DOUBLE-SIDED POLISHING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a double-sided polishing method capable of suppressing deterioration of the flatness, especially outer peripheral sagging, of a wafer after polishing due to a shape change of the inner peripheral surface of a resin insert of a carrier.SOLUTION: A double-sided polishing method comprises the steps of: holding a wafer W with a carrier 2 having a retention hole 4 for retaining the wafer W and a ring-shaped resin insert 3 arranged along the inner periphery of the retention hole 4 and having an inner peripheral surface coming in contact with the peripheral edge part of the retained wafer W; holding the carrier 2 with upper and lower platens 5 and 6 each having a polishing cloth 7 adhering thereto; and polishing both sides of the wafer W simultaneously. When the maximum difference of elevation of irregularities of the inner peripheral surface of the resin insert 3 is defined as the flatness of the inner peripheral surface and the angle between the line connecting the upper end part to the lower end part in the inner peripheral surface and the line perpendicular to the principal surface of the carrier is defined as the perpendicularity of the inner peripheral surface, both sides of the wafer W is polished while keeping the flatness at a level of 100 μm or smaller and the perpendicularity at a level of 5° or smaller.