A great deal of work has been done on identifying the sources of reticle haze. Researchers have sited haze contributions from the atmosphere, from pellicle, pellicle adhesive and from sulfate residuals left by mask cleaning. Residual sulfates from otherwise high performance cleaning processes can range from 30 ppb and up. This paper focuses on final clean methods within a single track tool that leave concentrations of ion residues approaching 1 ppb. We compare different spin processes which use ozonated water and ultra dilute ammonia and hydrogen water through a megasonic head. Other sources of haze producing ions may remain but eliminating contributions from the final cleaning process opens a productive path to higher yield with 65 and 45 nm design rules.

Date Published: 8 November 2005
PDF: 9 pages
Proc. SPIE 5992, 25th Annual BACUS Symposium on Photomask Technology, 59923H (8 November 2005); doi: 10.1117/12.632179

Published in SPIE Proceedings Vol. 5992:
25th Annual BACUS Symposium on Photomask Technology
J. Tracy Weed; Patrick M. Martin, Editor(s)