Ring-Shaped Insulator Layout for Uniform VHF Plasma Processing

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Solution Overview

Problem

Existing plasma processing apparatuses face challenges in achieving in-plane uniformity of plasma due to standing waves and higher-order modes of electromagnetic waves, leading to non-uniform plasma density and increased electric discharge.

Innovation Solution

A plasma processing apparatus with a concentrically ring-shaped structure around the upper electrode, featuring a ring-shaped insulating member with gas through-holes and a conductive member, which suppresses electric discharge and enhances plasma uniformity by using electromagnetic waves in the VHF band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromagnetic waves are supplied into the processing container to generate plasma, then plasma processing can be performed, but standing waves and higher-order modes cause non-uniform plasma density and increased electric discharge

Engineering Contradiction:

Improveplasma uniformityVSAvoidelectric discharge

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A ring-shaped insulating member is introduced as an intermediary component between the upper electrode and the processing space. This insulating member with gas through-holes serves as a mediator that distributes gas uniformly while preventing the formation of standing waves and higher-order modes, thereby reducing electric discharge and improving plasma uniformity without compromising the plasma generation function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a conventional overhead electrode structure is used, then the apparatus structure is simple, but in-plane uniformity of plasma cannot be achieved

Engineering Contradiction:

Improveplasma uniformityVSAvoidapparatus structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The overhead electrode structure is segmented by introducing a ring-shaped insulating member with multiple gas through-holes. This segmentation allows gas to be supplied through multiple distributed paths rather than a single central path, creating more uniform plasma density across the electrode surface while maintaining a relatively simple overall apparatus structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The insulating member is designed with non-uniform thickness or strategically positioned gas through-holes to create local variations in gas flow characteristics. This local quality adjustment ensures uniform plasma generation across different regions of the electrode, compensating for edge effects and center-region differences without requiring complete structural redesign.

Inventive Principle:

Principle #3Local quality

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 apparatus achieves improved in-plane uniformity of plasma, reducing non-uniformity and electric discharge, enabling precise film formation, etching, and ashing processes on substrates with enhanced control over plasma density.

Implementation Method 1

generates plasma by electromagnetic waves supplied into a processing container

Methodology Applied

Scientific EffectElectromagnetic waves:

Implementation Method 2

a ring-shaped insulating member provided between the upper electrode and the first shield member and between the upper electrode and the second shield member, and having a plurality of gas through-holes penetrating an inside of the ring-shaped insulating member

Methodology Applied

Scientific EffectGas flow through holes:

Implementation Method 3

a conductive member covering a first end portion of the insulating member and electrically interconnecting the first shield member to the second shield member

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

a first shield member configured to electrically shield the upper electrode and the power supply member; a second shield member configured to electrically shield the upper electrode and the power supply member

Methodology Applied

Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentUS12555751B2Plasma processing apparatus and semiconductor device manufacturing method

Publication Date: 2026.02.17 TOKYO ELECTRON LTD

AI summary

A plasma processing apparatus generating plasma by electromagnetic waves supplied into a processing container to process a substrate, includes an upper electrode disposed in an upper portion of the processing container, a power supply member connected to the upper electrode to supply electromagnetic waves to the upper electrode, a first shield member and a second shield member configured to electrically shield the upper electrode and the power supply member, a ring-shaped insulating member provided between the upper electrode and the first shield member and between the upper electrode and the second shield member, and having a plurality of gas through-holes penetrating inside thereof, and a conductive member covering a first end of the insulating member and electrically interconnecting the first shield member and the second shield member. The power supply member passes through an inner space in the insulating member and supplies electromagnetic waves to the upper electrode.