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1.
Properties of reactively sputtered W–B–N thin film as a diffusion barrier for Cu metallization on Si
L. C. Leu D. P. Norton L. McElwee-White T. J. Anderson 《Applied Physics A: Materials Science & Processing》2009,94(3):691-695
Thin films of W–B–N (10 nm) have been evaluated as diffusion barriers for Cu interconnects. The amorphous W–B–N thin films
were prepared at room temperature via reactive magnetron sputtering using a W2B target at various N2/(Ar + N2) flow ratios. Cu diffusion tests were performed after in-situ deposition of 200 nm Cu. Thermal annealing of the barrier stacks
was carried out in vacuum at elevated temperatures for one hour. X-ray diffraction patterns, sheet resistance measurement,
cross-section transmission electron microscopy images, and energy-dispersive spectrometer scans on the samples annealed at
500°C revealed no Cu diffusion through the barrier. The results indicate that amorphous W–B–N is a promising low resistivity
diffusion barrier material for copper interconnects. 相似文献
2.
H. Huth A. A. Minakov A. Serghei F. Kremer C. Schick 《The European physical journal. Special topics》2007,141(1):153-160
A differential AC-chip calorimeter capable to measure the
glass transition in nanometer thin films is described. Due to the
differential setup pJ/K sensitivity is achieved. Heat capacity can
be measured for sample masses below one nanogram even above room
temperature as needed for the study of the glass transition in
nanometer thin polymeric films. The calorimeter allows for the
frequency dependent measurement of complex heat capacity in the
frequency range from 1 Hz to 1 kHz. The glass transition in thin
films of polystyrene (PS) (100–4 nm) and polymethylmethacrylate
(PMMA) (400–10 nm) was determined at well defined experimental
time scales. No thickness dependency of the glass transition
temperature was observed within the error limits (±3 K) -
neither at constant frequency nor for the traces in the activation
diagrams (1 Hz–1 kHz). 相似文献
3.
V. P. Rotshtein Yu. F. Ivanov A. B. Markov D. I. Proskurovskii K. V. Oskomov V. V. Uglov S. N. Dub Y. Pauleau I. A. Shulepov 《Russian Physics Journal》2005,48(12):1221-1228
The surface topography, chemical composition, microstructure, nanohardness, and tribological characteristics of a Cu (film,
512 nm)-stainless steel 316 (substrate) system subjected to pulsed melting by a low-energy (20–30 keV), high-current electron
beam (2–3 μs, 2–10 J/cm2) were investigated. The film was deposited by sputtering a Cu target in the plasma of a microwave discharge in argon. To
prevent local exfoliation of the film due to cratering, the substrate was multiply pre-irradiated with 8–10 J/cm2. On single irradiation, the bulk of the film survived, and a diffusion layer containing the film and substrate components
was formed at the interface. The thickness of this layer was 120–170 nm irrespective of the energy density. The diffusion
layer consisted of subgrains of γ-Fe solid solution and nanosized particles of copper. In the surface layer of thickness 0.5–1 μm, which included the copper
film quenched from melt and the diffusion layer, the nanohardness and the wear resistance nonmonotonicly varied with energy
density, reaching, respectively, a maximum and a minimum in the range 4.3–6.3 J/cm2. As the number of pulsed melting cycles was increased to five in the same energy density range, there occurred mixing of
the film-substrate system and a surface layer of thickness ∼2 μm was formed which contained ∼20 at. % copper. Displacement
of the excess copper during crystallization resulted in the formation of two-phase nanocrystal interlayers separating the
γ-phase grains.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 6–13, December, 2005. 相似文献
4.
Ali Safaei 《Journal of nanoparticle research》2010,12(3):759-776
The size dependency of the cohesive energy of nanocrystals is obtained in terms of their averaged structural and energetic
properties, which are in direct proportion with their cohesive energies. The significance of the effect of the geometrical
shape of nanoparticles on their thermal stability has been discussed. The model has been found to have good prediction for
the case of Cu and Al nanoparticles, with sizes in the ranges of 1–22 nm and 2–22 nm, respectively. Defining a new parameter,
named as the surface-to-volume energy-contribution ratio, the relative thermal stabilities of different nanoclusters and their
different surface-crystalline faces are discussed and compared to the molecular dynamic (MD) simulation results of copper
nanoclusters. Finally, based on the size dependency of the cohesive energy, a formula for the size-dependent diffusion coefficient
has been presented which includes the structural and energetic effects. Using this formula, the faster-than-expected interdiffusion/alloying
of Au(core)–Ag(shell) nanoparticles with the core–shell structure, the Au-core diameter of 20 nm and the Ag-shell thickness of 2.91 nm, has been
discussed and the calculated diffusion coefficient has been found to be consistent with its corresponding experimental value. 相似文献
5.
