Semiconductor manufacturing apparatus and chemical exchanging method

Abstract

A semiconductor manufacturing apparatus for cleaning a semiconductor substrate comprises a high-temperature circulation type chemical bath which is filled with a chemical to be used for cleaning of a semiconductor substrate and in which the chemical is circulated and reused, a draining mechanism which drains the chemical in the chemical bath therefrom, an auxiliary fluid supplying mechanism which adds to the drained chemical regarded as a waste chemical an auxiliary fluid, and thereby heats the waste chemical, a heat exchanger in which the heated waste chemical is stored temporarily and a new chemical is allowed to flow, and which cools the waste chemical and raises temperature of the new chemical by heat exchange, and a pipe in which the new chemical having the temperature raised in the heat exchanger is supplied to the chemical bath.

1 . A semiconductor manufacturing apparatus comprising: 
 a high-temperature circulation type chemical bath which is filled with a chemical to be used for cleaning of a semiconductor substrate in a state that a temperature of the chemical is raised to a predetermined temperature, and in which the chemical is circulated and reused;    a draining mechanism which drains the chemical in the chemical bath therefrom;    an auxiliary fluid supplying mechanism which adds to the drained chemical regarded as a waste chemical an auxiliary fluid to generate heat by mixture with the waste chemical, and thereby heats the waste chemical;    a heat exchanger in which the heated waste chemical is stored temporarily and a new chemical is allowed to flow, and which cools the waste chemical and raises temperature of the new chemical by heat exchange between the waste chemical and the new chemical; and    a supply mechanism which supplies the new chemical having the temperature raised in the heat exchanger to the chemical bath.    
   
   
       2 . The apparatus according to  claim 1 , wherein volume of a pipe of the heat exchanger to the waste chemical is equivalent to or more than volume of the chemical supplied to the chemical bath.  
   
   
       3 . The apparatus according to  claim 1 , wherein the auxiliary fluid generates heat of dilution, reaction or neutralization by mixture with the waste chemical.  
   
   
       4 . The apparatus according to  claim 1 , wherein the chemical contains sulfuric acid, the auxiliary fluid is water and the chemical is heated with heat of dilution generated by mixture with the auxiliary fluid.  
   
   
       5 . The apparatus according to  claim 1 , wherein the chemical contains hydrochloric acid, the auxiliary fluid is an organic alkali and the chemical is heated with heat of neutralization generated by mixture with the auxiliary fluid.  
   
   
       6 . The apparatus according to  claim 1 , wherein the chemical contains at least ammonia, the auxiliary fluid is an organic acid and the chemical is heated with heat of reaction generated by mixture with the auxiliary fluid.  
   
   
       7 . The apparatus according to  claim 1 , wherein an addition volume of the auxiliary fluid is set in accordance with temperature of the waste chemical required to raise temperature of the new chemical to a predetermined temperature in the heat exchanger.  
   
   
       8 . The apparatus according to  claim 1 , further comprising a concentration gauge which measures concentration of at least one chemical in the chemical bath, 
 wherein an addition volume of the auxiliary fluid is determined in accordance with measurement result of the concentration gauge.    
   
   
       9 . The apparatus according to  claim 8 , wherein the addition volume of the auxiliary fluid is determined in accordance with concentration measured by the concentration gauge such that temperature of the waste chemical is temperature required to raise the temperature of the new chemical to the predetermined temperature.  
   
   
       10 . The apparatus according to  claim 1 , further comprising: 
 a chemical circuit which supplies a chemical overflowing from a top portion of the chemical bath, from a bottom portion of the chemical bath; and    a heater which is provided in a middle portion of the chemical circuit to raise temperature of a chemical to a predetermined temperature.    
   
   
       11 . The apparatus according to  claim 1 , further comprising a pipe which allows the new chemical to bypass the heat exchanger.  
   
   
       12 . The apparatus according to  claim 1 , further comprising another draining mechanism which allows a small quantity of waste chemical drained from the chemical bath not to be supplied to the heat exchange, but to be drained directly to outside.  
   
   
       13 . A semiconductor manufacturing apparatus comprising: 
 a high-temperature circulation type chemical bath which is filled with a chemical to be used for cleaning of a semiconductor substrate in a state that a temperature of the chemical is raised to a first temperature, and in which the chemical is circulated and reused;    a draining mechanism which drains the chemical in the chemical bath therefrom;    an auxiliary fluid supplying mechanism which adds to the drained chemical regarded as a waste chemical of second temperature lower than the first temperature an auxiliary fluid to generate heat by mixture with the waste chemical, and thereby heats the waste chemical at third temperature higher than the first temperature;    a heat exchanger in which the heated waste chemical is stored temporarily and a new chemical is allowed to flow, and which cools the waste chemical and raises temperature of the new chemical to the first temperature by heat exchange between the waste chemical and the new chemical; and    a supply mechanism which supplies the new chemical having the temperature raised in the heat exchanger to the chemical bath.    
   
   
       14 . A method of exchanging a chemical in a high-temperature circulation type chemical bath, comprising: 
 preparing a semiconductor manufacturing apparatus comprising the high-temperature circulation type chemical bath which is filled with a chemical to be used for cleaning of a semiconductor substrate, and in which the chemical is circulated and reused after the cleaning;    draining the chemical in the chemical bath therefrom;    adding to the drained chemical regarded as a waste chemical an auxiliary fluid to generate heat by mixture with the waste chemical, and thereby heating the waste chemical;    temporarily storing the heated waste chemical in a heat exchanger;    allowing a new chemical to flow in the heat exchanger, and cooling the waste chemical and raising temperature of the new chemical by heat exchange between the waste chemical and the new chemical in the heat exchanger; and    supplying the new chemical having the temperature raised to the chemical bath.    
   
   
       15 . The method according to  claim 14 , wherein a fluid which generates heat of dilution, reaction or neutralization by mixture with the waste chemical is used as the auxiliary fluid mixed with the waste chemical.  
   
   
       16 . The method according to  claim 14 , wherein an addition volume of the auxiliary fluid is set in accordance with temperature of the waste chemical required to raise temperature of the new chemical to a predetermined temperature in the heat exchanger.  
   
   
       17 . The method according to  claim 14 , wherein concentration of at least one chemical in the chemical bath is measured and an addition volume of the auxiliary fluid is set in accordance with the measurement result.  
   
   
       18 . The method according to  claim 17 , wherein the addition volume of the auxiliary fluid is set in accordance with the measured concentration of the chemical such that temperature of the waste chemical is temperature required to raise the temperature of the new chemical to the predetermined temperature.  
   
   
       19 . The method according to  claim 14 , wherein a small quantity of the waste chemical drained from the chemical bath is drained directly to outside.  
   
   
       20 . A method of manufacturing a semiconductor apparatus configured to house a semiconductor substrate in a high-temperature circulation type chemical bath which is filled with a chemical to be used for cleaning of a semiconductor substrate and in which the chemical is circulated and reused after the cleaning, and to clean the semiconductor substrate, 
 the method comprising:    draining the chemical in the chemical bath therefrom;    adding to the drained chemical regarded as a waste chemical an auxiliary fluid to generate heat by mixture with the waste chemical, and thereby heating the waste chemical;    temporarily storing the heated waste chemical in a heat exchanger;    allowing a new chemical to flow in the heat exchanger, and cooling the waste chemical and raising temperature of the new chemical by heat exchange between the waste chemical and the new chemical in the heat exchanger;    supplying the new chemical having the temperature raised to the chemical bath; and    housing the substrate in the chemical bath in which chemicals are exchanged by draining the waste chemical and supplying the new chemical, and thereby cleaning the substrate.