摘要 |
A planarizing pad having a leak resistant optical system to provide an optical path through the pad and to inhibit or prevent planarizing solution from leaking through the pad. In one embodiment of a planarizing machine, the machine includes a table having a support surface and an optical monitoring system coupled to the table. The optical monitoring system can have a light source and an optical sensor aligned with an opening in the table to direct and detect a light beam through the opening. The planarizing machine can further include a planarizing pad coupled to the support surface of the table. The planarizing pad comprises a planarizing medium, an optically transmissive window in the planarizing medium, and a backing member attached to the planarizing medium. The planarizing medium can have a planarizing surface, a backside opposite the planarizing surface, and at least one hole extending from the planarizing surface to the backside. The backing member has a top surface attached to the backside of the planarizing medium and an exposed section extending from the sidewall to either (a) span completely across the hole or (b) project across a portion of the hole for a cover distance that is measured normal to the sidewall. The optically transmissive window is positioned in the hole, and it has an interface surface the exposed section along a seal path that either spans completely across the hole or has a length greater than the cover distance.
|