Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions
Bubble-like and crater-like blisters were observed at the boundaries of the structures “thin Ni film–lithium niobate” and “thin Pd film–lithium tantalate” implanted by Ar⁺ ions. Analyses of these systems by AFM and SEM have shown that ion implantation essentially modifies near-surface structure...
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2010
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| Cite this: | Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions / V.O. Lysiuk, N.L. Moskalenko, V.S. Staschuk, M.I. Kluy, O.V. Vakulenko, I.G. Androsyuk, M.A. Surmach, V.I. Pogoda // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2010. — Т. 13, № 1. — С. 103-109. — Бібліогр.: 10 назв. — англ. |
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nasplib_isofts_kiev_ua-123456789-1178222025-06-03T16:26:26Z Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions Lysiuk, V.O. Moskalenko, N.L. Staschuk, V.S. Kluy, M.I. Vakulenko, O.V. Androsyuk, I.G. Surmach, M.A. Pogoda, V.I. Bubble-like and crater-like blisters were observed at the boundaries of the structures “thin Ni film–lithium niobate” and “thin Pd film–lithium tantalate” implanted by Ar⁺ ions. Analyses of these systems by AFM and SEM have shown that ion implantation essentially modifies near-surface structures with changing their optical, electrical and mechanical properties. Differences in the optical properties and surface structure between implanted and non-implanted systems are observed and explained by different properties of materials, widening interface “film–substrate” as well as by other known effects and phenomena. Enhanced adhesion of these films to substrate, nonselective spectral response is a base for effective and perspective application of the systems in development of high-sensitive pyroelectric detectors with a wide spectral range and high optical damage threshold. 2010 Article Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions / V.O. Lysiuk, N.L. Moskalenko, V.S. Staschuk, M.I. Kluy, O.V. Vakulenko, I.G. Androsyuk, M.A. Surmach, V.I. Pogoda // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2010. — Т. 13, № 1. — С. 103-109. — Бібліогр.: 10 назв. — англ. 1560-8034 PACS 68.55.Ln, 85.60.Gz https://nasplib.isofts.kiev.ua/handle/123456789/117822 en Semiconductor Physics Quantum Electronics & Optoelectronics application/pdf Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
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| description |
Bubble-like and crater-like blisters were observed at the boundaries of the
structures “thin Ni film–lithium niobate” and “thin Pd film–lithium tantalate” implanted
by Ar⁺
ions. Analyses of these systems by AFM and SEM have shown that ion
implantation essentially modifies near-surface structures with changing their optical,
electrical and mechanical properties. Differences in the optical properties and surface
structure between implanted and non-implanted systems are observed and explained by
different properties of materials, widening interface “film–substrate” as well as by other
known effects and phenomena. Enhanced adhesion of these films to substrate,
nonselective spectral response is a base for effective and perspective application of the
systems in development of high-sensitive pyroelectric detectors with a wide spectral
range and high optical damage threshold. |
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Article |
| author |
Lysiuk, V.O. Moskalenko, N.L. Staschuk, V.S. Kluy, M.I. Vakulenko, O.V. Androsyuk, I.G. Surmach, M.A. Pogoda, V.I. |
| spellingShingle |
Lysiuk, V.O. Moskalenko, N.L. Staschuk, V.S. Kluy, M.I. Vakulenko, O.V. Androsyuk, I.G. Surmach, M.A. Pogoda, V.I. Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions Semiconductor Physics Quantum Electronics & Optoelectronics |
| author_facet |
Lysiuk, V.O. Moskalenko, N.L. Staschuk, V.S. Kluy, M.I. Vakulenko, O.V. Androsyuk, I.G. Surmach, M.A. Pogoda, V.I. |
| author_sort |
Lysiuk, V.O. |
| title |
Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions |
| title_short |
Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions |
| title_full |
Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions |
| title_fullStr |
Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions |
| title_full_unstemmed |
Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions |
| title_sort |
formation of blisters in thin metal films on lithium niobate implanted by kev ar⁺ ions |
| publisher |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| publishDate |
2010 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/117822 |
| citation_txt |
