| 摘要 |
The present invention provides a wafer polishing apparatus capable of controlling the polishing quantity accurately. The wafer polishing apparatus comprises a rotatable polishing stool with a polishing cloth, a carrier for bringing a wafer into contact with the polishing cloth under a predetermined pressure, a pad arranged around the wafer in such a manner as to contact the polishing cloth under a predetermined pressure, a detector for detecting the change of the relative positions of the back of the wafer or the carrier and the pad, and a control unit for controlling the polishing operation in accordance with the polishing quantity computed from the detection signal of the detector, wherein an operating unit includes a sampling unit (82) for sampling the detection signal of the detector with such a sampling period that the number of times sampled per rotation of the polishing stool is plural, a moving average calculating unit (84) for calculating the moving average data by averaging the sampling data in the number equal to an integer multiple of the number of times sampled per rotation, and a polishing quantity computing unit (85) for computing the polishing quantity from the moving average data. |
