Polishing pad with two-section window having recess

摘要

A method of forming a polishing pad with a polishing layer having a polishing surface and a back surface. A plurality of grooves are formed on the polishing surface, and an indentation is formed in the back surface of the polishing layer. A region on the polishing surface corresponding to the indentation in the back surface is free of grooves or has shallower grooves.

主权项

1. A polishing pad, comprising:
a polishing article having a polishing surface and a bottom surface, an aperture formed through the polishing article from the polishing surface to the bottom surface, the aperture having a first portion adjacent the polishing surface with a first cross-sectional width and a second portion adjacent the bottom surface with a second cross-sectional width greater than the first cross-sectional width such that a projecting section of the polishing article extends over the second portion of the aperture; and a transparent body secured in the aperture, the transparent body including a first section positioned in the first portion of the aperture and a second section positioned in the second portion of the aperture, an upper surface of the second section adhesively secured to a lower surface of the projecting section, the transparent body including a recess formed in an underside of the second section, the recess having a cross-sectional width less than the first cross-sectional width of the first portion of the aperture, the recess extending upwardly from the underside of the second section past the upper surface of the second section and into the first section, the transparent body configured such that a top surface of the first section is held substantially fixed relative to the polishing surface.