Publication detail

Interfacial Oxide Formation during Anodization of Hafnium/Aluminium Superimposed Layers

SIKET, C. BENDOVÁ, M. MARDARE, C. HUBÁLEK, J. BAUER, S. HASSEL, A. MARDARE, A.

Original Title

Interfacial Oxide Formation during Anodization of Hafnium/Aluminium Superimposed Layers

Type

journal article in Web of Science

Language

English

Original Abstract

The anodization behaviour of Hf/Al stacked thin films, sequentially deposited from vapour phase without breaking vacuum, was investigated using scanning droplet cell microscopy. Surface microstructure and crystallographic analysis revealed the formation of highly textured and compact hexagonal Hf films for thicknesses above 7.5 nm. Cyclic voltammetry suggested the formation of discrete anodic layers starting with pure HfO2 on the surface, a mixture of HfO2 and Al2O3 as an intermediate layer and pure Al2O3 in depth of the films. Coulometric investigations revealed oxide formation factors of 2.2 nm/V for HfO2 while for pure Al2O3 a maximum of 1.4 nm/V was measured. Electrochemical impedance spectroscopy performed for various Hf thicknesses and different final anodization potentials revealed almost ideal dielectrics formed from mixed HfO2/Al2O3, permittivities up to 26 being measured for the anodized Hf/Al films. Surface analytical investigations and depth profiling as well as high resolution transmission electron microscopy confirmed the discrete anodic layer growth and the mixing of both anodic oxides. The significant thickness values found for the mixed oxide layer must redefine the general expectations for the use of anodized superimposed layers in various applications.

Keywords

combinatorial libraries; high-throughput experimentation; scanning droplet cell microscopy; anodic oxide film; hafnium oxide

Authors

SIKET, C.; BENDOVÁ, M.; MARDARE, C.; HUBÁLEK, J.; BAUER, S.; HASSEL, A.; MARDARE, A.

RIV year

2015

Released

1. 10. 2015

Publisher

PERGAMON-ELSEVIER SCIENCE LTD

ISBN

0013-4686

Periodical

Electrochimica Acta

Year of study

178

Number

1

State

United Kingdom of Great Britain and Northern Ireland

Pages from

344

Pages to

352

Pages count

9

URL

http://www.sciencedirect.com/science/article/pii/S0013468615301067

BibTex

@article{BUT118649,
  author="Christian M. {Siket} and Mária {Bendová} and Cezarina Cela {Mardare} and Jaromír {Hubálek} and Siegfried {Bauer} and Achim Walter {Hassel} and Andrei Ionut {Mardare}",
  title="Interfacial Oxide Formation during Anodization of Hafnium/Aluminium Superimposed Layers",
  journal="Electrochimica Acta",
  year="2015",
  volume="178",
  number="1",
  pages="344--352",
  doi="10.1016/j.electacta.2015.07.039",
  issn="0013-4686",
  url="http://www.sciencedirect.com/science/article/pii/S0013468615301067"
}