PURPOSE: To sufficiently and flatly polish a large-aperture wafer surface at its central part by providing polishing cloth with hard pads having grooves in the surfaces and by forming roundness on the corner parts of the grooves at their opening sides.
CONSTITUTION: Hard pads 12 are pasted on the top surface of a surface plate 11. A plurality of grooves 13 with a predetermined width and a predetermined depth are formed in a grid shape on the top surfaces of the hard pads 12. Roundness is formed on the corner parts of these grooves 13 at their opening sides. A soft pad 14 is buried in the inner part of each groove 13. Polishing cloth 15 is formed of these hard pads 12 and soft pads 14. The polishing cloth 15 flatly polishes the surface of a silicon wafer 17 regardless of irregularities on a back surface. In addition, in the large-aperture silicon wafer 17, abrasive power is held and supplied in the soft pads 14 of the grooves 13 to uniformly polish the surface of the central part as well as the surface of the peripheral edge part.
KOMATSU KEI
SATO TAIRA
MITSUBISHI MATERIALS CORP
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