In-situ endpoint detection and process monitoring method and apparatus for chemical-mechanical polishing.

摘要

An in-situ chemical-mechanical polishing process monitor apparatus (50) for monitoring a polishing process during polishing of a workpiece such as a silicon wafer (52) in a polishing machine, the polishing machine having a rotatable polishing table (62) provided with a polishing slurry (61), is disclosed. The apparatus comprises a window (72) embedded within the polishing table, whereby the window traverses a viewing path during polishing and further enables in-situ viewing of a polishing surface (58) 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 (74) is coupled to the window on the underside of the polishing table for measuring a reflectance. To generate 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.