Paper
30 July 2002 High-NA lithographic imagery at Brewster's angle
Author Affiliations +
Abstract
Recent advances have enabled exposure tool manufacturers to ship tools with Numerical Aperture (NA) equals 0.8, and to envision optics with even larger NA. Thus the lithography community must grapple with images formed by oblique waves close to Brewster's angle. (For a typical chemically amplified resist with index of refraction n equals 1.7, Brewster's angle is 59 degree(s), corresponding to NA equals 0.86.) This paper will consider some of the surprising phenomena that occur at such high NA. Both vector diffraction simulation results and experimental results from the IBM interferometric lithography apparatus will be discussed. One of the most interesting modeling predictions is that, near Brewster's angle, the swing curve for TM polarization is much smaller than normal, while the swing curve for TE polarization is much larger than normal, and experimental measurements verify this prediction. Special image cross sections using the Flagello decoration method will also demonstrate the loss of TM image contrast due to vector imaging effects.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Timothy A. Brunner, Nakgeuon Seong, William D. Hinsberg, John A. Hoffnagle, Frances A. Houle, and Martha I. Sanchez "High-NA lithographic imagery at Brewster's angle", Proc. SPIE 4691, Optical Microlithography XV, (30 July 2002); https://doi.org/10.1117/12.474473
Lens.org Logo
CITATIONS
Cited by 21 scholarly publications and 3 patents.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Polarization

Lithography

Reflectivity

Photoresist processing

Reflection

Interferometry

Image processing

Back to Top