Method and apparatus for in-situ monitoring of chemical mechanical planarization (CMP) process

A method and apparatus for in situ monitoring of a chemical mechanical planarization (CMP) process are disclosed. In one aspect, a CMP system includes a carrier configured to hold a substrate, a platen supporting a polishing pad, an optical detector positioned on an opposite side of the polishing pad from the substrate and configured to generate a first signal, one or more positioning encoders configured to generate a second signal, and a controller. The controller is configured to receive the first signal and the second signal, identify one or more measurement sites on the substrate based on the second signal, select one or more of the measurement sites for repeated measurements based on the first signal, and determine one or more measurement sites on the substrate based on the selected one or more measurement sites. And determining a removal rate and/or thickness of a film of the substrate at one or more of the selected measurement sites based on the first signal and the second signal. 公开了一种用于化学机械平坦化CMP工艺的原