Patent ID: 6146242
Filing Date: 2000-11-14
Classification: B24B,B24D

Abstract:
A system for planarizing the surface of a workpiece, wherein said system comprises a planarizing device including process chamber which houses a rotating platen with a polishing pad disposed on the platen surface, a polishing head for holding the workpiece over the polishing pad, a platen drive spindle which rotates the platen about its center, said device further comprising:a recess in the platen located radially displaced from the center of the platen, said recess having a bottom surface within the platen;an aperture in the polishing pad, said aperture overlying the recess in the platenan optical viewport assembly housed within the recess in the platen, said optical viewport assembly comprising a support member, a window casing, a window pane, and an optical fiber array, said support member resting on the bottom surface of the recess and supporting the optical fiber array, said window casing is disposed over the optical fiber array and is provided with an aperture disposed over the fiber array, said window casing being supported relative to the platen with at least one set screw which can be adjusted to raise and lower the window casing relative to the platen, at least one fastener for locking the window casing in place relative to the platen; andan optical fiber bundle communicating from the optical fiber array, radially inward toward the center of the platen, and then through the platen drive spool to an optical coupling.