Robin Danfelt, Senior Contamination Control Engineer, Nikon Precision, Belmont, CA, USA

ABSTRACT

It is clear that 193nm lithography photoresists and scanner optical components, as well as masks, are far more sensitive to airborne molecular contaminants (AMC) than those used in earlier lithography generations. However, even older equipment can be significantly affected by AMC. Additionally, although a fab may have AMC levels under control, excursions in the ambient environment or tool pressure differentials may impact process and equipment and, over time, may result in a significant effect on lithographic illumination power or uniformity.