Method and apparatus for solvent recycling

Abstract

A method of operating a wet process apparatus, includes dispensing a solution from a nozzle and directing the solution to a bath through an inlet port. A purge gas is injected into the bath to force flow of the solution from the bath to a buffer tank. A condition of the fluid within the buffer tank is monitored with a sensor. The solution is circulated to a pump and then through a filter before returning the solution to the nozzle. Overflow solution is directed out of the bath via an overflow path to a drain for preventing an overflow condition.

What is claimed is: 
     
         1 . A method of operating a wet process apparatus, comprising:
 dispensing a solution from a nozzle;   directing the solution to a bath through an inlet port;   injecting a purge gas into the bath to force flow of the solution from the bath to a buffer tank;   monitoring a condition of the fluid within the buffer tank with a sensor;   circulating the solution to a pump and then through a filter before returning the solution to the nozzle; and   directing overflow solution out of the bath via an overflow path to a drain for preventing an overflow condition.   
     
     
         2 . The method of  claim 1 , wherein the overflow path is disposed closer to the buffer tank than the gas inlet to prevent the overflow condition in the bath. 
     
     
         3 . The method of  claim 1 , the monitoring further comprising:
 determining a fluid level condition in the bath using the sensor; and   generating an alarm at a controller when a threshold value of the fluid level condition is determined.   
     
     
         4 . The method of  claim 3 , further comprising:
 measuring a flow rate of the solution by a flow meter.   
     
     
         5 . The method of  claim 1 , further comprising:
 monitoring a level of the solution in the buffer tank.   
     
     
         6 . The method of  claim 1 , further comprising:
 removing particles and contaminants from the solution.   
     
     
         7 . A method of operating a wet process apparatus in a semiconductor manufacturing process, comprising:
 dispensing a solution from a nozzle into a bath;   injecting a purge gas into the bath to force flow of the solution from the bath to a buffer tank; and   directing overflow solution out of the bath via an overflow path to a drain for preventing an overflow condition.   
     
     
         8 . The method of  claim 7 , further comprising:
 monitoring a contamination level of the solution in the buffer tank by a sensor.   
     
     
         9 . The method of  claim 8 , further comprising:
 generating an alarm based on readings of the sensor.   
     
     
         10 . The method of  claim 9 , further comprising:
 halting the semiconductor manufacturing process in response to the alarm.   
     
     
         11 . The method of  claim 9 , further comprising:
 initiating a clean in place process in response to the alarm.   
     
     
         12 . The method of  claim 7 , further comprising:
 removing particles and contaminants from the solution.   
     
     
         13 . A method of operating a wet process apparatus, comprising:
 dispensing a solvent from a nozzle onto a substrate, wherein the substrate is disposed between the nozzle and a bath so that the solvent is received into the bath;   injecting a purge gas into the bath to force flow of the solvent from the bath to a buffer tank; and   directing overflow solution out of the bath via an overflow path to a drain for preventing an overflow condition.   
     
     
         14 . The method of  claim 13 , further comprising:
 measuring a flow rate of the solution by a flow meter.   
     
     
         15 . The method of  claim 13 , further comprising:
 removing particles and contaminants from the solution.   
     
     
         16 . The method of  claim 13 , further comprising:
 monitoring a contamination level of the solution in the buffer tank by a sensor.   
     
     
         17 . The method of  claim 16 , further comprising:
 generating an alarm based on readings of the sensor.   
     
     
         18 . The method of  claim 17 , further comprising:
 halting a semiconductor manufacturing process in response to the alarm.   
     
     
         19 . The method of  claim 17 , further comprising:
 initiating a clean in place process in response to the alarm.   
     
     
         20 . The method of  claim 13 , further comprising:
 monitoring a level of the solvent in the buffer tank.