| 摘要 |
The surfaces of wafers polished in CMP equipment are monitored in real time to detect a normal/abnormal state of operation of the CMP equipment. A camera is disposed alongside a path along which a wafer is transferred to a cassette stage from a cleaning unit. The camera is oriented to capture an image of the surface of the wafer which has been polished and cleaned. An image processor processes the color image of the surface of the wafer captured by the camera into data of the contrast between and color of areas of the image. A controller receives the data output by the image processor. The controller is connected to a database in which data of at least one color reference image is stored. The reference image(s) is/are correlated to process conditions of the CMP process. The controller (selectively) compares the processed color image with the color reference image that is stored in the database, and based on the comparison determines whether a defect exists in the polishing process.
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