Formation of blisters in thin metal films on lithium niobate implanted by keV Ar⁺ ions / V.O. Lysiuk, N.L. Moskalenko, V.S. Staschuk, M.I. Kluy, O.V. Vakulenko, I.G. Androsyuk, M.A. Surmach, V.I. Pogoda // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2010. — Т. 13, № 1. — С. 103-109. — Бібліогр.: 10 назв. — англ. |
| series |
Semiconductor Physics Quantum Electronics & Optoelectronics |
| work_keys_str_mv |
AT lysiukvo formationofblistersinthinmetalfilmsonlithiumniobateimplantedbykevarions AT moskalenkonl formationofblistersinthinmetalfilmsonlithiumniobateimplantedbykevarions AT staschukvs formationofblistersinthinmetalfilmsonlithiumniobateimplantedbykevarions AT kluymi formationofblistersinthinmetalfilmsonlithiumniobateimplantedbykevarions AT vakulenkoov formationofblistersinthinmetalfilmsonlithiumniobateimplantedbykevarions AT androsyukig formationofblistersinthinmetalfilmsonlithiumniobateimplantedbykevarions AT surmachma formationofblistersinthinmetalfilmsonlithiumniobateimplantedbykevarions AT pogodavi formationofblistersinthinmetalfilmsonlithiumniobateimplantedbykevarions |
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2025-11-26T21:25:33Z |
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| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 103-109.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
103
PACS 68.55.Ln, 85.60.Gz
Formation of blisters in thin metal films
on lithium niobate implanted by keV Ar+ ions
V.O. Lysiuk1, 2, N.L. Moskalenko1, V.S. Staschuk2, M.I. Kluy1,
O.V. Vakulenko2, I.G. Androsyuk1, M.A. Surmach1, V.I. Pogoda1
1V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine
41, prospect Nauky, 03028 Kyiv, Ukraine; phone: +380(44) 525-6205; fax: +380(44) 525-5430
2Taras Shevchenko Kyiv National University, D epartment of Physics,
2, bld.1, prospect Glushkova, 03022 Kyiv, Ukraine
Abstract. Bubble-like and crater-like blisters were observed at the boundaries of the
structures “thin Ni film–lithium niobate” and “thin Pd film–lithium tantalate” implanted
by Ar+ ions. Analyses of these systems by AFM and SEM have shown that ion
implantation essentially modifies near-surface structures with changing their optical,
electrical and mechanical properties. Differences in the optical properties and surface
structure between implanted and non-implanted systems are observed and explained by
different properties of materials, widening interface “film–substrate” as well as by other
known effects and phenomena. Enhanced adhesion of these films to substrate,
nonselective spectral response is a base for effective and perspective application of the
systems in development of high-sensitive pyroelectric detectors with a wide spectral
range and high optical damage threshold.
Keywords: lithium niobate, ion implantation, thin films, pyroelectric photodetectors.
Manuscript received 28.05.09; accepted for publication 22.10.09; published online 30.12.09.
1. Introduction
Ferroelectrics lithium niobate and lithium tantalate are
widely used in optoelectronics and laser physics [1]
because of their unique electrooptical, acoustical,
piezoelectric, pyroelectric and nonlinear optical
properties. Both these pyroelectric crystals have a high
Courie temperature, excellent chemical and mechanical
stability, and high damage threshold, what is very
important for high-precision measurements of power
laser radiation where high stability, durability and
radiation stability are necessary [2].
Deposition of thin absorbing films on pyroelectrics
allows to increase sensitivity of systems thin film –
pyroelectric. This is a necessary requirement for
production of high-sensitive pyroeloectric detectors.
Characteristics of commercial pyroelectric
detectors don’t satisfy requirements of high radiation
stability, sensitivity and low time constant. This is
necessary for excluding the possibility of absorbing
layer damage by laser radiation, if the radiation power
exceeds its own critical point.
Such high-effective absorbing materials as golden
black, Ni-based and other thin metal films cannot
represent necessary radiation stability without ion
implantation as caused by low adhesion between these
thin films and substrate.
Processes that occur during ion implantation are
not completely investigated. But they allow to modify
surface, near-surface structure and interface film–
substrate, change optical, mechanical and electrical
characteristics of materials [3]. That is why, it is
necessary to investigate the influence of ion implantation
on optical properties of thin metal film on lithium
niobate (or lithium tantalate) as well as to compare
experimental results with the theoretically calculated
ones, with the purpose to find optimal materials and
technology for production of the system thin metal
film – pyroelectric with advanced optical, mechanical
and electrical properties [4].
