Customized polishing pads for CMP and methods of fabrication and use thereof
View Patent ↗The present application relates to polishing pads for chemical mechanical planarization (CMP) of substrates, and methods of fabrication and use thereof. The pads described in this invention are customized to polishing specifications where specifications include (but not limited to) to the material being polished, chip design and architecture, chip density and pattern density, equipment platform and type of slurry used. These pads can be designed with a specialized polymeric nano-structure with a long or short range order which allows for molecular level tuning achieving superior thermo-mechanical characteristics. More particularly, the pads can be designed and fabricated so that there is both uniform and nonuniform spatial distribution of chemical and physical properties within the pads. In addition, these pads can be designed to tune the coefficient of friction by surface engineering, through the addition of solid lubricants, and creating low shear integral pads having multiple layers of polymeric material which form an interface parallel to the polishing surface. The pads can also have controlled porosity, embedded abrasive, novel grooves on the polishing surface, for slurry transport, which are produced in situ, and a transparent region for endpoint detection.
1. An article comprising a unitary chemical mechanical polishing pad formed of a thermosetting polymer, wherein said pad contains hard polymeric domains and soft polymeric domains in a polishing surface of said pad, wherein said polymer contains hard segments and soft segments, the hard segments forming the hard polymeric domains and the soft segments forming said soft polymeric domains upon curing, wherein said polymer comprises poly(urethaneurea), wherein said pad contains a boundary at the polishing surface between first and second regions of the polishing surface, wherein said first and second regions of the polishing surface are first and second polymeric regions, the first and second regions each including both said hard and said soft domains, and wherein said first region has a porosity property for pores consisting of hollow microelements, the porosity property having a value different from a value for said porosity property in said second region, the porosity property selected from the group consisting of pore size and pore distribution.
2. An article according to claim 1 wherein said hard domains have a size of less than about 20 nm.
3. An article according to claim 1 or claim 2 wherein said soft domains have a size of less than about 100 nm.
4. An article according to claim 3 wherein said soft domains have a size greater than 10 nm.
5. An article according to claim 4 wherein said soft domains are larger than said hard domains.
6. An article according to claim 1 wherein said hard domains have a total of between one and about twenty urethane and urea groups.
7. An article according to claim 6 wherein said hard domains have a total of between two and about six urethane and urea groups.
8. An article according to claim 1 wherein said pad is a unitary chemical mechanical polishing pad formed by placing a polymer melt or mixture of reactants that form a polymer or both in a mold having dimensions suitable to form said unitary chemical mechanical polishing pad.
9. An article according to claim 1 wherein said pad contains a solid lubricant.
10. An article according to claim 1 wherein said pad contains an abrasive.
11. An article comprising a chemical mechanical polishing pad formed of a thermosetting polymer, wherein said pad contains hard polymeric domains and soft polymeric domains in a polishing surface of said pad, wherein said polymer contains hard segments and soft segments, the hard segments forming the hard polymeric domains and the soft segments forming said soft polymeric domains upon curing, wherein said polymer comprises poly(urethaneurea) containing repeating alkoxy units, wherein said pad contains a boundary at the polishing surface between first and second regions of the polishing surface, wherein said first and second regions of said polishing surface are first and second polymeric regions, the first and second regions each including both said hard and said soft domains, and wherein said first region has a porosity property for pores consisting of hollow microelements, the porosity property having a value different from a value for said porosity property in said second region, the porosity property selected from the group consisting of pore size and pore distribution.
12. An article according to claim 11 wherein said hard domains have a width of less than about 100 nm in any direction.
13. An article according to claim 12 wherein said hard domains have a width of less than about 20 nm.
14. An article according to any of claims 11 - 13 wherein said soft domains are larger than about 100 nm.
15. An article according to claim 11 wherein said hard domains have a total of between one and about twenty urethane and urea groups.
16. An article according to claim 15 wherein said hard domains have a total of between two and about six urethane and urea groups.
17. An article according to claim 11 wherein said pad is a unitary chemical mechanical polishing pad formed by placing a polymer melt or mixture of reactants that form a polymer or both in a mold having dimensions suitable to form said unitary chemical mechanical polishing pad.
18. An article according to claim 11 wherein said pad contains a solid lubricant.
19. An article according to claim 11 wherein said pad contains an abrasive.
20. An article according to claim 8 , wherein the mold is patterned with a complimentary groove design.
21. An article according to claim 17 , wherein the mold is patterned with a complimentary groove design.
22. An article according to claim 1 wherein said boundary is a discrete boundary.
23. An article according to claim 1 wherein said boundary is formed from a mixture of constituent polymers.
24. An article according to claim 11 wherein said boundary is a discrete boundary.
25. An article according to claim 11 wherein said boundary is formed from a mixture of constituent polymers.