Method of fabricating a polishing pad with an end-point detection region for eddy current end-point detection
View Patent ↗Methods of fabricating polishing pads with end-point detection regions for polishing semiconductor substrates using eddy current end-point detection are described.
1. A method of fabricating a polishing pad for polishing a semiconductor substrate, the method comprising:
forming, in a first formation mold, a partially cured end-point detection region precursor;
positioning the partially cured end-point detection region precursor on a receiving region of a lid of a second formation mold;
providing a polishing pad precursor mixture in the second formation mold;
moving, by bringing together the lid and a base of the second formation mold, the partially cured end-point detection region precursor into the polishing pad precursor mixture;
heating the polishing pad precursor mixture and the partially cured end-point detection region precursor to provide a molded homogeneous polishing body covalently bonded with a cured end-point detection region precursor, the molded homogeneous polishing body having a polishing surface and a back surface; and
recessing, relative to the back surface of the molded homogeneous polishing body, the cured end-point detection region precursor to provide an end-point detection region disposed in and covalently bonded with the molded homogeneous polishing body.
2. The method of claim 1 , wherein the recessing is performed by routing out a portion of the cured end-point detection region precursor.
3. The method of claim 1 , wherein the partially cured end-point detection region precursor includes a sacrificial layer, and wherein the recessing is performed by removing the sacrificial layer.
4. The method of claim 1 , wherein the end-point detection region comprises a material different from the molded homogeneous polishing body.
5. The method of claim 4 , wherein the end-point detection region is a local area transparency (LAT) region.
6. The method of claim 4 , wherein the end-point detection region is an opaque region having a hardness different from the hardness of the molded homogeneous polishing body.
7. The method of claim 1 , wherein the entire end-point detection region is recessed relative to the back surface of the molded homogeneous polishing body.
8. The method of claim 1 , wherein only an inner portion of the end-point detection region is recessed relative to the back surface of the molded homogeneous polishing body.
9. The method of claim 1 , wherein the molded homogeneous polishing body comprises a thermoset, closed cell polyurethane material.
10. The method of claim 1 , wherein the polishing surface comprises a pattern of grooves disposed in the polishing surface and formed from the lid of the second formation mold.
11. A method of fabricating a polishing pad for polishing a semiconductor substrate, the method comprising:
placing a support structure in a first formation mold;
providing a detection region precursor mixture in the first formation mold, above the support structure;
forming a partially cured end-point detection region precursor by heating the detection region precursor mixture in the first formation mold, the partially cured end-point detection region precursor coupled to the support structure;
positioning the support structure and the partially cured end-point detection region precursor on a recessed receiving region of a lid of a second formation mold by coupling the support structure to the recessed receiving region of the lid;
providing a polishing pad precursor mixture in the second formation mold;
moving, by bringing together the lid and a base of the second formation mold, the partially cured end-point detection region precursor into the polishing pad precursor mixture;
heating the polishing pad precursor mixture and the partially cured end-point detection region precursor to provide a molded homogeneous polishing body covalently bonded with a cured end-point detection region precursor, the molded homogeneous polishing body having a polishing surface and a back surface, and the end-point detection region coupled to the support structure; and
removing the support structure from the end-point detection region.
12. The method of claim 11 , further comprising:
subsequent to the heating, recessing the cured end-point detection region precursor relative to the back surface of the molded homogeneous polishing body to provide an end-point detection region disposed in and covalently bonded with the molded homogeneous polishing body.
13. The method of claim 11 , wherein the support structure comprises a rigid epoxy board.
14. The method of claim 13 , wherein providing the detection region precursor mixture in the first formation mold comprises providing the detection region precursor mixture on a polymer film adhered to the support structure.
15. The method of claim 14 , wherein coupling the support structure to the recessed receiving region of the lid comprises adhering the support structure to the recessed receiving region with a piece of two-sided tape.
16. The method of claim 12 , wherein the recessing is performed by routing out a portion of the cured end-point detection region precursor.
17. The method of claim 12 , wherein the partially cured end-point detection region precursor includes a sacrificial layer, and wherein the recessing is performed by removing the sacrificial layer.
18. The method of claim 11 , wherein the end-point detection region comprises a material different from the molded homogeneous polishing body.
19. The method of claim 18 , wherein the end-point detection region is a local area transparency (LAT) region.
20. The method of claim 18 , wherein the end-point detection region is an opaque region having a hardness different from the hardness of the molded homogeneous polishing body.
21. The method of claim 12 , wherein the entire end-point detection region is recessed relative to the back surface of the molded homogeneous polishing body.
22. The method of claim 12 , wherein only an inner portion of the end-point detection region is recessed relative to the back surface of the molded homogeneous polishing body.
23. The method of claim 11 , wherein the molded homogeneous polishing body comprises a thermoset, closed cell polyurethane material.
24. The method of claim 11 , wherein the polishing surface comprises a pattern of grooves disposed in the polishing surface and formed from the lid of the second formation mold.