Semiconductor fabrication processes

摘要

A method of using polish stop film to control dishing during copper chemical mechanical polishing. In one embodiment, the method comprises several steps. One step involves depositing a polish stop layer above a metal layer disposed on a semiconductor wafer. Another step involves placing the semiconductor wafer onto a polishing pad of a chemical mechanical polishing machine. A further step involves removing the metal layer of the semiconductor wafer and also preferentially removing the polish stop layer using a chemical mechanical polishing process. The benefit of the polish stop layer is to prevent dishing of the metal layer within the trench. Another step involves ceasing the chemical mechanical polishing process when the metal layer is removed from desired areas of the semiconductor wafer and the semiconductor wafer is substantially planar.