Metal-polishing composition and chemical mechanical polishing method by using the same

A chemical mechanical polishing method of polishing a material to be polished of a semiconductor device with a polishing pad on a polishing surface plate, by contacting and relatively moving the polishing pad and the material to be polished while supplying a metal-polishing composition to the polishing pad,

• the metal-polishing composition comprising (a) a compound represented by the following Formula A, (b) a compound represented by the following Formula B, (c) an abrasive grain, and (d) an oxidizing agent:
• in Formula A, R1 represents an alkyl group having 1 to 3 carbon atoms;
• and R2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and in Formula B, R3, R4, and R5 each independently represent a hydrogen atom, or an alkyl, aryl, alkoxy, amino, aminoalkyl, hydroxy, hydroxyalkyl, carboxy, carboxyalkyl or carbamoyl group.