July 14–FRANKLIN, Mass.–Metrology will play an increasingly critical role in preventing molecular contamination of deep UV optics and resists in 193nm lithography, according to participants in Extraction Systems’ recent Lithography Contamination Control and Monitoring Roadmap Workshop.

“Based on presentations and group discussions during the workshop, it’s clear that 193nm lithography is here to stay, and will be the mainstay of semiconductor production through the 45nm technology node much longer than most anticipated. This tightens process parameters like never before, and leaves absolutely no budget for contamination-induced variables,” said Devon Kinkead, president and CEO of Extraction. “At these very low K1 factors, contamination induced light scattering and CD variation will no longer be a nuisance, they will cause a direct yield loss.”

This is the third year Extraction has hosted the workshop, which is designed to outline the challenges related to lithography contamination control in the 130nm to 45nm technology nodes. Since its inception in 2001, the event has expanded into a two-day event, attracting dozens of thought-leaders representing companies, consortia and academia from throughout the deep UV lithography community. This year’s workshop featured working groups, a panel discussion and more than 25 presentations from speakers with expertise in exposure tools, optics, resists, metrology, and semiconductor manufacturing, including presentations from chip makers, exposure and development tool makers, research and consortia organizations, resist makers and academia.

According to workshop participants, current filtration systems are doing a good job of protecting 193nm resists, and much progress has been made in maturing the measurement and control of pollutants that threaten optics. The need to understand filter performance for acids, bases and organics increases as the wavelength drops. Because of variation in molecular challenges from fab to fab, filter breakthrough is difficult to predict. Consequently, lithographers need a simple and reliable method to determine the filter’s end of life point. Low K1 factor 193nm lithography and developing immersion and imprint technologies present significant contamination measurement and control challenges.

In total, more than 40 participants attended the Lithography Contamination Control and Monitoring Workshop, held June 8-9, 2003 in Wellesley, Mass. Next year’s workshop will be held June 14-15, 2004.