Reduction of polarization and swing effects in a high numerical aperture exposure system by utilizing resist antireflective coatings
Journal
Microelectronic Engineering
Journal Volume
86
Journal Issue
1
Pages
83-87
Date Issued
2009
Author(s)
Abstract
Exposure systems having high numerical apertures (NAs) are essential for increasing the resolution of optical lithography. The efficiency of conventional single-layer bottom antireflective coating (BARC) structures, however, degrades as the angle of incidence increases. In this paper we demonstrate a multilayer BARC structure for high-NA systems employed in ArF lithography. Because the reflection difference between transverse electric (TE or s) and transverse magnetic (TM or p) polarization at the air-resist interface results in low image contrast for high-NA exposure systems, we also describe a single-layer top antireflective coating (TARC) layer that can be used to reduce the polarization effect. By combining the optimized TARC and multilayer BARC structures, the swing effect can be alleviated and the image contrast can be improved for angles of incidence ranging from 0° to 70° (i.e., NA = ca. 0.93). © 2008 Elsevier B.V. All rights reserved.
SDGs
Type
journal article