Abstract: A wafer is produced at a step of polishing a predetermined face of a wafer to flatten the predetermined face while supplying a polishing liquid onto a bonded abrasive cloth, wherein the bonded abrasive cloth comprises a urethane bonding material consisting of a soft segment having a polyfunctional isocyanate and a hard segment having a polyfunctional polyol and having an expansion ratio of 1.1-4 times and silica having an average particle size of 0.2-10 ?m and a hydroxy group, and has a given ratio of the hard segment occupied in the urethane bonding material, a given volume ratio of silica and a given Shore D hardness.

Abstract: A bonded wafer is produced by bonding an ion-implanted wafer for an active layer onto a wafer for a supporting substrate, and thereafter exfoliating the wafer for the active layer at the ion-implanted position through a heat treatment and then polishing a terrace portion of the resulting active layer with a predetermined fixed grain abrasive cloth to remove island-shaped projections on the terrace portion while controlling a scattering of terrace width and smoothness of an outer peripheral face of the active layer.

Abstract: A bonded wafer is produced by bonding an ion-implanted wafer for an active layer onto a wafer for a supporting substrate, and thereafter exfoliating the wafer for the active layer at the ion-implanted position through a heat treatment and then polishing a terrace portion of the resulting active layer with a predetermined fixed grain abrasive cloth to remove island-shaped projections on the terrace portion while controlling a scattering of terrace width and smoothness of an outer peripheral face of the active layer.

Abstract: A wafer is produced at a step of polishing a predetermined face of a wafer to flatten the predetermined face while supplying a polishing liquid onto a bonded abrasive cloth, wherein the bonded abrasive cloth comprises a urethane bonding material consisting of a soft segment having a polyfunctional isocyanate and a hard segment having a polyfunctional polyol and having an expansion ratio of 1.1-4 times and silica having an average particle size of 0.2-10 ?m and a hydroxy group, and has a given ratio of the hard segment occupied in the urethane bonding material, a given volume ratio of silica and a given Shore D hardness.