Kla Corporation

Boshi Huang

Ge Cong

Bjorn Brauer

Hucheng Lee

Sangbong Park

Santosh Bhattacharyya

Erfan Soltanmohammadi

Vladimir Tumakov

Sanbong Park

Vahid Noormofidi

A care area is determined in an image of a semiconductor wafer. The care area is divided into sub-care areas based on the shapes of polygons in a design file associated with the care area. A noise scan of a histogram for the sub-care areas is then performed. The sub-care areas are clustered into groups based on the noise scan of the histogram.

Clustering sub-care areas based on noise characteristics

Methods and systems for aligning images of a specimen are provided. One method includes reducing noise in a test image generated for a specimen by an imaging subsystem thereby generating a denoised test image. The method also includes detecting one or more patterned features in the denoised test image extending in at least a horizontal or vertical direction. In addition, the method includes designating an area of the denoised test image in which the detected one or more patterned features are located as a region of interest in the denoised test image. The method further includes aligning the denoised test image to a reference image for the specimen using only the region of interest in the denoised test image and a corresponding area in the reference image.

Image alignment for noisy images

A rendered image is aligned with a scanning electron microscope (SEM) image to produce an aligned rendered image. A reference image is aligned with the SEM image to produce an aligned reference image. A threshold probability map also is generated. Dynamic compensation of the SEM image and aligned reference image can produce a corrected SEM image and corrected reference image. A thresholded defect map can be generated and the defects of the thresholded probability map and the signal-to-noise-ratio defects of the thresholded defect map are filtered using a broadband-plasma-based property to produce defect-of-interest clusters.

BBP assisted defect detection flow for SEM images

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San Jose, CA, United States of America

Boshi Huang