摘要 |
The present invention relates to a defect review system, and/or particularly, to an apparatus and method of defect review sampling, review method and classification on a semiconductor wafer or a pattern lithography reticle during integrated circuit fabrication. These objects are achieved in comparing a reviewed image with a reference image pick-up through a smart sampling filter. A clustering computer system base on high speed network will provide data cache and save operation time and memory. A smart review sampling filter automatically relocate abnormal pattern or defects and classify the device location extracted from design database and/or from golden die image on the same substrate. The column of the present defect review system is comprised of the modified SORIL type objective lens. This column provides solution of improving throughput during sample review, material identification better image quality, and topography image of defect. One embodiment of the present invent adopts an optical auto focusing system to compromise micro height variation due wafer surface topography. And another embodiment adopts surface charge control system to regulate the charge accumulation due to electron irradiation during the review process.
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