Selective chemical-mechanical polishing properties of a cross-linked polymer and specific applications therefor
View Patent ↗The present invention is directed, in general, to a method of polishing a surface on substrates, such as semiconductor wafers and, more specifically, to a polishing pad suitable for this purpose. The polishing pad comprises a polishing body that includes a cross-linked polymer material, and may be incorporated into a polishing apparatus. Polishing includes positioning the substrate containing at least one layer against the polishing body and polishing the layer.
1. A polishing pad comprising:
a polishing body comprising a cross-linked polymer having a hardness ranging from about 34 Shore A to about 60 Shore A and said cross-linked polymer has a selectivity of Cu to Ta removal rates of greater than about 27:1.
2. The polishing pad as recited in claim 1 wherein said cross-linked polymer is a thermoplastic foam.
3. The polishing pad as recited in claim 1 wherein said cross-linked polymer has a closed cell structure.
4. The polishing pad as recited in claim 3 wherein said cross-linked polymer is polyethylene.
5. The polishing pad as recited in claim 1 wherein said polishing body includes a base pad and said cross-linked polymer forms a polishing surface located over said base pad.
6. The polishing pad as recited in claim 1 wherein said cross-linked polymer is a polyethylene having a closed cell structure.
7. The polishing pad as recited in claim 1 wherein said hardness is about 34 Shore A.