Reticle Storage Purge System for Haze Control

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Solution Overview

Problem

Semiconductor manufacturing facilities face challenges with particulate and airborne molecular contaminants (AMC) causing reticle defects, such as hazing, despite the use of reticle pods for protection, as contaminants accumulate and traditional nitrogen purging is inefficient and poses safety concerns.

Innovation Solution

A reticle handling system that maintains a low humidity environment using extra dry clean air or adsorbent media, with a filter media that can be recharged during purging, to reduce haze formation by minimizing water presence and contaminants on reticles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If periodic cleanings are performed to minimize contaminants in reticle pod, then contaminant levels are reduced, but manufacturing efficiency decreases

Engineering Contradiction:
Improvecontaminant levelVSAvoidmanufacturing efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The system implements continuous purging operation where filtered air constantly flows through the reticle containment environment, maintaining low contaminant levels without interruption to manufacturing operations. This eliminates the need for periodic shutdowns for cleaning.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system pre-filters ambient air through HEPA and AMC filters before introducing it to the reticle containment, proactively preventing contaminant accumulation rather than reacting to contamination levels with periodic cleanings.

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 system effectively reduces haze formation on reticles by maintaining a controlled environment with low humidity, minimizing the risk of water introduction and contaminant accumulation, thereby protecting reticles during storage and transportation.

Implementation Method 1

By substantially continually maintaining either a purge of preferably extra dry clean air having a reduced humidity level on reticles

Methodology Applied
Scientific EffectHumidity control through dry air purging: Evaporation

Implementation Method 2

or by temporarily storing the reticle in a container in proximity to an adsorbent or dessicant media when not being purged

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

or by temporarily storing the reticle in a container in proximity to an adsorbent or dessicant media

Methodology Applied
Scientific EffectDesiccation: Desiccation

Implementation Method 4

Moreover, a filter media in the container may be positioned to be 'recharged' during the substantially continual purging of the reticle

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP2453310B1System for purging reticle storage
Publication Date: 2015.12.09 ENTEGRIS INC
  • EP2453310B1 patent drawingFigure 1a
  • EP2453310B1 patent drawingFigure 1b~2
  • EP2453310B1 patent drawingFigure 3~5b

AI summary

The present invention provides a method, system, and components for protecting reticles and specifically for minimizing haze formation on reticles during storage and use. By substantially continually maintaining a purge in a storage housing having a reduced humidity level on reticles or by temporarily storing the reticle in a container in proximity to a desiccant or getter when not being purged, haze formation can be eliminated, minimized, or sufficiently controlled. Moreover, a filter media in the container may be positioned to be "recharged" during the substantially continual purging of the reticle, a reduced desireable humidity level can be readily maintained in the reticle container when the container is not currently being purged. Additionally, the system of the invention can comprise an ionizer associated with the purge system. For example, the ionizer can be associated with at least one of the plurality of purge lines of the purge system. The system of the invention can also include a purge gas source connected to the purge system that comprises a source of CDA or extra CDA. The storage housing can comprise a plurality of shelves that each include a plurality of reticle storage receptacles.