Distributed temperature control system for point of dispense temperature control on track systems utilizing mixing of hot and cold streams

Abstract

A point of dispense temperature control apparatus for a track lithography system. The apparatus includes a first liquid source characterized by a first temperature and a first flow controller coupled to the first liquid source. The apparatus also includes a second liquid source characterized by a second temperature and a second flow controller coupled to the second liquid source. The apparatus further includes a mixing element coupled to the first flow controller and the second flow controller. The mixing element is adapted to provide a mixed stream characterized by a total flow volume and a temperature intermediate to the first temperature and the second temperature. The apparatus additionally includes a sensor coupled to the mixed stream, a point of dispense heat exchanger coupled to the mixed stream, and a control loop coupled to the sensor and at least one of the first flow controller or the second flow controller. The control loop is adapted to provide a consistent total flow volume at the intermediate temperature.

1 . A point of dispense temperature control apparatus for a track lithography system, the apparatus comprising: 
 a first liquid source characterized by a first temperature;    a first flow controller coupled to the first liquid source;    a second liquid source characterized by a second temperature;    a second flow controller coupled to the second liquid source;    a mixing element coupled to the first flow controller and the second flow controller, the mixing element being adapted to provide a mixed stream characterized by a total flow volume and a temperature intermediate to the first temperature and the second temperature;    a sensor coupled to the mixed stream;    a point of dispense heat exchanger coupled to the mixed stream; and    a control loop coupled to the sensor and at least one of the first flow controller or the second flow controller, wherein the control loop is adapted to provide a consistent total flow volume at the intermediate temperature.    
   
   
       2 . The apparatus of  claim 1  wherein the first liquid source and the second liquid source are packaged in a single unit.  
   
   
       3 . The apparatus of  claim 1  wherein the control loop is coupled to the sensor and the first flow controller.  
   
   
       4 . The apparatus of  claim 1  wherein the control loop is coupled to the sensor and the second flow controller.  
   
   
       5 . The apparatus of  claim 1  further comprising: 
 a third flow controller coupled to the mixed stream and the first liquid source; and    a fourth flow controller coupled to the mixed stream and the second liquid source.    
   
   
       6 . The apparatus of  claim 5  wherein a flow rate of the first fluid through the first flow controller is substantially equal to a flow rate of the mixed stream through the third flow controller.  
   
   
       7 . The apparatus of  claim 1  wherein the sensor is a resistance temperature detector sensor.  
   
   
       8 . The apparatus of  claim 1  wherein the control loop comprises a proportional-integral-derivative controller.  
   
   
       9 . The apparatus of  claim 8  wherein the proportional-integral-derivative controller provides a control signal utilized to modulate the flow rate of the second fluid through the second flow controller.  
   
   
       10 . The apparatus of  claim 1  wherein the first flow controller and the second flow controller are adapted to pressure balance a first fluid pressure associated with the first liquid source and a second fluid pressure associated with the second liquid source.  
   
   
       11 . The apparatus of  claim 1  wherein the point of dispense heat exchanger is coupled to a photolithography chemical dispense system.  
   
   
       12 . A point of dispense temperature control apparatus for a track lithography system, the apparatus comprising: 
 a first fluid source characterized by a first temperature;    a first flow regulator coupled to the first fluid source;    a second fluid source characterized by a second temperature;    a second flow regulator coupled to the second fluid source;    a mixing element coupled to the first fluid source and the second fluid source, the mixing element being adapted to provide a mixed stream characterized by a temperature intermediate to the first temperature and the second temperature;    a sensor coupled to the mixed stream;    a point of dispense heat exchanger coupled to the mixed stream;    a fluid return path coupled to the point of dispense heat exchanger and adapted to deliver fluid to at least one of the first fluid source or the second fluid source; and    a control loop coupled to the sensor and at least one of the first flow controller or the second flow controller.    
   
   
       13 . The apparatus of  claim 12  wherein the flow rate of the mixed stream is characterized by a constant total flow rate during a predetermined time period.  
   
   
       14 . The apparatus of  claim 12  wherein the sensor is a resistance temperature detector sensor.  
   
   
       15 . The apparatus of  claim 12  wherein the control loop comprises a proportional-integral-derivative controller and an electro-pneumatic regulator.  
   
   
       16 . The apparatus of  claim 15  wherein the proportional-integral-derivative controller provides a control signal utilized to modulate the flow rate of the second fluid through the second flow controller.  
   
   
       17 . A method of providing distributed temperature control for multiple point of dispense heat exchangers in a track lithography system, the method comprising: 
 providing a first fluid stream characterized by a first temperature;    providing a second fluid stream characterized by a second temperature;    providing a first fluid flow path coupled to the first fluid stream;    providing a second fluid flow path coupled to the second fluid stream;    mixing the first fluid stream and the second fluid stream to provide a mixed fluid stream characterized by a third temperature;    monitoring the third temperature;    modulating a flow rate of at least one of the first fluid stream or the second fluid stream in response to monitoring the third temperature; and    coupling the mixed stream to a plurality of point of dispense heat exchangers adapted to control a temperature associated with photolithography chemistry.    
   
   
       18 . The method of  claim 17  wherein the third temperature is intermediate to the first temperature and the second temperature.  
   
   
       19 . The method of  claim 17  wherein each of the plurality or point of dispense heat exchangers are coupled to a portion of a photolithography chemistry dispense system.  
   
   
       20 . The method of  claim 19  wherein the portions of the photolithography chemistry dispense system are operable to provide independent temperature set points for photolithography chemistry fluids.