Microelectronic substrate cleaning systems with polyelectrolyte and associated methods

Abstract

Several embodiments of cleaning systems using polyelectrolyte and various associated methods for cleaning microelectronic substrates are disclosed herein. One embodiment is directed to a system that has a substrate support for holding the microelectronic substrate, a dispenser positioned above the substrate support and facing a surface of the microelectronic substrate, a reservoir in fluid communication with the dispenser via a conduit, and a washing solution contained in the reservoir. The washing solution includes a polyelectrolyte.

1 . A system for cleaning a microelectronic substrate, the system comprising:
 a substrate support for holding the microelectronic substrate;   a dispenser positioned above the substrate support and facing a surface of the microelectronic substrate;   a reservoir in fluid communication with the dispenser via a conduit; and   a washing solution contained in the reservoir, the washing solution including a polyelectrolyte formed from monomers individually having an electrolytic function group selected from the groups consisting of a hydroxyl group (—OH), a carboxyl group (—COOH), a carboxamide group (—CONH 2 ), an amino group (—NH 2 ), an imine group (—C═NR), an imide group (RCONCOR′, in which R is an alkyl group different than R′), a vinyl pyrrolidone group   
       
         
           
           
               
               
           
         
       
       a vinyl pyridine group 
       
         
           
           
               
               
           
         
       
       a nitro group (—NO 2 ), a sulfonate group (—HSO 3 ), a sulfate group (—HSO 4 ), and a phosphate group (—HPO 4 ). 
     
     
         2 . The system of  claim 1  wherein the washing solution includes about 3 parts hydrogen peroxide and about 2 parts ammonium hydroxide in 100 parts deionized water, and wherein the washing solution further includes about 0.1% by weight of the polyelectrolyte, and further wherein the polyelectrolyte includes a polyacrylic acid having a molecular weight of about 50,000, and further wherein the washing solution has a pH of about 10.0 to about 10.3 and a temperature of about 30° C. to about 75° C. 
     
     
         3 . The system of  claim 1  wherein the polyelectrolyte includes a polyacrylic acid or a polyacrylate salt having a molecular weight of about 2,000 to about 450,000. 
     
     
         4 . The system of  claim 1  wherein the polyelectrolyte includes a polyacrylic acid or a polyacrylate salt having a molecular weight of about 2,000 to about 450,000, and wherein the washing solution includes about 0.01% to about 5% by weight of the polyacrylic acid or the polyacrylate salt. 
     
     
         5 . A system for cleaning a microelectronic substrate, the system comprising:
 a vessel for holding the microelectronic substrate;   a transducer disposed within the vessel;   a signal delivery device operably coupled with the transducer, the signal delivery device is configured to output an electrical signal that oscillates the transducer; and   a washing solution in the vessel, the washing solution containing a polyelectrolyte having a plurality of ionic functional groups on a carbon backbone, wherein the microelectronic substrate is submerged in the washing solution.   
     
     
         6 . The system of  claim 5  wherein the ionic functional group includes at least one of a hydroxyl group (—OH), a carboxyl group (—COOH), a carboxamide group (—CONH 2 ), an amino group (—NH 2 ), an imine group (—C═NR), an imide group (RCONCOR′, in which R is an alkyl group different than R′), a vinyl pyrrolidone group 
       
         
           
           
               
               
           
         
       
       a vinyl pyridine group 
       
         
           
           
               
               
           
         
       
       a nitro group (—NO 2 ), a sulfonate group (—HSO 3 ), a sulfate group (—HSO 4 ), and a phosphate group (—HPO 4 ). 
     
     
         7 . The system of  claim 5  wherein the ionic functional group includes a carboxyl group, and wherein the polyelectrolyte is configured to form an array of ionized carboxyl group (—COO − ) carried by a carbon backbone. 
     
     
         8 . The system of  claim 6  wherein the ionic functional group includes a carboxyl group, and wherein the polyelectrolyte is configured to form an array of ionized carboxyl groups (—COO − ) carried by a carbon backbone, and wherein the array of ionized carboxyl groups has a sphere, a spiral, or a zigzag arrangement. 
     
     
         9 . A cleaning solution for cleaning a semiconductor substrate, comprising:
 an oxidizer having a concentration of about 0.1% to about 10% by volume;   a base having a concentration of about 0.1% to about 10% by volume; and   a polyacrylic acid having a concentration of about 0.01% to about 5% by weight, the polyacrylic acid having a molecular weight of about 2,000 to about 450,000.   
     
     
         10 . The cleaning solution of  claim 9  wherein the polyacrylic acid has a molecular weight of about 50,000, and wherein the cleaning solution has a pH of about 10.0, and further wherein the oxidizer includes hydrogen peroxide and the base includes ammonium hydroxide. 
     
     
         11 . The cleaning solution of  claim 9 , further comprising at least one of a pH buffer, a chelating agent, a corrosion inhibitor, and a surfactant.