Open AccessDepth profiling of very thin HfO2/Al2O3 stacks by ellipsometry
Author(s) -
Y. Karmakov,
A. Paskaleva,
D. Spassov
Publication year - 2022
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2240/1/012049
Subject(s) - materials science , ellipsometry , atomic layer deposition , thin film , dielectric , annealing (glass) , fabrication , analytical chemistry (journal) , optoelectronics , profiling (computer programming) , nanotechnology , chemistry , composite material , computer science , medicine , alternative medicine , pathology , chromatography , operating system
Ellipsometry (VASE and MAIE) with appropriate algorithms for experimental data interpretation was applied for quantitative characterization of thin Al 2 O 3 /HfO 2 multilayers formed by atomic layer deposition (ALD) applicable to the fabrication of charge-trapping nonvolatile memories. A substantial benefit of the algorithms is the depth profiling of the stacks. In this work, the depth profiles were retrieved of the HfO 2 constituent in very thin (Al 2 O 3 :HfO 2 ) stacks embedded in thin Al 2 O 3 surrounding layers. The peculiarities in the achieved depth profiles are used to determine the bi-layer blocks and their sub-layer thicknesses. The influence of a rapid thermal annealing in O 2 on the depth profile and the sub-layer thicknesses is studied; substantial changes are thus revealed in the thickness and composition of the stacks. This information could be used in optimizing the dielectric and electrical properties of the stacks and multilayers.