Electrolytic plating solution, electrolytic plating method, and method for manufacturing semiconductor device

Abstract

An electrolytic plating solution includes a polar solvent, copper sulfate dissolved in the polar solvent, an accelerator including a sulfur compound, and a reducing agent having a smaller molecular weight than the accelerator.

1 . An electrolytic plating solution, comprising:
 a polar solvent,   copper sulfate dissolved in the polar solvent,   an accelerator including a sulfur compound, and   a reducing agent having a smaller molecular weight than the accelerator.   
   
   
       2 . The electrolytic plating solution according to  claim 1 , wherein the reducing agent is a compound having a water-soluble aldehyde group or ketone group. 
   
   
       3 . The electrolytic plating solution according to  claim 1 , wherein the reducing agent has a molecular weight of 300 or less. 
   
   
       4 . The electrolytic plating solution according to  claim 1 , wherein the reducing agent is a monosaccharide. 
   
   
       5 . The electrolytic plating solution according to  claim 1 , wherein the reducing agent comprises glucose. 
   
   
       6 . The electrolytic plating solution according to  claim 1 , wherein the accelerator comprises disulfide propanesulfonic acid. 
   
   
       7 . The electrolytic plating solution according to  claim 1 , further comprising polyethylene glycol as a suppressor. 
   
   
       8 . An electrolytic plating method, comprising:
 immersing a treated substrate, on which a copper seed layer is formed, in an electrolytic plating solution, and   depositing a copper layer on the treated substrate immersed in the electrolytic plating solution by electrolytic plating,   wherein the electrolytic plating solution comprises:
 a polar solvent, 
 copper sulfate dissolved in the polar solvent, 
 an accelerator including a sulfur compound, and 
 a reducing agent having a smaller molecular weight than the accelerator. 
   
   
   
       9 . The electrolytic plating method according to  claim 8 , wherein energization is started after the treated substrate is immersed in the electrolytic plating solution. 
   
   
       10 . A method for manufacturing a semiconductor device, comprising:
 forming a recess in an insulating film on a treated substrate,   forming a barrier metal film, in a shape conforming to a shape of the recess, on the insulating film so as to continuously cover a side wall surface and bottom surface of the recess,   forming a copper seed layer, in a shape conforming to the shape of the recess, on the insulating film, covering the barrier metal film,   filling the recess with a copper layer by electrolytic plating using the copper seed layer as an electrode, and   removing the copper layer on the insulating film by a chemical mechanical polishing method until a surface of the insulating film is exposed,   wherein an electrolytic plating solution used for forming the copper layer comprises:
 a polar solvent, 
 copper sulfate dissolved in the polar solvent, 
 an accelerator including a sulfur compound, and 
 a reducing agent having a smaller molecular weight than the accelerator. 
   
   
   
       11 . The method for manufacturing a semiconductor device according to  claim 10 , wherein the electrolytic plating method comprises:
 immersing the treated substrate in the electrolytic plating solution, and   performing energization in the electrolytic plating solution, using the copper seed layer as an electrode,   wherein the energization is started after the treated substrate is immersed in the electrolytic plating solution.