Patent ID: 7488236

Claim:
A method of polishing a semiconductor wafer, which comprises: providing a semiconductor wafer polishing pad having a polishing layer constituted by resin foam of closed-cell type, wherein the number of closed cells in the polishing layer is 200 to 600 per mm 2 and the average diameter of the closed cells is 30 to 60 μm; and rotating the polishing pad and simultaneously positioning the polishing pad to abut on a semiconductor wafer while supplying an abrasive between the polishing layer and the semiconductor wafer; wherein a resin constituting the resin foam consists of a polyurethane resin produced by mixing a first component containing an isocyanate group-containing compound with a second component containing an active hydrogen group-containing compound followed by hardening the mixture by heating, said mixture containing a curing agent and a silicone-based surfactant the resin foam has a hardness of 45 or more and less than 65 as measured using a D-type rubber hardness meter, and the closed cells solely contain gas selected from the group consisting of nitrogen, oxygen, a rare gas, dry air, and a mixed gas of the foregoing.