Abstract: The present invention provides a chemical mechanical polishing pad comprising a window formed in the polishing pad, the window having a void provided on a side thereof. The polishing pad further comprises a void-pressure relief channel provided in the polishing pad from the void to a periphery of the polishing pad.

Abstract: A method of forming a layered polishing pad is disclosed. The method includes double-laminating a subpad on opposing sides with respective adhesive layers and bonding a polishing pad top layer to the subpad via the upper adhesive layer. The polishing pad optionally includes a window. Because the subpad is double-laminated, an opening can be formed through both the top and bottom adhesive layers as well as the subpad. Thus, when bonded to a top polishing pad layer having a window, the result is a layered polishing pad with a through optical path that does not include an adhesive layer.

Abstract: The present invention provides a chemical mechanical polishing pad having reduced stress windows. In addition, the present invention provides a method of forming a chemical mechanical polishing pad, the method comprising, primary annealing a window separate from a polishing pad material and providing the polishing pad material in a periphery of the primary annealed window before a predetermined quench temperature of the primary annealed window. The method further comprises secondary annealing the window and the polishing pad material together and cutting the secondary annealed window and the polishing pad material to a predetermined thickness.