Vacuum Assisted Filtration

Abstract

An apparatus includes a chemical filter fluidly coupled between a source for a processing solution and a nozzle to dispense the processing solution. The chemical filter is configured to filter the processing solution from the source. The apparatus may include a vacuum pump that is configured to apply a vacuum to the chemical filter. The apparatus may include a valve system configured to operate in a first operating state and a second operating state, where in the first operating state the valve system is configured to couple the source to the chemical filter and block the vacuum to the chemical filter, and where in the second operating state the valve system is configured to couple the vacuum to the chemical filter and block the source to the chemical filter.

What is claimed is: 
     
         1 . An apparatus comprising:
 a chemical filter fluidly coupled between a source for a processing solution and a nozzle to dispense the processing solution, the chemical filter configured to filter the processing solution from the source;   a vacuum pump configured to apply a vacuum to the chemical filter; and   a valve system configured to operate in a first operating state and a second operating state, wherein in the first operating state the valve system is configured to couple the source to the chemical filter and block the vacuum to the chemical filter, and wherein in the second operating state the valve system is configured to couple the vacuum to the chemical filter and block the source to the chemical filter.   
     
     
         2 . The apparatus of  claim 1 , further comprising:
 a controller configured to switch the valve system from the first operating state to the second operating state.   
     
     
         3 . The apparatus of  claim 1 , wherein the valve system comprises a three-way valve that switches the valve system between the first operating state and the second operating state. 
     
     
         4 . The apparatus of  claim 1 , wherein the chemical filter comprises:
 a housing comprising a first port configured to be coupled to the source or the vacuum pump, a second port coupled to the nozzle, a third port coupled to an exhaust vent; and   a filter disposed in the housing.   
     
     
         5 . The apparatus of  claim 1 , wherein the chemical filter comprises:
 a housing comprising a first port coupled to the source, a second port coupled to the nozzle, a third port coupled to an exhaust vent, and a fourth port coupled to the vacuum pump; and   a chemical filter disposed in the housing.   
     
     
         6 . The apparatus of  claim 1 , wherein the chemical filter comprises:
 a housing comprising a first port configured to be coupled to the nozzle or the vacuum pump, a second port coupled to the source, a third port coupled to an exhaust vent; and   a chemical filter disposed in the housing.   
     
     
         7 . The apparatus of  claim 1 , further comprising a vent system coupled to the chemical filter, wherein the vent system is configured to flush the processing solution. 
     
     
         8 . A method of supplying a processing solution, the method comprising:
 shutting off a feed line supplying the processing solution to a chemical filter;   installing a dry chemical filter in a filter housing of the chemical filter;   closing an output line from the filter housing to a nozzle configured to dispense the processing solution;   applying vacuum to the filter housing; and   opening the feed line while locking in the vacuum within the filter housing.   
     
     
         9 . The method of  claim 8 , further comprising opening the output line after filling the filter housing with the processing solution. 
     
     
         10 . The method of  claim 8 , further comprising removing a used chemical filter from the filter housing before installing the dry chemical filter. 
     
     
         11 . The method of  claim 8 , further comprising venting the processing solution before applying the vacuum. 
     
     
         12 . The method of  claim 8 , wherein the processing solution comprises chemicals for a photolithography process, wet cleaning process, deposition process liquid precursor, or etching process liquid precursor. 
     
     
         13 . The method of  claim 8 , wherein installing the chemical filter in the filter housing comprises installing a dry chemical filter that is devoid of liquid chemicals before the installing. 
     
     
         14 . The method of  claim 8 , wherein applying the vacuum to the filter housing comprises reaching a pressure inside the filter housing between 10 mTorr and 500 mTorr. 
     
     
         15 . The method of  claim 8 , further comprising processing a semiconductor wafer with the chemical dispensed from the nozzle. 
     
     
         16 . A device comprising:
 a memory storing a program to be executed in a processor, the program comprising instructions to
 shut off a feed line supplying a processing solution to a chemical filter; 
 after installing a chemical filter in a filter housing of the chemical filter, close an output line from the filter housing to a nozzle configured to dispense the processing solution; 
 apply vacuum to the filter housing; and 
 open the feed line while locking in the vacuum within the filter housing. 
   
     
     
         17 . The device of  claim 16 , wherein the program comprises further instructions for opening the output line after filling the filter housing with the processing solution. 
     
     
         18 . The device of  claim 16 , wherein the program comprises further instructions for venting the processing solution before applying the vacuum. 
     
     
         19 . The device of  claim 16 , wherein the program comprises further instructions for reaching a pressure inside the filter housing between 10 mTorr and 500 mTorr. 
     
     
         20 . The device of  claim 16 , further comprising a processor to execute the program.