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Oxygen Influence on the Growth of Thin Hf Films on the 6H‐SiC(0001) Surfaces
Author(s) -
Mazur Piotr,
Markowski Leszek
Publication year - 2010
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.3606
Subject(s) - x ray photoelectron spectroscopy , annealing (glass) , scanning tunneling microscope , nanocrystalline material , oxygen , materials science , microstructure , hafnium , band bending , analytical chemistry (journal) , binding energy , crystallography , chemistry , nanotechnology , chemical engineering , metallurgy , zirconium , atomic physics , optoelectronics , organic chemistry , chromatography , engineering , physics
Initial stages of Hf growth on the SiC(0001) surface and the influence of annealing on the evolution of microstructure of the formed Hf films were investigated by XPS and scanning tunneling microscopy (STM). The character of XPS spectra and the shifts of the binding energies of Hf 4f, Si 2p, C 1s, O 1s levels, observed with increasing Hf depositions, indicate that even at room temperature a hafnium oxide in the form of HfO 2 was created. The registered band bending created at the HfO 2 /SiC interface is about 0.4 eV. Hafnium tended to grow irregularly with a tendency to form nanocrystalline grains near terraces edges, and preferably on the surface regions not covered by additional graphite carbon layers which together with oxygen were present on the virgin SiC(0001) surface. The grain sizes were sensitive to annealing and efficiently increased during heating the sample at 1100 °C. These surface morphology changes proceeded through merging smaller nanoparticels into clusters. For longer Hf depositions, with average thickness over 10 monolayers, excess carbon segregated and migrated towards the surface, with simultaneous formation of Hf–C and O‐C‐O bonds. Copyright © 2010 John Wiley & Sons, Ltd.