| 摘要 |
PROBLEM TO BE SOLVED: To provide a polishing pad having a window structure which is useful for suppressing polishing defect and is useful for reducing fluctuation in signal transmission.SOLUTION: A polishing pad 10 is suitable for polishing or flattening at least one of a semiconductor substrate, an optical substrate, and a magnetic substrate. The polishing pad 10 has a polishing surface 16, an opening in the polishing pad, and a transparent window 20 in the opening in the polishing pad. The transparent window has a recessed surface 32 of which a depth increases as the polishing pad is used. A signal region inclines downward to a center region so as to facilitate removal of polishing sludges, and a polishing sludge discharge groove 12A extends in the polishing pad through the center region 36. When the polishing pad rotates in a state that a polishing fluid is in the polishing sludge discharge groove, the polishing sludges are delivered into the polishing pad through the polishing sludge discharge groove from the center region.SELECTED DRAWING: Figure 1C |
