Adjustable Edge Coupling Ring for Plasma Etch Uniformity

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Solution Overview

Problem

Existing substrate processing systems require the processing chamber to be opened to adjust or replace edge coupling rings, which is undesirable, as it disrupts the etching process and leads to non-uniform etching due to plasma erosion.

Innovation Solution

An actuator system, including piezoelectric, stepper motor, or pneumatic drive actuators, is used to move portions of the edge coupling ring relative to the substrate without opening the processing chamber, allowing for real-time adjustment of the edge coupling profile based on erosion detection by sensors like depth gauges or laser interferometers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the edge coupling ring is made adjustable to correct erosion, then the etching uniformity can be restored, but the processing chamber must be opened which disrupts the etching process

Engineering Contradiction:

Improveetching uniformityVSAvoidetching process continuity

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The edge coupling ring is transformed from a static component to a dynamically adjustable one. The ring can be moved radially inward or outward along the pedestal surface using an actuator mechanism, allowing real-time adjustment of the edge coupling effect to compensate for erosion without requiring chamber opening or replacement

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system incorporates sensors that automatically detect erosion of the edge coupling ring and feed this information to a controller, which then automatically adjusts the ring position to maintain etching uniformity. This self-regulating mechanism eliminates the need for manual intervention and chamber opening

Inventive Principle:

Principle #25Self-service

2Manufacturing precision

If the edge coupling ring position is changed to adjust etch profile, then the edge coupling effect can be optimized, but the processing chamber must be opened which is undesirable

Engineering Contradiction:

Improveetch profile controlVSAvoidadjustment convenience

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The manual mechanical adjustment system is replaced with an automated actuator mechanism controlled by electronic sensors and a controller. The actuator can be piezoelectric, electromagnetic, or another suitable type that provides precise radial movement of the edge coupling ring without requiring physical access to the chamber interior

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

An actuator mechanism serves as an intermediary between the control system and the edge coupling ring. This intermediary component enables position adjustment through the chamber wall or through accessible external interfaces, eliminating the need to open the processing chamber for adjustments

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If a single edge coupling ring is used to control etching, then the structure is simple, but the etching uniformity deteriorates due to plasma erosion

Engineering Contradiction:

Improveedge coupling ring structureVSAvoidetching uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The static single-ring structure is enhanced by adding dynamic adjustment capability. The single ring remains structurally simple but gains the ability to move radially to compensate for erosion, maintaining simplicity while restoring precision through controlled repositioning

Inventive Principle:

Principle #15Dynamics

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 solution enables continuous, uniform etching by allowing for the adjustment of the edge coupling profile without stopping the process, improving etch uniformity and extending the life of the edge coupling ring by preventing excessive erosion.

Implementation Method 1

The actuator includes a piezoelectric actuator

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The actuator includes a stepper motor actuator

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

During use, plasma 42 is directed at the substrate 33 to etch the exposed portions of the substrate 33

Methodology Applied

Scientific EffectPlasma etching: Plasma

Implementation Method 4

When the edge coupling ring is eroded by plasma during etching

Methodology Applied

Scientific EffectErosion: Erosion

Data Source

PatentUS11605546B2Moveable edge coupling ring for edge process control during semiconductor wafer processing

Publication Date: 2023.03.14 LAM RES CORP

AI summary

A substrate processing system includes a processing chamber. A pedestal is arranged in the processing chamber. An edge coupling ring is arranged adjacent to the pedestal and around a radially outer edge of the substrate. An actuator is configured to selectively move a first portion of the edge coupling ring relative to the substrate to alter an edge coupling profile of the edge coupling ring.