Ellipsometry of hybrid noble metal-dielectric nanostructures
Angular ellipsometric measurements of thin Ag and Cu films covered by a HfO₂ protective layer were performed. The ellipsometric parameters ψ and ∆ were measured in θ = 43°…85° light incidence angle range, where ψ is the azimuth of restored linear polarization, ∆ and is the phase shift between p- and...
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2018
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| Цитувати: | Ellipsometry of hybrid noble metal-dielectric nanostructures / A.L. Yampolskiy, O.V. Makarenko, L.V. Poperenko, V.O. Lysiuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2018. — Т. 21, № 4. — С. 412-416. — Бібліогр.: 16 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860479636338638848 |
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| author | Yampolskiy, A.L. Makarenko, O.V. Poperenko, L.V. Lysiuk, V.O. |
| author_facet | Yampolskiy, A.L. Makarenko, O.V. Poperenko, L.V. Lysiuk, V.O. |
| citation_txt | Ellipsometry of hybrid noble metal-dielectric nanostructures / A.L. Yampolskiy, O.V. Makarenko, L.V. Poperenko, V.O. Lysiuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2018. — Т. 21, № 4. — С. 412-416. — Бібліогр.: 16 назв. — англ. |
| collection | DSpace DC |
| container_title | Semiconductor Physics Quantum Electronics & Optoelectronics |
| description | Angular ellipsometric measurements of thin Ag and Cu films covered by a HfO₂ protective layer were performed. The ellipsometric parameters ψ and ∆ were measured in θ = 43°…85° light incidence angle range, where ψ is the azimuth of restored linear polarization, ∆ and is the phase shift between p- and s-components of reflected light. For comparison, a thin Au film (traditional sensor for surface plasmon resonance (SPR)) was examined as well. The curve ∆(θ) for all the samples investigated falls down with increasing angle of light incidence, while ψ(θ) changes relatively weakly. It has been ascertained that the increase in the thickness of the HfO₂ layer affects the tan(ψ) value, while tan(ψ) deviation is mainly determined by the type of metallic film. With the growth of the HfO₂ layer, the minimum position of tan(ψ) shifts to smaller angles. From these angular dependences, one could choose the appropriate SPR-compatible structure due to the maximal deviation of tan(ψ). To optimize layer thickness for a high SPR-response, spectral measurements and additional calculations are required.
|
| first_indexed | 2026-03-23T18:47:25Z |
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ISSN 1560-8034, 1605-6582 (On-line), SPQEO, 2018. V. 21, N 4. P. 412-416.
© 2018, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
412
Optics
Ellipsometry of hybrid noble metal-dielectric nanostructures
A.L. Yampolskiy
1, *
, O.V. Makarenko
1
, L.V. Poperenko
1
, V.O. Lysiuk
2
1
Taras Shevchenko Kyiv National University, Department of Physics, 4, Hlushkova ave., 03022 Kyiv, Ukraine
*
E-mail: uv365nm@ukr.net
2
V. Lashkaryov Institute of Semiconductor Physics of the National Academy of Sciences of Ukraine
41, prospect Nauky, 03680 Kyiv, Ukraine
Abstract. Angular ellipsometric measurements of thin Ag, Cu films covered by HfO2
protective layer were performed. The ellipsometric parameters ψ and ∆ were measured in
θ = 43°…85° light incidence angle range, where ψ is the azimuth of restored linear
polarization, ∆ is the phase shift between p- and s-components of reflected light. For
comparison, thin Au film (traditional sensor for surface plasmon resonance (SPR)) was
examined as well. The curve ∆(θ) for all the samples investigated falls down with
increasing angle of light incidence, while ψ(θ) changes relatively weakly. It has been
ascertained that the increase in the thickness of HfO2 layer affects the tan(ψ) value, while
tan(ψ) deviation is mainly determined by the type of metallic film. With the growth of HfO2
layer, the minimum position of tan(ψ) shifts to smaller angles. From these angular
dependences, one could choose the appropriate SPR-compatible structure due to maximal
deviation of tan(ψ). To optimize layer thickness for a high SPR-response, spectral
measurements and additional calculations are required.
