Sealed polishing pad, system and methods
A polishing pad, polishing system, method of making a polishing pad and method of using a polishing pad. The polishing pad includes a polishing layer having a polishing surface, a backing layer with an aperture and a first portion that is permeable to liquid, and a sealant that penetrates a second portion of the backing layer adjacent to and surrounding the aperture such that the second portion is substantially impermeable to liquid. The aperture is positioned below a substantially fluid-impermeable element.
1. A polishing pad for use in a chemical mechanical polishing system, the polishing pad comprising:
a polishing layer having a polishing surface;
a backing layer including a first portion that is permeable to liquid;
a window from the polishing surface to a bottom surface of the polishing pad, the window including a transparent portion that is substantially impermeable to liquid secured to the polishing pad and an aperture in the backing layer aligned with the transparent portion and positioned on a side of the transparent portion opposite the polishing surface; and
a sealant that penetrates a second portion of the backing layer adjacent to and surrounding the aperture such that the second portion is substantially impermeable to liquid.
2. The polishing pad of claim 1 , wherein the backing layer comprises a foam.
3. The polishing pad of claim 1 , wherein the sealant comprises silicone.
4. The polishing pad of claim 1 , wherein the polishing layer is generally impermeable to liquid.
5. The polishing pad of claim 1 , wherein a top surface of the transparent portion is coplanar with the polishing surface.
6. The polishing pad of claim 1 , wherein a bottom surface of the transparent portion is coplanar with a lower surface of the polishing layer.
7. The polishing pad of claim 1 , wherein the first portion extends adjacent to an outer peripheral edge of the backing layer.
8. The polishing pad of claim 1 , further comprising a recess formed in the lower surface of the transparent portion.
9. The polishing pad of claim 1 , wherein the backing layer is softer than the polishing layer.
10. The polishing pad of claim 1 , wherein the backing layer comprises a fibrous mat.
11. The polishing pad of claim 1 , wherein the transparent portion is molded to the polishing pad.
12. The polishing pad of claim 1 , wherein the transparent portion is adhesively attached to the polishing pad.