Contaminant Detection Using Fluorescence and OCT Imaging

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Solution Overview

Problem

Conventional contaminant detection systems in semiconductor manufacturing and other industries face challenges in accurately determining the location and type of contaminants adhering to objects, which can lead to reduced yield rates and inefficient cleaning processes.

Innovation Solution

A contaminant detection system that uses a light source to emit excitation light on the object, a camera to capture fluorescence emitted by contaminants, and a processor to determine the location and type of contaminants based on the fluorescence, with a network configuration that includes an edge computer, on-premises server, and cloud server for data processing and display control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional fluorescence detection is used to detect contaminants, then contaminant presence can be detected, but the location and type of contaminants cannot be accurately determined

Engineering Contradiction:

Improvecontaminant location and type identification accuracyVSAvoidcontaminant location and type information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent transitions from conventional 2D fluorescence imaging to 3D optical coherence tomography (OCT) imaging, adding the depth dimension to contaminant detection. This enables precise determination of contaminant location (depth, lateral position) and type (based on fluorescence characteristics) by combining OCT structural information with fluorescence signals, thereby resolving the information loss about contaminant location and type

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If comprehensive contaminant analysis is performed to determine location and type, then cleaning effectiveness is improved, but detection time and system complexity increase

Engineering Contradiction:

Improvecleaning process effectivenessVSAvoidcontaminant detection time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements continuous scanning measurement where the light source and detector move continuously across the inspection surface, capturing OCT and fluorescence signals in a single continuous operation rather than discrete steps. This continuous acquisition method reduces detection time while maintaining comprehensive contaminant analysis capability, ensuring both location and type information is obtained efficiently

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent merges OCT imaging and fluorescence detection into a single integrated inspection system that simultaneously captures structural information (OCT) and chemical information (fluorescence). By combining these two measurement modalities in one system, the patent achieves comprehensive contaminant characterization (location and type) without requiring separate detection processes, thereby reducing total detection time while improving reliability

Inventive Principle:

Principle #5Merging (Combining)

3Power

If multiple servers and edge computers are deployed for data processing, then data processing capability is improved, but system complexity increases

Engineering Contradiction:

Improvedata processing capabilityVSAvoidnetwork system complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The patent segments the data processing function across multiple hierarchical levels: edge computers perform local real-time processing of inspection data, on-premises servers handle intermediate data storage and processing, and cloud servers provide centralized data management and advanced analysis. This segmented architecture distributes computational load appropriately, improving overall data processing capability while managing system complexity through functional separation

Inventive Principle:

Principle #1Segmentation

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 efficiently detects contaminants and provides precise location and type identification, enabling effective cleaning methods and reducing maintenance downtime by supporting technicians with real-time data and automated cleaning processes.

Implementation Method 1

a light source configured to emit excitation light on the object to be inspected; a detector configured to detect fluorescence emitted from the contaminants adhering to the object to be inspected; and a processor. The fluorescence is caused by emission of the excitation light from the light source onto the object to be inspected

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS11776105B2Contaminant detection system, contaminant detecting method, and semiconductor manufacturing apparatus

Publication Date: 2023.10.03 TOKYO ELECTRON LTD

AI summary

A contaminant detection system includes a light source configured to emit excitation light on an object to be inspected; a detector configured to detect fluorescence emitted from a contaminant adhering to the object to be inspected; and a processor. The fluorescence is caused by emission of the excitation light from the light source onto the object to be inspected. The processor is configured to perform a determination of a location of the contaminant and a type of the contaminant, based on the fluorescence emitted from the contaminant; and output a result of the determination.