Laksminarayana Rao Naveen Krishna Reddy Sylvain Coulombe Jean-Luc Meunier Richard J. Munz 《Journal of nanoparticle research》2007,9(4):689-695
This communication reports on a new method for the collection of nanoparticles using carbon nanotubes (CNT) as collecting
surfaces, by which the problem of agglomeration of nanoparticles can be circumvented. CNT (10–50 nm in diameter, 1–10 μm in
length) were grown by thermal CVD at 923 K in a 7 v/v% C2H2 in N2 mixture on electroless nickel-plated copper transmission electron microscopy (TEM) grids and Monel coupons. These samples
were then placed downstream of an arc plasma reactor to collect individual copper nanoparticles (5–30 nm in diameter). It
was observed that the Cu nanoparticles preferentially adhere onto CNT and that the macro-particles (diameter >1 μm), a usual
co-product obtained with metal nanoparticles in the arc plasma synthesis, are not collected. Cu–Ni nanoparticles, a catalyst
for CNT growth, were deposited on CNT to grow multibranched CNT. CNT-embedded thin films were produced by re-melting the deposited
nanoparticles. 相似文献
6.
S. L. Gafner L. V. Redel Yu. Ya. Gafner 《Journal of Experimental and Theoretical Physics》2012,114(3):428-439
We have investigated the heat capacity of ideal Cu and Ni fcc clusters with diameters from 2 to 6 nm in the temperature range
200–800 K by the molecular-dynamics method using a modified tight-binding potential. Our analysis has shown consistency with
the experimental results at temperatures of 200–300 K. The data obtained are also indicative of several regularities that
are in agreement with the analytical calculations. We have concluded from the results of our computer simulations that the
heat capacity in the case of isolated free clusters can exceed that of a bulk material, with this difference decreasing as
the nanoparticle grows proportionally to the reduction in the fraction of surface atoms. The excess of the heat capacity for
ideal copper and nickel nanoclusters with D = 6 nm at T = 200 K has been found to be 10% and 13%, respectively. Consequently, the large heat capacities of copper and nickel nanostructures
observed in some real experiments cannot be related to the characteristics of free clusters. We hypothesize that these properties
of a nanomaterial depend on the degree of agglomeration of its constituent particles, i.e., the surfaces and interphase boundaries
of interconnected nanoclusters can have a strong effect. To test this hypothesis, we took nickel and copper clusters of various
sizes (4000–7200 atoms) produced through the simulation of condensation from the gas phase. At high temperatures, we failed
to adequately assess the role of the interphase boundaries in calculating the heat capacity of nanoparticles. The reason was
the mass diffusion of Ni or Cu atoms to impart an energetically more favorable shape and structure to the synthesized clusters.
At low temperatures, the heat capacity of such clusters exceeded that of clusters with an ideal shape and structure by a value
from 3.2% to 10.6%. We have concluded that the Ni and Cu clusters produced in real experiments cannot be applied in devices
using the thermal energy of such clusters without a preliminary optimization stage, because their external shape and interior
structure are nonideal. 相似文献
7.
K. SrinivasaRao B. Rajini Kanth P. K. Mukhopadhyay 《Applied Physics A: Materials Science & Processing》2009,96(4):985-990
Ultra-thin MoO3 films were deposited onto glass and Si substrates by r.f. magnetron sputtering. The optical and IR properties of the films
were studied in the range of 250 to 1000 nm and 400 to 1500 cm−1, respectively. The optical transmission spectra show a significant shift in absorption edge. The energy gap of the films
deposited at 373 K and 0.1 mbar was found to be 3.93 eV, and it decreases with increasing substrate temperature and decreasing
sputtering pressure. The IR transmittance spectra shows strong modes of vibrations of Mo=O and Mo–O–Mo units of MoO3 molecule. A significant change in energy gap and a shift in frequency of IR modes were observed in ultra-thin MoO3 films. 相似文献
8.
