Die level chemical mechanical polishing

Abstract

A method of polishing a wafer at the die level with a targeted slurry delivery system. The wafer is placed on a wafer carrier exposing the top side of the wafer, the wafer contains a die. The polishing apparatus will polish a portion of the die using a pad that is smaller than the die and the pad is located above the die. A slurry is applied to a portion of the die being polished. Embodiments of the invention provide multiple pads working on the same die.

What is claimed is: 
     
         1 . An apparatus comprising:
 a wafer carrier that is configured to harness a back side of a wafer such that a front side of the wafer is exposed;   a pad, a pad carrier, and a polishing carrier, wherein the pad having a lower surface above the wafer carrier, the pad carrier located above the pad and connected to the pad, and the polishing carrier located above the pad carrier and connected to the pad carrier; and   a slurry delivery system, wherein the slurry delivery system is located above the wafer carrier and the slurry delivery system is movable relative to the wafer carrier.   
     
     
         2 . The apparatus of  claim 1 , wherein the pad is capable of lateral movement relative to the wafer carrier. 
     
     
         3 . The apparatus of  claim 1 , wherein the pad is capable of rotational movement relative to the wafer carrier. 
     
     
         4 . The apparatus of  claim 1 , wherein the pad is capable of changing a pressure relative to the pad carrier. 
     
     
         5 . The apparatus of  claim 1 , wherein the pad is capable of changing a height relative to the pad carrier. 
     
     
         6 . The apparatus of  claim 1 , further comprising:
 multiple pads located at different locations on the polishing carrier.   
     
     
         7 . The apparatus of  claim 1 , further comprising:
 multiple slurry delivery systems capable of lateral movement relative to the wafer carrier.   
     
     
         8 . The apparatus of  claim 1 , further comprising:
 multiple slurry delivery systems capable of rotational movement relative to the wafer carrier.   
     
     
         9 . The apparatus of  claim 1 , wherein the pad consists of a compressible polyurethane foam. 
     
     
         10 . The apparatus of  claim 1 , further comprising a pad head containing the pad and pad carrier, wherein the pad head is coupled to a bottom surface of the polishing carrier. 
     
     
         11 . The apparatus of  claim 10 , wherein the pad head is capable of movement relative to the polishing carrier. 
     
     
         12 . The apparatus of  claim 10 , wherein the pad head is fixed to the polishing carrier. 
     
     
         13 . The apparatus of  claim 10 , wherein the pad head and the slurry delivery system are both coupled to a bottom surface of the polishing carrier. 
     
     
         14 . The apparatus of  claim 1 , wherein the slurry delivery system moves in a lateral direction relative to the polishing carrier. 
     
     
         15 . The apparatus of  claim 1 , wherein the slurry delivery system moves in a vertical direction relative to the polishing carrier. 
     
     
         16 . The apparatus of  claim 1 , wherein the slurry delivery system delivers a slurry to a targeted region of a die positioned in the wafer carrier. 
     
     
         17 . The apparatus of  claim 16 , wherein the slurry is delivered as droplets or a spray.