Polishing slurry for silicon oxide, additive liquid and polishing method

Abstract

The polishing slurry of the invention is a polishing slurry for polishing a silicon oxide film on polysilicon, which contains an abrasive, polysilicon polishing inhibitor, and water. As the polishing inhibitor, it is preferable to use (1) a water-soluble polymer having a N-monosubstituted or N,N-disubstituted skeleton substituted by any member selected from the group consisting of acrylamide, methacrylamide, and α-substituted derivatives thereof, (2) polyethylene glycol, (3) an oxyethylene adduct of an acetylene-based diol, (4) a water-soluble organic compound having an acetylene bond, (5) an alkoxylated linear aliphatic alcohol, or (6) a copolymer containing polyvinyl pyrrolidone or vinyl pyrrolidone. There is provided a polishing method which is capable of polishing a silicon oxide film on a polysilicon film at a high speed, and inhibiting the progress of polishing of a polysilicon film in exposed parts in the manufacturing method for a semiconductor.

1 . A polishing slurry for silicon oxide for polishing a silicon oxide film on polysilicon, which contains an abrasive, a polysilicon polishing inhibitor, and water.  
   
   
       2 . The polishing slurry for silicon oxide according to  claim 1 , wherein the ratio of the polishing rate for silicon oxide to that for polysilicon is 10 or more.  
   
   
       3 . The polishing slurry for silicon oxide according to  claim 1  or  2 , wherein the polysilicon polishing inhibitor is a water-soluble polymer having a N-monosubstituted or N,N-disubstituted skeleton substituted by any member selected from the group consisting of acrylamide, methacrylamide, and α-substituted derivatives thereof.  
   
   
       4 . The polishing slurry for silicon oxide according to  claim 3 , wherein the water-soluble polymer is a polymer or copolymer containing at least one selected from the group consisting of a polymerizable monomer represented by the following general formula (I) and a polymerizable monomer represented by the following general formula (II).  
     
       
         
         
             
             
         
       
       (In the general formula (I), R 1  represents a hydrogen atom, methyl group, phenyl group, benzyl group, chloro group, difluoromethyl group, trifluoromethyl group, or cyano group, and R 2  and R 3  each independently represents a hydrogen atom, alkyl chain of C 1  to C 18 , methylol group, or acetyl group with the proviso that the case where both of them simultaneously represent a hydrogen atom is excluded.)  
       
         
           
           
               
               
           
         
       
       (In the general formula (II), R 1  represents a hydrogen atom, methyl group, phenyl group, benzyl group, chloro group, difluoromethyl group, trifluoromethyl group, or cyano group, R 4  represents a morpholino group, thiomorpholino group, pyrrolidino group, or piperidino group.)  
     
   
   
       5 . The polishing slurry for silicon oxide according to  claim 1  or  2 , wherein the polysilicon polishing inhibitor is polyethylene glycol.  
   
   
       6 . The polishing slurry for silicon oxide according to  claim 1  or  2 , wherein the polysilicon polishing inhibitor is an oxyethylene adduct of a acetylene-based diol.  
   
   
       7 . The polishing slurry for silicon oxide according to  claim 1  or  2 , wherein the polysilicon polishing inhibitor is at least either of the compound represented by the following general formula (III) and the compound and represented by the following general formula (IV). 
 [Formula 3]     R 1 —C≡C—R 2   (III)    (In the general formula (III), R 1  represents a hydrogen atom or substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R 2  represents a substituted or unsubstituted alkyl group having 4 to 10 carbon atoms.)                          (In the general formula (IV), R 3  to R 6  each independently represent a hydrogen atom or substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R 7  and R 8  each independently represent a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, and m and n each independently represents 0 or a positive number.)    
   
   
       8 . The polishing slurry for silicon oxide according to  claim 1  or  2 , wherein the polysilicon polishing inhibitor is an alkoxylated linear aliphatic alcohol.  
   
   
       9 . The polishing slurry for silicon oxide according to any of claims  1  or  2 , which contains two or more types of the polysilicon polishing inhibitor.  
   
   
       10 . The polishing slurry for silicon oxide according to  claim 9 , wherein the polysilicon polishing inhibitor includes two or more compounds selected from a water-soluble polymer having a N-monosubstituted or N,N-disubstituted skeleton substituted by any member selected from the group consisiting of acrylamide, methacrylamide, and α-substituted derivatives thereof, 
 polyethylene glycol,    an oxyethylene adduct of an acetylene-based diol,    a compound represented by the following general formula (III),    a compound represented by the following general formula (IV), and an alkoxylated linear aliphatic alcohol.    [Formula 9]     R 1 —C≡C—R 2   (III)    (In the general formula (III), R 1  represents a hydrogen atom or substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R 2  represents a substituted or unsubstituted alkyl group having 4 to 10 carbon atoms.)                          (In the general formula (IV), R 3  to R 6  each independently represent a hydrogen atom or substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R 7  and R 8  each independently represent a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, and m and n each independently represents 0 or a positive number.)    
   
   
       11 . The polishing slurry for silicon oxide according to  claim 3 , wherein the content of the polysilicon polishing inhibitor is 0.005% by mass or more and 2% by mass or less.  
   
   
       12 . The polishing slurry for silicon oxide according to  claim 3 , wherein the pH is 5.0 to 8.0.  
   
   
       13 . The polishing slurry for silicon oxide according to any of claims  1  or  2 , which contains at least one selected from polyacrylic acid, polyacrylate, and a copolymer containing acrylate.  
   
   
       14 . The polishing slurry for silicon oxide according to any of claims  1  or  2 , wherein the abrasive contains cerium oxide.  
   
