Polishing pad with foundation layer and window attached thereto
View Patent ↗Polishing pads having a foundation layer and a window attached to the foundation layer, and methods of fabricating such polishing pads, are described. In an example, a polishing pad for polishing a substrate includes a foundation layer having a first modulus. A polishing layer is attached to the foundation layer and has a second modulus less than the first modulus. A first opening is through the polishing layer and a second opening is through the foundation layer. The first opening exposes at least a portion of the second opening and exposes a portion of the foundation layer. A window is disposed in the first opening and is attached to the exposed portion of the foundation layer.
1. A polishing pad for polishing a substrate, the polishing pad comprising:
a foundation layer having a first modulus;
a polishing layer attached to the foundation layer and having a second modulus less than the first modulus;
a first opening through the polishing layer and a second opening through the foundation layer, the first opening exposing at least a portion of the second opening and exposing a portion of the foundation layer; and
a window disposed in the first opening and attached to the exposed portion of the foundation layer, wherein the window has a portion extending into the second opening, and wherein the window is attached to the exposed portion of the foundation layer by a snap-fit arrangement.
2. The polishing pad of claim 1 , wherein the first opening exposes the entire second opening.
3. The polishing pad or claim 1 , wherein the window is attached to the exposed portion of the foundation layer by an adhesive layer selected from the group consisting of a pressure sensitive adhesive (PSA) layer, a two-component epoxy layer, a UV-cured resin layer, a silicone-based adhesive layer, a transfer tape layer, and a hot melt layer.
4. The polishing pad of claim 3 , wherein the adhesive layer is a non-differential two-sided tape PSA layer.
5. The polishing pad of claim 3 , wherein the adhesive layer is a first two-sided tape PSA layer, and wherein the polishing layer is attached to the foundation layer using a second two-sided tape PSA layer having a thickness approximately the same as a thickness of the first two-sided tape PSA layer attaching the window to the foundation layer.
6. The polishing pad of claim 3 , wherein the adhesive layer is a differential two-sided tape PSA layer.
7. The polishing pad or claim 1 , wherein the window is attached to the exposed portion of the foundation layer by a welded region.
8. The polishing pad of claim 7 , wherein the welded region is a region selected from the group consisting of a spot weld region, a line weld region, and a multi-line weld region.
9. The polishing pad of claim 1 , further comprising:
a sub pad attached to the foundation layer on a side of the foundation layer opposite the polishing layer; and
a third opening through the sub pad, the third opening substantially sized and aligned with the second opening.
10. The polishing pad of claim 1 , wherein, from a plan view perspective of the polishing layer, the window has substantially a same shape as the first opening.
11. The polishing pad of claim 10 , wherein the shape is selected from the group consisting of a circle, an oval, a square, a rectangle, and a rectangle having rounded corners.
12. The polishing pad of claim 10 , wherein a perimeter of the window is reduced in size at all portions of the perimeter by an amount approximately in the range of 5-15 mils relative to a perimeter of the first opening.
13. The polishing pad of claim 1 , wherein, with respect to the foundation layer, the window has an uppermost surface lower than an uppermost surface of the polishing layer.
14. The polishing pad of claim 1 , wherein, from a plan view perspective of the polishing layer, the first opening has substantially a same shape as the second opening, and wherein a perimeter of the second opening is reduced in size at all portions of the perimeter by an amount approximately in the range of 10-500 mils relative to a perimeter of the first opening.
15. The polishing pad of claim 14 , wherein the perimeter of the second opening is reduced in size at all portions of the perimeter by an amount approximately in the range of 100-300 mils relative to the perimeter of the first opening.
16. The polishing pad of claim 1 , wherein the polishing layer is attached to the foundation layer by an adhesive layer.
17. The polishing pad of claim 1 , wherein the polishing layer is attached to the foundation layer through covalent bonding of the polishing layer to the foundation layer.
18. The polishing pad of claim 1 , wherein the window comprises a material selected from the group consisting of a polyethylene terephthalate material, a polyurethane material, a cyclic olefin copolymer material, a polycarbonate material, a polyester material, a polypropylene material, and a polyethylene material.
19. The polishing pad of claim 1 , wherein the window comprises a material transparent to a broad spectrum irradiation approximately in the range of 300-800 nanometers.
20. The polishing pad of claim 1 , wherein the foundation layer has an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C.
21. The polishing pad of claim 1 , wherein the foundation layer comprises a material selected from the group consisting of a polycarbonate material, an epoxy board material, a polyurethane material, a composite fiber board, a polymethylmethacrylate (PMMA) material, and a cyclic olefin copolymer material.
22. The polishing pad of claim 1 , wherein the polishing layer has an energy loss factor of greater than approximately 1000 KEL at 1/Pa at 40° C.
23. The polishing pad of claim 1 , wherein a combination of the foundation layer and the polishing layer has an energy loss factor of less than approximately 1000 KEL at 1/Pa at 40° C.
24. The polishing pad of claim 1 , wherein the polishing layer comprises a thermoset polyurethane material, the foundation layer comprises a polycarbonate layer, and the window comprises a polyethylene terephthalate material.
25. The polishing pad of claim 1 , wherein the polishing layer has an elastic storage modulus (E′) at 40 degrees Celsius approximately in the range of 50 MPa-100 MPa, and wherein the foundation layer has an elastic storage modulus (E′) at 40 degrees Celsius approximately in the range of 1500 MPa-3000 MPa.
26. The polishing pad of claim 1 , wherein the foundation layer has a hardness approximately in the range of 70-90 Shore D, and the polishing layer has a hardness approximately in the range of 20-65 Shore D.
27. The polishing pad of claim 1 , wherein the polishing layer has grooves disposed therein, the grooves formed to a depth of approximately 10%-60% of a total thickness of the polishing layer.
28. The polishing pad of claim 27 , wherein the grooves are formed to a depth of approximately half of the total thickness of the polishing layer.