Plasma Abatement Device Gas Stream Segmentation

Solution Overview

Problem

The high flow rate of purge gas in gas stream exhaust from semiconductor or flat panel display device chambers reduces the destruction efficiency of abatement devices for perfluorinated gases, increasing energy requirements and operational costs.

Innovation Solution

A method and apparatus that divert a portion of the gas stream away from the plasma abatement device, treating it separately to reduce flow rates and enhance destruction efficiency, and return it as a purge gas to the vacuum pump, creating a closed loop system to ensure complete treatment of perfluorinated species.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a high flow rate of purge gas is added to the exhaust gas, then the vacuum pump can operate effectively, but the destruction efficiency of the abatement device decreases and energy requirements increase

Engineering Contradiction:

Improvevacuum pump operationVSAvoiddestruction efficiency

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The gas stream is divided into two separate streams: one portion is treated by the plasma abatement device while the other portion is used as purge gas for the vacuum pump. This segmentation allows the system to maintain effective vacuum pump operation while reducing the flow rate through the abatement device, thereby improving destruction efficiency of perfluorinated species.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flow rate parameter of the gas stream through the plasma abatement device is reduced by diverting a portion of the gas stream. This parameter change enhances the destruction efficiency of the abatement device while the diverted portion continues to serve as purge gas, maintaining vacuum pump operation.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If a high flow rate of purge gas is added to the exhaust gas, then the vacuum pump can operate effectively, but the energy requirement of the abatement device increases

Engineering Contradiction:

Improvevacuum pump operationVSAvoidenergy requirement of abatement device

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The gas stream is divided into two separate streams: one portion is treated by the plasma abatement device while the other portion is used as purge gas for the vacuum pump. This segmentation allows the system to maintain effective vacuum pump operation while reducing the flow rate through the abatement device, thereby improving destruction efficiency of perfluorinated species.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flow rate parameter of the gas stream through the plasma abatement device is reduced by diverting a portion of the gas stream. This parameter change enhances the destruction efficiency of the abatement device while the diverted portion continues to serve as purge gas, maintaining vacuum pump operation.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the flow rate of gas stream through the plasma abatement device is reduced, then the destruction efficiency increases, but the concentration of perfluorinated species increases over time in the diverted portion

Engineering Contradiction:

Improvedestruction efficiencyVSAvoidconcentration of perfluorinated species

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The diverted portion of the gas stream, which contains accumulated perfluorinated species, is returned to the vacuum pump inlet to be pumped through the system again. This feedback mechanism ensures that perfluorinated species are eventually treated by the plasma abatement device, preventing their release to the atmosphere while maintaining high destruction efficiency.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system maintains continuous treatment of perfluorinated species by recirculating the diverted gas portion through the vacuum pump and abatement device. This ensures that all perfluorinated species are eventually treated, maintaining continuous effective action without compromising destruction efficiency.

Inventive Principle:

Principle #20Continuity of useful action

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

This approach significantly enhances the destruction efficiency of the plasma abatement device, reduces energy requirements, and minimizes the need for fresh purge gas, ensuring complete treatment of perfluorinated species while reducing operational costs.

Implementation Method 1

removing a second species from the first portion of the gas stream using a second, plasma abatement device

Methodology Applied

Scientific EffectPlasma: Plasma

Data Source

PatentEP1981618B1Method of treating a gas stream

Publication Date: 2012.05.02 EDWARDS LTD

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AI summary

A method is described for controlling the efficiency of an abatement system for treating a gas stream, in which a portion of the gas stream is diverted away from a plasma abatement device for removing a perfluorinated species from the gas stream, and returned to the gas stream upstream from the abatement device as a purge gas for a vacuum pump. This can reduce both the power requirement of the abatement device and the amount of inert gas added to the gas stream to make up the purge gas.