Patent ID: 6932672

Claim:
A polishing pad for mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies on a stationary table having a first dimension extending along a pad travel path and an illumination site from which a light beam can emanate from the table, the pad comprising: a planarizing medium having a planarizing surface configured to engage a substrate assembly and a backside to face towards the table, the planarizing medium being moveable over the table along the pad travel path to place a fresh portion of the planarizing surface at one side of a planarizing zone on the table and to remove a worn portion of the planarizing surface from an opposite side of the planarizing zone; and an optical pass-through system in the planarizing medium, the optical pass-through system having a plurality of view sites extending along a length of the planarizing medium in a direction generally parallel to the pad travel path, each view site providing an optically transmissive path through the pad.