The saddle field fast atom beam sputtered (ABS) 50 nm thick molybdenum carbide (Mo2C) films as a diffusion barrier for copper metallization were investigated. To study the diffusion barrier properties of Mo2C films, the as-deposited and annealed samples were characterized using four probes, X-ray diffraction, field enhanced scanning electron microscopy, energy dispersive X-ray analysis, atomic force microscopy and Rutherford back scattering techniques. The amorphous structure of the barrier films along with presence of carbon atoms at the molybdenum carbide-silicon interface is understood to reduce effective grain boundaries and responsible for increased thermal stability of Cu/Mo2C/Si structure. The lowest resistivity of the as-deposited molybdenum carbide barrier films was ∼29 μΩ cm. The low carbon containing molybdenum carbide was found thermally stable up to 700 °C, therefore can potentially be used as a diffusion barrier for copper metallization. 相似文献
9.
R. Fardel M. Nagel T. Lippert F. Nüesch A. Wokaun B.S. Luk’yanchuk 《Applied Physics A: Materials Science & Processing》2008,90(4):661-667
The laser ablation of a photosensitive triazene polymer was investigated with a ns XeCl excimer laser over a broad range of
thicknesses (10–400 nm). We found that the ablation threshold fluence increased dramatically with decreasing film thickness
for films thinner than 50 nm. Ablation on substrates with different thermal properties (sapphire, fused silica, PMMA) was
investigated as well, and a clear influence of the substrate material was obtained. A mathematical model combining thermal
diffusion and absorption effects was used to explain the experimental data. The model is in good agreement with the experimental
data and shows that heat diffusion into the substrate plays a crucial role for the ablation process of very thin films.
PACS 52.38.Mf; 44.05.+e; 81.05.Lg 相似文献
10.
D. R. Lee S. H. Choi H. H. Lee J.-Y. Kim C.-J. Yu 《The European physical journal. Special topics》2009,167(1):163-169
We studied ~0.5 μm and 30–80 ? thick films of a normal dielectric
liquid, tetrakis(2-ethylhexoxy)silane (TEHOS), at temperature range 228–286 K,
deposited onto silicon (111) substrate with native oxide using X-ray
reflectivity. TEHOS is spherical with size ~10 ?, non-polar,
non-reactive, and non-entangling; TEHOS has been reported to show interfacial
layering at room temperature and surface layering at 0.23 Tc (Tc≈
950 K). For films m thick, the reflectivity data did not change
significantly as a function of temperature; for films 30–80 ? thick, the
reflectivity data did change. The data could be fitted with an electron density
model composed of a minimum necessary number of Gaussians and a uniform density
layer with error-function broadened interfaces. When the film thickness is 60–80 ? below 246 K, we found that the interface
and the surface layering coexist
but do not overlap. When the film thickness is 30–40 ? below 277 K, they
overlap and the electron density profile shows slowly decreasing molecular
oscillations at the air-liquid interface. 相似文献
11.
D. I. Sagaidak G. G. Fedoruk B. G. Shulitskii V. V. Grigor’ev 《Journal of Applied Spectroscopy》1997,64(4):518-522
Visible and IR absorption spectra are studied for copper phthalocyanin (CuPc)-polyyimide composites. The composite films are
obtained by vacuum codeposition of CuPc, pyromellitedianhydride, and diaminodiphenyloxide followed by temperature-induced
imidization. On the basis of IR spectra it is shown that in the prepared composites imidization occurs over the whole CuPc
concentration range (10–90%). From the visible spectra it is found that CuPc is deposited mainly in the form of a-microcrystals,
which are destroyed during imidization to produce noncrystalline molecular aggregates. Subsequent heat treatment (320–350°C)
gives rise to CuPc β-microscrystals.
A. N. Sevchenko Research Institute of Applied Physical Problems, 7, Kurchatov St., 220064, Minsk, Belarus. Translated from
Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 4, pp. 502–506, July–August, 1997. 相似文献
12.