For this purpose, there are the following tasks to be
solved:
to determine optimal absorbing film properties
(material, thicknesses, deposition method, processing
methods etc.), calculating appropriate ions energy and
dose for making maximal distribution of ion stopping
profile on the interface film – substrate; to investigate
the influence of ion implantation on optical properties
(reflectance and absorption) of the samples in the wide
wavelength range (0.25–15 µm); to investigate the
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 103-109.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
104
surface structure of the systems and compare with
existing models; to analyze and determine optical
characteristics of the developed pyroelectric photo-
detector based on the system thin metal film –
pyroelectric and compare with the existing ones [5].
3. Experimental
To create and optimize technology of metal film
deposition on lithium niobate and lithium tantalate
substrates, the main tasks are as follows: maximization
of adhesion of metal films to substrate, deposition of
stable to degradation films with the highest possible
absorption and the lowest value of time constant of
produced sample [6, 7]. Optimal technological regimes
were determined for metal film deposition and further
processing (thermal annealing, ion implantation, etc.).
As a substrate, slices of monocrystalline lithium
niobate with the thickness close to 100 µm and normal
orientation of the polarization vector as to the sample
area. Ni, Mo and Pd were used for deposition. The films
were deposited up to thicknesses of 15, 20, 30 and
40 nm. The films with the thickness less than 15 nm
possessed an island-like structure and were not selected
for investigations. The films with thicknesses over
50 nm did not allow penetration of radiation to the
substrate through them. That is why the samples with
only mentioned thicknesses were chosen for investi-
gations.
All the films (Ni, Mo, Pd) were deposited by the
ion-plasma method in Ar atmosphere with the pressure
approximately 0.5 mPa.
To determine optimal regimes of Ni, Mo and Pd
film deposition with necessary characteristics, such as
resistance and transmission coefficient, series of samples
were produced at various substrate temperatures (70-
320 °С). As a result, the optimal regime that gave
maximal film homogeneity as selected for production of
samples.
To realize the ion implantation method, Ar+ ions
were chosen. Ion implantation with Ar+ ions was made
using Vesuviy 2/450 implanter at the ion current value
ji = 2–3 А/cm2 at the pressure 0.5 mPa, varying the
energy of ions from 50 up to 150 keV and ion dose from
5·1015 up to 2·1016 cm-2. Determination of the optimal
ion energy and dose were carried out using the Monte-
Carlo method based on calculation of ions and recoil
atoms stopping profiles in the systems thin metal films –
lithium niobate (lithium tantalate).
During ion implantation with energies about
100 keV, the following processes occur: ions,
accelerated to the energy E, collide with atoms of
substrate and transfer a part of their kinetic energy,
decelerate, change its direction from the initial one, but
continue their motion to sample’s depth, and collide with
new atoms again. The atoms that obtain a partial energy
from accelerated ions start its motion and after N new
collisions decelerate and, finally, stop [8]. Owing to N
new atoms and the obtained energy, new collisions
occur. As a result, cascade of recoil atoms that move in
the same direction with the implanted ion and, finally
stops. To determine the distribution function for ions and
recoil atoms as depending on the ion type and its energy,
the Monte-Carlo method have been used. Using the
computer modelling, ions and recoil atom distributions
for Ni, Mo and Pd films of 20, 40 and 60 nm thicknesses
on the lithium niobate substrate 100 µm thick were
calculated.
Fig. 1 represents the ion stopping profile in the thin
Ni film on lithium niobate for the energy of ions 50, 100
and 150 keV. It is shown that maximum number of ions
accelerated to 50 keV stops at 20 nm from the sample
surface, exactly where the interface film–substrate is
located, and for the energy of ions 100 and 150 keV – at
the distances 40 and 60 nm, accordingly. So, for the
mentioned sample 50 keV is the optimal ion energy for
the most effective intermixing atoms of film and
substrate at their interface.
Fig. 2 represents the distribution of ions for the
systems thin Pd film – lithium niobate and thin Mo
film – lithium niobate (film thickness of which is 40 nm)
for ion energies 50, 100 and 150 keV. As seen, the
mentioned profiles have small differences, and what is
important – the peaks are located at the same positions.
