EUV Reticle Carrier Decontamination via Nested Purge

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Solution Overview

Problem

Semiconductor manufacturing facilities face challenges in maintaining high cleanliness levels during the storage of sensitive workpieces due to contamination risks from particles and reactive species, which can lead to physical and chemical damage, especially with the critical dimensions of modern semiconductor devices surpassing 0.1 microns.

Innovation Solution

A decontamination chamber using a purge gas system and high vacuum to periodically clean and outgas stored objects, employing a double-container carrier system with nitrogen purging to prevent contamination, and a robot-assisted monitoring system to ensure cleanliness levels are maintained.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If sealed storage areas with constant purging and inert gas flow are used, then cleanliness level is improved, but device complexity increases

Engineering Contradiction:

Improvecleanliness levelVSAvoiddevice complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements a double-container carrier system where an inner container holding the workpiece is nested within an outer container. Both containers have sealing flanges that mate together to form a sealed storage volume. This nested structure provides enhanced cleanliness protection through multiple sealing barriers while maintaining manageable system complexity by organizing the containment function in a hierarchical manner.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The storage system is segmented into multiple independent components: the inner container, outer container, sealing flanges, and purge gas system. This segmentation allows each component to be optimized independently for its specific function (workpiece holding, sealing, purging) while collectively achieving the overall cleanliness objective. The modular nature reduces system complexity by allowing independent maintenance and replacement of individual segments.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If load-locked access to storage areas is implemented, then cleanliness level is improved, but productivity decreases

Engineering Contradiction:

Improvecleanliness levelVSAvoidproductivity

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The double-container carrier system is designed to be self-contained and self-protecting. The sealed inner and outer containers maintain their own isolated clean environment without requiring continuous external intervention. The purge gas system automatically maintains pressure differentials and gas flow to prevent contamination, allowing the system to protect itself during storage and transfer operations, thereby reducing the need for complex external load-lock mechanisms.

Inventive Principle:

Principle #25Self-service

3Reliability

If double-container carrier system with sealing flanges is used, then reliability is improved, but device complexity increases

Engineering Contradiction:

ImprovereliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #7Nested doll (Nesting)

4Manufacturing precision

If periodic decontamination with vacuum pumping is performed, then cleanliness level is improved, but loss of time increases

Engineering Contradiction:

Improvecleanliness levelVSAvoidloss of time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system performs preliminary decontamination actions by maintaining continuous purge gas flow and pressure differentials during normal storage operations. This preliminary cleaning action prevents contaminant accumulation, reducing the need for extensive periodic decontamination cycles. The vacuum pumping system is ready to perform rapid decontamination when needed, but the continuous preliminary protection minimizes the frequency and duration of these operations.

Inventive Principle:

Principle #10Preliminary action

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 solution effectively reduces particulate and trace contaminant levels, maintaining high cleanliness standards for semiconductor workpieces by periodically decontaminating and purging the storage environment, thereby preventing contamination and ensuring the integrity of stored objects.

Implementation Method 1

a vacuum pump for maintaining a vacuum within the decontamination chamber

Methodology Applied

Scientific EffectVacuum: Vacuum

Implementation Method 2

a heater for heating the workpiece and/or the decontamination chamber

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

a sensor, such as a RGA (residue gas analyzer), can also be included to monitor levels of contamination of the object

Methodology Applied

Scientific EffectResidual Gas Analyzer:

Data Source

PatentEP2727137B1Semiconductor stocker systems and methods.

Publication Date: 2022.04.20 BROOKS AUTOMATION GERMANY

Figure 1A~1B
Figure 2A~2B
Figure 3A~3B

AI summary

In an embodiment, the present invention discloses cleaned storage processes and systems for high level cleanliness articles, such as extreme ultraviolet (EUV) reticle carriers. A decontamination chamber can be used to clean the stored workpieces. A purge gas system can be used to prevent contamination of the articles stored within the workpieces. A robot can be used to detect the condition of the storage compartment before delivering the workpiece. A monitor device can be used to monitor the conditions of the stocker.