Adsorption of titanium,chromium, and copper atoms on thin aluminum and magnesium oxide film surfaces
I. V. Tvauri A. M. Turiev N. I. Tsidaeva M. E. Gazzaeva G. G. Vladimirov T. T. Magkoev 《Russian Physics Journal》2012,54(11):1226-1231
Methods of Auger electron spectroscopy (AES), spectroscopy of characteristic electron energy losses (SCEEL), slow electron
diffraction (SED), and contact potential difference (CPD) in ultrahigh vacuum are used to investigate the adsorption-emission
properties and stability of two-component film systems formed by putting of Ti, Cr, and Cu atoms on MgO–Mo(011) and Al2O3–Mo(011) surfaces. All atoms have the properties of electronegative adsorbates. Continuous adatom monolayers are formed on
the Al2O3–Mo(011) system surface, and three-dimensional islands are formed on the MgO–Mo(011) surface. The properties of monoatomic
films on the oxide layer surface are close to those observed for bulk materials. No radical changes of the system properties
are detected with increasing dielectric layer thickness. The thermal stability of the newly formed structures decreases in
the order Ti, Cr, Cu, Al2O3(MgO), and Mo(011). 相似文献
13.
Doping of ZnS crystals with background impurities and ZnS:Al crystals by various concentrations of copper from a bismuth melt
has been carried out. The photoluminescence spectra of the starting ZnS crystals annealed in the bismuth melt and doped by
copper have been investigated. Interpretation of the experimental results according to the model in which the associates (Cu
Zn
′
Cu
i
●
) are responsible for the B-Cu band (≈460 nm) and the donor—receptor pairs [Cu
i
●
-(Cu
Zn
′
Cu
i
●
)] are responsible for the G-Cu band (≈505 nm) is given. It is assumed that doping by copper from a bismuth melt is accompanied
by the separation of a CuxS-type phase. It has been shown that heat treatment of ZnS crystals in the Bi melt does not lead to the appearance of luminescence
centers based on BiZn, BiS, and Bii.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 794–798, November–December, 2005. 相似文献
14.
S. Bo J. Wang H. Zhao H. Ren Q. Wang G. Xu X. Zhang X. Liu Z. Zhen 《Applied physics. B, Lasers and optics》2008,91(1):79-83
Oleic acid modified LaF3:Er,Yb nanocrystals have been synthesized with a molar ratio of La:Yb:Er=75:20:5 and dispersed in toluene with 40 wt. % sol–gel
derived organic–inorganic hybrid materials for films. The nanocomposite films showed strong 1540-nm luminescence intensity
under the excitation of 980 nm after heat treatment below 150 °C. The full width at half maximum bandwidth was 51-nm wide
around 1540 nm. We also fabricated reverse-mesa ridge waveguides using LaF3:Er,Yb nanocrystals containing sol–gel materials. With an input pump of 150 mW, a signal enhancement of 2.3 dB at the wavelength
of 1550 nm was measured in a 1.3-cm-long waveguide.
PACS 42.00.00; 42.70.-a; 42.82.Et 相似文献
15.
I. Fasaki A. Giannoudakos M. Stamataki M. Kompitsas E. György I.N. Mihailescu F. Roubani-Kalantzopoulou A. Lagoyannis S. Harissopulos 《Applied Physics A: Materials Science & Processing》2008,91(3):487-492
Transparent nickel oxide thin films were grown by reactive pulsed laser deposition. An ArF* (λ=193 nm, τ=12 ns) excimer laser
source was used to ablate the Ni targets in a controlled pressure of ambient oxygen. The substrates were either kept at room
temperature or heated to a selected temperature within the 200–400 °C range. Post-deposition heat treatment, which was applied
to further promote crystallization and overcome any oxygen deficiency, yielded transparent thin films. The surface morphology
and crystalline status of the synthesized thin structures were analyzed in correlation with their optical properties. A significant
response to several concentrations of hydrogen was demonstrated when heating the nickel oxide films at 185 °C.
PACS 78.66.Hf; 81.15.Fg; 82.47.Rs 相似文献
16.
A. A. Movchikova O. V. Malyshkina O. N. Kalugina 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2012,6(1):33-36
A new method for determining the thermal diffusion coefficient of thin dielectric films deposited on a ferroelectric crystal
detector is presented. The surface of the specimen was periodically heated by a rectangular modulated heat flow. The impact
of the ratio of the film thickness to the detector thickness, as well as the film thermal diffusion coefficient on the shape
of the system’s pyroelectric response is analyzed. Optimal conditions for the measurements are offered. Approbation of the
method was carried out on an unannealed lead zirconate titanate (PZT) film deposited on a lithium tantalate crystal. The thermal
diffusion coefficient of the specimen was α = 1.5 × 10−7 m2/s, which correlates with an independent estimation of this magnitude for polarized films. 相似文献
17.
