Apparatus for in-situ optical endpointing on web-format planarizing machines in mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies

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;
• an optically transmissive backing sheet having a top surface and an under surface, the top surface of the backing sheet adjacent the backside of the planarizing medium, the top surface having at least one ridge extending along a length of the planarizing medium in a direction generally parallel to the pad travel path, the ridge projecting outwardly from the top surface and extending from backside of the planarizing medium to the planarizing surface through a slot, the slot defining an optical transmission path.

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;
• an optically transmissive backing sheet having a top surface and an under surface, the top surface of the backing sheet adjacent the backside of the planarizing medium, the top surface having at least one ridge extending along the entire planarizing zone of the planarizing medium in a direction generally parallel to the pad travel path, the ridge extending into a slot defined by the planarizing medium and defining an optical transmission path.

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, the planarizing medium having an opening that extends from the backside of the planarizing medium to the planarizing surface, the opening having a first dimension along the pad travel path that is substantially greater than a second dimension perpendicular to the pad travel path;
• and
• an optically transmissive backing sheet having a top surface and an under surface, the top surface of the backing sheet adjacent the backside of the planarizing medium the top surface having a ridge extending along a portion of a length of the planarizing medium in a direction generally parallel to the pad travel path, the ridge extending into the opening defined by the planarizing medium.