A method for forming a semiconductor device utilizing a chemical-mechanical polishing (CMP) process is provided. In one example, the method includes sequentially performing a first CMP process for removing a first portion of an oxide surface of a semiconductor device using a high selectivity slurry (HSS) and a first polish pad, interrupting the first CMP process, cleaning the semiconductor device and the first polish pad, and performing a second CMP process for removing a second portion of the oxide surface.