Keywords: ellipsometry, thin film, noble metals, surface plasmon resonance, hafnium
oxide.
doi: https://doi.org/10.15407/spqeo21.04.412
PACS 73.20.mf, 72.20.-e
Manuscript received 29.10.18; revised version received 19.11.18; accepted for publication
29.11.18; published online 03.12.18.
1. Introduction
Thin metal films attract considerable interest in both
science and technology. They often have optical
properties different from the same bulk material. Partial
transparency and conductivity allow using them as
electrodes for solar cells [1] and other optoelectronic
devices [2, 3]. Thin metal films are widely used in optical
instrumentation (mirrors, beam splitters, different
specific coatings and so on).
But, perhaps, the most extensive field of their
modern application is electrochemistry and bioanalysis
[4]. Gas sensors acting due to conductivity changes upon
interaction of molecules with the metal film surface are
developed [5]. In surface acoustic waves or
electrowetting process, thin metal films are used for
precise manipulation of liquid microdroplets [6].
Electrosensing is notable for its sensitivity, relative
simplicity and low power consumption. It is used for
detection of simple molecules. Conductivity-based thin-
film sensors react to molecules adsorbed on the surface
and are used for gas detection, for direct detection of
DNA and in food quality controlling [6].
Of particular importance are sensors based on
surface plasmon resonance (SPR), which are the subject
of this work. SPR sensing has established itself as an
important tool in characterization of biomolecular
interactions [7, 8]. Such instruments allow real-time
detection of various chemical and biological substances
and their combinations. However, there still remains a
considerable space for the improvement of these devices,
particularly, increasing their resistance to external and
explored environments as well as lifetime. The aim of
this work is to examine hybrid multilayer noble metal-
dielectric structures by using the optical ellipsometry
method to propose the physical and technical approach
for developing more efficient SPR-sensors.
2. About SPR
The surface plasmon-polariton (SPP) is a quasi-particle
corresponding to the quantization of the collective
plasma oscillations of the electron gas in solids under
action of p-polarized light. The area of their localization
is near the interface of media, where surface charges are
concentrated. Surface plasmon-polariton waves are the
waves of changes in the electric charge density, which
can arise and propagate in the electron plasma of metal
along the interface of metal film surface. Surface
plasmon (SP) is the extreme case of SPP, which is a two-
dimensional wave localized at the surface.
SPQEO, 2018. V. 21, N 4. P. 412-416.
Yampolskiy A.L., Makarenko O.V., Poperenko L.V., Lysiuk V.O. Ellipsometry of hybrid noble metal-dielectric …
413
Fig. 1. Hybrid multilayer structure of the investigated samples
based on Au (a), Ag (b) and Cu (c) thin films.
Surface plasmonic resonance (SPR) usually occurs
with total internal reflection when an electromagnetic
wave propagates along the reflecting surface at a rate that
depends on the angle of incidence. The resonant
phenomenon consists in the transfer of energy from the
photon flux to the electron plasma of the metal when
light falls at a certain angle onto surface. In this case, a
decrease in the intensity of the reflected light and a
change in the azimuth of the restored linear polarization
are observed [9].
Surface plasmons are extremely sensitive to their
local dielectric environment. Adding nanoparticles of a
certain size and shape, one can configure such a sensor to
detect a given type of the adsorbed objects. That’s why
SPR-sensors are so perspective in biotechnology.
Gold has long been known as the highest quality
plasmonic material for the visible and near-infrared
applications. It does not oxidize, has a large value of the
refractive index and a small imaginary part of the
dielectric function, high adhesion and affinity for organic
molecules. Thin Ag and Cu films has also similar SPR
properties, sometimes even better [10], and lower cost.
