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Proceedings Paper

Intrafield CD variation by stray light from neighboring field
Author(s): Chang-Moon Lim; Jung-Ho Song; Sung-Soo Woo; Ki-Sung Kwon; Chang-Nam Ahn; Ki-Soo Shin
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Paper Abstract

The main object of this paper is to investigate the root cause of CD change by neighboring field observed in KrF scanner (max. 0.70NA) and to measure the amount of stray light from neighboring field precisely. Line widths of gate pattern are measured at the isolated and surrounded field and the amount of CD change by neighboring field is found to be proportional to the clear ratio of mask. By exposing with special configuration, it is found that the line width is linearly decreased as the dose of neighboring field increases. From this linear dependency on doses of neighboring field, it is clear that non-negligible amount of light is scattered out into the adjacent field. The amount of this stray light level coming from neighboring field is obtained quantitatively by synthetic analysis of above result and double exposure to mimic background DC light by flare. About 1.2% of stray light from outside of the field is observed at the slit position close to the boundary of neighboring field. Disappearing pad test is also performed to measure the flare from exposure of field itself. Finally, it is obtained the distribution of total stray light - nominal flare plus flare from adjacent field - and it is found to be existed around 0.7% deviation of stray light across the slit.

Paper Details

Date Published: 30 July 2002
PDF: 9 pages
Proc. SPIE 4691, Optical Microlithography XV, (30 July 2002); doi: 10.1117/12.474525
Show Author Affiliations
Chang-Moon Lim, Hynix Semiconductor, Inc. (South Korea)
Jung-Ho Song, Hynix Semiconductor, Inc. (South Korea)
Sung-Soo Woo, Hynix Semiconductor, Inc. (South Korea)
Ki-Sung Kwon, Hynix Semiconductor, Inc. (South Korea)
Chang-Nam Ahn, Hynix Semiconductor, Inc. (South Korea)
Ki-Soo Shin, Hynix Semiconductor, Inc. (South Korea)

Published in SPIE Proceedings Vol. 4691:
Optical Microlithography XV
Anthony Yen, Editor(s)

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