Autor: |
Rodenbücher, C., Hildebrandt, E., Szot, K., Sharath, S. U., Kurian, J., Komissinskiy, P., Breuer, U., Waser, R., Alff, L. |
Rok vydání: |
2016 |
Předmět: |
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Zdroj: |
Appl. Phys. Lett. 108, 25, 252903 (2016) |
Druh dokumentu: |
Working Paper |
DOI: |
10.1063/1.4954714 |
Popis: |
On highly oxygen deficient thin films of hafnium oxide (hafnia, HfO$_{2-x}$) contaminated with adsorbates of carbon oxides, the formation of hafnium carbide (HfC$_x$) at the surface during vacuum annealing at temperatures as low as 600 {\deg}C is reported. Using X-ray photoelectron spectroscopy the evolution of the HfC$_x$ surface layer related to a transformation from insulating into metallic state is monitored in situ. In contrast, for fully stoichiometric HfO$_2$ thin films prepared and measured under identical conditions, the formation of HfC$_x$ 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. |
Databáze: |
arXiv |
Externí odkaz: |
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