CMP polishing pad with uniform window
AssigneeRohm and Haas Electronic Materials CMP Holdings, Inc.
InventorsMauricio E. Guzman, Nestor A. Vasquez, Matthew R. Gadinski, Michael E. Mills
Life of this patent
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Abstract
A polishing pad useful in chemical mechanical polishing comprising a polishing portion having a top polishing surface and comprising a polishing material an opening through the polishing pad, and a transparent window within the opening in the polishing pad, the transparent window being secured to the polishing pad and being transparent to at least one of magnetic and optical signals, the transparent window having a thickness and a top surface having a plurality of elements separated by interconnected recesses to provide a pattern in the top surface that includes recesses for improved deflection into a cavity in the polishing pad during polishing.
Claims9
A polishing pad useful in chemical mechanical polishing of a semiconductor, optical or magnetic substrate comprising
- a polishing portion having a top polishing surface, a bottom layer for mounting to a platen and a polishing material, the top polishing surface including grooves;
- an opening through the polishing pad, and
- a transparent window within the opening in the polishing pad, the transparent window being flexible and having a thickness measured from a bottom of the transparent window to the top polishing surface of the transparent window and being secured to the polishing pad with the transparent window spaced from the platen to form a cavity and being transparent to at least one of magnetic and optical signals, the transparent window having a plurality of projecting elements at a perimeter of the transparent window and a plurality of projecting elements filling the center of the transparent window, the tops of the plurality of projecting elements representing the top polishing surface of the transparent window, the projecting elements having an initial height of at least thirty percent of the thickness of the transparent window, the projecting elements being coplanar with the top polishing surface separated by interconnected recesses that extend to a peripheral edge of the transparent window to provide a projecting element pattern in the top surface wherein a majority of the recesses have partial or complete misalignment with the grooves in the top polishing surface and the projecting element pattern allows bending about multiple axes with the transparent window bending into the cavity and at least two of the multiple axes are non-parallel, or the projecting element is a center projecting element, the center projecting element surrounded by one or more recesses that bend downward into the cavity with the center projecting element having a width less than half a longest dimension of the transparent window for reducing contact pressure with the substrate during polishing.
Dependencies are inferred from the claim text.