Automated Wafer Inspection for Weak Pattern Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current wafer inspection methods rely on human eyes and are limited by small sample sizes, prone to error, and lack automation, making it difficult to detect and quantify systematic defects effectively, especially with increased data volume and sensitivity.

Innovation Solution

A system with a processor-configured wafer inspection tool that performs pattern grouping, identifies regions of interest, and automatically detects and validates weak patterns by simulating wafer processes and using SEM images, enabling automated hotspot detection and quantification without human intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If human eyes are used to determine the presence of defects, then manual classification can be performed, but the inspection process is limited to small sample sizes and is prone to error

Engineering Contradiction:
Improvedefect detection accuracyVSAvoidinspection throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical human visual inspection system with an automated computer-based inspection system that uses algorithms to detect and classify defects. This substitution enables processing of large datasets without the limitations of human fatigue and attention span, thereby increasing productivity while maintaining or improving measurement precision through consistent automated classification.

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

Solution Approach 2:

The inspection system performs self-classification of defects using automated algorithms that analyze defect patterns and characteristics. The system independently identifies weak patterns and classifies them without requiring human intervention, enabling the processing of large sample sizes while maintaining high accuracy through systematic automated decision-making.

Inventive Principle:
Principle #25Self-service

2Quantity of substance

If sampling is used to review defects, then manual classification can be performed, but the sample size is typically limited to no more than about 5 thousand defects

Engineering Contradiction:
Improvesample sizeVSAvoidinspection reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The system performs preliminary automated classification and identification of weak patterns before any potential human review. By pre-processing the entire dataset with automated algorithms to identify suspicious patterns and weak defects, the system enables reliable analysis of large sample sizes without the sampling limitations that constrain manual inspection reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces manual sampling and classification with automated computer-based inspection that can process and reliably analyze tens of thousands of defects. This substitution eliminates the 5,000-defect sample size limitation by using algorithms that maintain reliability across large datasets through consistent application of classification criteria.

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

3Loss of information

If simulations are used to predict risky sites, then pattern prediction can be performed, but they do not help identify if the sites actually fail post processing

Engineering Contradiction:
Improveprediction informationVSAvoidfailure detection accuracy
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The inspection system incorporates feedback by comparing simulated predictions with actual post-processing inspection results. The system uses actual defect data from processed wafers to validate and refine predictions, creating a closed-loop system that improves both prediction accuracy and failure detection by continuously learning from actual outcomes rather than relying solely on theoretical simulations.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11688052B2Computer assisted weak pattern detection and quantification system
Publication Date: 2023.06.27 KLA CORP
  • US11688052B2 patent drawing
  • US11688052B2 patent drawing
  • US11688052B2 patent drawing

AI summary

Methods and systems for providing weak pattern (or hotspot) detection and quantification are disclosed. A weak pattern detection and quantification system may include a wafer inspection tool configured to inspect a wafer and detect defects present on the wafer. The system may also include at least one processor in communication with the wafer inspection tool. The at least one processor may be configured to: perform pattern grouping on the detected defects based on design of the wafer; identify regions of interest based on the pattern grouping; identify weak patterns contained in the identified regions of interest, the weak patterns being patterns deviating from the design by an amount greater than a threshold; validate the weak patterns identified; and report the validated weak patterns or facilitate revision of the design of the wafer based on the validated weak patterns.