Outlier substrate inspection

US7440607B1 · kind B1 · utility

Assignee

• KLA-TENCOR CORPORATION · US

Inventors

• Jason Z. Lin · Saratoga, US
• Hong Chen · Changzhou City, CN
• Evgeni Shifrin · Sunnyvale, US
• Ashok Kulkarni · San Jose, US
• Santosh Bhattacharyya · San Jose, US
• Wei Zhao · East Setauket, US
• Chien-Huei Chen

Key dates

• Filing date: Nov 3, 2004
• Grant date: Oct 21, 2008
• Expiry date: Feb 10, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/8887
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method of detecting anomalies in a test image. Test features of pixels within the test image are selected, and reference features of pixels within at least one reference image are also selected. A signal distribution of test features and reference features in a multi-dimensional feature space is created, and stored. Those test features of the test image that do not satisfy a set of criteria for normalcy are selected as candidate points. Those candidate points that are statistical outliers are identified as anomalies. Positions of the anomalies are located using the stored signal distribution within which the defects have been identified as a lookup table.