| abstract |
An in-situ chemical-mechanical polishing process monitor apparatus for monitoring a polishing process during polishing of a workpiece in a polishing machine, the polishing machine having a rotatable polishing table provided with a polishing slurry, is disclosed. The apparatus comprises a window embedded within the polishing table, whereby the window traverses a viewing path during polishing and further enables in-situ viewing of a polishing surface of the workpiece from an underside of the polishing table during polishing as the window traverses a detection region along the viewing path. A reflectance measurement means is coupled to the window on the underside of the polishing table for measuring a reflectance, the reflectance measurement means providing a reflectance signal representative of an in-situ reflectance, wherein a prescribed change in the in-situ reflectance corresponds to a prescribed condition of the polishing process. |