Bottom Purge Baffle Structure for Uniform Plasma Pressure

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Solution Overview

Problem

In semiconductor device manufacturing, residue materials from deposition processes in processing chambers lead to particulate contamination, requiring frequent cleaning and maintenance, which reduces substrate throughput and increases downtime.

Innovation Solution

A baffle is positioned in the purge volume of a plasma processing chamber to deflect and reduce the velocity of purge gas, improving mass flow uniformity and reducing unwanted deposition on internal chamber surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If purge gas is supplied at high velocity to the purge volume, then gas flow rate is improved, but mass flow uniformity deteriorates and unwanted deposition increases

Engineering Contradiction:

Improvepurge gas velocityVSAvoidmass flow uniformity

Core Design Contradiction:

SpeedVSManufacturing precision

Solution Approach 1:

A baffle structure is introduced as an intermediary element between the purge gas source and the processing chamber. The baffle deflects the high-velocity purge gas jet, causing it to impinge on the baffle surface and redirect into the purge volume. This mediation transforms the direct high-velocity jet into a more uniform flow pattern that fills the purge volume effectively while maintaining mass flow uniformity at the processing chamber inlet.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The baffle structure changes the flow parameters of the purge gas by deflecting it at specific angles and positions. By adjusting the baffle geometry and position, the gas flow velocity, direction, and distribution are modified to achieve optimal mass flow uniformity in the processing chamber while still utilizing high-velocity purge gas supply.

Inventive Principle:

Principle #35Parameter changes

2Speed

If purge gas velocity is high, then gas flow rate is improved, but residue deposition on chamber surfaces increases

Engineering Contradiction:

Improvepurge gas velocityVSAvoidresidue deposition

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The baffle acts as an intermediary that intercepts the high-velocity purge gas jet and redirects it into the purge volume. This prevents the direct impingement of high-velocity gas on chamber surfaces that would cause residue deposition, while still maintaining effective purge gas flow through the processing chamber.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The baffle structure converts the potentially harmful high-velocity jet into a beneficial flow pattern. By deflecting the jet onto the baffle surface and redirecting it, the high velocity is transformed into effective purge gas circulation that improves mass flow uniformity without causing harmful deposition on chamber surfaces.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If no baffle is used, then device complexity is reduced, but mass flow uniformity and deposition control deteriorate

Engineering Contradiction:

Improvepurge volume structureVSAvoidplasma pressure profile uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

A relatively simple baffle structure is introduced as an intermediary element that provides significant improvement in mass flow uniformity and deposition control. The baffle's simple geometry (essentially a deflecting plate) minimizes added complexity while effectively managing the purge gas flow to achieve uniform plasma pressure profiles across the substrate.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances the uniformity of the plasma pressure profile across the substrate, decreasing the frequency of chamber cleaning and downtime by minimizing residue deposition on chamber surfaces.

Implementation Method 1

The baffle is configured to deflect a trajectory of the purge gas entering the purge volume

Methodology Applied

Scientific EffectGas deflection:

Implementation Method 2

The baffle is configured to reduce a velocity of the purge gas at the first equalizer hole to less than 20 percent of the velocity of a purge gas jet at the purge port

Methodology Applied

Scientific EffectVelocity reduction:

Data Source

PatentUS12183553B2Baffle implementation for improving bottom purge gas flow uniformity

Publication Date: 2024.12.31 APPLIED MATERIALS INC

AI summary

The present disclosure generally relates to an apparatus for improving azimuthal uniformity of a pressure profile of a processing gas. In one example, a processing chamber includes a lid, sidewalls, and a substrate support defining a processing volume. A bottom bowl, a chamber base, and a wall define a purge volume. The purge volume is disposed beneath the processing volume. The bottom bowl includes a first surface having a first equalizer hole. A passage couples the processing volume to the purge volume via the first equalizer hole and an inlet. The passage is positioned above the first equalizer hole. The chamber base has a purge port coupleable to a purge gas line for supplying a purge gas to the purge volume. A baffle is disposed in the purge volume at a height above the purge port, and is configured to deflect a trajectory of the purge gas.