including one or more of: a) a vortexing apparatus which induces a contaminant-bearing gas into a helical flow; b) an initial scrubbing fluid spray section configured so as to project a spray of scrubbing fluid into the contaminant-bearing gas stream; c) an absorption structure; d) a condenser; and e) first and second scrubbing fluid decontamination systems that may be engaged or disengaged independently of each other. In some embodiments, the worksite comprises a clean room or one or more semiconductor processing tools, which may include photolithography tools or photolithography tool clusters. In some embodiments, the active wet scrubbing filtration system may be useful in cleaning and recycling air or other process gasses for use in clean rooms or semiconductor processing tools.