But they oxidize relatively quickly, limiting long-term
device applications [11]. A potential solution to this is to
use HfO2 very thin layer as a protection of the
copper/silver plasmonic film. It was chosen HfO2 as a
dielectric layer because of its very stable chemical
behaviour and high refractive index about 1.9…2.0 in the
visible spectrum [12]. Combination of plasmonic film
with such dielectric layer has yielded significant
advances in SPR sensing due to the interference of
reflected waves on interfaces metal/dielectric and
promotes the path extension of the plasmon wave
propagation along thin surface layer.
3. Samples and experiment
All metal films studied in this work were deposited using
electron-beam evaporation onto glass substrates of the
thickness 1 mm. The films were grown in a commonly
available deposition apparatus with base pressures within
Table 1. The list of samples investigated.
# Substrate Layer 1 Layer 2 Layer 3
1 glass Cr (1.5 nm) Au (47 nm) –
2 glass Cr (1.5 nm) Ag (45 nm) HfO2 (7 nm)
3 glass Cr (1.5 nm) Ag (45 nm) HfO2 (8 nm)
4 glass Cr (1.5 nm) Cu (43 nm) HfO2 (7 nm)
5 glass Cr (3 nm) Cu (35 nm) HfO2 (10 nm)
10
–5
to 10
–6
Torr range. The growth of metal films was
monitored using a calibrated quartz crystal microbalance
(QCM). Before deposition of Au (Ag, Cu) films, thin
adhesive layers with the thickness about of 1.5 nm (Cr)
were also deposited onto the clean glass substrates by
using electron beam evaporation. To achieve the best
adhesion and smooth surface with good optical
performance sputtering rates were selected as follows:
0.14 nm/s for Au, 5…7 nm/s for Ag and 1 nm/s for Cu.
On the top of Ag (Cu) films, HfO2 layer was deposited
with the small rate 0.05…0.1 nm/s. The structure of the
samples is shown in Fig. 1 schematically.
In this paper, we will consider five heterostructures
with different thicknesses of layers. The detailed list of
samples investigated is given in Table 1.
The research was carried out on a multifunctional
automated goniopolarimetric installation, built on the
basis of the goniometer Г5 [13]. The experiment is
controlled by a personal computer using the NI6221 Data
Acquisition Card manufactured by National
Instruments®, our own electronic automation system and
the LabVIEW graphical programming environment.
The scheme of the experimental instrument is
shown in Fig. 2. The radiation source is LED with λ =
625 nm, ∆λ = 10 nm. The collimator lens forms a parallel
beam of light, which then passes through the polarizer P
and falls on the sample to be studied. After the reflection
from the sample, light passes through the analyzer A and
it focused by the chamber lens onto the surface of the
sensor (photodiode).
The ellipsometric studies are carried out as follows.
The sample is installed on the table of the goniometer for
performing its alignment and positioning. The polarizer P
Fig. 2. Scheme of the experimental setup: collimator lens – Col,
polarizer – P, analyzer – A, chamber lens – Cham.
SPQEO, 2018. V. 21, N 4. P. 412-416.
Yampolskiy A.L., Makarenko O.V., Poperenko L.V., Lysiuk V.O. Ellipsometry of hybrid noble metal-dielectric …
414
Fig. 3. Angular dependences of parameters ψ and ∆ for the Au
(reference) sample.
Fig. 4. Angular dependences of parameters ψ and ∆ for
Ag-based samples.
Fig. 5. Angular dependences of parameters ψ and ∆ for
Cu-based samples.
is set to 45° relatively to the p-plane. With an automatic
drive, the sample turns to the required incidence angle θ,
and after that the analyzer A begins to rotate. During
rotation of the analyzer, the signal from the photodetector
is permanently recorded. Then, the sample is positioned
at a subsequent angle of incidence, etc. Measurements
are continued until all the required range of light
incidence angles has been passed. Using the obtained
data, the special computer program reproduces the shape
of the polarization ellipse of the reflected light and
displays the angular dependence of the ellipsometric
parameters ψ and ∆ in the plot.
