CPC G03F 7/70875 (2013.01) [G03F 7/70033 (2013.01)] | 19 Claims |
1. A method for reducing particulate deposition rate on a photomask, comprising:
generating a plasma that emits EUV radiation in a radiation source chamber and also produces particulates;
producing turbulence within the radiation source chamber by changing the temperature in the radiation source chamber between a first temperature setpoint and a second temperature setpoint, wherein the first temperature setpoint and the second temperature setpoint differ by at least 50° C.; and
wherein the turbulence reduces a level of particulates exiting the radiation source chamber and entering a processing chamber containing the photomask.
|