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Deep‐UV antireflective coating: ellipsometry and XPS characterization
Author(s) -
Boddaert X.,
Caramante A.,
Josse E.,
Delahaye B.
Publication year - 2000
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/1096-9918(200008)30:1<531::aid-sia840>3.0.co;2-q
Subject(s) - x ray photoelectron spectroscopy , ellipsometry , refractive index , anti reflective coating , materials science , analytical chemistry (journal) , coating , absorption (acoustics) , optics , optoelectronics , chemistry , thin film , nanotechnology , physics , nuclear magnetic resonance , composite material , organic chemistry
Oxynitride deep‐ultraviolet antireflective coating (DARC) of Si wafers is used to get better lithography at 248 nm. The thickness and the optical parameters of these films have to be optimized to get good and reproducible results. In this context, DARC layers with different N 2 O flows have been processed and characterized by ellipsometry and XPS in order to determine the optical parameters n (refractive index) and k (absorption index), the stoichiometry and the nature of the Si bonds. The DARC layers appear to be homogeneous, although short‐range variations (1 nm) could hardly be detected by XPS. The correlation between XPS and ellipsometry results is fairly good and confirms that absorption is directly correlated to the amount of Si–Si bonds. A ‘three‐component mode’ assuming that the DARC layer constitutes Si, SiO 2 and Si 3 N 4 has been used to calculate the refractive index. The agreement between this calculated index and the one determined by ellipsometry is fairly good. Copyright © 2000 John Wiley & Sons, Ltd.