Fig. 6. Angular dependences of tan(ψ) for all the samples
investigated.
Fig. 7. Spectral dependences of ellipsometric parameter ψ of
the heterostructure Cr (3 nm), Au (30 nm), HfO2 (45 nm) for
different angles of light incidence.
4. Results and discussion
For the above-mentioned samples (Fig. 1), the angular
measurements of the ellipsometric parameters were
performed within 43°…85° range. ψ is the azimuth of
restored linear polarization, ∆ is the phase shift between
p- and s-components of incident light. The samples were
probed from the upper side (not through glass). The
results of the measurements are shown in Figs. 3 to 6.
As one can see from these plots (Figs. 3 to 5), the
optical properties of these metal heterostructures are
similar. There is slightly different principle of light
incidence angle (the angles, where phase shift ∆ between
p- and s-components is equal to 90°) for these samples.
The curve ∆(θ) falls down with increasing angle of light
incidence while ψ(θ) changes relatively weakly.
Usually surface plasmon resonance manifests itself
in the form of a sharp decrease in the intensity of the
reflected p-polarized electromagnetic wave in the vicinity
of the specific angle of incidence. The reflection
efficiency for SPR depends on the thickness of dielectric
(HfO2) and noble-metal films due to the former changes
the electromagnetic field distribution of the surface
plasma oscillations. The reflectivity spectra R(λ) of the
sample reach the minimum at plasmonic resonances. To
increase SPR efficiency, one should minimize the
p-polarized reflection spectra and its full width at half
maximum (FWHM) [14].
SPQEO, 2018. V. 21, N 4. P. 412-416.
Yampolskiy A.L., Makarenko O.V., Poperenko L.V., Lysiuk V.O. Ellipsometry of hybrid noble metal-dielectric …
415
Table 2. Characteristics of the samples and measurement data.
Sample
Principal
angle*,
deg.
tan(ψ),
minimal
value
Angular
position**,
deg.
tan(ψ)
deviation
Cr 1.5 nm,
Au 47 nm
71.9 0.933 73.2 0.051
Cr 1.5 nm,
Ag 45 nm,
HfO2 7 nm
71.5 0.973 76.3 0.019
Cr 1.5 nm,
Ag 45 nm,
HfO2 8nm
72.9 0.989 72.0 0.019
Cr 1.5 nm,
Cu 43 nm,
HfO2 7 nm
70.8 0.970 74.8 0.067
Cr 3 nm,
Cu 35 nm,
HfO2 10 nm
70.2 0.887 69.8 0.055
*
Principal angle of light incidence
**
tan(ψ) minimal angular position, deg.
The angular dependence of the reflection coefficient
R(θ) as a shape of the resonance curve, in particular, the
angular position of its minimum, depends on the
wavelength λ, the optical constants n and κ of the sample
and the ambient, as well as a film thickness d and optical
characteristics of the film deposited on the top of this
heterostructure. So, if we plot tan(ψ), which is expressed
as a reflected p- and s-components ratio, these curves
should demonstrate a depression at the resonant angle of
light incidence.
On the plots in Fig. 6, there are actually observed
minima, but they are comparatively small in their
amplitude (at the resonance, reflection must typically
decrease close to 0). It is seen from Fig. 7, where
appropriate minima are observed for spectral
dependences ψ(λ) of similar specimen presented at [15],
then it becomes obvious that the reason for the
occurrence of such weak minima in Fig. 6 consists in the
difference of our source wavelength (λ = 625 nm) from
the resonant ones for the samples investigated.
To create some effective SPR-sensor, it is necessary
to optimize the thickness of appropriate layers. It is
optimal near d = 47.5 nm for the film based on gold [16].
Hence, one should also explore the spectral dependences
of ψ for this selection. From angular dependences, one
could only choose the appropriate SPR-compatible
structure due to a minimal value of tan(ψ).
