Method for monitoring polishing pad used in chemical-mechanical planarization process

摘要

A method for monitoring a condition of a polishing pad used in a chemical-mechanical planarization (CMP) process to polish a semiconductor wafer is disclosed. The method uses a linear multi-dimensional scanning device arranged above the polishing pad in a radial direction to monitor the changes in profile of the surface of the polishing pad, and determines the condition of the polishing pad according to the profile information. When the change in profile of the surface of the polishing pad substantially exceeds a preset value, e.g. 2 mm, it is indicated that the polishing pad should be changed.