Patent ID: 8338806

Claim:
A processing system for irradiating a substrate with a gas cluster ion beam (GCIB), the system comprising: a first nozzle for forming and emitting gas clusters beams through an outlet thereof, and a stagnation chamber upstream of and adjacent the first nozzle and having an inlet, the first nozzle being configured to direct a gas cluster beam toward the substrate; an ionizer positioned downstream of the outlet and configured to ionize the gas cluster beam to form the GCIB; a first gas supply in fluid communication with the inlet of the stagnation chamber and including a first gas source and a first valve between the first gas source and the first nozzle for controlling flow of a first gas between the first gas source and the first nozzle; and a second gas supply in fluid communication with the inlet of the stagnation chamber and including a second gas source and a second valve between the second gas source and the stagnation chamber for controlling flow of a second gas between the second gas source and the first nozzle, wherein the first and second valves are positioned to define a common gas-holding volume between the first and second valves and the inlet of the stagnation chamber, the common gas-holding volume being less than about 2 cm 3 to thereby enable rapid evacuation and switching of gas to the first nozzle between the first gas and the second gas without mixing the first and second gases, and wherein the first and second valves are actuatable to permit selective supply of the first gas from the first gas source or the second gas from the second gas source.