2 June 2000 Protecting the DUV process and optimizing optical transmission
Author Affiliations +
It has been well documented that DUV lithographic processes are sensitive to airborne contamination such as ammonia and n- methyl-2-pyrrolidone (NMP). Chemical filtration technologies have aided in minimizing the problems associated with these contaminants in the photolithographic process. As the demand for smaller features increases, so will the need to operate within even cleaner environments than are available today. One such area where airborne contamination has proven to be of significant concern, is within the lensing system of the tool. With decreasing feature size, the lithographic process has proven to be more sensitive to contamination of the lens itself, and within the environment surrounding the lens. Condensation on the lens (hazing) and the presence of contamination between the lens and substrate can result in poor optical transmission. To minimize these problems, a purge gas is typically employed. Even though high purity gases are used, contamination within the gas still is an issue. This work describes our efforts directed at understanding the purge gas and lens environments. In addition, we will address our efforts that have focused on the development of chemical filters that provide environments for optimized optical transmission in lithographic applications.
© (2000) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Andrew J. Dallas, Debbie Arends, Kristen Fischer, Jon Joriman, Kristine M. Graham, Richard Ringold, "Protecting the DUV process and optimizing optical transmission", Proc. SPIE 3998, Metrology, Inspection, and Process Control for Microlithography XIV, (2 June 2000); doi: 10.1117/12.386451; https://doi.org/10.1117/12.386451

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