共查询到20条相似文献,搜索用时 203 毫秒
1.
Holmelund E. Thestrup B. Schou J. Larsen N.B. Nielsen M.M. Johnson E. Tougaard S. 《Applied Physics A: Materials Science & Processing》2002,74(2):147-152
Indium tin oxide (ITO) films have been deposited by pulsed laser deposition (PLD) at 355 nm. Even though the absorption of
laser light at the wavelength 355 nm is much smaller than that of the standard excimer lasers for PLD at 248 nm and 193 nm,
high-quality films can be produced. At high fluence and at high substrate temperatures, the specific resistivity of the films,
2–3×10-4 Ω cm, is comparable to values obtained with excimer lasers, whereas the resistivities obtained at room temperature are somewhat
higher than those of films produced by excimer lasers. The transmission coefficient of visible light, about 0.9, is also comparable
to values for films deposited by excimer lasers. The crystalline structure of films produced at 355 nm is similar to that
of samples produced by these lasers.
Received: 16 January 2001 / Accepted: 24 July 2001 / Published online: 17 October 2001 相似文献
2.
Z.Y. Chen J.P. Zhao T. Yano T. Ooie 《Applied Physics A: Materials Science & Processing》2002,75(2):213-216
Raman characteristics of carbon nitride films synthesized by nitrogen-ion-beam-assisted pulsed laser deposition were investigated.
In addition to the D (disorder) band and G (graphitic) band commonly observed in carbon nitride films, two Raman bands located
at 1080–1100 and 1465–1480 cm-1 were found from our carbon nitride films. These two bands were well matched with the predicted Raman frequencies for βC3N4 and the observed Raman bands reported for carbon nitride films, indicating their relation to carbon-nitrogen stretching vibrations.
Furthermore, the relative intensity ratio of the two Raman bands to the D and G bands increased linearly with increasing nitrogen
content of the carbon nitride films.
Received: 30 October 2000 / Accepted: 5 February 2001 / Published online: 2 October 2001 相似文献
3.
X. Zhu S. Lu H.L.W. Chan C.L. Choy K.H. Wong 《Applied Physics A: Materials Science & Processing》2003,76(2):225-229
Compositionally graded (Ba1-xSrx)TiO3 (BST) (x:0.0∼0.25) thin films were grown on Pt (111)/TiO2/SiO2/Si (100) substrates using layer-by-layer pulsed laser deposition in the temperature range 550–650 °C. Both downgraded (Ba/Sr
ratio varying from 100/0 at the bottom surface to 75/25 at the top surface) and upgraded (Ba/Sr ratio varying from 75/25 at
the bottom surface to 100/0 at the top surface) BST films were prepared. Their microstructures were systematically studied
by X-ray diffractometry and scanning electron microscopy. A grain morphology transition from large ‘rosettes’ (>0.30 μm) to
small compact grains (70–110 nm) was observed in the downgraded BST films as the deposition temperature was increased from
550 to 650 °C. No such grain morphology transition was detected in the upgraded BST films. Dielectric measurements with metal
electrodes revealed an enhanced dielectric behavior in the downgraded films. This enhancement is mainly attributed to the
large compressive stress field built up near the interface between the downgraded film and substrate. Furthermore, the BaTiO3 layer in the downgraded BST films not only serves as a bottom layer but also as an excellent seeding layer for enhancing
the crystallization of the subsequent film layers in the downgraded films.
Received: 10 December 2001 / Accepted: 12 March 2002 / Published online: 19 July 2002
RID="*"
ID="*"Corresponding author. Fax: 86-25/359-5535, E-mail: xhzhu@public1.ptt.js.cn 相似文献
4.
K.-H. Shim M.C. Paek B.T. Lee C. Kim J.Y. Kang 《Applied Physics A: Materials Science & Processing》2001,72(4):471-474
Effects of thermal treatments on the electrical properties and microstructures of indium–tin oxide (ITO)/GaN contacts have
been investigated using a rf-magnetron sputter deposition followed by rapid thermal annealing. ITO films annealed at 800 °C
revealed Schottky contact characteristics with a barrier height corresponding to ITO’s work function of 4.62 eV. The evolution
of electrical properties of ITO/GaN contacts was attributed to the preferential regrowth of In2O3 (222)//GaN (0001) with an ideal metal–semiconductor Schottky contact. The feasible use of ITO/GaN as a transparent Schottky
contact would be realized by the enhanced regrowth of In2O3 at high temperature.
