Kruskal-Wallis Test for Defect Source Identification in IC Manufacturing

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Solution Overview

Problem

Current defect detection techniques in integrated circuit manufacturing are inadequate for identifying sources of defects, particularly due to assumptions of normal distribution and the inability to detect latent defects, leading to inefficiencies and increased costs in semiconductor fabrication.

Innovation Solution

The use of non-parametric statistical tools, specifically the Kruskal-Wallis test, to analyze defect characteristics and identify likely sources by processing steps and tools, enabling the detection of abnormal distributions and latent defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If non-parametric statistical tools (Kruskal-Wallis test) are used to analyze defect characteristics, then defect detection accuracy is improved, but computational complexity increases

Engineering Contradiction:
Improvedefect detection accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transforms the defect analysis approach by changing the statistical parameters from parametric assumptions (normal distribution) to non-parametric methods (Kruskal-Wallis test). This parameter change enables accurate detection of latent defects and abnormal distributions without requiring defects to follow normal distribution patterns, thereby improving defect detection accuracy while managing computational complexity through established statistical algorithms.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If automated defect detection system is implemented, then productivity is improved, but system complexity increases

Engineering Contradiction:
Improvedefect detection efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements an automated defect detection system that performs self-service by automatically collecting defect data from multiple sources, applying the Kruskal-Wallis test algorithm, and generating analysis results without requiring manual intervention. The system autonomously identifies latent defects and abnormal distributions, improving productivity while containing system complexity through modular architecture that integrates data collection, statistical analysis, and result generation in an automated workflow.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If multiple processing steps and tools are monitored, then measurement precision is improved, but data processing complexity increases

Engineering Contradiction:
Improvedefect source identification accuracyVSAvoiddata processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the complex data processing task into distinct modules: defect data collection from multiple processing steps and tools, Kruskal-Wallis test application for statistical analysis, and result interpretation for identifying latent defects and abnormal distributions. This segmentation allows precise monitoring of multiple processing steps and tools while managing data processing complexity through structured, modular analysis that processes data from each source systematically.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS7991497B2Method and system for defect detection in manufacturing integrated circuits
Publication Date: 2011.08.02 SEMICON MFG INT (SHANGHAI) CORP
  • US7991497B2 patent drawing
  • US7991497B2 patent drawing
  • US7991497B2 patent drawing

AI summary

Method and system for defect detection in manufacturing integrated circuits. In an embodiment, the invention provides a method for identifying one or more sources for possible causing manufacturing detects in integrated circuits. The method includes a step for providing a plurality of semiconductor substrates. The method includes a step for processing the plurality of semiconductor substrates in a plurality of processing steps using a plurality of processing tools. The method additionally includes a step for providing a database, which includes data associated with the processing of the plurality of semiconductor substrates. The method further includes a step for testing the plurality of semiconductor wafers after the processing of the plurality of semiconductor substrates. Additionally, the method includes a step for detecting at least one defect characteristic associated with the plurality of the semiconductor substrates that have been processed. Moreover, the method includes a step for identifying a set of processing steps. For example, the set of processing step are possibly associated with the defect characteristic.