Semiconductor wafer washing system and method of supplying chemicals to the washing tanks of the system

Abstract

A semiconductor wafer washing system can execute a method in which the washing solution is quickly changed over and over again without the need to alter the structure of the system. The wafer washing system includes a washing solution supply section in which a plurality of chemicals are stored separately, and from which selected ones of the chemicals can be supplied in a predetermined ratio into a washing tank. A circulation section includes circulation piping connected to the washing tank for circulating the washing solution to and from the tank. A discharge section selectively discharges residual chemicals or washing solution from the washing solution supply section, the washing tank and the circulation section. A controller controls the flow of chemicals and washing solution in the washing solution supply section, the circulation section and the discharge section, respectively.

1 - 12 . (canceled)  
   
   
       13 . A semiconductor wafer washing system comprising: 
 a washing solution supply section including chemical storage tanks each containing a respective chemical for use in washing semiconductor wafers, supply piping comprising respective supply pipes extending from the tanks, and flow control means for controlling the flow of chemicals from the tanks through the supply pipes;    a washing tank including a main part connected to said plurality of tanks of said washing solution supply section via respective portions of the supply piping thereof so as to receive chemicals from the washing solution supply section at a rate set by said flow control means wherein a washing solution for washing wafers is formed in the main part, and a supplementary part disposed relative to said main part so as to receive washing solution that overflows the main part;    a circulation section including circulation piping extending between and connecting said main part and said supplementary part of the washing tank and through which circulation piping the washing solution is circulated between said supplementary and main parts of the washing tank, and flow control means for controlling the flow of washing solution through said circulation piping;    a discharge section including a drain, and discharge piping comprising a discharge pipe connecting said washing tank to said drain, and flow control means for controlling the flow of chemicals through said discharge pipe; and    a controller operatively connected to the flow control means of said washing solution supply section, said circulation section, and said discharge section so as to issue control signals thereto that control the flow of the chemicals from said washing solution supply section to the main part of said washing tank, between said supplementary and main parts of said washing tank, and from said washing tank to said drain.    
   
   
       14 . The system as defined in  claim 13 , wherein the flow control means of said circulation section comprises a flow control valve disposed in said circulation piping, and a pump connected to said circulation piping, and said circulation section further comprises a filter connected to said circulation piping for filtering the washing solution.  
   
   
       15 . The system as defined in  claim 14 , wherein said circulation section further comprises a heat exchanger that maintains the washing solution flowing in the circulation piping at a predetermined temperature.  
   
   
       16 . The system as defined in  claim 14 , wherein the flow control means of said circulation section further comprises a pressure gauge connected to said circulation piping and to said controller, and operative to measure the pressure of the washing solution flowing through the circulation piping pump and to output a signal representative of the pressure to the controller, and said circulation section further includes a check valve interposed between said circulation piping and said discharge piping so as to open said circulation piping to said discharge piping when the pressure of the washing solution in said circulation piping exceeds a predetermined pressure.  
   
   
       17 . A semiconductor wafer washing system comprising: 
 a washing solution supply section including chemical storage tanks each containing a respective chemical for use in washing semiconductor wafers, supply piping comprising respective supply pipes extending from the tanks, and flow control means for controlling the flow of chemicals from the tanks through the supply pipes;    a washing tank connected to said plurality of tanks of said washing solution supply section via respective portions of the supply piping thereof so as to receive chemicals from the washing solution supply section at a rate set by said flow control means wherein a washing solution for washing wafers is formed in the washing tank;    a discharge section including a drain, discharge piping comprising a discharge pipe connecting said washing tank to said drain, and flow control means for controlling the flow of chemicals through said discharge pipe;    a washing solution storage section including at least one washing solution storage tank in which washing solution for washing semiconductor wafers is stored, and connection piping connecting said at least one washing solution storage tank to said washing tank separately from said washing solution supply system, and flow control means for controlling the flow of the washing solution from each said at least one washing solution storage tank to said washing tank via said connection piping, whereby the washing solution can be supplied from each said at least one washing solution storage tank to the washing tank separately from the chemicals contained in the chemical storage tanks of said washing solution supply system; and    a controller operatively connected to the flow control means of said washing solution supply section, said discharge section, and said washing solution storage section so as to issue control signals thereto that control the flow of chemicals from said washing solution supply section to said washing tank, from said washing tank to said drain, and from each said at least one washing solution storage tank to the washing tank.    
   
   
       18 . A semiconductor wafer washing system comprising: 
 a washing solution supply section including chemical storage tanks each containing a respective chemical for use in washing semiconductor wafers, supply piping comprising respective supply pipes extending from the tanks, and flow control means for controlling the flow of chemicals from the tanks through the supply pipes;    a washing tank connected to said plurality of tanks of said washing solution supply section via respective portions of the supply piping thereof so as to receive chemicals from the washing solution supply section at a rate set by said flow control means wherein a washing solution for washing wafers is formed in the washing tank;    a discharge section including a drain, discharge piping comprising a discharge pipe connecting said washing tank to said drain, and flow control means for controlling the flow of chemicals through said discharge pipe;    a circulation section including circulation piping extending to and from the washing tank and through which circulation piping the washing solution is circulated, and flow control means for controlling the flow of washing solution through said circulation piping;    a washing solution storage section including at least one washing solution storage tank in which washing solution for washing semiconductor wafers is stored, and connection piping connecting said at least one washing solution storage tank to said circulation piping, whereby the washing solution can be supplied from each said at least one washing solution storage tank to the washing tank separately from the chemicals contained in the chemical storage tanks of said washing solution supply system; and    a controller operatively connected to the flow control means of said washing solution supply section, said discharge section, and said circulation section, so as to issue control signals thereto that control the flow of chemicals from said washing solution supply section to said washing tank, from said washing tank to said drain, and to and from said washing tank through said circulation piping.    
   
   
       19 - 34 . (canceled)