Share Email Print

Proceedings Paper

EUV simulation extension study for mask shadowing effect and its correction
Author(s): Hoyoung Kang; Steve Hansen; Jan van Schoot; Koen van Ingen Schenau
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

It is well known from 193nm simulation studies that accounting for the electromagnetic (EM) interaction between the incident light and the mask become more important as the mask geometry shrinks. In particular this transition occurs when the size of the mask pattern becomes comparable to the wavelength of light. Early simulation work in EUV lithography indicated rigorous EM calculations are required to predict the subtle effects associated with the mask absorber shadowing effect. These calculations generally show that non-normal mask incidence creates several problems, including HV-bias, slit position dependent bias, and slit position dependent pattern shift. These results are surprising because the mask sizes studied are much larger than the 13.5nm wavelength. If approximate methods could be used rather than the rigorous EM calculations then EUV simulations would be much faster and more accessible. In this study, rigorous EM simulation results are compared with a Kirchoff approximation. The results show that Kirchoff simulations can mimic the shadowing effect with a simple mask bias. It is also found that the pattern shift effect is an artifact caused by a misinterpretation of the rigorous simulation results. With proper biasing depending on the pattern orientation and field position, simple Kirchoff simulation can be used. Thus Any MBOPC tool currently available can handle EUV proximity correction with minor modifications.

Paper Details

Date Published: 3 April 2008
PDF: 11 pages
Proc. SPIE 6921, Emerging Lithographic Technologies XII, 69213I (3 April 2008); doi: 10.1117/12.772487
Show Author Affiliations
Hoyoung Kang, ASML Korea Co., Ltd. (South Korea)
Steve Hansen, ASML US, Inc. (United States)
Jan van Schoot, ASML Netherlands B.V. (Netherlands)
Koen van Ingen Schenau, ASML Netherlands B.V. (Netherlands)

Published in SPIE Proceedings Vol. 6921:
Emerging Lithographic Technologies XII
Frank M. Schellenberg, Editor(s)

© SPIE. Terms of Use
Back to Top