Method of fabricating a polishing
View Patent ↗Polishing pads with apertures are described. Methods of fabricating polishing pads with apertures are also described.
1. A method of fabricating a polishing pad for polishing a substrate, the method comprising:
mixing a set of polymerizable materials to form a mixture in a base of a formation mold;
moving a lid of the formation mold into the mixture, the lid having disposed thereon a pattern of protrusions and an aperture protrusion with a height greater than the pattern of protrusions; and, with the lid placed in the mixture,
at least partially curing the mixture to form a molded homogeneous polishing body comprising a back surface and a polishing surface having disposed therein a pattern of grooves and an opening defining an aperture region.
2. The method of claim 1 , wherein forming the molded homogeneous polishing body comprises forming an aperture disposed in the molded homogeneous polishing body from the back surface through to the polishing surface at the aperture region.
3. The method of claim 1 , further comprising:
removing a portion of the homogeneous polishing body from the back surface to form a polishing pad having a second back surface and to form an aperture disposed in the molded homogeneous polishing body from the second back surface through to the polishing surface at the aperture region.
4. The method of claim 1 , wherein forming the molded homogeneous polishing body comprises forming the aperture region to comprise a sidewall having a ramp feature with a slope to provide a narrowest region of the aperture region proximate to the back surface of the molded homogeneous polishing body and a widest region of the aperture region at the polishing surface of the molded homogeneous polishing body.
5. The method of claim 1 , wherein forming the molded homogeneous polishing body comprises forming the polishing surface to comprise a first groove of the pattern of grooves that is a circumferential groove continuous with the aperture region at a first sidewall of the aperture region but discontinuous with a second sidewall of the aperture region, and a second groove of the pattern of grooves that is continuous with the aperture region at the second sidewall.
6. The method of claim 1 , wherein forming the molded homogeneous polishing body comprises forming the polishing surface to comprise a first groove of the pattern of grooves that is a first radial groove continuous with the aperture region at a first sidewall of the aperture region, and a second groove of the plurality of grooves that is a second radial groove continuous with the aperture region at a second sidewall of the aperture region, wherein the first sidewall is opposite the second sidewall.
7. The method of claim 1 , wherein forming the molded homogeneous polishing body comprises forming a thermoset polyurethane material.
8. The method of claim 1 , wherein the mixing further comprises adding a porogen material to the set of polymerizable materials to form a plurality of closed cell pores in the molded homogeneous polishing body, each closed cell pore having a physical shell.
9. The method of claim 1 , wherein the mixing further comprises injecting a gas into the set of polymerizable materials, or into a product formed there from, to form a plurality of closed cell pores in the molded homogeneous polishing body, each closed cell pore having no physical shell.
10. The method of claim 1 , wherein mixing the set of polymerizable materials comprises mixing an isocyanate and an aromatic diamine compound.
11. The method of claim 1 , wherein the mixing further comprises adding an opacifying particle filler to the set of polymerizable materials to form an opaque molded homogeneous polishing body.
12. The method of claim 1 , wherein curing the mixture comprises first partially curing in the formation mold and then further curing in an oven.