Edge-sealed pad for CMP process
AssigneeTexas Instruments Incorporated
InventorYanghua He
Life of this patent
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Abstract
The present invention discloses a polishing pad that can facilitate process stability, extend length of use, and mitigate process non-uniformity and process induced defects for chemical mechanical planarization processes. The polishing pad of the present invention is a composite of a top pad and a sealed sub-pad. The sealed sub-pad has a sealing mechanism that mitigates liquid penetration into the sub-pad thereby maintaining a substantially uniform compressibility of the sub-pad and the polishing pad and extending a useable life of the polishing pad.
Claims12
A polishing pad comprising:
- a top pad having a substantially circular shape, wherein the top pad is comprised of a relatively rigid top polishing surface;
- a sealed sub-pad having a substantially circular shape, wherein a top surface of said sealed sub-pad is affixed to a bottom surface of said top pad;
- and,
- a groove cut into a bottom surface of said sealed sub-pad near an outside edge of said sealed sub-pad wherein said groove is filled with a liquid resistant material that mitigates liquid from entering an inner portion of said sealed sub-pad.
A polishing system for performing chemical mechanical planarization comprising:
- a platen rotatable about a first axis;
- a pad attached to the platen comprising:
- a top pad having a substantially circular shape, wherein the top pad is comprised of a relatively rigid top polishing surface;
- a sealed sub-pad having a substantially circular shape, wherein a top surface of said sealed sub-pad is affixed to a bottom surface of said top pad;
- and
- a groove cut into a bottom surface of said sealed sub-pad near an outside edge of said sealed sub-pad wherein said groove is filled with a liquid resistant material that mitigates liquid from entering an inner portion of said sealed sub-pad;
- a drive mechanism coupled to the platen to impart rotational movement to the platen and the pad in a first direction and at a first velocity;
- a polishing head mounted above the platen and the pad and rotatable about a second axis, wherein the second axis is parallel to the first axis;
- and
- a polishing head displacement mechanism coupled to the polishing head to impart rotational movement to the polishing head in a second direction at a second velocity.
Dependencies are inferred from the claim text.