Tunable Polish Rates By Varying Dissolved Oxygen Content

Abstract

A system for tunable removal rates and selectivity of materials during chemical-mechanical polishing using a chemical slurry or solution with increased dissolved oxygen content. The slurry can optionally include additives to improve removal rate and/or selectivity. Further selectivity can be obtained by varying the concentration and type of abrasives in the slurry, using lower operating pressure, using different pads, or using other additives in the dispersion at specific pH values.

What is claimed is: 
     
         1 . A system for selectively removing a target material on a surface of a substrate, the system comprising:
 a substrate comprising a target material and a non-target material;   a polishing solution having a pH of from about 1 to about 13, wherein the polishing solution comprises a plurality of functionalized abrasive particles;   a polishing solution chamber comprising an oxygen inlet and at least a portion of said polishing solution, wherein oxygen is applied to said polishing solution until the concentration of oxygen dissolved in said polishing solution is at or between approximately 8.6 mg/L and approximately 16.6 mg/L; and   a polishing pad configured to contact the surface of said substrate in the presence of at least a portion of said polishing solution;   wherein said polishing pad selectively removes a predetermined thickness of the target material, and further wherein varying the dissolved oxygen content of the polishing solution varies the removal ratio of target material to non-target material during the removal step.   
     
     
         2 . The system of  claim 1 , wherein the plurality of abrasive particles comprise silica. 
     
     
         3 . The system of  claim 1 , wherein at least some of the plurality of abrasive silica particles are functionalized with n-(trimethoxysilylpropyl)isothiouronium chloride. 
     
     
         4 . The system of  claim 1 , wherein the plurality of abrasive particles comprise a compound selected from the group consisting of ceria, zirconia, titania, alumina, germania, chromium dioxide, manganese di dioxide, and combinations thereof. 
     
     
         5 . The system of  claim 1 , wherein said polishing solution further comprises an additive. 
     
     
         6 . The system of  claim 5 , wherein said additive is selected from the group consisting of amines, amino acids, and combinations thereof. 
     
     
         7 . The system of  claim 1 , wherein said applied oxygen is substantially pure oxygen. 
     
     
         8 . The system of  claim 1 , further comprising an oxygen sensor.