Substrate treating apparatus

Abstract

A substrate treating apparatus for heating a treating solution formed of a chemical and a diluent, and immersing substrates in the treating solution for treatment. The apparatus includes a treating tank for storing the treating solution, a heater for heating the treating solution, a temperature detector for detecting temperature of the treating solution, a temperature controller for controlling the heater so that a detected temperature of the treating solution reaches a set temperature, a supplementing device for supplement the treating tank with the diluent, a concentration detector for detecting concentration of the treating solution, and a concentration controller, operable only when the temperature detector detects the treating solution being in a temperature range close to the set temperature, for controlling the supplementing device to adjust an amount of the diluent supplemented so that the concentration of the treating solution detected by the concentration detector becomes slightly higher than a boiling-point concentration corresponding to the set temperature of the treating solution.

What is claimed is:  
     
         1 . A substrate treating apparatus for heating a treating solution formed of a chemical and a diluent, and immersing substrates in the treating solution for treatment, comprising: 
 a treating tank for storing the treating solution;    heating device for heating the treating solution;    temperature detecting device for detecting temperature of the treating solution;    temperature control device for controlling the heating device so that a detected temperature of the treating solution reaches a set temperature;    supplementing device for supplement the treating tank with the diluent;    concentration detecting device for detecting concentration of the treating solution; and    concentration control device, operable only when the temperature detecting device detects the treating solution being in a temperature range close to the set temperature, for controlling the supplementing device to adjust an amount of the diluent supplemented so that the concentration of the treating solution detected by the concentration detecting device becomes slightly higher than a boiling-point concentration corresponding to the set temperature of the treating solution.    
     
     
         2 . An apparatus as defined in  claim 1 , further comprising: 
 a collecting tank for collecting the treating solution overflowing the treating tank; and    a circulating system for returning the treating solution collected in the collecting tank to the treating tank.    
     
     
         3 . An apparatus as defined in  claim 2 , wherein said heating device includes a tank heater attached to the treating tank for heating the treating solution in the treating tank, and a circulating system heater for heating the treating solution circulating through the circulating system.  
     
     
         4 . An apparatus as defined in  claim 1 , wherein said concentration detecting device is arranged to detect the concentration of the treating solution by substantially detecting specific gravity of the treating solution.  
     
     
         5 . An apparatus as defined in  claim 4 , wherein said concentration detecting device has a detecting element disposed at a predetermined depth in the treating tank for detecting a pressure of the treating solution applied to the detecting element.  
     
     
         6 . An apparatus as defined in  claim 1 , wherein said concentration control device is arranged to supplement the diluent when a detected concentration of the treating solution exceeds a target concentration, and stop supplementing the diluent when the detected concentration of the treating solution is less than the target concentration.  
     
     
         7 . An apparatus as defined in  claim 1 , wherein said treating solution is a phosphoric acid solution formed of phosphoric acid acting as the chemical and deionized water acting as the diluent.  
     
     
         8 . An apparatus as defined in  claim 2 , wherein said treating solution is a phosphoric acid solution formed of phosphoric acid acting as the chemical and deionized water acting as the diluent.  
     
     
         9 . An apparatus as defined in  claim 3 , wherein said treating solution is a phosphoric acid solution formed of phosphoric acid acting as the chemical and deionized water acting as the diluent.  
     
     
         10 . A substrate treating apparatus for heating a treating solution formed of a chemical and a diluent, and immersing substrates in the treating solution for treatment, comprising: 
 a treating tank for storing the treating solution;    heating device for heating the treating solution;    piping including an air control valve for supplementing the diluent to the treating solution heated by the heating device;    an electropneumatic converter for applying an output pressure to the air control valve;    concentration detecting device for detecting concentration of the treating solution; and    concentration control device operable based on a result of detection by said concentration detecting device, for adjusting the output pressure of the electropneumatic converter to control the air control valve and adjust an amount of the diluent supplemented.    
     
     
         11 . An apparatus as defined in  claim 10 , further comprising: 
 temperature detecting device for detecting temperature of the treating solution; and    temperature control device for controlling the heating device so that a detected temperature of the treating solution reaches a set temperature;    wherein said concentration control device is arranged to adjust the output pressure of the electropneumatic converter so that the concentration of the treating solution detected by the concentration detecting device becomes slightly higher than a boiling-point concentration corresponding to the set temperature of the treating solution.    
     
     
         12 . An apparatus as defined in  claim 10 , further comprising: 
 a collecting tank for collecting the treating solution overflowing said treating tank; and    a circulating system for returning the treating solution collected in the collecting tank to the treating tank.    
     
     
         13 . An apparatus as defined in  claim 12 , wherein said heating device includes a tank heater attached to the treating tank for heating the treating solution in the treating tank, and a circulating system heater for heating the treating solution circulating through the circulating system.  
     
     
         14 . An apparatus as defined in  claim 10 , wherein said concentration detecting device is arranged to detect the concentration of the treating solution by substantially detecting specific gravity of the treating solution.  
     
     
         15 . An apparatus as defined in  claim 14 , wherein said concentration detecting device has a detecting element disposed at a predetermined depth in the treating tank for detecting pressure of the treating solution applied to the detecting element.  
     
     
         16 . An apparatus as defined in  claim 10 , further comprising: 
 temperature detecting device for detecting temperature of the treating solution; and    temperature control device for controlling the heating device so that a detected temperature of the treating solution reaches a set temperature;    wherein said concentration control device is operable only when the treating solution is in a temperature range close to the set temperature.    
     
     
         17 . An apparatus as defined in  claim 10 , wherein said concentration control device is arranged to supplement the diluent when a detected concentration of the treating solution exceeds a target concentration, and stop supplementing the diluent when the detected concentration of the treating solution is less than the target concentration.  
     
     
         18 . An apparatus as defined in  claim 16 , wherein said concentration control device is arranged to supplement the diluent when a detected concentration of the treating solution exceeds a target concentration, and stop supplementing the diluent when the detected concentration of the treating solution is less than the target concentration.  
     
     
         19 . An apparatus as defined in  claim 10 , wherein said treating solution is a phosphoric acid solution formed of phosphoric acid acting as the chemical and deionized water acting as the diluent.  
     
     
         20 . An apparatus as defined in  claim 11 , wherein said treating solution is a phosphoric acid solution formed of phosphoric acid acting as the chemical and deionized water acting as the diluent.