Patent ID: 7651385
Filing Date: 2010-01-26
Classification: B24B,B24D,H01L

Abstract:
1. A polishing system, comprising: a platen; a polishing pad on the platen; a carrier head to hold a surface of a substrate against the polishing pad on the platen; a monitoring module including a light source and a detector; an optical fiber having a proximate end coupled to the monitoring module and a distal end; and an optical head removably mounted in the platen, the optical head holding the distal end of the optical fiber to direct light through a solid window in the polishing pad to the surface of the substrate and receive reflected light from the surface of the substrate, the optical head configured to adjust a distance from the distal end of the fiber to the window, the distal end located as close as possible to a bottom of the window without contacting the window.