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Proceedings Paper

Measuring after etch overlay and characterizing tilt fingerprints in multi-tier 3D-NAND structures
Author(s): Hong-Goo Lee; Dong-Young Lee; Jun-Yeob Kim; Sang-Jun Han; Chan-Ha Park; Jaap Karssenberg; Mir Shahrjerdy; Arno van Leest; Nang-Lyeom Oh; Dong-Hak Lee; Aileen Soco; Tjitte Nooitgedagt
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Paper Abstract

In next generation 3D-NAND devices, accurately determining after-etch overlay for the multi-layer stack is a major challenge. This is especially the case for the multi-tier 3D-NAND structures, where the overlay of the channel holes is an important performance parameter. The most commonly used after-etch metrology suffer both from the high aspect ratio of the channel holes and from the potential presence of large tilts.

Using In-Device Metrology (IDM), we show results of non-destructive overlay measurements on 3D-NAND memory holes. Once the overlay signal has been determined, the remaining asymmetry information in the measurement can be used to characterize tilt phenomena densely through the memory array.

Using hyper-dense in-device measurements show the overlay effects of intra-die stress. A new lithography scanner model is used to correct specifically for such intra-die overlay fingerprints.

Paper Details

Date Published: 26 March 2019
PDF: 8 pages
Proc. SPIE 10959, Metrology, Inspection, and Process Control for Microlithography XXXIII, 1095907 (26 March 2019); doi: 10.1117/12.2515299
Show Author Affiliations
Hong-Goo Lee, SK Hynix, Inc. (Korea, Republic of)
Dong-Young Lee, SK Hynix, Inc. (Korea, Republic of)
Jun-Yeob Kim, SK Hynix, Inc. (Korea, Republic of)
Sang-Jun Han, SK Hynix, Inc. (Korea, Republic of)
Chan-Ha Park, SK Hynix, Inc. (Korea, Republic of)
Jaap Karssenberg, ASML (Netherlands)
Mir Shahrjerdy, ASML (Netherlands)
Arno van Leest, ASML (Netherlands)
Nang-Lyeom Oh, ASML (Korea, Republic of)
Dong-Hak Lee, ASML (Korea, Republic of)
Aileen Soco, ASML (Netherlands)
Tjitte Nooitgedagt, ASML (Netherlands)

Published in SPIE Proceedings Vol. 10959:
Metrology, Inspection, and Process Control for Microlithography XXXIII
Vladimir A. Ukraintsev; Ofer Adan, Editor(s)

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