COMPOSITE SUBSTRATE POLISHING METHOD AND COMPOSITE SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a composite substrate polishing method where the prevention effect of outer periphery sagging is stably obtained without making difference in each polishing and to provide a composite substrate.SOLUTION: A support substrate 14 side of a composite substrate 10 joining a piezoelectric substrate 12 and a support substrate 14 is attached to the rear surface of a substrate carrier 126 via a suede sheet 130. The substrate carrier 126 is pressed toward a polishing surface plate 122 so that the piezoelectric substrate 12 is brought into contact with the polishing surface plate 122 to which a suede pad 132 adheres. The piezoelectric substrate 12 is polished by rotating the substrate carrier 126 and the polishing surface plate 122 while supplying a slurry containing colloidal silica to the suede pad 132. The suede pad 132 and the suede sheet 130 are deformed by the composite substrate 10 when the substrate carrier 126 is pressed toward the polishing surface plate 122.