Patent ID: 7699901

Claim:
An alumina-film-polishing composition for use in chemical mechanical polishing of an object to be polished, the object including an alumina film with an irregular surface, for planarizing the irregular surface, the composition containing: an alumina abrasive grain; and a protection-film-forming agent for forming a protection film on the surface of each of the alumina film and the alumina abrasive grain, the protection-film-forming agent being polyethylene glycol dimethyl ether that has a weight average molecular weight within a range of 200 to 300 and that is obtained by polymerizing a monomer having at least one OH group or COOH group in its molecule, wherein the alumina abrasive grain content is within a range of 0.1 to 30 wt %, and the polyethylene glycol dimethyl ether content is 0.050 to 0.1 wt %.