Abstract: A method of removing the micro-scratches on a metal layer is described, wherein the metal layer is formed on a barrier layer conformally onto a dielectric layer having a hole thereon, and wherein the metal layer over-fills the hole. The method comprises three chemical-mechanical polishing steps as described hereinbelow. The first chemical-mechanical polishing step is that oxidizing and polishing away the metal layer outside the hole, with a first slurry, wherein the first slurry has a chemical solution and has a plurality of abrasive particles. The second chemical-mechanical polishing step is that polishing away the barrier layer outside the hole, with a second slurry, whereby a plurality of micro-scratches are formed on the metal layer after the barrier layer is chemical-mechanically polished. The third chemical-mechanical polishing step is that buffing the metal layer, with the first slurry, thereby removing the micro-scratches on the metal layer.