Received: 1 September 2000 / Accepted: 15 November 2000 / Published online: 28 February 2001 相似文献
5.
Fatigue-free Pb(Zr0.52Ti0.48)O3 (PZT) ferroelectric thin films were successfully prepared on indium tin oxide (ITO) coated glass substrates using the sol-gel
method combined with a rapid thermal annealing process (RTA). The films post-annealed at a temperature of 700 °C for 2 min
by RTA process formed (110)-oriented Pb(Zr0.52Ti0.48)O3 thin films with pure perovskite structure, and had a good morphology as well. The good ferroelectricity of the prepared PZT
films was confirmed by P–E hysteresis loop measurements. Fatigue characteristics showed stable behavior. Degradation in polarization
was not found while the repeating cycles were up to 1011, and a low leakage current density of 10−8 A/cm2 was also obtained from the highly fatigue-resisted PZT thin films on ITO/glass substrates.
Received: 19 October 1998 / Accepted: 29 March 1999 / Published online: 26 May 1999 相似文献
6.
The relationship between the macroscopic properties of PECVD silicon nitride and oxynitride layers and the characteristics of their networks 总被引:1,自引:0,他引:1
Silicon nitride and oxynitride films have been deposited on silicon wafers using plasma-enhanced chemical vapour deposition.
Various amounts of ammonia, silane and nitrous oxide gases were applied at fixed total gas flow and at the same deposition
temperature. The dependence of the macroscopic properties of the layers such as refractive index, internal stress and etch
rate on the reaction atmosphere during deposition has been demonstrated. The chemical structure of amorphous layers was studied
using infrared spectroscopy. The network was found to be characterised by SiNxOyHz tetrahedra, joined to each other by common corners. The characteristic vibrational bands due to species that join tetrahedral
units (N(-Si≡)3, ≡Si-N-Si≡, ≡Si-O-Si≡) and species that stop this interconnection (Si-H, N-H) were determined and discussed with reference
to the corresponding species available during deposition. The analysis resulted in the determination of the relationship between
the chemical structure of the network and the layer’s refractive index, internal stress and etch rate.
Received: 24 July 2000 / Accepted: 30 May 2001 / Published online: 30 August 2001 相似文献
7.
S.D. Cheng X.Q. Han C.H. Kam Y. Zhou Y.L. Lam J.T. Oh X.W. Xu T.C. Chong 《Applied Physics A: Materials Science & Processing》2001,73(4):511-514
We have successfully prepared highly c-axis-textured LiNbO3 films on hydrogen-terminated Si (111) substrate using sol-gel spin-coating and rapid thermal annealing. These highly c-axis-textured
films were obtained with a preheating at 300 °C for 15 min followed by a rapid thermal annealing at 500–700 °C for 120 s.
The c-axis orientation of the LiNbO3 film is due to a weak effect caused by the 3-fold symmetry match between the film and the Si (111) substrate. The c-axis
orientation of LiNbO3 films is very useful in integrated optics devices and metal–ferroelectric–semiconductor nonvolatile memory applications.
Received: 15 September / Accepted: 4 December / Published online: 3 April 2001 相似文献
8.
C. Popov P. Petkov Y. Nedeva P. Ilchev W. Kulisch 《Applied Physics A: Materials Science & Processing》2003,77(1):145-147
Thin chalcogenide films from the systems (GeSe4)1-xGax and (GeSe5)1-xGax with gallium contents up to 20 at. % have been prepared by vacuum evaporation and their stress has been investigated by a
cantilever technique. The addition of gallium to the Ge-Se matrix plays an important role in stress formation in the films:
films without gallium possess negligible stress, while all gallium-containing films are under compressive stress. The increase
of the gallium content leads to structural changes and an increase in the density, which results in higher stress values.
For all films, stress reduction with time is observed due to spontaneous relaxation.
Received: 2 October 2002 / Accepted: 22 November 2002 / Published online: 28 March 2003
RID="*"
ID="*"Corresponding author. Fax: +49-561/8044-136, E-mail: popov@schottky.physik.uni-kassel.de 相似文献
9.
We report on the first layer growth of a Mn6+-doped material. Large-size BaSO4 substrates of 10×6×4 mm3 were grown from a LiCl solvent by the flux method. Flat surfaces of undoped BaSO4 were then achieved by use of liquid-phase epitaxy (LPE) from a CsCl–KCl–NaCl solvent. Finally, BaSO4:Mn6+ layers were grown by LPE with growth velocities of approximately 3 μm h-1, at temperatures of 550–508 °C. Absorption, luminescence, luminescence-excitation and luminescence-decay measurements confirmed
the incorporation of manganese solely in its hexavalent oxidation state. This material possesses potential as a near-infrared
tunable laser with a wavelength range larger than Ti:sapphire.
