Cleanroom AMC Detection and Response Using CFD and TOF-MS

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Solution Overview

Problem

The semiconductor industry faces challenges in detecting and responding to airborne molecular contamination (AMC) in cleanrooms, leading to delays in identifying and addressing contaminant leaks, which can result in out-of-control and out-of-specification events.

Innovation Solution

The implementation of a contaminant management system that employs time-of-flight mass spectrometry (TOF-MS) for rapid detection of AMC parameters, combined with computational fluid dynamics (CFD) for contaminant distribution analysis, and automated guided vehicles (AGVs) for localized cleaning, enables quasi-real-time detection and response to contaminant leaks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If traditional contaminant detection methods are used, then the system is simpler and easier to operate, but the detection speed is slow and response time is delayed

Engineering Contradiction:
Improvedetection speedVSAvoidsystem complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The cleanroom is divided into multiple zones with distributed sampling points, each equipped with sensors. This segmentation allows parallel detection across different areas, significantly improving overall detection speed while keeping individual sensor units relatively simple

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A centralized control system acts as an intermediary that receives data from multiple simple sensor nodes, processes the information using CFD models, and coordinates the response. This allows the system to achieve fast detection through distributed sensing while maintaining manageable complexity through centralized intelligence

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If traditional contaminant detection and response methods are used, then the system is simpler, but the time to identify and address contaminant leaks is delayed, leading to out-of-control events

Engineering Contradiction:
Improveresponse timeVSAvoidmanagement system complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

Computational fluid dynamics (CFD) models are pre-computed for various contaminant source locations and release scenarios. When a contaminant is detected, the system immediately queries pre-computed models to predict contaminant distribution and identify the source, eliminating the need for real-time complex calculations and enabling rapid response

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors contaminant levels and compares them against predicted values from CFD models. This feedback mechanism allows the system to quickly identify deviations indicating leaks, trace them to specific sources, and trigger automated responses, reducing response time while managing complexity through model-based decision making

Inventive Principle:
Principle #23Feedback

3Productivity

If automated guided vehicles are deployed for localized cleaning, then contaminant removal becomes more targeted and efficient, but the system complexity and cost increase

Engineering Contradiction:
Improvecleaning efficiencyVSAvoidautomation system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Automated guided vehicles (AGVs) are equipped with onboard sensors and contaminant removal capabilities, allowing them to autonomously navigate to identified contaminant sources and perform cleaning without human intervention. This self-service capability improves cleaning efficiency and response speed, while the modular AGV design helps manage system complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The centralized control system serves as an intermediary that coordinates AGV deployment based on contaminant detection data. Rather than requiring complex autonomous decision-making in each AGV, the control system directs vehicles to specific locations and monitors their effectiveness, improving cleaning productivity while keeping individual vehicle units relatively simple

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

This system allows for quick identification of contaminant sources, rapid reduction of contaminant levels, and minimization of production disruptions, thereby enhancing the yield and reliability of semiconductor manufacturing processes.

Implementation Method 1

employs time-of-flight mass spectrometry (TOF-MS) for rapid detection of AMC parameters

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Implementation Method 2

combined with computational fluid dynamics (CFD) for contaminant distribution analysis

Methodology Applied
Scientific EffectComputational fluid dynamics:

Data Source

PatentUS12202015B2Airborne contaminant management method and system
Publication Date: 2025.01.21 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD
  • US12202015B2 patent drawing
  • US12202015B2 patent drawing
  • US12202015B2 patent drawing

AI summary

A method includes: generating a contaminant distribution map by sampling an environment of a cleanroom; selecting a first fabrication tool of the cleanroom by comparing the contaminant distribution map with at least one diffusion image in a first database; comparing parameters of the first fabrication tool against process utility information in a second database; and when the parameters are consistent with the process utility information, taking at least one action. The one action may include moving a cleaning tool to a location associated with a contaminant concentration of the contaminant distribution map; turning on a fan of the cleaning tool; stopping pod transit to the first fabrication tool; or halting production by the first fabrication tool.