POLISHING AGENT AND POLISHING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a polishing agent and a polishing method, while maintaining a sufficiently high polishing speed to a silicon oxide film, low suppressing the polishing speed to a silicon nitride film and capable of achieving a high selection ratio.SOLUTION: Provided is a polishing agent comprising: cerium oxide particles; water; and specified monocarboxylic acid and/or its salt, and having a pH of 3.5 to 7. The monocarboxylic acid includes levulinic acid, N-acetyl glycin, acetyl glycolate or the like.