Received: 7 January 2002 / Revised version: 30 March 2002 / Published online: 8 August 2002 相似文献
10.
R. Dinu M. Dinescu J.D. Pedarnig R.A. Gunasekaran D. Bäuerle S. Bauer-Gogonea S. Bauer 《Applied Physics A: Materials Science & Processing》1999,69(1):55-61
Ferroelectric SrBi2Ta2O9 (SBT) films were grown by pulsed-laser deposition (PLD) at different substrate temperatures and fluences. A correlation between
film structure and ferroelectric properties is established. The dielectric function ε′ of thin SBT films shows a Curie–Weiss behavior well below the peak temperature Tmax and relaxor-like behavior in the vicinity of Tmax. Domain walls have a strong influence on the dielectric and ferroelectric properties and on the polarization fatigue of SBT
films below 100 °C. The formation of ferroelectric phases is favored at lower substrate temperatures by incorporating Bi2O3 template layers into the structure.
Received: 18 March 1999 / Accepted: 19 March 1999 / Published online: 5 May 1999 相似文献
11.
X. Hao J. Ma D. Zhang X. Xu Y. Yang H. Ma S. Ai 《Applied Physics A: Materials Science & Processing》2002,75(3):397-399
Transparent conducting antimony-doped tin oxide (SnO2:Sb) films were deposited on organic substrates by r.f. magnetron-sputtering. Polycrystalline films with a resistivity of
≈ 6.5×10-3 Ω cm, a carrier concentration of≈ 1.2×1020 cm-3 and a Hall mobility of ≈ 9.7 cm2 v-1 s-1 were obtained. The average transmittance of these films reached 85% in the wavelength range of the visible spectrum.
Received: 20 April 2001 / Accepted: 23 July 2001 / Published online: 17 October 2001 相似文献
12.
G. Kuri G. Materlik V. Hagen R. Wiesendanger 《Applied Physics A: Materials Science & Processing》2001,73(3):265-271
MgO (100) single crystals are implanted with 1.50-MeV Al+ and 3.00-MeV Al2
+ ions at a fluence of 1×1015 Al atoms cm-2 under high-vacuum conditions. The surface morphology of the substrate is measured in air using atomic force microscopy and
X-ray reflectometry followed by computer-simulated spectrum analysis. The ion-irradiated areas are found to protrude to different
heights on the nanometre scale. Small height differences are observed in the areas irradiated by Al+ and Al2
+ ions of comparable energy, dose rate and total fluence. The results indicate that protrusions are most likely caused by implantation-induced
point defects (vacancies) generated in the crystal during implantation. Other possibilities for the cause of protrusions are
discussed. Thermal treatment stimulates a partial recovery of the implantation damage and alters the topography of MgO surfaces.
Received: 22 May 2001 / Accepted: 30 May 2001 / Published online: 25 July 2001 相似文献
13.
R.A. Gunasekaran J.D. Pedarnig M. Dinescu 《Applied Physics A: Materials Science & Processing》1999,69(6):621-624
A parametric study of the growth of La0.5Sr0.5CoO3 (LSCO) thin films on (100) MgO substrates by pulsed-laser deposition (PLD) is reported. Films are grown under a wide range
of substrate temperature (450–800 °C), oxygen pressure (0.1–0.9 mbar), and incident laser fluence (0.8–2.6 J/cm2). The optimum ranges of temperature, oxygen pressure, and laser fluence to produce c-axis oriented films with smooth surface morphology and high metallic conductivity are identified. Films deposited at low
temperature (500 °C) and post-annealed in situ at higher temperatures (600–800 °C) are also investigated with respect to their
structure, surface morphology, and electrical conductivity.
Received: 20 November 1998 / Accepted: 6 July 1999 / Published online: 21 October 1999 相似文献
14.
J. Wollschläger 《Applied Physics A: Materials Science & Processing》2002,75(1):155-166
The growth of CaF2 on vicinal Si (111) surfaces was studied by scanning tunneling microscopy (STM) and atomic force microscopy (AFM) for the
temperature range from 300 to 750 °C. In the submonolayer range a transition from terrace to step nucleation is observed for
increasing temperature. The first monolayer grows in the step-flow growth mode since second layer islands are not nucleated
before completion of the wetting layer. For the subsequent growth of CaF2 on the CaF interface layer, substrate-induced steps do not act as preferential nucleation sites, but rather as growth barriers.