   
       15 . The polishing slurry for silicon oxide according to  claim 1  or 2, wherein the polysilicon polishing inhibitor contains polyvinyl pyrrolidone or a copolymer containing vinyl pyrrolidone.  
   
   
       16 . The polishing slurry for silicon oxide according to  claim 15 , wherein the content of the polysilicon polishing inhibitor is 0.005 to 5% by mass.  
   
   
       17 . The polishing slurry for silicon oxide according to  claim 15 , wherein the pH is 5.0 to 12.0.  
   
   
       18 . The polishing slurry for silicon oxide according to  claim 15 , which contains at least one selected from polyacrylic acid, polyacrylate, or a copolymer containing acrylate.  
   
   
       19 . The polishing slurry for silicon oxide according to  claim 15 , wherein the abrasive contains cerium oxide.  
   
   
       20 . The polishing slurry for silicon oxide according to  claim 13 , wherein the content of at least one selected from polyacrylic acid, polyacrylate, and a copolymer containing acrylate is 0.01 to 5% by mass.  
   
   
       21 . The polishing slurry for silicon oxide according to any of claims  1  or  2 , wherein the abrasive contains silicon oxide.  
   
   
       22 . A method for polishing a semiconductor substrate using the polishing slurry for silicon oxide according to  claim 1 .  
   
   
       23 . An additive liquid for polishing slurry used in a polishing slurry for polishing a silicon oxide film on polysilicon, which contains a polysilicon polishing inhibitor and water.  
   
   
       24 . The additive liquid for polishing slurry according to  claim 23 , wherein the polysilicon polishing inhibitor is a water-soluble polymer having a N-monosubstituted or N,N-disubstituted skeleton substituted by any member selected from the group consisting of acrylamide, methacrylamide, and α-substituted derivatives thereof.  
   
   
       25 . The additive liquid for polishing slurry according to  claim 24 , wherein the water-soluble polymer is a polymer or copolymer containing at least one selected from the group consisting of a polymerizable monomer represented by the following general formula (I) and a polymerizable monomer represented by the following general formula (II).  
     
       
         
         
             
             
         
       
       (In the general formula (I), R 1  represents a hydrogen atom, methyl group, phenyl group, benzyl group, chloro group, difluoromethyl group, trifluoromethyl group, or cyano group, and R 2  and R 3  each independently represents a hydrogen atom, alkyl chain of C 1  to C 18 , methylol group, or acetyl group with the proviso that the case where both of them simultaneously represent a hydrogen atom is excluded.)  
       
         
           
           
               
               
           
         
       
       (In the general formula (II), R 1  represents a hydrogen atom, methyl group, phenyl group, benzyl group, chloro group, difluoromethyl group, trifluoromethyl group, or cyano group, R 4  represents a morpholino group, thiomorpholino group, pyrrolidino group, or piperidino group.)  
     
   
   
       26 . The additive liquid for polishing slurry according to  claim 23 , wherein the polysilicon polishing inhibitor is polyethylene glycol.  
   
   
       27 . The additive liquid for polishing slurry according to  claim 23 , wherein the polysilicon polishing inhibitor is an oxyethylene adduct of an acetylene-based diol.  
   
   
       28 . The additive liquid for polishing slurry according to  claim 23 , wherein the polysilicon polishing inhibitor is at least either of the compound represented by the following general formula (III) and the compound and represented by the following general formula (IV). 
 [Formula 7]     R 1 —C≡C—R 2   (III)    (In the general formula (III), R 1  represents a hydrogen atom or substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R 2  represents a substituted or unsubstituted alkyl group having 4 to 10 carbon atoms.)                          (In the general formula (IV), R 3  to R 6  each independently represent a hydrogen atom or substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R 7  and R 8  each independently represent a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, and m and n each independently represents 0 or a positive number.)    
   
   
       29 . The additive liquid for polishing slurry according to  claim 23 , wherein the polysilicon polishing inhibitor is an alkoxylated linear aliphatic alcohol.  
   
   
       30 . The additive liquid for polishing slurry according to any of claims  23  through  29 , which contains two or more types of the polysilicon polishing inhibitor.  
   
   
       31 . The additive liquid for polishing slurry according to  claim 30 , wherein the polysilicon polishing inhibitor includes two or more compounds selected from a water-soluble polymer having a N-monosubstituted or N,N-disubstituted skeleton substituted bv any member selected from the group, consisting of acrylamide, methacrylamide, and α-substituted derivatives thereof, polyethylene glycol, an oxyethylene adduct of an acetylene-based diol, a compound represented by the following general formula (III), a compound represented by the following general formula (IV), and an alkoxylated linear aliphatic alcohol. 
 [Formula 11]     R 1 —C≡C—R 2   (III)    (In the general formula (III), R 1  represents a hydrogen atom or substituted or unsubstituted alkyl group having 1 to 5 carbon atoms R 2  represents a substituted or unsubstituted alkyl group having 4 to 10 carbon atoms.)                          (In the general formula (IV), R 3  to R 6  each independently represent a hydrogen atom or substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R 7  and R 8  each independently represent a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, and m and n each independently represents 0 or a positive number.)    
   
   
       32 . The additive liquid for polishing slurry according to any of claims  23  through  29 , which further contains at least one selected from polyacrylic acid, polyacrylate, and a copolymer containing acrylate.  
   
   
       33 . A polishing method using the polishing slurry for silicon oxide according to  claim 1 , wherein the object to be polished is held against a polishing pad with the surface thereof to be polished facing the polishing pad, and polished by being slid relative to the polishing pad while the polishing slurry is supplied between the polishing pad and the surface to be polished.