Patent ID: 7470171

Claim:
A surface polishing method that polishes the surface of a hard brittle material, such as a glass substrate, an oxide film of a silicon wafer, and a ceramic substrate, wherein: a fixed abrasive grain polishing tool is used, in which fixed abrasive grains are a porous substance of granule type in which many primary grains are partially bonded with each other with spaces among them without having the binder therein, and the surface polishing method comprising the steps of: supplying loose abrasive grain slurry between the fixed abrasive grain polishing tool and a surface to be polished of an object; and dressing top parts of the fixed abrasive grains of the fixed abrasive grain polishing tool which top parts contact the surface to be polished of the object by the supplied loose abrasive grains, wherein the fixed abrasive grains have a compression to failure strength that is 20 MPa to 160 MPa, wherein an average diameter of the fixed abrasive grains is 20 μm to 300 μm, wherein a maximum height of a roughness carved parameter Rz is 10 μm to 120 μm at a polishing surface of the fixed abrasive grain polishing tool, and wherein the abrasive grains in the fixed abrasive grain polishing tool are made of zirconium oxide (ZrO 2 ), and the loose abrasive grains in the loose abrasive grain slurry are made of cerium oxide (CeO 2 ).