Thus CaF2 films grow very inhomogeneously at high temperatures. At lower deposition temperatures, the film homogeneity increases due
to the increased (homogeneous) nucleation rate on terraces. The lattice mismatch leads to (lateral) relaxation of thicker
CaF2 film close to substrate steps. In addition, CaF2 self-decoration effects are caused by the relaxed regions close to the film steps at temperatures above 500 °C.
Received: 7 August 2001 / Accepted: 23 October 2001 / Published online: 3 April 2002 相似文献
15.
Synthesis of carbon nitride films by direct current plasma assisted pulsed laser deposition 总被引:1,自引:0,他引:1
Y.H. Cheng X.L. Qiao J.G. Chen Y.P. Wu C.S. Xie S.B. Muo Y.B. Sun B.K. Tay 《Applied Physics A: Materials Science & Processing》2002,74(2):225-231
Carbon nitride films were deposited by pulsed laser ablation of a graphite target under a nitrogen atmosphere at room temperature.
A direct current discharge apparatus was used to supply active nitrogen species during the deposition of carbon nitride films.
The composition and bonding structure of carbon nitride films were determined by Fourier-transform infrared (FTIR) spectroscopy
and X-ray photoelectron spectroscopy. The incorporation of nitrogen atoms in the films is greatly improved by the using of
a dc glow discharge. The ratio N/C can reach 0.34 at the discharge voltage of 400 V. Six peaks centered at 1025 cm-1, 1226 cm-1, 1381 cm-1, 1534 cm-1, 1629 cm-1, and 2200 cm-1 can be clearly distinguished from the FTIR spectra of the deposited films, which indicates the existence of C–N, C=N, and
C≡N bonds. The fraction of sp2 C, C≡N bonds, and C=N bonds in the deposited films increases with increasing discharge voltage. Deconvolution results of
C 1s and N 1s spectra also indicate that nitrogen atoms in the films are chemically bonded to sp1 C, sp2 C, and sp3 C atoms. Most of the nitrogen atoms are bonded to sp2 C atoms. Increasing the discharge voltage leads to a decrease of the fraction of nitrogen atoms bonded to sp2 C and the fraction of amorphous carbon; however, it leads to an increase of the fraction of nitrogen atoms bonded to sp3 C and the fraction of sp2 C and sp3 C atoms bonded to nitrogen atoms.
Received: 7 June 2000 / Accepted: 19 February 2001 / Published online: 27 June 2001 相似文献
16.
Structural and electrical properties of tantalum nitride thin films fabricated by using reactive radio-frequency magnetron sputtering 总被引:2,自引:0,他引:2
H.B. Nie S.Y. Xu S.J. Wang L.P. You Z. Yang C.K. Ong J. Li T.Y.F. Liew 《Applied Physics A: Materials Science & Processing》2001,73(2):229-236
TaN thin film is an attractive interlayer as well as a diffusion barrier layer in [FeN/TaN]n multilayers for the application as potential write-head materials in high-density magnetic recording. We synthesized two
series of TaN films on glass and Si substrates by using reactive radio-frequency sputtering under 5-mtorr Ar/N2 processing pressure with varied N2 partial pressure, and carried out systematic characterization analyses of the films. We observed clear changes of phases
in the films from metallic bcc Ta to a mixture of bcc Ta(N) and hexagonal Ta2N, then sequentially to fcc TaN and a mixture of TaN with N-rich phases when the N2 partial pressure increased from 0.0% to 30%. The changes were associated with changes in the grain shapes as well as in the
preferred crystalline orientation of the films from bcc Ta [100] to [110], then to random and finally to fcc TaN [111], correspondingly. They were also associated with a change in film resistivity from metallic to semiconductor-like
behavior in the range of 77–295 K. The films showed a typical polycrystalline textured structure with small, crystallized
domains and irregular grain shapes. Clear preferred (111) stacks parallel to the substrate surface with embedded amorphous
regions were observed in the film. TaN film with [111]-preferred orientation and a resistivity of 6.0 mΩ cm was obtained at
25% N2 partial pressure, which may be suitable for the interlayer in [FeN/TaN]n multilayers.
Received: 6 December 1999 / Accepted: 24 July 2000 / Published online: 9 November 2000 相似文献
17.
