Paper
29 June 1998 Differences in pattern displacement error under different illumination conditions
Nakgeuon Seong, Jongwook Kye, Hoyoung Kang, Joo-Tae Moon
Author Affiliations +
Abstract
Off-axis illumination (OAI) technique is one of the most widely used resolution enhancement methods for sub 0.2 micrometer resolution in KrF lithography. Repeated patterns in DRAM drove many applications of OAI technique, such as annular, quadruple. There are optimum illumination shapes depending on pattern shapes and pitches. We measured pattern displacement error differences under two types of illumination shapes using box-and-box type overlay keys and real patterns to which we optimized illumination shapes. We focused on the differences of pattern displacement error between two pattern sets rather than pattern displacement error itself. The results show huge differences of overlay readings under various strong OAI settings. Finally, we suggested applying correction tables calculated by simulation with aberration data.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Nakgeuon Seong, Jongwook Kye, Hoyoung Kang, and Joo-Tae Moon "Differences in pattern displacement error under different illumination conditions", Proc. SPIE 3334, Optical Microlithography XI, (29 June 1998); https://doi.org/10.1117/12.310821
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KEYWORDS
Overlay metrology

Lithographic illumination

Fiber optic illuminators

Resolution enhancement technologies

Printing

Lead

Lithography

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