In comparison with Fig. 1, the ion peak that corresponds
to the ion energy 150 keV shifts inside the sample bulk
to the value d = 80 nm. The ion peaks that correspond to
the ion energies 50 and 100 keV have the same
locations: d = 20 and d = 40 nm, accordingly. Monte-
Carlo method calculations have shown that Ni, Mo or Pd
films 40 nm thick deposited on lithium niobate substrate
should be implanted by Ar+ ions with energies close to
100 keV for the maximal effect of increased adhesion. In
this case, the maximal number of implanted ions will
stop exactly at the interface film – substrate.
Fig. 1. Distribution of Ar+ ions with energies of 50, 100 and
150 keV in the system thin Ni film (20 nm) – lithium niobate.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 103-109.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
105
a)
b)
Fig. 2. Distribution of Ar+ ions with energies of 50, 100 and
150 keV in the system thin Pd film (40 nm) – lithium niobate
(a) and thin Mo film (40 nm) – lithium niobate (b).
2. Results and discussion
Investigation of the surface structure of nonimplanted
and implanted by Ar+ ions thin metal films on pyro-
electrics have been made using electron microscopy and
atomic force microscopy. It is shown (Fig. 3) that before
ion implantation the surfaces of Ni, Mo and Pd films on
lithium niobate were smooth without any structures,
except single defects created at film deposition.
There are no sufficient differences between micro-
relief of nonimplanted systems Ni-LiNbO3, Mo-LiNbO3
and Pd-LiNbO3 observed, and parameter rmax of every
sample is less than 10 nm.
The surface state of the system thin metal film –
lithium niobate implanted by Ar+ ions is strongly
changed after ion implantation and different for the
samples with Ni, Mo and Pd films.
We identified that ion implantation stimulates
appearance of blisters on the surface of Ni-LiNbO3
(Fig. 4). Geometry of blisters is similar to bubbles with
the intrinsic diameter from 50 nm to 2 µm, and their
maximal height is 82 nm.
a)
b)
Fig. 3. Electron microscopy images of deposited Ni films
(40 nm) on lithium niobate with magnification of 3·103 (a) and
105 (b) obtained by Zeiss Ultra 55 Electron Microscope.
a)
b)
Fig. 4. Typical micro-relief of the Ni film (40 nm) on lithium
niobate implanted by Ar+ ions with the energies 100 keV and
dose 1016 cm–2, obtained by Electron Microscope DGSM-35
(a) and Atomic Force Microscope (b).
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 103-109.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
106
Blisters appeared not immediately after ion
implantation, but after thermal annealing. The
mechanism of stimulation of blister formation is exit of
argon gas outside from the film bulk during system
relaxation. This result is confirmed by qualitative X-ray
investigations that have shown absence of argon inside
the samples.
Surface structure investigations for thin Mo film –
lithium niobate have shown that ion implantation
stimulates formation of layered structure in Mo film as a
result of partial exfoliation of Mo under action of high-
energy Ar+ ions. The obtained maximal height of the
structures rmax is 20 nm, what is sufficiently less than
that for thin Ni films on lithium niobate.
Dimensions of craters vary from 200 nm to 10 µm,
and their height is limited by 2 µm. Mechanism of crater
formation in the systems thin Pd film – lithium niobate
starts from bubble-like blisters like to that for Ni film on
lithium niobate. Bubble damages are created due to a
low hardness limit and surface tension coefficient of Pd
in comparison with those of Ni and Mo.
X-ray analyses have shown amorphyzation of thin
metal film as well as subsurface layer of lithium niobate.
Modification of the surface structure of the samples
should change their optical properties.
Transmission spectra of non-implanted systems Ni-
LiNbO3, Mo-LiNbO3 and Pd-LiNbO3 measured in the
wide spectral range (0.2–15 µm) are similar. The
increase in the metal film thickness causes a decrease in
transmission. Optical properties of the system in the
shortwave (UV and visible) range is mainly caused by
film properties, and in the infrared mainly by substrate
properties.
The most interesting micro-relief images were
obtained for thin Pd films on lithium niobate implanted
with Ar+ ions.
By contrast to Ni and Mo films, in this system ion
implantation causes formation of craters.
Fig. 5. Micro-relief of Mo film (40 nm) on lithium niobate
implanted with Ar+ ions with the energy 100 keV and dose
1016 cm–2 obtained using AFM.
a)
b)
c)
Fig. 6. Micro-relief of thin Pd film (40 nm) on lithium niobate
implanted by Ar+ ions with the energy 100 keV and dose
1016 cm–2 obtained using electron microscopes DGSM-35 (a),
Zeiss Ultra 55 (b) and AFM (c).
