Polishing compositions containing charged abrasive

Abstract

Polishing compositions that can selectively and preferentially polish certain dielectric films over other dielectric films are provided herein. These polishing compositions include either cationic or anionic abrasives based on the target dielectric film to be removed and preserved. The polishing compositions utilize a novel electrostatic charge based design, where based on the charge of the abrasives and their electrostatic interaction (forces of attraction or repulsion) with the charge on the dielectric film, various material removal rates and polishing selectivities can be achieved.

1 - 20 . (canceled) 
     
     
         21 . A polishing composition, comprising:
 a) an anionic silica abrasive, wherein the anionic silica abrasive is prepared by a sol-gel reaction from tetramethyl orthosilicate or tetraethyl orthosilicate, the anionic silica abrasive has a mean particle size of from about 1 nm to about 5000 nm, and the anionic abrasive comprises terminal groups of formula (I):
   —O m —Si—(CH 2 ) n —Y   (I),
 
   
       in which m is an integer from 1 to 3; n is an integer from 1 to 10; and Y is a carboxylic acid group or a salt thereof;
 b) an acid, a base, or a mixture thereof; and 
 c) water. 
 
     
     
         22 . The composition of  claim 21 , wherein the polishing composition has a pH of about 2 to about 7. 
     
     
         23 . The composition of  claim 21 , wherein the composition has a zeta potential in the range of from about −0.01 mV to about −100 mV. 
     
     
         24 . The composition of  claim 21 , wherein the anionic abrasive comprises anionic colloidal silica. 
     
     
         25 . The composition of  claim 21 , wherein the anionic abrasive is present in the composition in an amount of from about 0.01 wt % to about 50 wt % based on the total weight of the composition. 
     
     
         26 . The composition of  claim 21 , wherein the acid is selected from the group consisting of formic acid, acetic acid, malonic acid, citric acid, propionic acid, malic acid, adipic acid, succinic acid, lactic acid, oxalic acid, hydroxyethylidene diphosphonic acid, 2-phosphono-1,2,4-butane tricarboxylic acid, aminotrimethylene phosphonic acid, hexamethylenediamine tetra(methylenephosphonic acid), bis(hexamethylene)triamine phosphonic acid, amino acetic acid, peracetic acid, potassium acetate, phenoxyacetic acid, glycine, bicine, diglycolic acid, glyceric acid, tricine, alanine, histidine, valine, phenylalanine, proline, glutamine, aspartic acid, glutamic acid, arginine, lysine, tyrosine, benzoic acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphonic acid, hydrochloric acid, periodic acid, and mixtures thereof. 
     
     
         27 . The composition of  claim 21 , wherein the base is selected from the group consisting of potassium hydroxide, sodium hydroxide, cesium hydroxide, ammonium hydroxide, triethanolamine, diethanolamine, monoethanolamine, tetrabutylammonium hydroxide, tetramethylammonium hydroxide, lithium hydroxide, imidazole, triazole, aminotriazole, tetrazole, benzotriazole, tolytriazole, pyrazole, isothiazole, and mixtures thereof. 
     
     
         28 . The composition of  claim 21 , wherein the acid or base is present in the composition in an amount of from about 0.0001 wt % to about 30 wt % based on the total weight of the composition. 
     
     
         29 . The composition of  claim 21 , wherein the composition has a conductivity in the range of from about 0.01 mS/cm to about 100 mS/cm. 
     
     
         30 . A method, comprising:
 applying the polishing composition of  claim 21  to a substrate; and   bringing a pad into contact with the substrate and moving the pad in relation to the substrate.   
     
     
         31 . The method of  claim 30 , wherein the substrate comprises a material selected from the group consisting of metals, metal oxides, metal nitrides and dielectric materials. 
     
     
         32 . The method of  claim 31 , wherein the substrate comprises at least one of cobalt, copper, tungsten, tantalum, titanium, ruthenium, and aluminum. 
     
     
         33 . The method of  claim 31 , wherein the substrate comprises at least one of hafnium oxide, zirconium oxide, and yttrium oxide. 
     
     
         34 . The method of  claim 30 , further comprising producing a semiconductor device from the substrate treated by the polishing composition.