TU Darmstadt / ULB / TUbiblio

Hafnium carbide formation in oxygen deficient hafnium oxide thin films

Rodenbücher, C. and Hildebrandt, E. and Szot, K. and Sharath, S. U. and Kurian, J. and Komissinskiy, P. and Breuer, U. and Waser, R. and Alff, L. (2016):
Hafnium carbide formation in oxygen deficient hafnium oxide thin films.
In: Applied Physics Letters, AIP Publishing, p. 252903, 108, (25), ISSN 0003-6951,
[Online-Edition: http://doi.org/10.1063/1.4954714],
[Article]

Abstract

On highly oxygen deficient thin films of hafnium oxide (hafnia, HfO2−x) contaminated with adsorbates of carbon oxides, the formation of hafnium carbide (HfCx) at the surface during vacuum annealing at temperatures as low as 600 °C is reported. Using X-ray photoelectron spectroscopy the evolution of the HfCx surface layer related to a transformation from insulating into metallic state is monitored in situ. In contrast, for fully stoichiometric HfO2 thin films prepared and measured under identical conditions, the formation of HfCx was not detectable suggesting that the enhanced adsorption of carbon oxides on oxygen deficient films provides a carbon source for the carbide formation. This shows that a high concentration of oxygen vacancies in carbon contaminated hafnia lowers considerably the formation energy of hafnium carbide. Thus, the presence of a sufficient amount of residual carbon in resistive random access memory devices might lead to a similar carbide formation within the conducting filaments due to Joule heating.

Item Type: Article
Erschienen: 2016
Creators: Rodenbücher, C. and Hildebrandt, E. and Szot, K. and Sharath, S. U. and Kurian, J. and Komissinskiy, P. and Breuer, U. and Waser, R. and Alff, L.
Title: Hafnium carbide formation in oxygen deficient hafnium oxide thin films
Language: English
Abstract:

On highly oxygen deficient thin films of hafnium oxide (hafnia, HfO2−x) contaminated with adsorbates of carbon oxides, the formation of hafnium carbide (HfCx) at the surface during vacuum annealing at temperatures as low as 600 °C is reported. Using X-ray photoelectron spectroscopy the evolution of the HfCx surface layer related to a transformation from insulating into metallic state is monitored in situ. In contrast, for fully stoichiometric HfO2 thin films prepared and measured under identical conditions, the formation of HfCx was not detectable suggesting that the enhanced adsorption of carbon oxides on oxygen deficient films provides a carbon source for the carbide formation. This shows that a high concentration of oxygen vacancies in carbon contaminated hafnia lowers considerably the formation energy of hafnium carbide. Thus, the presence of a sufficient amount of residual carbon in resistive random access memory devices might lead to a similar carbide formation within the conducting filaments due to Joule heating.

Journal or Publication Title: Applied Physics Letters
Volume: 108
Number: 25
Publisher: AIP Publishing
Uncontrolled Keywords: Carbon, Hafnium, Carbides, X-ray photoelectron spectroscopy, Thin film devices
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Advanced Thin Film Technology
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences
Date Deposited: 18 May 2017 08:04
Official URL: http://doi.org/10.1063/1.4954714
Identification Number: doi:10.1063/1.4954714
Funders: This work was supported in part by the Deutsche Forschungsgemeinschaft under Project Nos. SFB 917 and AL560/13-2., Funding by the Federal Ministry of Education and Research (BMBF) under Contract No. 16ES0250 is also gratefully acknowledged., We thank funding by ENIAC JU within the project PANACHE.
Export:

Optionen (nur für Redakteure)

View Item View Item