Cymer, Inc.
Laser discharge chamber passivation by plasma
Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode. Plasma cleaning and passivation of laser discharge chambers is safer, more efficient, and more effective than conventional thermal cleaning and passivation processes.
Cymer, Inc.
H B B B H H G
H01S B82Y B08B B08B H01S H01J G03F
inventional inventional inventional inventional additional inventional inventional
Richard L. Robert E. Tom A. Richard G. Mark R. John P.
Sandstrom Weeks Watson Morton Lewis Quitter