F. Sánchez M.V. García-Cuenca C. Ferrater M. Varela 《Applied Physics A: Materials Science & Processing》2002,75(3):381-385
We report on the epitaxial growth of yttria-stabilised zirconia (YSZ) buffer layers on X-cut LiNbO3 (LNO) single crystals by pulsed laser deposition. Despite the low chemical stability of the substrates at high temperature,
high quality fully reproducible films were obtained over a relatively broad range of processing conditions. The films were
(00h) out-of-plane single oriented and the in-plane edge of the YSZ unit cell was aligned with the polar axis of the LNO.
However, the YSZ deposition also promoted the formation of the compound LiNb3O8. This compound is epitaxial and located at the interface. The homogeneous YSZ film presents a uniform surface, free of outgrowths
and with a low roughness. These characteristics are suitable for the epitaxial growth of other oxides, as has been demonstrated
with the preparation of YBa2Cu3O7/CeO2/YSZ/LNO heterostructures. The superconducting YBa2Cu3O7 films were epitaxial, with the c axis perpendicular to the surface and single in-plane orientation, and presented good transport
properties (critical temperatures around 86 K and critical current densities close to 106 A/cm2 at 77 K).
Received: 5 April 2001 / Accepted: 30 July 2001 / Published online: 30 October 2001 相似文献
18.
D.J. Fu Y.Y. Lei J.C. Li M.S. Ye H.X. Guo Y.G. Peng X.J. Fan 《Applied Physics A: Materials Science & Processing》1998,67(4):441-445
60 films by means of ionized cluster beam (ICB) deposition. X-ray diffraction (XRD) measurement showed the C60 films to be polycrystalline. The films show negative resistance–temperature coefficients, and their room-temperature resistivity
is greater than 102 Ω cm. The films were implanted with 80-keV phosphorus, BBr3, Ar, and He ions, under doses ranging up to 1016 cm-2. The resistivity of the implanted films decreases with increasing doses. n-type electrical conduction was observed for phosphorus-implanted
C60 films. The interaction of impinging ions with C60 clusters was found to force the C60 molecules to disintegrate and the films to amorphize. p-type conduction was observed for the C60 films doped with aluminum by simultaneously sputtering aluminum during deposition. C60/Si structures show heterojunction characteristics that can be influenced by light illumination. The photoelectric properties
of the films were found to be improved by doping with aluminum.
Received: 12 January 1998/Accepted: 24 March 1998 相似文献
19.
The ac electrical properties of metal-free phthalocyanine (H2PC) thin films have been studied in the frequency range from 102 to 2×104 Hz and in the temperature range from 150 to 475 K. The ac conductivity σ was found to vary as ωs with the index s≤1. Although these general values of s appear to be consistent with a hopping process, the present σ values
do not increase monotonically with temperature. At low frequency, the capacitance and loss tangent were found to be constant
over the entire frequency range, in good qualitative agreement with the equivalent circuit model consisting of an inherent
capacitance in parallel with a resistive element. Moreover, at constant frequency, the two parameters increased with increasing
temperature up to approximately 300 K. Above this temperature, another sharp decrease in both capacitance and loss tangent
was obtained. This type of behavior was interpreted in terms of nomadic (delocalized) polarization, which leads to an increase
in the dielectric constant. The drastic decrease of the capacitance and loss tangent observed above room temperature is thought
to be related to the decrease in the dielectric constant, which results from the inability of the domains to hold the increases
in free charge carrier concentration due to the increase of temperature.
Received: 6 December 2001 / Accepted: 7 January 2002 / Published online: 19 July 2002
RID="*"
ID="*"Corresponding author. Fax: +972-2/279-6960, E-mail: asaleh@science.alquds.edu 相似文献
20.
Large third-order nonlinear optical susceptibility of Au-Al2O3 composite films near the resonant frequency 总被引:2,自引:0,他引:2
2 O3 composite films with high Au concentrations (30%–60% in volume fraction) were prepared by reactive co-sputtering and post
rapidly thermal annealing. The structure of the films and the size distributions of the Au nanoclusters were examined by TEM,
and the third-order nonlinear optical susceptibility χ(3) was measured by degenerated four-wave mixing using a 70-ps pulse laser at 532 nm. The maximum value of the χ(3) was about 1.2×10-6 esu in the annealed films and occurred at around 45% Au concentration. The figure of merit, χ(3)/α (α is the absorption coefficient), has a value of 7×10-12 esu cm over a wide range of Au concentrations.
Received: 23 July 1997 相似文献