Compositions and methods for modifying a surface suited for semiconductor fabrication

Abstract

The method of the present invention comprises providing a wafer including a first, second and third material; contacting the third material in the presence of a working liquid with abrasive composites fixed to an abrasive article; and moving the wafer until an exposed surface of the wafer is substantially planar and comprises at least one area of exposed third material and one area of exposed second material. The components of the working liquid include an aqueous solvent; a pH buffer exhibiting a pK a greater than 7 and comprising a basic pH adjusting agent and a multidentate acidic complexing agent; and a non-ionic surfactant. The nonionic surfactant exhibits a hydrophile-lipophile balance of at least about 4. The working liquid is substantially free of loose abrasive particles and exhibits a pH of about 7-12.

1 . A method of modifying a surface of a wafer suited for fabrication of a semiconductor device comprising the steps of:
 a. providing a wafer comprising at least a first material having a surface etched to form a pattern, a second material deployed over at least a portion of the surface of the first material, and a third material deployed over at least a portion of the surface of the second material;   b. contacting the third material of the wafer, in the presence of a working liquid, with a plurality of three-dimensional abrasive composites fixed to an abrasive article, the three-dimensional abrasive composites comprising a plurality of abrasive particles fixed and dispersed in a binder, wherein the working liquid is an aqueous solution of initial components substantially free of loose abrasive particles, the components comprising:
 i. an aqueous solvent, wherein the aqueous solvent comprises water; 
 ii. a pH buffer exhibiting at least one pK a  greater than 7, wherein the pH buffer comprises a basic pH adjusting agent and a multidentate acidic complexing agent, wherein the multidentate acidic complexing agent comprises at least one of an amino acid or a dipeptide formed from an amino acid; and 
 iii. a non-ionic surfactant, wherein the nonionic surfactant exhibits a hydrophile-lipophile balance of at least about 4, and 
 iv. wherein the working liquid exhibits a pH from about 7 to about  12; and    
   c. relatively moving the wafer while the third material is in contact with the plurality of abrasive composites until an exposed surface of the wafer is substantially planar and comprises at least one area of exposed third material and one area of exposed second material.   
     
     
         2 . The method of  claim 1 , wherein the working liquid basic pH adjusting agent is selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxide, and mixtures thereof. 
     
     
         3 . The method of  claim 1 , wherein the amino acid is selected from alanine, proline, glycine, histidine, lysine, arginine, ornithene, cysteine, tyrosine, and combinations thereof. 
     
     
         4 . The method of  claim 3 , wherein the amino acid is L-proline. 
     
     
         5 . The method of  claim 1 , wherein the nonionic surfactant is selected from a linear primary alcohol ethoxylate, a secondary alcohol ethoxylate, a branched secondary alcohol ethoxylate, an octylphenol ethoxylate, an acetylenic primary alcohol ethoxylate, an acetylenic primary di-alcohol ethoxylate, an alkane di-alcohol, a hydroxyl-terminated ethylene oxide-propylene oxide random copolymer, a fluoroaliphatic polymeric ester, and mixtures thereof. 
     
     
         6 . The method of  claim 1 , wherein the nonionic surfactant is present in an amount of at least about 0.025% and at most about 0.2% by weight of the working liquid. 
     
     
         7 . The method of  claim 1 , wherein the acidic complexing agent is present in an amount from about 0.1% by weight to about 5% by weight of the working liquid. 
     
     
         8 . The method of  claim 1 , wherein the basic pH adjusting agent is present in an amount sufficient to produce a pH from about 10 to about 11, the acidic complexing agent comprises L-proline in an amount from about 2% to about 4% by weight of the working liquid, and the surfactant comprises an ethoxylated alcohol in an amount from about 0.05% to about 0.5% by weight of the working liquid. 
     
     
         9 . The method of modifying a surface of a wafer suited for fabrication of a semiconductor device of  claim 1 , wherein the working liquid exhibits a pH from about 9 to about 11. 
     
     
         10 . A method of modifying a surface of a wafer suited for fabrication of a semiconductor device, comprising:
 a. providing a wafer comprising at least a barrier material deployed over at least a portion of the wafer; and a dielectric material deployed over at least a portion of the barrier material;   b. contacting the dielectric material of the wafer, in the presence of a working liquid according to  claim 1 , with a plurality of three-dimensional abrasive composites fixed to an abrasive article, the three-dimensional abrasive composites comprising a plurality of abrasive particles fixed and dispersed in a binder, wherein the working liquid is an aqueous solution of initial components substantially free of loose abrasive particles, the components comprising:
 i. an aqueous solvent, wherein the aqueous solvent comprises water; 
 ii. a pH buffer exhibiting at least one pK a  greater than 7, wherein the pH buffer comprises a basic pH adjusting agent and a multidentate acidic complexing agent, wherein the multidentate acidic complexing agent comprises at least one of an amino acid or a dipeptide formed from an amino acid; and 
 iii. a non-ionic surfactant, wherein the nonionic surfactant exhibits a hydrophile-lipophile balance of at least about 4, and 
 iv. wherein the working liquid exhibits a pH from about 7 to about  12; and    
   c. relatively moving the wafer while the dielectric material is in contact with the plurality of abrasive composites until an exposed surface of the wafer is substantially planar and comprises at least one area of exposed dielectric material and one area of exposed barrier material.   
     
     
         11 . The method of  claim 10 , wherein the barrier material comprises silicon nitride, and the dielectric material comprises silicon oxide. 
     
     
         12 . The method of  claim 10 , wherein the working liquid basic pH adjusting agent is selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxide, and mixtures thereof. 
     
     
         13 . The method of  claim 10 , wherein the amino acid is selected from alanine, proline, glycine, histidine, lysine, arginine, ornithene, cysteine, tyrosine, and combinations thereof. 
     
     
         14 . The method of  claim 13 , wherein the amino acid is L-proline. 
     
     
         15 . The method of  claim 10 , wherein the nonionic surfactant is selected from a linear primary alcohol ethoxylate, a secondary alcohol ethoxylate, a branched secondary alcohol ethoxylate, an octylphenol ethoxylate, an acetylenic primary alcohol ethoxylate, an acetylenic primary di-alcohol ethoxylate, an alkane di-alcohol, a hydroxyl-terminated ethylene oxide-propylene oxide random copolymer, a fluoroaliphatic polymeric ester, and mixtures thereof. 
     
     
         16 . The method of  claim 10 , wherein the nonionic surfactant is present in an amount of at least about 0.025% and at most about 0.2% by weight of the working liquid. 
     
     
         17 . The method of  claim 10 , wherein the acidic complexing agent is present in an amount from about 0.1% by weight to about 5% by weight of the working liquid. 
     
     
         18 . The method of  claim 10 , wherein the basic pH adjusting agent is present in an amount sufficient to produce a pH from about 10 to about 11, the acidic complexing agent comprises L-proline in an amount from about 2% to about 4% by weight of the working liquid, and the surfactant comprises an ethoxylated alcohol in an amount from about 0.05% to about 0.5% by weight of the working liquid. 
     
     
         19 . The method of  claim 10 , wherein the working liquid exhibits a pH from about 9 to about 11.