Active Gas Electrode Layout for Abnormal Discharge Suppression

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Solution Overview

Problem

Conventional active gas generating apparatuses using dielectric barrier discharge often experience abnormal discharge due to dielectric breakdown in surrounding gas flows, leading to metal contamination and degraded semiconductor performance, especially under reduced pressure where the electric field intensity required for breakdown is lower.

Innovation Solution

The apparatus features a configuration with integrated electrode units, where the first power feeding unit covers the high-voltage metal electrode entirely and the second power feeding unit covers the ground metal electrode, along with dielectric films to control electric field intensity at the outer edges, preventing abnormal discharge by equalizing potential and reducing electric field intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If dielectric barrier discharge is used to generate active gas, then active gas production is achieved, but abnormal discharge occurs in surrounding gas flow causing metal contamination

Engineering Contradiction:
Improveactive gas productionVSAvoidmetal contamination from abnormal discharge
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The invention applies different properties to different parts of the electrode structure. Specifically, the outer edges of the metal electrodes are covered with dielectric films, while the central regions maintain metal conductivity. This local differentiation prevents abnormal discharge at the edges (where it would cause contamination) while preserving the active gas generation function in the discharge space.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The dielectric films act as intermediary layers between the metal electrodes and the surrounding gas flow. These films mediate the electric field distribution, preventing direct dielectric breakdown in the gas flow at the electrode edges, thereby eliminating the source of metal contamination while allowing controlled discharge in the intended discharge space.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If reduced pressure is applied to enhance discharge, then active gas generation efficiency improves, but electric field intensity required for breakdown decreases causing more abnormal discharge

Engineering Contradiction:
Improveactive gas generation efficiencyVSAvoidabnormal discharge suppression
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The dielectric films are selectively applied only to the outer edges of the metal electrodes, creating a local property difference. This localized dielectric coverage specifically addresses the abnormal discharge problem at the edges while maintaining the overall discharge efficiency in the central discharge space, even under reduced pressure conditions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The dielectric films on the outer edges of the metal electrodes help equalize the electric field distribution by preventing field concentration at sharp edges. This creates a more uniform potential distribution that reduces the likelihood of abnormal discharge initiation, allowing the system to operate reliably at reduced pressures.

Inventive Principle:
Principle #12Equipotentiality

3Power

If metal electrodes are used for power feeding, then electrical conductivity is improved, but electric field intensity at outer edges increases causing dielectric breakdown

Engineering Contradiction:
Improveelectrical conductivityVSAvoiddielectric breakdown at electrode edges
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The invention maintains metal electrodes for their excellent electrical conductivity in the central regions, but selectively applies dielectric films only to the outer edges. This local quality differentiation preserves the power transmission function while eliminating the edge effect that causes dielectric breakdown and abnormal discharge.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The dielectric films serve as intermediary layers at the outer edges of the metal electrodes. These films mediate the electric field interaction at the boundaries, preventing the concentration of electric field lines that would otherwise cause dielectric breakdown in the surrounding gas, while allowing the metal electrodes to maintain their full conductivity function in the discharge space.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration effectively suppresses abnormal discharge at the outer edges of the metal electrodes, preventing metal contamination and ensuring improved semiconductor film formation performance by maintaining low electric field intensity and covering the metal electrodes with dielectric films.

Implementation Method 1

A type of active gas generating apparatus uses dielectric barrier discharge that is generated in a discharge space formed between a pair of dielectric electrodes

Methodology Applied
Scientific EffectDielectric barrier discharge: Plasma

Implementation Method 2

generates an active gas obtained by activating a source gas supplied to a discharge space

Methodology Applied
Scientific EffectGas activation: Ionisation

Data Source

PatentEP3641506B1Active gas generating device
Publication Date: 2023.12.06 TOSHIBA MITSUBISHI ELECTRIC IND SYST CORP
  • EP3641506B1 patent drawingFigure 1
  • EP3641506B1 patent drawingFigure 2
  • EP3641506B1 patent drawingFigure 3

AI summary

An object of the present invention is to provide a configuration of an active gas generating apparatus configured to suppress abnormal discharge. In an active gas generating apparatus according to the present invention, a power feeder (23) is provided above metal electrodes (10A and 10B) in an integrated high-voltage electrode unit (1). When seen in plan view, the power feeder (23) has a shape that entirely covers the metal electrodes (10A and 10B) in the integrated high-voltage electrode unit (1). Each of power feeding units (33A and 33B) is provided below the metal electrodes (20A and 20B) in an integrated ground electrode unit (2). When seen in plan view, each of the power feeding units (33A and 33B) has a shape that entirely covers the metal electrodes (20A and 20B) of the integrated ground electrode unit (2).