Annular Baffle with Curved Wall for Plasma Confinement

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Solution Overview

Problem

In semiconductor substrate processing, unconfined plasmas lead to etch-byproduct deposition on chamber walls, contamination, and particle formation, necessitating an improved baffle assembly to confine plasma within the processing region.

Innovation Solution

A baffle assembly comprising a ring and a lower baffle portion with a curved wall, where the ring can be made of silicon carbide and the lower baffle portion of aluminum, along with a heating assembly for temperature control, is designed to confine plasma within the processing space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If plasma is left unconfined in the processing chamber, then the plasma can freely distribute throughout the chamber, but etch-byproduct deposition on chamber walls increases and contamination occurs

Engineering Contradiction:

Improveplasma distribution freedomVSAvoidetch-byproduct deposition

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The baffle assembly divides the processing chamber into distinct regions: a processing region above the substrate where plasma is confined, and a downstream region where etch-byproducts are directed. The baffle structure segments the plasma flow path, preventing uncontrolled distribution while maintaining beneficial plasma confinement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The baffle assembly acts as an intermediary component between the plasma source and chamber walls. It intercepts and redirects plasma and etch-byproducts, serving as a mediator that prevents direct contact between reactive plasma species and chamber wall surfaces, thereby reducing deposition and contamination.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If plasma is confined within the processing region using a baffle assembly, then etch-byproduct deposition on chamber walls is reduced, but device complexity increases

Engineering Contradiction:

Improveetch-byproduct depositionVSAvoidbaffle assembly structure

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The baffle assembly utilizes a thin-walled annular structure that provides effective plasma confinement with minimal material usage. The curved wall design creates an efficient barrier against plasma while maintaining structural integrity, achieving substantial deposition reduction with relatively simple geometry.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The baffle assembly features a curved wall that extends between a flange portion and a lower frame portion. This curvature optimizes plasma flow redirection and structural strength, allowing the baffle to effectively confine plasma and redirect etch-byproducts with a simple, elegant geometric form rather than complex angular structures.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Reliability

If the baffle assembly uses a curved wall design, then plasma confinement is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveplasma confinement effectivenessVSAvoidcurved wall fabrication

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The baffle assembly is constructed from composite materials, specifically a ceramic material (such as silicon carbide) for the curved wall portion and a metal material (such as aluminum) for the flange and frame portions. This composite construction allows each material to be optimized for its specific function: the ceramic provides plasma resistance and structural stability for the curved confinement surface, while the metal provides ease of fabrication and mechanical support.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The baffle assembly is divided into separate manufacturable components: a curved wall portion that can be formed using ceramic processing techniques, and flange/frame portions that can be manufactured using conventional metal forming methods. These segmented components are then assembled together, allowing each part to be optimized for its manufacturing process while achieving the overall curved geometry needed for effective plasma confinement.

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 baffle assembly effectively confines plasma, reducing etch-byproduct deposition on chamber walls, minimizing contamination and particle formation, and maintaining process stability.

Implementation Method 1

A heating assembly may be present within the lower frame portion to control the temperature of the baffle

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

The baffle assembly may help confine the plasma within the processing space in the chamber

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentUS10012248B2Annular baffle

Publication Date: 2018.07.03 APPLIED MATERIALS INC

AI summary

A baffle assembly for an etching apparatus is disclosed. The baffle assembly comprises a ring and a lower baffle portion having a curved wall extending between a flange portion and a lower frame portion. A heating assembly may be present within the lower frame portion to control the temperature of the baffle. The baffle assembly may help confine the plasma within the processing space in the chamber. The ring may comprise silicon carbide and the lower baffle portion may comprise aluminum.