8 August 1993 Aerial image-based design of rim phase-shift masks with annular illumination
Author Affiliations +
Abstract
A wide variety of lithography enhancement techniques have been introduced in recent years. Each method has certain virtues, such as improving the resolution of tightly packed features or increasing the depth of focus for isolated ones. Normally, these schemes are analyzed for areas in which they work best. However, it is desirable to have a phase-shift method and illumination system which improves the depth of focus for a large variety of patterns. To satisfy both requirements, promising techniques must be biased to obtain the best process improvement. These issues are particularly relevant for masks with random logic. To address the two problems, we have developed an E-D tree based computer aided design system which analyzes phase-shift masks and illumination methods for one-dimensional features and calculates the proper bias for them. Our simulations concentrate on analyzing constant width lines and spaces of varying duty cycle. The results from analyzing the features illustrate that both phase-shifting masks and off-axis illumination have regions of reduced performance, or dead zones, in which the depth of focus is degraded. Examples of dead zones are evident with many types of phase-shift masks, such as attenuating, alternate aperture, and rim, and with illumination systems, such as annular illumination. Combinations of enhancement techniques, however, can reduce the effect.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
David M. Newmark, Joseph G. Garofalo, and Sheila Vaidya "Aerial image-based design of rim phase-shift masks with annular illumination", Proc. SPIE 1927, Optical/Laser Microlithography, (8 August 1993); doi: 10.1117/12.150484; https://doi.org/10.1117/12.150484
PROCEEDINGS
16 PAGES


SHARE
Advertisement
Advertisement
RELATED CONTENT

Printability of 2D mask quality
Proceedings of SPIE (December 16 2003)
CD-measurement technique for hole patterns on stencil mask
Proceedings of SPIE (December 05 2004)
Application of deep UV attenuated PSM to 0.2 um contact...
Proceedings of SPIE (December 26 1996)
Full field imaging with a 157-nm scanner
Proceedings of SPIE (May 27 2004)

Back to Top