https://doi.org/10.1140/epjb/e2005-00142-3
Spectroscopic ellipsometric evidence of the solid-state reactions in Ni/Si multilayered films, induced by ion-beam mixing and thermal annealing
1
Quantum
Photonic Science Research Center and Department of Physics,
Hanyang University, Seoul, 133-791 Korea
2
Institute of Metal
Physics, National Academy of Sciences of Ukraine, 36 Vernadsky
str, 03142, Kiev-142, Ukraine
3
NTU “Kiev Polytechnical
Institute”, 37 Pobedy ave., Kiev, Ukraine
4
Department of
Physics, Hoseo University, Asan, Choongnam 336-795, Korea
Corresponding author: a yplee@hanyang.ac.kr
Received:
27
March
2004
Published online:
30
May
2005
Solid-state reactions, induced by ion-beam mixing (IBM)
and thermal annealing, in Ni/Si multilayered films (MLF) with an
overall stoichiometry of Ni2Si, NiSi and NiSi2, while
keeping the nominal thickness of Ni sublayer constant (3.0 nm),
were studied by using spectroscopic ellipsometry as well as X-ray
diffraction (XRD). The mixing was performed with Ar+ ions of
an energy of 80 keV and a dose of Ar+/cm2. Unlike the results of our previous
study on Fe/Si MLF [Y.V. Kudryavtsev et al., Phys. Rev. B
65, 104417 (2002)], it was shown that an amorphous phase of
NiSi in the B20 phase was formed during deposition independent
of the overall stoichiometry of MLF, i.e., the nominal
thickness of Si sublayer. IBM leads to some structural changes in
the Ni/Si MLF, which cannot be detected by XRD but are confidently
recognized by optical tools. A thermal annealing at 673 K of the
Ni/Si MLF with an overall stoichiometry of NiSi and NiSi2 causes formation of the
-NiSi phase. The first trace of
NiSi2 phase on the background of the
-NiSi phase was
detected by XRD after an annealing at 1073 K, while, according to
the optical results, NiSi2 turned out to be the dominant phase
for the annealed Ni/Si MLF with an overall stoichiometry of NiSi2.
PACS: 78.66.Bz – Metals and metallic alloys / 78.67.Pt – Multilayers; superlattices / 78.20.Bh – Theory, models, and numerical simulation / 61.80.Jh – Ion radiation effects
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005