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Proceedings Paper

Image reversal trilayer materials and processing
Author(s): David J. Abdallah; Kazunori Kurosawa; Elizabeth Wolfer; Victor Monreal; M. Dalil Rahman; DongKwan Lee; Mark Neisser; Ralph R. Dammel
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Paper Abstract

Image reversal trilayer (IRT) combines three lithographic patterning enhancement approaches: image reversal, spin on hard masks, and shrink for recess types of features. With IRT, photoresist imaging is done directly on top of the carbon underlayer. Thick IRT-Carbon Hard Masks (CHM) films provide effective antireflection with high NA lithography and are more etch resistant than common photoresist. IRT-Silicon Hard Masks (SiHM) can be coated over the resist patterns in the lithography track. IRT etching reverses the resist pattern into the IRT-SiHM and transfers this image to the IRTCHM. The recessed patterns in the IRT-CHM are smaller than the CD of the photoresist feature from an inherent shrinking capability of the IRT-SiHM. Continuous improvements to both IRT-SiHM and IRT-CHM have been made. Silicon contents in IRT-SiHM have been pushed as high as possible while not impacting other important properties such as stability, coating quality and resist compatibility. Newer polysiloxane IRT-SiHM no longer require resist freezing prior to coating. Carbon contents in IRTCHM have been pushed as high as possible while maintaining solubility and a low absorption which is important when resist imaging is done directly on top of the IRT-CHM. Feasibility of this image reversal trilayer process was previously demonstrated on L/S and pillar gratings. Recent work focused on nonsymmetrical 2D gratings and simultaneous patterning of L/S gratings at different pattern densities. Particular emphasis is given to pattern density effects which are applicable to any top-coating image reversal process. This paper describes the lithography, pattern transfer process and 2nd generation hard mask materials developed for IRT processing.

Paper Details

Date Published: 11 December 2009
PDF: 12 pages
Proc. SPIE 7520, Lithography Asia 2009, 75200L (11 December 2009); doi: 10.1117/12.837017
Show Author Affiliations
David J. Abdallah, AZ Electronic Materials (United States)
Kazunori Kurosawa, AZ Electronic Materials (Japan)
Elizabeth Wolfer, AZ Electronic Materials (United States)
Victor Monreal, AZ Electronic Materials (United States)
M. Dalil Rahman, AZ Electronic Materials (United States)
DongKwan Lee, AZ Electronic Materials (United States)
Mark Neisser, AZ Electronic Materials (United States)
Ralph R. Dammel, AZ Electronic Materials (United States)

Published in SPIE Proceedings Vol. 7520:
Lithography Asia 2009
Alek C. Chen; Woo-Sung Han; Burn J. Lin; Anthony Yen, Editor(s)

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