Fig. 7. Transmission spectra T (λ) of thin Ni film on lithium
niobate with the Ni film thicknesses 15 (1, 2), 20 (3, 4), 30
(5, 6) and 40 nm (7, 8) before (2, 4, 6, 8) and after ion
implantation (1, 3, 5, 7) in comparison with lithium niobate
single crystal (9).
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 103-109.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
107
a)
b)
Fig. 8. Reflectance spectra of thin Ni film – lithium niobate (a),
thin Mo film – lithium niobate (b) with the film thicknesses 15
(1, 2), 20 (3, 4), 30 (5, 6) and 40 nm (7, 8) before (2, 4, 6, 8)
and after ion implantation (1, 3, 5, 7) in comparison with bulk
Ni and Mo polycrystals (9) and monocrystalline lithium
niobate (10).
It has been shown that two absorption bands are
observed near λ = 5.5 and 6.2 µm, which can be related
with presence of H-O-H in LiNbO3 and by oscillation of
H2O molecular complexes and other inclusions. In the
spectral range near λ = 10.5 µm, an intensive band that
causes a decrease in transmission is observed. This band
is related with valent bridge oscillations of oxygen in the
octahedron NbO6. These oscillations are fundamental
phonons of lithium niobate that have almost the same
frequencies as lithium tantalate as a result of the same
molecular structure – the same point group symmetry
(3m) and transition group symmetry (R3с).
As shown in Fig. 7, ion implantation causes rise of
transmission of Ni-LiNbO3 in visible and near infrared
(0.4–6.0 µm), what is the result of widening the interface
film–substrate and disorder in the near-surface structure
of the metal film.
Results of spectral investigations of reflectance
spectra in the wide spectral range (λ = 0.25–15 µm) have
shown that the reflection coefficients for Ni–LiNbO3 and
Mo–LiNbO3 decrease in all the spectral range after ion
implantation [9, 10]. The maximal differrence between
nonimplanted and implanted samples is obtained for the
Ni film with the thickness 15 nm and Mo film with the
thickness 30 nm. Comparing the optical properties and
surface structure of the mentioned samples, it is possible
to conclude that decrease of reflectance spectra may be
related with creation of a rough surface as a result of
blister formation and decrease of heterogeneity of the
interface film–substrate. Calculations of reflectance
spectra for the Ni surface as dependent on the roughness
have shown that light scattering on blisters is not the
only factor that provides the decrease in the reflection
coefficient of the systems.
Reflectance spectra of ion implanted thin Pd films
on lithium niobate strongly differ from those of ion
implanted thin Ni or Mo films on lithium niobate. Ion
implantation causes a decrease in reflectance spectra for
thin Mo or Pd films on lithium niobate.
Differences between nonimplanted and implanted
systems are sufficiently higher for maximal film
thicknesses in comparison with their less value. As a
result of ion implantation of Pd films (30 and 40 nm) on
lithium niobate, the reflection coefficient is not selective
(i.e. independent from the wavelength) in the wide
spectral range (1–15 µm). Loosing selectivity may be
related with the crater-like structure arising after ion
implantation, what causes an increased absorption and
appropriate decrease in the reflection coefficient of the
systems, what is also confirmed theoretically, if taking
into account the roughness of implanted Pd film.
Absorption spectra was obtained using relation
A(λ) = 1 – R(λ) – T(λ) within the spectral range (λ = 0.25
– 15 µm). It is important result that ion implantation
causes an increased absorption of the samples in the
infrared (Figs 8 and 9) as a result of the following
factors: surface microrelief and its roughness changes,
light scattering on blisters and absorption by craters,
amorphyzation of metal film and pyroelectric sub-
surface layer; decrease of heterogeneity of the interface
film–substrate as caused by its widening.
Fig. 9. Reflectance spectra of thin Pd films on lithium niobate
with the Pd film thicknesses of 15 (1, 2), 20 (3, 4), 30 (5, 6)
and 40 nm (7, 8) before (1, 3, 5, 7) and after ion implantation
(2, 4, 6, 8) in comparison with those of bulk polycrystalline Pd
(9) and lithium niobate single crystal (10).
