Polishing pad window for a chemical-mechanical polishing tool

Abstract

A polishing pad assembly for use in a chemical-mechanical polishing apparatus comprises a polishing pad having at least a first aperture therethrough and a platen for supporting the polishing pad having a second aperture therethrough at least a portion of which is larger than the first aperture. A substantially transparent plug includes at least a first section having a first dimension for positioning substantially within the first aperture and at least a second section having a second dimension larger than the first dimension for positioning substantially within the second aperture. The optical plug is made of a polymeric material which may be press-fit through the platen into polishing pad.

Dependencies are inferred from the claim text.