Processing Chamber Purge Gas Flow Path Design

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Solution Overview

Problem

In processing chambers, the processing gas fails to evacuate effectively without the introduction of purge gas, leading to recirculation within the chamber.

Innovation Solution

The apparatus introduces purge gas from two locations: between the stem and shaft wall at the bottom of the chamber and through the slit valve opening, ensuring the processing gas flows towards the vacuum pump for evacuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If processing gas is evacuated through the bottom of the chamber, then gas evacuation is enabled, but processing gas recirculates within the plenum instead of being removed from the chamber

Engineering Contradiction:

Improvegas evacuation efficiencyVSAvoidgas flow control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Purge gas is introduced as an intermediary substance to mediate between the processing gas and the vacuum pump. The purge gas flows through the plenum and directs the processing gas toward the vacuum pump outlet, preventing recirculation while maintaining effective evacuation. This intermediary gas flow solves the problem of processing gas getting trapped in the plenum space.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If purge gas is introduced through the slit valve and along the stem, then processing gas is directed toward the vacuum pump, but additional gas introduction complexity is required

Engineering Contradiction:

Improvegas evacuation efficiencyVSAvoidgas introduction system

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The vacuum pump serves multiple functions: it evacuates processing gas from the chamber and also receives purge gas from the plenum through its outlet. The slit valve and stem structure are utilized not only for their primary functions but also as pathways for introducing purge gas. This multi-functionality reduces the need for separate dedicated components for purge gas introduction.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 introduction of purge gas facilitates the effective evacuation of processing gas from the chamber, preventing recirculation and ensuring efficient gas flow out of the chamber.

Implementation Method 1

Processing gas is pulled down below a heater plate by a vacuum pump

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

Purging gas is introduced through the slit valve as well as along the stem holding up the heater plate. The purge gas collectively directs the processing gas to flow towards the vacuum pump.

Methodology Applied

Scientific EffectGas flow:

Data Source

PatentUS10385448B2Apparatus and method for purging gaseous compounds

Publication Date: 2019.08.20 APPLIED MATERIALS INC

AI summary

A processing chamber is described having a gas evacuation flow path from the center to the edge of the chamber. Purge gas is introduced at an opening around a support shaft that supports a heater plate. A shaft wall around the opening directs the purge gas along the support shaft to an evacuation plenum. Gas flows from the evacuation plenum through an opening in a second plate near the shaft wall and along the chamber bottom to an opening coupled to a vacuum source. Purge gas is also directed to the slit valve.