Abstract: A polishing composition of the present invention is to be used for polishing an object including a portion containing a high-mobility material and a portion containing a silicon material. The polishing composition comprises an oxidizing agent and abrasive grains having an average primary particle diameter of 40 nm or less. The polishing composition preferably further contains a hydrolysis-suppressing compound that bonds to a surface OH group of the portion containing a silicon material of the object to function to suppress hydrolysis of the portion containing a silicon material. Alternatively, a polishing composition of the present invention contains abrasive grains, an oxidizing agent, and a hydrolysis-suppressing compound. The polishing composition preferably has a neutral pH.

Abstract: A polishing composition contains a deterioration inhibitor for inhibiting deterioration of polishing capability of the polishing composition, an abrasive, and water. The deterioration inhibitor is at least one selected from polysaccharide and polyvinyl alcohol. The polysaccharide is starch, amylopectin, glycogen, cellulose, pectin, hemicellulose, pullulan, or elsinan. Among them, pullulan is preferable. The abrasive is at least one selected from aluminum oxide and silicon dioxide, preferably at least one selected from fumed silica, fumed alumina, and colloidal silica. The polishing composition can be suitably used in polishing for forming wiring a semiconductor device.