Progressive mask defects are a critical mask-reliability issue in DUV lithography. It is well known that the majority of the defects are ammonium sulfates. We have found using ToF-SIMS that metallic atoms are localized at ammonium-sulfate defects on the mask surface, can influence the growth of the defects. Carbon compounds containing nitrogen atoms are also localized at the some defects. These carbon compounds are the result of the adsorption of organic volatiles outgassing from a reticle SMIF pod. Metal residues and organic contamination on a photomask as well as airborne acidic and basic contamination must be controlled to avoid progressive defects on photomasks.

Date Published: 30 October 2007
PDF: 7 pages
Proc. SPIE 6730, Photomask Technology 2007, 673019 (30 October 2007); doi: 10.1117/12.746375

Published in SPIE Proceedings Vol. 6730:
Photomask Technology 2007
Robert J. Naber; Hiroichi Kawahira, Editor(s)