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 103-109.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
108
a)
b)
Fig. 10. Absorption spectra of thin Ni (а) and Mo (b) films
with the thicknesses 15 (1, 2), 20 (3, 4), 30 (5, 6), and 40 nm
(7, 8) on lithium niobate before (2, 4, 6, 8) and after implan-
tation (1, 3, 5, 7) in comparison with that of monocrystalline
lithium niobate (9).
Fig. 11. Absorption spectra of thin Pd film – lithium niobate
with film thicknesses 30 (1, 2), and 40 nm (3, 4) before (1, 3)
and after ion implantation (2, 4) in comparison with that of
monocrystalline lithium niobate (5).
Measurements and calculations of technical
characteristics of pyroelectric photodetector have shown
a number of advantages in comparison with existing
commercial devices.
Characteristics of pyroelectric photodetectors based
on the investigated systems in comparison with analogs
and other thermal detectors of infrared spectroscopy are
represented in Table 1. Most of characteristics of the
investigated system have better values than those of
analogs. And what is the most important, implanted
systems thin metal film–lithium niobate have nonselec-
tive spectral response in the infrared (λ = 1 – 15 m).
The obtained results have practical meaning
according to the possibility of application of the systems
thin metal film – lithium niobate implanted with Ar+ ions
in spectral optoelectronic devices owing to their
characteristics and nonselective response.
Table 1. Characteristics of different types of pyroelectric photodetectors.
Type of
photodetector
Area of
sensitive
element
(mm2)
Sensitivity
(V/W)
Effective
noise voltage
(V·Hz–1/2)
Detectivity
(cm·Hz1/2/W)
Time
constant
(s)
Damage
threshold
(W)
LTA G2 PC
(Dias)
4 > 200 < 10–7 > 3.7 · 108 – –
LTSI Q3
(Dias)
9 > 180 < 6·10–8 109 – 0.38
PY 55
(Goodrich)
9 845 2.9·10–10 109 < 50 –
Pyroelectric,
coated by
graphene
9 – – – – 0.5–1.1
LiNbO3 bulk – 3·104 – 1.2·108 5.2·103 –
Ni Bolometer 0.76 11 10-6 0.87·106 22·103 –
Ni-LiNbO3
implanted
8 3.5·103 5·10-7 5.1 ·107 5 50
Pd-LiNbO3
implanted
8 4.9·103 2.3·10-7 1.2 ·108 8 45
Pd-LiTaO3
implanted
8 5.5·103 10-6 2.5·108 12 30
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2010. V. 13, N 1. P. 103-109.
© 2010, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
109
3. Conclusions
1. It has been shown that the ion energies of 50-
150 keV are optimal for effective structure modification
in the interface film–substrate where the maximal
number of ions stops.
2. It has been ascertained that blisters on the
surface of Ni films appear in the result of tensions
caused by Ar gas between film and substrate during
thermal annealing. At the same conditions of ion
implantation, detachment of metal slices is observed for
Mo films, and craters from 1 to 15 m for Pd films on
LiNbO3 that may be related with damages of bubble-like
blisters in the result of a less value of surface tensions
for Pd film than for Ni melt as well as their tensile
strength.
3. Sharp decrease of the reflectance R() and
appropriate increase of absorption А() in the systems
Pd-LiNbO3 and nonselective spectral response are
mainly caused by the obtained surface structure, and
secondary by widening the interface film–substrate as a
result of ion implantation.
4. Blisters were formed as a result of exit of Ar
out of the film bulk. Bubble-like blisters for Ni films
differ from crater-like blisters for Pd films owing to
different surface tension coefficients and tensile strength
(both less for Pd).
5. It has been shown that decrease of reflectance
and increase of absorption of the implanted systems “Pd
film 40 nm – LiNbO3” and nonselectivity in the wide
spectral range are caused by close values of crater
dimensions and the wavelength of radiation. According
to Mie theory, such structures increase light scattering
forward, increasing absorption and decreasing reflection
at the same time.
Development of high-effective sensors of infrared
radiation based on the implanted system Pd-LinbO3 is
proposed according to its high sensitivity – 2.5·108 V/W,
time constant – 1.6 m, non-selectivity, damage
threshold – 5·103 W/cm2, what is competitive with
industrial thermal photodetectors. This circumstance
allows using the developed photodetectors in detector
systems for IR radiation.
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