Method and apparatus for recycling inert gas

Abstract

A method for recycling an inert gas evacuated from a material deposition process chamber 10 comprises cooling the evacuated inert gas and recirculating a proportion of the cooled gas to the chamber 10 at a first temperature for use as a cooling gas in the material deposition process 12 , and recirculating a proportion of the cooled gas to the chamber 10 at a second temperature for use as a shielding gas in the material deposition process 12 , the second temperature being higher than the first temperature. Apparatus 22 for recycling an inert gas is also disclosed.

1 - 12 . (canceled) 
   
   
       13 . Apparatus for recycling an inert gas evacuated from a material deposition process chamber, the apparatus comprising means for cooling the evacuated inert gas to provide a cooled gas, means for recirculating a proportion of the cooled gas to the chamber at a first temperature for use as a cooling gas in the material deposition process, and means for recirculating a proportion of the cooled gas to the chamber at a second temperature for use as a shielding gas in the material deposition process, the second temperature being higher than the first temperature. 
   
   
       14 . Apparatus according to  claim 13 , wherein the means for cooling the evacuated inert gas comprises a gas cooler operable to cool the evacuated gas to the first temperature. 
   
   
       15 . Apparatus according to  claim 14 , wherein the means for recirculating the cooled gas at the first temperature comprises a pump device for recirculating the cooled gas directly from the gas cooler to the chamber at the first temperature. 
   
   
       16 . Apparatus according to  claim 14 , wherein the means for recirculating the cooled gas at the second temperature comprises a gas mixing device for mixing a proportion of the gas cooled to the first temperature with a proportion of the uncooled evacuated gas to raise the temperature of the gas to the second temperature, prior to recirculation to the chamber. 
   
   
       17 . Apparatus according to  claim 13 , wherein the apparatus further comprise a gas scrubber, located between the chamber and the means for cooling the evacuated gas, for removing impurities from the evacuated gas. 
   
   
       18 . Apparatus according to  claim 13 , wherein the apparatus comprises means for directing the cooled gas at the first temperature onto material deposited in the material deposition process to cool the deposited material. 
   
   
       19 . Apparatus according to  claim 18 , wherein the apparatus comprises shielding means between the directing means and a heat source used in the material deposition process. 
   
   
       20 . Apparatus according to  claim 13 , wherein the apparatus comprises a monitoring system for monitoring the first and second temperatures, the monitoring system including a controller for adjusting the recirculation rate to compensate for temperature variations.