Deep Learning Ensemble for Semiconductor Defect Detection

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Solution Overview

Problem

Current methods for detecting defects in semiconductor manufacturing are inadequate for high volume manufacturing (HVM) due to high false positive rates and sensitivity to optimizer parameters, lacking theoretical foundations for performance improvement with increased computational resources.

Innovation Solution

A system utilizing an ensemble of deep learning (DL) models with a pseudo-loss function is employed for defect detection. The ensemble is trained with a training dataset to minimize the pseudo-loss function, achieving a balance between true defect capture and false positive reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current defect detection methods are used in high volume manufacturing, then throughput can be maintained, but false positive rates remain high and reliability deteriorates

Engineering Contradiction:
Improvedefect detection accuracyVSAvoidthroughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent divides the defect detection task into multiple independent deep learning models that process different aspects or features of the inspection data. Each model in the ensemble specializes in detecting specific defect patterns, and their predictions are combined to achieve high accuracy while maintaining throughput through parallel processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces traditional mechanical or rule-based defect detection systems with deep learning-based automated detection. This substitution enables the system to achieve both high throughput through efficient computational processing and high reliability through learned patterns from training data, eliminating the trade-off between speed and accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If traditional optimization methods are used for defect detection, then computational resources can be limited, but performance improvement with increased resources lacks theoretical foundation

Engineering Contradiction:
Improvedetection accuracyVSAvoidcomputational resource requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameters of the deep learning models systematically, including network architecture, learning rates, and ensemble sizes, to optimize performance. The theoretical framework guides these parameter changes to ensure that increased computational resources translate into predictable and measurable improvements in detection accuracy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback mechanisms where the performance of the ensemble model is continuously evaluated against ground truth data, and the results are used to refine the model parameters and training processes. This feedback loop ensures that computational resources are efficiently utilized to achieve optimal detection accuracy.

Inventive Principle:
Principle #23Feedback

3Reliability

If deep learning models are trained with extensive hyperparameter tuning, then detection accuracy can be improved, but manufacturing cost and time increase

Engineering Contradiction:
Improvefalse positive rateVSAvoidtraining time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary actions by pre-training the deep learning models on large datasets and pre-tuning the hyperparameters using systematic search methods before deployment. This preliminary preparation reduces the need for extensive hyperparameter tuning during actual manufacturing operations, thereby reducing both time and cost while maintaining high detection accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent discards poorly performing models or hyperparameter configurations from the ensemble during the selection process, and recovers computational resources by focusing training efforts only on the most promising configurations. This selective approach reduces overall training time while achieving the desired false positive rate.

Inventive Principle:
Principle #34Discarding and recovering

Data Source

PatentUS12211196B2Ensemble of deep learning models for defect review in high volume manufacturing
Publication Date: 2025.01.28 KLA CORP
  • US12211196B2 patent drawing
  • US12211196B2 patent drawing
  • US12211196B2 patent drawing

AI summary

Methods and systems for detecting defects in images of a specimen are provided. One system includes a computer subsystem configured for training an ensemble of deep learning models by altering one or more parameters of the ensemble until a pseudo-loss function determined based on output of the ensemble is approximately equal to but not greater than 0.5. The computer subsystem is also configured for detecting defects in runtime specimen images by inputting the runtime specimen images into the trained ensemble and generating runtime labels for the runtime specimen images indicating if a defect has been detected in the runtime specimen images based on outputs of the deep learning models in the trained ensemble.