Deep Learning Difference Filter and Aperture Selection

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Solution Overview

Problem

Current methods for selecting difference filters and aperture settings in image acquisition are manual, time-consuming, and prone to errors, particularly when dealing with multiple types of defects or multi-mode imaging, as they rely on iterative and intuition-based approaches.

Innovation Solution

A system and method utilizing a deep learning network classifier to generate difference filter and aperture setting recipes by applying and classifying various filters and settings on training images, extracting convolution layer filters, and performing mathematical analyses to optimize image acquisition for efficient defect review and classification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual iterative methods are used to select aperture settings, then the selection process allows user intuition and flexibility, but the process becomes time-consuming and tedious

Engineering Contradiction:
Improveuser flexibility in selectionVSAvoidtime required for iterative testing
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The system performs preliminary classification of defects and pre-selection of optimal aperture settings before actual imaging. The controller classifies defects in training images and determines optimal aperture settings in advance, creating a lookup table that guides subsequent imaging operations without requiring real-time iterative testing

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system enables self-service automation where the controller automatically selects aperture settings based on defect classification without requiring manual user input. The system uses machine learning models to autonomously determine optimal settings, reducing both time consumption and reliance on user expertise

Inventive Principle:
Principle #25Self-service

2Ease of manufacture

If pre-selected difference filter recipes are used, then the method provides a set of predefined options for users, but the approach remains manual and intuition-based leading to errors

Engineering Contradiction:
Improveavailability of predefined optionsVSAvoidaccuracy of filter selection
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The system replaces manual mechanical selection of difference filters with an automated computational system. The controller uses machine learning models to automatically select optimal difference filters based on defect classification, substituting human intuition with algorithmic decision-making to improve reliability while maintaining the availability of predefined filter options

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

3Extent of automation

If algorithm selector software is used to estimate difference filters, then the method provides automated estimation, but the approach is still prone to error and not optimized for multiple defect types

Engineering Contradiction:
Improveautomated filter estimationVSAvoidoptimization for multiple defect types
Core Design Contradiction:
Extent of automationVSAdaptability or versatility

Solution Approach 1:

The system segments the filter selection process by creating separate optimization paths for different defect types. The controller classifies defects into categories and selects difference filters specifically optimized for each defect type, rather than using a single generic estimation approach. This segmentation enables the system to handle multiple defect types effectively while maintaining high automation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system creates a universal difference filter selection mechanism that can handle multiple defect types through a single integrated controller. The machine learning model is trained on diverse defect types and can automatically select appropriate filters for any defect category, making the system versatile across different inspection scenarios

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Measurement precision

If iterative testing of all aperture setting combinations is performed, then the method ensures comprehensive evaluation of options, but the process becomes excessively time-consuming

Engineering Contradiction:
Improvecompleteness of evaluationVSAvoidinspection throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs preliminary classification of defects and pre-determination of optimal aperture settings before actual inspection. By classifying defects in training images and determining optimal settings in advance, the system creates a lookup table that enables rapid selection during production inspection, maintaining evaluation quality while dramatically improving throughput

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11151707B2System and method for difference filter and aperture selection using shallow deep learning
Publication Date: 2021.10.19 KLA CORP
  • US11151707B2 patent drawing
  • US11151707B2 patent drawing
  • US11151707B2 patent drawing

AI summary

A system for defect review and classification is disclosed. The system may include a controller, wherein the controller may be configured to receive one or more training images of a specimen. The one or more training images including a plurality of training defects. The controller may be further configured to apply a plurality of difference filters to the one or more training images, and receive a signal indicative of a classification of a difference filter effectiveness metric for at least a portion of the plurality of difference filters. The controller may be further configured to generate a deep learning network classifier based on the received classification and the attributes of the plurality of training defects. The controller may be further configured to extract convolution layer filters of the deep learning network classifier, and generate one or more difference filter recipes based on the extracted convolution layer filters.