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Proceedings Paper

Effect of azimuthally polarized illumination imaging on device patterns beyond 45nm node
Author(s): Ken Ozawa; Boontarika Thunnakart; Tokihisa Kaneguchi; Isao Mita; Atsushi Someya; Toshiharu Nakashima; Hisashi Nishinaga; Yasushi Mizuno; Tomoyuki Matsuyama; Masato Hamatani
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Paper Abstract

For an ultra-high numerical aperture (NA), such as that exceeding 0.9, the p-polarized component of light that has passed through a region at the limit of the NA of a high-NA lithography tool, degrades contrast because of the so-called vector imaging effect, and is therefore detrimental to the formation of optical images. Polarized illumination removes the effect of the p-polarized light component and provides illumination light composed of s-polarized light. The higher the NA, the greater are the benefits of polarized illumination. Therefore, in lithography at the 45-nm node and below, polarized illumination is viewed as an indispensable technology. We explore the applicability of polarized illumination to device manufacturing processes at the 45-nm node and beyond, with a focus on the utilization of azimuthally polarized illumination, which enables one mask exposure. The data used in this research were obtained through imaging simulations and experiments using a dry lithography tool equipped with a 0.92-NA projection lens. In imaging simulations using a lithography simulator, the application of azimuthally polarized illumination improved image contrast in resists by approximately 20% for half pitch (HP) 65-nm dense patterns. As a result, device patterns showed enhanced robustness with respect to exposure dose error; extended process windows; and reduced mask error enhancement factor (MEEF), line edge roughness (LER), and line end shortening (LES). This paper examines the results of experiments conducted using imaging simulations and lithography tools on other product device like patterns (besides special patterns in which benefits can clearly be expected, including dense (L/S) patterns), and reports the results.

Paper Details

Date Published: 15 March 2006
PDF: 12 pages
Proc. SPIE 6154, Optical Microlithography XIX, 61540C (15 March 2006); doi: 10.1117/12.656242
Show Author Affiliations
Ken Ozawa, Sony Corp. (Japan)
Boontarika Thunnakart, Sony Corp. (Japan)
Tokihisa Kaneguchi, Sony Corp. (Japan)
Isao Mita, Sony Corp. (Japan)
Atsushi Someya, Sony Corp. (Japan)
Toshiharu Nakashima, Nikon Corp. (Japan)
Hisashi Nishinaga, Nikon Corp. (Japan)
Yasushi Mizuno, Nikon Corp. (Japan)
Tomoyuki Matsuyama, Nikon Corp. (Japan)
Masato Hamatani, Nikon Corp. (Japan)

Published in SPIE Proceedings Vol. 6154:
Optical Microlithography XIX
Donis G. Flagello, Editor(s)

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