S. H. Bo J. Hu Z. Chen Q. Wang G. M. Xu X. H. Liu Z. Zhen 《Applied physics. B, Lasers and optics》2009,97(3):665-669
The oleic acid (OA)-modified LaF3:Er,Yb and LaF3:Er,Yb–LaF3 core-shell nanocrystals are synthesized. The lifetime values could be further improved by incorporating core-shell nanocrystals.
A kind of sol–gel derived organic–inorganic hybrid material (SGHM) allows for 50 wt.% or even more of both the two nanocrystals
in the matrix, and we give the explanation from scattering analysis. It’s precisely because we use the erbium nanocrystals
rather than erbium organic complexes, and avoid the undesirable luminescence quenching by Er–Er clustering with a high Er3+ concentration. LaF3:Er,Yb–LaF3/SGHM transparent films and optical waveguides are also fabricated. The nanocomposite films show strong 1550 nm luminescence
intensity under the excitation of 980 nm after heat treatment below 150 °C and the full-width-at-half-maximum is about 51
nm. The loss and optical gain of the waveguide are measured. A relative gain of about 3.5 dB is measured at 1550 nm in a 1.7 cm
long waveguide. 相似文献
18.
T. N. Vasilevskaya N. S. Andreev I. A. Drozdova V. N. Filipovich S. G. Yastrebov T. K. Zvonareva 《Physics of the Solid State》1999,41(11):1918-1925
A study of the nanostructure of a-C:H:Cu films by x-ray small-angle scattering, x-ray diffraction, TEM, and visible and UV spectroscopy is reported. It has
been established that introduction of 9–16 at.% Cu not only decorates the original carbon fragments but produces extended
(up to 4 μm in length) formations of copper-decorated strongly elongated ellipses as well. At 14–16 at.% Cu, these linear
clusters represent copper nanotubes with a core made up of the original ellipses drawn in a line. It is these conducting copper
formations that account primarily for the strong increase in conductivity at 12–16 at.% Cu contents in a-C:H films.
Fiz. Tverd. Tela (St. Petersburg) 41, 2088–2096 (November 1999) 相似文献
19.
A. Schönhals H. Goering C. Schick B. Frick M. Mayorova R. Zorn 《The European physical journal. Special topics》2007,141(1):255-259
The effect of a nanometer confinement on the molecular
dynamics of poly(methyl phenyl siloxane) (PMPS) was studied by
dielectric spectroscopy (DS), temperature modulated DSC (TMDSC) and
neutron scattering (NS). Nanoporous glasses with pore sizes of
2.5–20 nm have been used. DS and TMDSC experiments show that for
PMPS in 7.5 nm pores the molecular dynamics is faster than in the
bulk which originates from an inherent length scale of the
underlying molecular motions. For high temperatures the temperature
dependence of the relaxation rates for confined PMPS crosses that of
the bulk state. Besides finite states effects also the thermodynamic
state of nano-confined PMPS is different from that of the bulk. At a
pore size of 5 nm the temperature dependence of the relaxation
times changes from a Vogel/Fulcher/Tammann like to an Arrhenius
behavior where the activation energy depends on pore size. This is
in agreement with the results obtained by NS. The increment of the
specific heat capacity at the glass transition depends strongly on
pore size and vanishes at a finite length scale between 3 and 5 nm
which can be regarded as minimal length scale for glass transition
to appear in PMPS. 相似文献
20.
A new theoretical model is proposed to describe the behavior of films of composite hydrogen-containing compounds during heat
treatment. The model is based on the thermal generation of hydrogen atoms and atoms of the composite compounds with their
subsequent diffusion to the boundaries of the film and percolation through the surface into the atmosphere. Calculations are
performed for the heat treatment of films of silicon nitride. A comparison with the experimental data in the literature demonstrates
the high efficiency of the proposed model.
Zh. Tekh. Fiz. 67, 105–110 (August 1997) 相似文献