Hafnium carbide formation in oxygen deficient hafnium oxide thin films

Journal Article · Mon Jun 20 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4954714· OSTI ID:22590819

Rodenbücher, C. ^[1]; Hildebrandt, E.; Sharath, S. U.; Kurian, J.; Komissinskiy, P.; Alff, L. ^[2]; Szot, K. ^[1]; Breuer, U. ^[3]; Waser, R. ^[1]

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1. Forschungszentrum Jülich GmbH, Peter Grünberg Institute (PGI-7), JARA-FIT, 52425 Jülich (Germany)
2. Technische Universität Darmstadt, Institute of Materials Science, 64287 Darmstadt (Germany)
3. Forschungszentrum Jülich GmbH, Central Institute for Engineering, Electronics and Analytics (ZEA-3), 52425 Jülich (Germany)

On highly oxygen deficient thin films of hafnium oxide (hafnia, HfO{sub 2−x}) contaminated with adsorbates of carbon oxides, the formation of hafnium carbide (HfC{sub x}) at the surface during vacuum annealing at temperatures as low as 600 °C is reported. Using X-ray photoelectron spectroscopy the evolution of the HfC{sub x} surface layer related to a transformation from insulating into metallic state is monitored in situ. In contrast, for fully stoichiometric HfO{sub 2} thin films prepared and measured under identical conditions, the formation of HfC{sub x} 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.

• OSTI ID: 22590819
• Journal Information: Applied Physics Letters, Vol. 108, Issue 25; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ANNEALING
CARBON OXIDES
CARBON SOURCES
FILAMENTS
FORMATION HEAT
HAFNIUM CARBIDES
HAFNIUM OXIDES
JOULE HEATING
LAYERS
MEMORY DEVICES
RANDOMNESS
THIN FILMS
VACANCIES
X-RAY PHOTOELECTRON SPECTROSCOPY