Kla Corporation

Weifeng Zhou

Siqing Nie

Chunwei Song

Sangbong Park

Xiaochun Li

Zhuang Liu

Methods and systems for detecting defects on a specimen are provided. One system computes different candidate reference images from different combinations of images of the specimen generated by an inspection subsystem and combines different portions of the candidate reference images without modification to thereby generate a final reference image. The final reference image is then used for defect detection, which may be single or double detection. The embodiments are particularly useful for defect detection in areas of specimens including only non-resolvable, repeating device patterns, like cell regions, but may be used for inspection of other types of areas as well.

Detecting defects on specimens

Methods and systems for detecting defects in an array region on a specimen are provided. One method includes determining a center of a page break in output generated by an inspection subsystem for a specimen in an array region. The page break separates cell regions in the array region, and the cell regions include repeating patterned features. The method also includes determining an offset between the center of the page break in the output and a center of the page break in a design for the specimen and identifying portions of the output that correspond to care areas in the array region based on the offset. In addition, the method includes detecting defects in the array region by applying a defect detection method to the portions of the output that correspond to the care areas.

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Shanghai, China

Weifeng Zhou