A VAPOR PHASE CLEAN TO REMOVE SODIUM USING 1,1,1,5,5,5-HEXAFLUORO-2,4-PENTANEDIONE

Sodium is removed from silicon wafer surfaces by a vapor phase method utilizing the chelation compound 1,1,1,5,5,5-hexafluoro2,4-pentanedione (H+ hfac). At a total pressure of 7.6 Torr, sodium is removed from the wafer surface at temperatures above 190°C. Several mechanisms may play a role in the reaction of H+ hfac with surface sodium species. © Air Products and Chemicals, Inc. 1998. S1099-0062(98)07-003-5.