Edge Ring Gas Flow for Plasma Etch Byproduct Buildup Control

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Solution Overview

Problem

Plasma etching processes in semiconductor fabrication lead to byproduct material accumulation on chamber surfaces, causing adverse conditions like electrical arcing and particle contamination, which existing methods fail to prevent during the process.

Innovation Solution

A method and system involving a wafer support structure with an edge ring structure and a byproduct volatizing gas supply to manage byproduct accumulation in a lower peripheral open region, using gases like oxygen, carbon dioxide, and carbon monoxide to control material buildup during plasma exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If plasma etching process is performed to remove material from semiconductor wafer, then material removal is achieved, but byproduct material accumulates on chamber surfaces causing electrical arcing and particle contamination

Engineering Contradiction:

Improvematerial removal rateVSAvoidelectrical arcing and particle contamination

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes byproduct material from the lower peripheral open region during the plasma etching process using a separate gas flow system. This allows continuous removal of harmful byproducts without interrupting the main etching process, preventing accumulation that would cause electrical arcing and particle contamination.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a mediator gas flow (separate from the plasma process gas) that flows through the lower peripheral open region to transport byproduct materials away from critical surfaces. This intermediary gas stream acts as a carrier to remove harmful byproducts without directly interfering with the plasma etching process above the wafer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If existing methods are used to manage byproduct accumulation, then some control is achieved, but process interruption is required which reduces productivity

Engineering Contradiction:

Improvebyproduct accumulation controlVSAvoidprocess continuity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements continuous byproduct removal during the entire plasma etching process through a dedicated gas flow system. The separate gas stream continuously flows through the lower peripheral open region, maintaining continuous byproduct management without requiring process interruptions or batch cleaning cycles.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent applies preliminary action by establishing a separate gas flow path through the lower peripheral open region before byproduct accumulation becomes problematic. This preventive approach continuously manages byproduct removal throughout the process, preventing the need for interruptive cleaning operations.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If byproduct material accumulates on surfaces near the wafer, then electrical arcing and particle contamination occur, but existing methods cannot prevent this during the process

Engineering Contradiction:

Improveelectrical arcing preventionVSAvoidprocess complexity

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent segments the gas flow system into separate streams: the main plasma process gas for etching and a separate byproduct removal gas flowing through the lower peripheral open region. This segmentation allows independent control of material removal and byproduct management, preventing electrical arcing without significantly complicating the overall manufacturing process.

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

Prevents electrical arcing and particle contamination by effectively managing byproduct material accumulation, enabling longer plasma-based fabrication processes without interrupting the process.

Implementation Method 1

supplying a byproduct volatizing gas to the lower peripheral open region to control the accumulation of the byproduct material

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

a semiconductor wafer that includes semiconductor devices under manufacture is exposed to a plasma within a plasma processing chamber. The plasma interacts with at least one material on the semiconductor wafer so as to remove the at least one material

Methodology Applied

Scientific EffectPlasma: Plasma

Data Source

PatentUS20250364233A1Methods and Systems for Managing Byproduct Material Accumulation During Plasma-Based Semiconductor Wafer Fabrication Process

Publication Date: 2025.11.27 LAM RES CORP

AI summary

A wafer is supported on a wafer support structure such that a lower peripheral open region exists between a peripheral portion of a bottom surface of the wafer and an edge ring structure. The edge ring structure is configured to circumscribe both the wafer support structure and the wafer. A plasma is generated above a top surface of the wafer. The plasma causes accumulation of byproduct material within the lower peripheral open region. A byproduct volatizing gas is supplied to the lower peripheral open region to control the accumulation of the byproduct material within the lower peripheral open region during generation of the plasma. Use of the byproduct volatizing gas to control the accumulation of the byproduct material within the lower peripheral open region serves to prevent electrical arcing and particle contamination.