Dielectric Member Design for Plasma Processing Abnormal Discharge Prevention

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Solution Overview

Problem

Plasma processing apparatuses face challenges in preventing abnormal discharges caused by electromagnetic waves with frequencies of the VHF band or higher, which can lead to inefficiencies and equipment damage.

Innovation Solution

A plasma processing apparatus is designed with a dielectric member on the inner wall of the processing container that protrudes towards the stage and is inserted into a recess, effectively reflecting and attenuating surface waves of electromagnetic waves, thereby preventing abnormal discharges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dielectric member is provided on the inner wall to prevent abnormal discharge, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improveprevention of abnormal dischargeVSAvoidstructure of dielectric member

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The dielectric member is divided into multiple sections: a first dielectric member protruding from the inner wall, a second dielectric member inserted into a recess, and a third dielectric member connecting them. This segmentation allows each part to perform specific functions in controlling electromagnetic wave propagation while maintaining overall reliability against abnormal discharge.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The dielectric members are arranged in different spatial dimensions and orientations relative to the inner wall. The protruding portion extends outward, the recessed portion goes inward, creating a three-dimensional configuration that effectively controls electromagnetic wave propagation paths without requiring a complete coating of the inner wall.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If the dielectric member protrudes towards the stage, then abnormal discharge is prevented, but the processing space is reduced

Engineering Contradiction:

Improveprevention of abnormal dischargeVSAvoidprocessing space

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The dielectric member protrudes only at specific locations on the inner wall where electromagnetic wave concentration and abnormal discharge are most likely to occur. This localized approach provides effective protection while minimizing the encroachment into the processing space, maintaining adequate volume for substrate processing.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The dielectric member protrudes partially towards the stage rather than fully blocking the processing space. This partial action is sufficient to control the electromagnetic waves and prevent abnormal discharge at critical points while preserving enough processing space for normal operation.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If a recess is formed in the inner wall for the dielectric member, then electromagnetic wave control is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveelectromagnetic wave controlVSAvoidinner wall structure

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The inner wall structure is segmented into protruding portions, recessed portions, and flat portions. Each segment serves a specific function in guiding and controlling electromagnetic wave propagation. The recesses are strategically positioned to create appropriate impedance transitions and control wave behavior without requiring complete restructuring of the entire inner wall.

Inventive Principle:

Principle #1Segmentation

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 prevents abnormal discharges by weakening electric fields within the dielectric member, ensuring stable plasma processing and reducing the risk of equipment damage.

Implementation Method 1

electromagnetic waves having a frequency of the VHF band or higher are introduced into a processing container

Methodology Applied

Scientific EffectSurface wave propagation: Surface Acoustic Wave

Implementation Method 2

a dielectric member provided on the inner wall through which the electromagnetic waves propagate

Methodology Applied

Scientific EffectDielectric attenuation: Dielectric

Data Source

PatentUS20230064817A1Plasma processing apparatus

Publication Date: 2023.03.02 TOKYO ELECTRON LTD

AI summary

A plasma processing apparatus, which introduces electromagnetic waves having a frequency of the VHF band or higher into a processing container and processes a substrate by using plasma generated from a gas, includes: a stage which is provided inside the processing container and on which the substrate is placed; an electromagnetic wave introducer formed to face an inner wall of the processing container and configured to introduce the electromagnetic waves into the processing container; and a dielectric member provided on the inner wall through which the electromagnetic waves propagate, wherein a first portion of the dielectric member protrudes from the inner wall toward the stage, and wherein a second portion of the dielectric member is inserted into a recess or step portion of the inner wall.