Apparatus and method for providing a signal port in a polishing pad for optical endpoint detection

• Main Authors: LACY MICHAEL S, BOYD JOHN M
• Format: Patent
• Language: English
• Published: 11.10.2005
• Edition: 7
• Subjects: DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS; GRINDING; MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; PERFORMING OPERATIONS; POLISHING; TOOLS FOR GRINDING, BUFFING, OR SHARPENING; TRANSPORTING

A method and apparatus for providing a substantially constant environment in the cavity surrounding the optical pathway during the chemical mechanical planarization (CMP) operation is provided. In one embodiment, a system for planarizing the surface of a substrate is provided. The system includes a platen configured to rotate about its center axis. The platen supports an optical view-port assembly for assisting in determining a thickness of a layer of the substrate. A polishing pad disposed over the platen is included. The polishing pad has an aperture overlying a window of the optical view-port assembly. A carrier for holding the substrate over the polishing pad is also included. A cavity defined between the surface of the substrate and the window is included. A fluid delivery system adapted to provide a stable environment in the cavity during a chemical mechanical planarization (CMP) operation is included.