SENSORS IN CARRIER HEAD OF A CMP SYSTEM

摘要

Sensors can be located in a carrier head for a chemical mechanical polishing system. In some implementations the carrier head includes a flexible membrane, and a thermocouple is positioned on the lower surface of the flexible membrane or embedded in the flexible membrane adjacent the lower surface. In some implementations, the carrier head optical sensor is secured to the head and positioned to sense a reflectivity of a spot on a back surface of a substrate held in the carrier head, and a controller is configured to receive a signal from the optical sensor and determine precession of the substrate based on the signal.