One can compare behavior of ellipsometric
parameters for Au-, Ag- and Cu-based samples with
different thicknesses of films of these metals (see
Table 2).
In Table 2, the principal angles of light incidence in
appropriate heterostructure investigated, the angular
positions and the values of tan(ψ) minima, as well as
tan(ψ) amplitude deviations are presented. We can notice
at comparison Au-based and Cr (3 nm), Cu (35 nm),
HfO2 (10 nm) samples that the increase of the thickness
of the HfO2 layer only weakly independently of selected
metal for film affects the ψ amplitude. Namely, tan(ψ)
deviation is mainly defined by the type of metallic layer
of that film. With the growth of HfO2 layer, the minimum
position of tan(ψ) for these structures shifts to the smaller
angles θ.
5. Conclusions
The HfO2-protected Ag and Cu layers provide a possible
alternative to the conventional noble metals (usually,
pure Au) in plasmonics applications. In this case, they
are relatively stable and high-quality plasmonic
materials, which is suitable for effective sensor
fabrication that requires low plasmonic losses.
A few nm thick HfO2 layer on the top of Cu or Ag
film improves its SPR stability and lifetime, though it
changes SPR-response. From angular ellipsometrical
measurements, one can suppose that the samples with
greater tan(ψ) deviation are the best candidates for
SPR-sensors among the heterostructures examined.
Acknowledgments
The authors would like to thank Dr. V.G. Kravets
(University of Manchester, UK) for his kindness and
helpful discussion on SPR-sensors and multilayer
heterostructures ellipsometry.
References
1. Khan M.S., Reza A. Optical and electrical
properties of optimized thin gold films as top layer
of MIS solar cells. Appl. Phys. A. 1992. 54, No 2.
P. 204–207. DOI: 10. 1007/BF00323913.
2. Sung W. Kim, Lin Pang, Brandon Hong, Joanna
Ptasinski, and Yeshaiahu Fainman. Experimental
demonstration of quenched transmission effect of an
ultrathin metallic grating. Opt. Lett. 2016. 41.
P. 1522–1525.
3. Harsha Reddy, Urcan Guler, Kildishev A.V.,
Boltasseva A., and Shalaev V.M. Temperature-
dependent optical properties of gold thin films. Opt.
Mater. Exp. 2016. 6. P. 2776–2802.
4. Kostyukevych S.A., Kostyukevych K.V.,
Khristosenko R.V. et al. Multielement surface
plasmon resonance immunosensor for monitoring of
blood circulation system. Opt. Eng. 2017. 56,
No 12. P. 121907-1–121907-8.
5. James D., Scott S.M., Ali Z., O’Hare W.T.
Chemical sensors for electronic nose systems.
Microchim. Acta. 2005. 149. P. 1–17.
http://dx.doi.org/10.1007/s00604-004-0291-6.
6. Juskova P. and Foret F. Application of thin metal
film elements in bioanalysis. Journal of Separation
Science. 2011. 34, No 20. P. 2779–2789.
7. Homola J., Yee S.S., and Gauglitz G. Surface
plasmon resonance sensors: Review. Sensors and
Actuators B: Chem. 1999. 54, No 1. P. 3–15.
SPQEO, 2018. V. 21, N 4. P. 412-416.
Yampolskiy A.L., Makarenko O.V., Poperenko L.V., Lysiuk V.O. Ellipsometry of hybrid noble metal-dielectric …
416
8. Anker J.N., Hall W.P., Lyandres O., Shah N.C.,
Zhao J., and Van Duyne R.P. Biosensing with
plasmonic nanosensors. Nature Materials. 2008. 7,
No 6. P. 442–453.
9. Poperenko L.V. and Staschuk V.S. Fundamentals of
Physics of Optical Materials. Kyiv, Ukraine: VPC
“Kyiv University”, 2011. P. 256–266 (in Ukrainian).
10. Zhang Y.M., Terrill R.H., Bohn P.W.
Chemisorption and chemical reaction effects on the
resistivity of ultrathin gold films at the liquid-solid
interface. Anal. Chem. 1999. 71, No 1. P. 119–125.
