Storage tank for process liquids with a reduced amount of bubbles

Abstract

In a storage tank for a process liquid, such as a plating liquid for a plating reactor, one or more barriers are implemented so as to define an inlet area and an outlet area, wherein a fluid flow path is substantially determined by the barrier to significantly suppress the migration of bubbles from the inlet area to the outlet area. In particular embodiments, the introduction of liquid into the storage tank is achieved by inlet lines terminating closely beneath the liquid surface so as to substantially avoid bubble generation and to remove moderately sized bubbles that are conveyed in the inlet lines.

1 . A storage tank for a process liquid, comprising: 
 an inlet area for receiving said process liquid;    an outlet area connectable to a supply line; and    a barrier having an upper portion and a lower portion, the lower portion facing a bottom of said storage tank, the barrier being disposed between said inlet area and said outlet area, the lower portion defining an opening near a bottom portion of said storage tank to provide fluid communication between said inlet area and said outlet area.    
     
     
         2 . The storage tank of  claim 1 , wherein said inlet area comprises an inlet line end portion terminating into said inlet area.  
     
     
         3 . The storage tank of  claim 2 , further comprising a height adjustment member connected to said end portion and being configured to adapt a height of an outlet opening of said end portion to a liquid level in said inlet area.  
     
     
         4 . The storage tank of  claim 2 , wherein said end portion includes a bent portion.  
     
     
         5 . The storage tank of  claim 4 , wherein said bent portion has a substantially U-shaped configuration.  
     
     
         6 . The storage tank of  claim 1 , further comprising a second barrier having an upper portion and a lower portion, the lower portion connected to a bottom of said storage tank, said upper portion of said second barrier defining a second opening to provide fluid flow path between said inlet area and said outlet area.  
     
     
         7 . The storage tank of  claim 6 , further comprising a second height adjustment member coupled to said second barrier, the second height adjustment member being configured to adapt a position of said second opening to a liquid level in said storage tank.  
     
     
         8 . The storage tank of  claim 1  configured to contain a plating solution.  
     
     
         9 . A plating tool, comprising: 
 a process chamber configured to receive and support a substrate;    a supply line configured to convey a plating solution to said substrate;    a discharge line configured to remove excess plating solution from said process chamber; and    a storage tank including: 
 an inlet area connected to said discharge line;  
 an outlet area connected to said supply line; and  
 a barrier having an upper portion and a lower portion, the lower portion facing a bottom of said storage tank, the barrier being disposed between said inlet area and said outlet area and defining with its lower portion an opening near the bottom to provide fluid communication between said inlet area and said outlet area.  
   
     
     
         10 . The plating tool of  claim 9 , wherein said discharge line comprises an end portion terminating into said inlet area.  
     
     
         11 . The plating tool of  claim 10 , further comprising a height adjustment member connected to said end portion and being configured to adapt a height of an outlet opening of said end portion to a liquid level in said inlet area.  
     
     
         12 . The plating tool of  claim 10 , wherein said end portion includes a bent portion.  
     
     
         13 . The plating tool of  claim 12 , wherein said bent portion has a substantially U-shaped configuration.  
     
     
         14 . The plating tool of  claim 9 , further comprising a second barrier having an upper portion and a lower portion, the lower portion connected to a bottom of said storage tank, the second barrier forming with said upper portion a second opening to provide fluid communication between said inlet area and said outlet area.  
     
     
         15 . The plating tool of  claim 14 , further comprising a second height adjustment member coupled to said second barrier, the second height adjustment member being configured to adapt a position of said second opening to a liquid level in said storage tank.  
     
     
         16 . A method of operating a storage tank for a process liquid, the method comprising: 
 supplying said process liquid to an inlet area of said storage tank; and    generating a liquid flow to an outlet area via a communicating opening that is disposed in the vicinity of a bottom of said storage tank to substantially prevent bubbles from moving into said outlet area.    
     
     
         17 . The method of  claim 16 , further comprising adjusting a height of an opening of an inlet line terminating in said inlet area to be located a predefined distance below a liquid surface of said process liquid.  
     
     
         18 . The method of  claim 17 , further comprising forcing said liquid flow between said inlet area and said outlet area to flow partially at the vicinity of said liquid surface to further remove bubbles in said liquid flow.  
     
     
         19 . The method of  claim 18 , further comprising adjusting a distance of said liquid flow flowing at least partially in the vicinity of said liquid surface to a predefined value.  
     
     
         20 . The method of  claim 16 , wherein said process liquid is supplied to a process chamber of a plating tool.