Plasma CVD Apparatus Side Walls for Particle Management

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Solution Overview

Problem

In plasma CVD processes, abnormal discharge and surface contamination of electrodes and targets lead to inconsistent film deposition speed and quality, with particles generated in the gas phase contributing to poor film quality and increased maintenance needs.

Innovation Solution

A plasma CVD apparatus with side walls on either side of the substrate, featuring gas supply holes aligned in rows and a gas exhaust opening, where the gas supply holes are electrically insulated from the plasma generation electrode, and a magnet is used to generate a magnetic flux on the plasma generation electrode, allowing for controlled plasma generation and particle management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If plasma is generated between the plasma generation electrode and the main roll to decompose the source gas for film deposition, then film deposition speed is improved, but particles are generated by coagulation and solidification of unused source gas components, leading to poor film quality and electrode contamination

Engineering Contradiction:
Improvefilm deposition speedVSAvoidfilm quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention extracts and removes particles from the deposition space using a particle removal electrode that generates plasma to ionize and remove particles, thereby preventing particle inclusion in the deposited film while maintaining high deposition speed

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a particle removal electrode as an intermediary component between the plasma generation electrode and the substrate, which actively removes particles through plasma generation, serving as a mediator to protect film quality without affecting deposition productivity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If plasma is generated to increase film deposition speed, then productivity is improved, but the decomposition of source gas produces particles that deform the discharge electrode surface and change the electric field, leading to loss of consistency in film deposition speed and quality

Engineering Contradiction:
Improvefilm deposition speedVSAvoidconsistency of film deposition speed and quality
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The invention applies continuous plasma generation at the particle removal electrode throughout the deposition process to continuously remove particles, ensuring consistent film quality and deposition speed without interruption or variation

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The invention creates a feedback mechanism where particles generated during deposition are continuously detected and removed by the particle removal electrode, maintaining stable plasma conditions and consistent film properties throughout the deposition process

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If more frequent cleaning of the apparatus is performed to remove particles, then film quality is improved, but productivity is reduced due to increased maintenance time

Engineering Contradiction:
Improvefilm qualityVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention enables the system to self-clean particles during the deposition process itself through the particle removal electrode, eliminating the need for separate cleaning operations and maintaining both high film quality and productivity

Inventive Principle:
Principle #25Self-service

4Productivity

If the source gas is supplied from the vertically lower side of the substrate, then film deposition is promoted, but particles generated in the plasma are more likely to be deposited on the substrate, worsening film quality

Engineering Contradiction:
Improvefilm deposition speedVSAvoidfilm quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention converts the harmful effect of particle generation into a beneficial process by using plasma to ionize and remove particles, transforming the particle problem into an opportunity for active particle management and improved film quality

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 reduces abnormal discharge, suppresses contamination, and ensures consistent film deposition speed and quality by effectively managing plasma and particles, resulting in high-quality thin films with reduced particle contamination.

Implementation Method 1

plasma is generated between the plasma generation electrode P7 and the main roll P6, and the source gas is decomposed

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 2

chemical reaction of the source gas is promoted by using the thus generated plasma to thereby form a thin film on the surface of the long substrate

Methodology Applied
Scientific EffectChemical Vapour Deposition: Chemical Vapour Deposition

Implementation Method 3

Magnets are also provided in the main roll on the side of the reaction tube and on the mesh electrode at the side opposite to the main roll to thereby generate a magnetic field in the film deposition space to thereby form a high density plasma

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 4

an injection hole for generating hollow cathode discharge is further provided on the plasma generation electrode on the side opposing the cooling drum. Damages done to the long substrate is suppressed by focusing the plasma to the surface of the plasma generation electrode

Methodology Applied
Scientific EffectHollow cathode discharge: Electric Arc

Data Source

PatentEP2692898B1Plasma CVD apparatus and plasma CVD method
Publication Date: 2020.03.25 TORAY INDUSTRIES INC
  • EP2692898B1 patent drawingFigure 1~2
  • EP2692898B1 patent drawingFigure 3(a)~4
  • EP2692898B1 patent drawingFigure 5~6

AI summary

A plasma CVD apparatus comprising a vacuum chamber, and a main roll and a plasma generation electrode in the vacuum chamber, wherein a thin film is formed on a surface of a long substrate which is conveyed along the surface of the main roll is provided. At least one side wall extending in transverse direction of the long substrate is provided on each of the upstream and downstream sides in the machine direction of the long substrate, and the side walls surrounds the film deposition space between the main roll and the plasma generation electrode. The side walls are electrically insulated from the plasma generation electrode. The side wall on either the upstream or the downstream side in the machine direction of the long substrate is provided with at least one raw of gas supply holes formed by gas supply holes aligned in the transverse direction of the long substrate.