DOI: 10.1021/ac980571y.
11. West P.R., Ishii S., Naik G.V., Emani N.K., Shalaev
V.M., and Boltasseva A. Searching for better
plasmonic materials. Laser & Photonics Reviews.
2010. 4, No 6. P. 795–808.
12. Kravets V.G., Petford-Long A.K., Kravetz A.F.
Optical and magneto-optical properties of
(CoFe)x(HfO2)1-x magnetic granular films. J. Appl.
Phys. 2000. 87, No 4. P. 1762–1768.
13. Rogovets A.V., Karlenko B.V., Makarenko A.V.,
Yampolskiy A.L. Measurements automation: the
algorithm for visual scale recognition realized in
LabView. Bulletin of Taras Shevchenko National
University of Kyiv. Series Physics & Mathematics.
2017. No 4. P. 193–196.
14. Kravets V.G., Kuryoz P.Yu., Poperenko L.V. High
reflection efficiency for surface plasmon resonance
in glass/Cr/Au, glass/Cr/Au/HfO2 films. 13-th
Intern. Young Scientists Conf. Optics and High
Technology Material Science – SPO-2012. Ukraine,
Kyiv, October 25–28, 2012. P. 136. Kyiv: VPC
“Kyiv University”.
15. Kuryoz P.Yu., Kravets V.G., Poperenko L.V.
Spectral ellipsometric observation of surface
plasmon resonance in metal-dielectric
nanocomposites. 14-th Intern. Young Scientists
Conf. Optics and High Technology Material
Science – SPO-2013. Ukraine, Kyiv, October 24-27,
2013. P. 92. Kyiv: VPC “Kyiv University”.
16. Kuryoz P.Yu., Poperenko L.V., and Kravets V.G.
Correlation between dielectric constants and
enhancement of surface plasmon resonances for thin
gold films. phys. status solidi (a). 2013. 210, No 11.
P. 2445–2455.
Authors and CV
Yampolskiy Andriy Leonidovych,
born in 1993, MSc in Physics (Laser
and Optoelectronic Technique) in
2017. At present PhD student in
Physics and Astronomy. Scientific
interests: ellipsometry, optically
anisotropic materials, nanotechnolo-
gy, optoelectronics, experimental
devices development. Taras Shevchenko Kiev National
University, Department of Physics, Chair of Optics.
Taras Shevchenko Kyiv National University
Makarenko Olexiy Volodymyrovych,
born in 1974, Cand. Sci. (Phys. &
Math.) in 2001. Working since 1997
as an engineer, Assistant Professor
(2001) and then as Associate
Professor (2005) in Taras Shevchenko
National University of Kyiv.
O.V. Makarenko is specialized in
color, lens design and creating of optoelectronic devices,
optics of inhomogeneous media and polarized light. He
has more than 20 scientific articles.
Taras Shevchenko Kyiv National University
Leonid V. Poperenko got his PhD
degree in 1982, and doctorate degree
in 1992. In 1994 he become professor
of optics division at Department of
Physics, Taras Shevchenko National
University of Kyiv. Since 1999 he is
chair of Optics Division. Since 2001
he is advisor of SPIE Student Chapter at Taras
Shevchenko National University of Kyiv. Participated at
internship in ICTP (Trieste, Italy), Retherford Lab
(Oxfordsheer, UK), Institute of spectrochemistry and
spectroscopy (Berlin, Germany); Institute of technical
Physics and Material Science (Budapest, Hungary),
Institute of Ion Beam Physics (Rossendorf, Germany).
Visiting lecturer of University of Cincinnati, USA;
Changchun, China, Shizuoka, Japan. He has more than
200 publications. His research interests are ellipsometry,
thin films, metallo optics, ion implantation, plasmonics.
