EFEM Pressure-Zone Structure for Transfer Chamber Gas Containment

Solution Overview

Problem

Existing equipment front end modules (EFEMs) in semiconductor manufacturing face challenges in maintaining cleanliness by preventing harmful gases from escaping and external gases from entering the transfer chamber, leading to potential contamination and exposure risks.

Innovation Solution

The EFEM incorporates a multi-chamber structure with controlled pressure zones, where the first chamber maintains a lower pressure than the transfer chamber and the second chamber maintains a higher pressure than the first, effectively blocking gas exchange between the transfer chamber and the external environment, using supply and exhaust parts and controllers to manage pressure and gas flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If gases are supplied into the transfer chamber to maintain cleanliness, then the cleanliness in the transfer chamber is improved, but the pressure inside the transfer chamber becomes higher than outside, causing gases to escape and contamination to occur

Engineering Contradiction:

Improvecleanliness in transfer chamberVSAvoidgas escape and contamination

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The EFEM is divided into multiple sealed chambers (transfer chamber, storage chamber, process chamber) with independent pressure control. Each chamber can maintain different pressure levels to prevent gas escape while preserving cleanliness. The load port is further segmented with separate sealing mechanisms for FOUP loading and transfer chamber access.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A pressure control system with supply and exhaust parts acts as an intermediary between the transfer chamber and external environment. This intermediary mechanism regulates pressure differences, allowing the transfer chamber to maintain positive pressure for cleanliness while preventing uncontrolled gas escape through controlled venting.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the transfer chamber is sealed to prevent gas escape, then gas containment is improved, but leaks may still occur in large-sized EFEM, allowing harmful gases to escape and expose workers

Engineering Contradiction:

Improvesealing effectivenessVSAvoidharmful gas escape and worker exposure

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The EFEM is divided into multiple sealed chambers (transfer chamber, storage chamber, process chamber) with independent pressure control. Each chamber can maintain different pressure levels to prevent gas escape while preserving cleanliness. The load port is further segmented with separate sealing mechanisms for FOUP loading and transfer chamber access.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Pressure sensors and controllers provide continuous feedback to monitor and adjust pressure levels in each chamber. This feedback mechanism detects pressure changes that indicate potential leaks and automatically adjusts sealing mechanisms or pressure levels to maintain containment and prevent harmful gas escape.

Inventive Principle:

Principle #23Feedback

3Object-affected harmful factors

If multi-chamber structure with pressure control is implemented, then gas exchange blocking is improved, but device complexity increases

Engineering Contradiction:

Improvegas exchange blockingVSAvoidmulti-chamber structure complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The EFEM is divided into multiple sealed chambers (transfer chamber, storage chamber, process chamber) with independent pressure control. Each chamber can maintain different pressure levels to prevent gas escape while preserving cleanliness. The load port is further segmented with separate sealing mechanisms for FOUP loading and transfer chamber access.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The pressure control system with supply and exhaust parts serves multiple functions: maintaining cleanliness, preventing gas escape, controlling pressure differentials across chambers, and enabling controlled access. This multi-functional design reduces the need for separate systems for each function, thereby managing complexity.

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

This configuration effectively prevents harmful gases from escaping while blocking external air from entering the transfer chamber, ensuring a cleaner and safer environment by maintaining a sealed gas exchange within the EFEM.

Implementation Method 1

at least one first chamber provided between the transfer chamber and an outside of the EFEM, and configured such that a pressure therein is maintained lower than a lower pressure from among a pressure inside the transfer chamber and a pressure outside the EFEM; and at least one second chamber provided between the first chamber and the outside of the EFEM, and configured such that a pressure therein is maintained higher than that inside the first chamber

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentUS12106989B2Equipment front end module

Publication Date: 2024.10.01 PICO & TERA CO LTD

AI summary

Proposed is an EFEM configured to perform wafer transfer between a wafer storage device and process equipment. More particularly, proposed is an EFEM that prevents harmful gases inside a transfer chamber in which wafer transfer is performed from escaping out of the EFEM.