Abstract: A polishing tool and methodology are disclosed, particularly useful for chemical mechanical polish (CMP) applications (e.g., polishing and planarizing). In an embodiment, the tool includes a carrier structure configured to support a workpiece, a polishing pad configured to rotate and polish at least a portion of the workpiece, a source configured to generate excitation radiation directed towards the workpiece, and a detector configured to receive fluorescence radiation from the workpiece. The fluorescence radiation is generated by absorption of the excitation radiation by a polymer material on the workpiece. The polishing tool also includes a controller configured to, based on a magnitude of the received fluorescence radiation, change at least one operating condition of the polishing tool. For instance, the controller can speed or slow the polishing process, and stop the polishing process when a target thickness is achieved.