Abstract: A polishing composition contains a polishing accelerator, a water-soluble polymer including a constitutional unit originating from a polymerizable compound having a guanidine structure such as dicyandiamide, and an oxidant. The water-soluble polymer may be a water-soluble polymer including a constitutional unit originating from dicyandiamide and a constitutional unit originating from formaldehyde, a diamine or a polyamine.

Abstract: The present invention provides a polishing composition that can be suitably used in polishing of polysilicon, and a polishing method using the polishing composition. The polishing composition contains a nitrogen-containing nonionic surfactant and abrasive grains and has a pH of 9 to 12. The content of the nitrogen-containing nonionic surfactant in the polishing composition is preferably 20 to 500 ppm. The abrasive grains contained in the polishing composition are preferably colloidal silica. The average primary particle diameter of the abrasive grains contained in the polishing composition is preferably 10 to 90 nm. The content of the abrasive grains in the polishing composition is preferably 1.0 to 5.0% by mass.

Abstract: The present invention provides a polishing composition that can be suitably used in polishing of polysilicon, and a polishing method using the polishing composition. The polishing composition contains abrasive grains and an anionic surfactant having a monooxyethylene group or a polyoxyethylene group and has a pH of 9 to 12. If the anionic surfactant contained in the polishing composition has a polyoxyethylene group, the number of repeating oxyethylene units in the polyoxyethylene group is preferably 2 to 8. The anionic surfactant contained in the polishing composition can be an anionic surfactant that has a phosphate group, a carboxy group, or a sulfo group as well as a monooxyethylene group or a polyoxyethylene group. The content of the anionic surfactant in the polishing composition is preferably 20 to 500 ppm.