The immersion fluid in the lens - wafer gap of advanced lithography scanners has the propensity to be a transport media for imaging defects. A great deal of effort has been devoted to understanding and eliminating the root causes of patterned defects in immersion lithography. Characterization of patterned and unpatterned defects on the wafer top surface has helped to drive improvements in lithography equipment, processes and materials design that subsequently enabled immersion defect density levels to be commensurate with dry lithography. This has enabled the insertion of immersion lithography into mainstream manufacturing. However, the "ever improving" yield impetus drives the need to search for and eliminate defect sources beyond the conventional top surface. This paper describes progress in extending these efforts to and beyond the wafer's edge.

Date Published: 7 March 2008
PDF: 10 pages
Proc. SPIE 6924, Optical Microlithography XXI, 69244O (7 March 2008); doi: 10.1117/12.776363

Published in SPIE Proceedings Vol. 6924:
Optical Microlithography XXI
Harry J. Levinson; Mircea V. Dusa, Editor(s)