Polishing composition and polishing method

摘要

A polishing composition contains silica abrasive grains and an iodine compound. The silica abrasive grains exhibit a negative zeta potential in the polishing composition. The silica abrasive grains have an average primary particle size of 30 nm or smaller, and the polishing composition has a pH of 4 or lower. The polishing composition is suitable for polishing a polysilicon film and a silicon nitride film.