Forming a transparent window in a polishing pad for a chemical mechanical polishing apparatus

摘要

The disclosure relates to a polishing pad for a chemical mechanical polishing apparatus, and a method for making the same. The polishing pad (18) has a covering layer (22) with a polishing surface (23) and a backing layer (20) which is adjacent to the platen (16). A first opening (630) in the covering layer with a first cross-sectional area and a second opening (632) in the backing layer with a second, different cross-sectional area form an aperture through the polishing pad. A substantially transparent polyurethane plug (600) is positioned in the aperture, and an adhesive material fixes the plug in the aperture.