POLISHING PAD
An object of the present invention is to provide a polishing pad which hardly generates scratches on the surface of an object to be polished, and has improved dressability. Another object of the present invention is to provide a method for manufacturing a semiconductor device using the polishing pad. A polishing pad of the present invention includes a polishing layer made of a fine cell-containing polyurethane resin foam, wherein the polyurethane resin foam contains a polyurethane resin having an Asker D hardness of 20 to 60 degrees and an abrasion parameter, which is expressed by the following equation, of 1 to 3. Abrasion parameter={1/(Tensile breaking strength [MPa]×Tensile breaking elongation [%]/100)}×100
1 . A polishing pad comprising a polishing layer made of a fine cell-containing polyurethane resin foam, wherein the polyurethane resin foam contains a polyurethane resin having an Asker D hardness of 20 to 60 degrees and an abrasion parameter, which is expressed by the following equation, of 1 to 3.
Abrasion parameter={1/(Tensile breaking strength [MPa]×Tensile breaking elongation [%]/100)}×100
2 . The polishing pad according to claim 1 , wherein the polyurethane resin foam has a cell number of 200/mm 2 or more and an average cell diameter of 50 μm or less.
3 . The polishing pad according to claim 1 , wherein the polyurethane resin contains, as raw material components, a chain extender and an isocyanate-terminated prepolymer obtained by reacting a prepolymer raw material composition containing a polymerized diisocyanate and an aromatic diisocyanate as isocyanate components, a high molecular weight polyol, and an active hydrogen group-containing low molecular weight compound.
4 . The polishing pad according to claim 3 , wherein a content of the polymerized diisocyanate is 15 to 60% by weight based on the total isocyanate components, and an NCO wt % of the isocyanate-terminated prepolymer is 5 to 8 wt %.
5 . The polishing pad according to claim 3 , wherein the polymerized diisocyanate is a polymerized aliphatic diisocyanate, and the aromatic diisocyanate is toluene diisocyanate.
6 . The polishing pad according to claim 5 , wherein the polymerized aliphatic diisocyanate is a polymerized hexamethylene diisocyanate.
7 . The polishing pad according to claim 1 , wherein the polyurethane resin foam has an Asker D hardness of 10 to 45 degrees.
8 . The polishing pad according to claim 1 , wherein the polyurethane resin foam has a specific gravity of 0.5 to 1.0.
9 . The polishing pad according to claim 1 , wherein the fine cell is made of hollow microspheres.
10 . A method for manufacturing the polishing pad according to claim 1 , comprising a step of producing the polyurethane resin foam by stirring a first component containing an isocyanate-terminated prepolymer, a silicone surfactant, and a tertiary amine catalyst with a non-reactive gas so that the non-reactive gas is dispersed as fine cells to prepare a cell dispersion liquid, then mixing the cell dispersion liquid with a second component containing a chain extender, followed by curing the mixture,
wherein the isocyanate-terminated prepolymer is a prepolymer obtained by reacting a prepolymer raw material composition containing a polymerized diisocyanate and an aromatic diisocyanate as isocyanate components, a high molecular weight polyol, and an active hydrogen group-containing low molecular weight compound, and
a content of the tertiary amine catalyst is 0.1 to 3 parts by weight based on 100 parts by weight of the isocyanate-terminated prepolymer.
11 . A method for manufacturing a semiconductor device, comprising a step of polishing a surface of a semiconductor wafer by using the polishing pad according to claim 1 .