Taras Shevchenko Kyiv National University
Viktor O. Lysiuk received his PhD in
physics and mathematics from
Taras Shevchenko National
University of Kyiv (2011) and senior
scientific researcher title (2014).
Sr. researcher at Lab of Optics and
Optoelectronic registering media at
V. Lashkariov Institute of Semiconductor Physics, NAS
of Ukraine. OSA Member. Head of department of
experimental physics of Kyiv Junior Academy of
Sciences. Advisor of OSA Student chapter at Kyiv Junior
Academy of Sciences. His research interests are ion
implantation, thin films, plasmonics, ferroelectrics, and
optical biosensors.
V. Lashkaryov Institute of Semiconductor Physics of
National Academy of Sciences of Ukraine
|
| id | nasplib_isofts_kiev_ua-123456789-215317 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1560-8034 |
| language | English |
| last_indexed | 2026-03-23T18:47:25Z |
| publishDate | 2018 |
| publisher | Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| record_format | dspace |
| spelling | Yampolskiy, A.L. Makarenko, O.V. Poperenko, L.V. Lysiuk, V.O. 2026-03-12T08:53:24Z 2018 Ellipsometry of hybrid noble metal-dielectric nanostructures / A.L. Yampolskiy, O.V. Makarenko, L.V. Poperenko, V.O. Lysiuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2018. — Т. 21, № 4. — С. 412-416. — Бібліогр.: 16 назв. — англ. 1560-8034 PACS: 73.20.mf, 72.20.-e https://nasplib.isofts.kiev.ua/handle/123456789/215317 https://doi.org/10.15407/spqeo21.04.412 Angular ellipsometric measurements of thin Ag and Cu films covered by a HfO₂ protective layer were performed. The ellipsometric parameters ψ and ∆ were measured in θ = 43°…85° light incidence angle range, where ψ is the azimuth of restored linear polarization, ∆ and is the phase shift between p- and s-components of reflected light. For comparison, a thin Au film (traditional sensor for surface plasmon resonance (SPR)) was examined as well. The curve ∆(θ) for all the samples investigated falls down with increasing angle of light incidence, while ψ(θ) changes relatively weakly. It has been ascertained that the increase in the thickness of the HfO₂ layer affects the tan(ψ) value, while tan(ψ) deviation is mainly determined by the type of metallic film. With the growth of the HfO₂ layer, the minimum position of tan(ψ) shifts to smaller angles. From these angular dependences, one could choose the appropriate SPR-compatible structure due to the maximal deviation of tan(ψ). To optimize layer thickness for a high SPR-response, spectral measurements and additional calculations are required. The authors would like to thank Dr. V.G. Kravets (University of Manchester, UK) for his kindness and helpful discussion on SPR-sensors and multilayer heterostructures ellipsometry. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Optics Ellipsometry of hybrid noble metal-dielectric nanostructures Article published earlier |
| spellingShingle | Ellipsometry of hybrid noble metal-dielectric nanostructures Yampolskiy, A.L. Makarenko, O.V. Poperenko, L.V. Lysiuk, V.O. Optics |
| title | Ellipsometry of hybrid noble metal-dielectric nanostructures |
| title_full | Ellipsometry of hybrid noble metal-dielectric nanostructures |
| title_fullStr | Ellipsometry of hybrid noble metal-dielectric nanostructures |
| title_full_unstemmed | Ellipsometry of hybrid noble metal-dielectric nanostructures |
| title_short | Ellipsometry of hybrid noble metal-dielectric nanostructures |
| title_sort | ellipsometry of hybrid noble metal-dielectric nanostructures |
| topic | Optics |
| topic_facet | Optics |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/215317 |
| work_keys_str_mv | AT yampolskiyal ellipsometryofhybridnoblemetaldielectricnanostructures AT makarenkoov ellipsometryofhybridnoblemetaldielectricnanostructures AT poperenkolv ellipsometryofhybridnoblemetaldielectricnanostructures AT lysiukvo ellipsometryofhybridnoblemetaldielectricnanostructures |