共查询到20条相似文献,搜索用时 15 毫秒
1.
《Thin solid films》2002,402(1-2):307-310
In this work, the growth and study of dielectric properties of Ba0.7Sr0.3TiO3 (BST) thin films grown on thin Bi layer coated Pt(111)/Ti/SiO2/Si substrates, depending on thin Bi layer thickness is reported. The BST thin film (thickness 180 nm) grown on 10-nm-thick Bi layer exhibited more improved structural and dielectric properties than that grown on bare Pt(111)/Ti/SiO2/Si substrate. The 10-nm-thick Bi layer in optimum configuration was effective for the grain growth of BST phase and suppressed the formation of the oxygen-deficient layer at the interface between the BST thin film and bottom electrode, which resulted in an increase in dielectric constant and a decrease in leakage current density of the Pt/BST thin film/Pt capacitor. 相似文献
2.
Using pulsed magnetron sputtering at low substrate temperature (Ts = 580 °C) the homoepitaxial growth on Si(111) was studied. The films were comprehensively characterized by cross-section transmission electron microscopy and various diffraction methods. Up to a film thickness of 1240 nm no breakdown of the epitaxial growth was observed. The surface microstructure, characterized by electron backscatter diffraction, exhibits exclusively crystalline structure with (111) orientation. Careful analysis of selected area electron diffraction patterns and high-resolution X-ray diffraction data clearly proves the existence of twinning/stacking faults in the {111} planes. Besides these defects – which are typical for low-temperature epitaxy – no additional significant defects related to the energetic particle bombardment by the sputter deposition method are observed. 相似文献
3.
M. V. Baidakova A. V. Bobyl’ V. G. Malyarov V. V. Tret’yakov I. A. Khrebtov I. I. Shaganov 《Technical Physics Letters》1997,23(7):520-522
Multi-technique structural and electrophysical investigations of VO2 films on SiO2/Si substrates are carried out to study the microscopic nature of fluctuator defects — sources of lowfrequency flicker noise.
It is established that the noise intensity is determined by the magnitude of the microstress fluctuations 〈ε 〉={〈(δc/c)2〉}, where c is the lattice parameter along the c-axis parallel to [011] direction in the blocks of which the film is formed. The dimensions of the blocks were determined
in the direction of the c-axis (t
c∼1000 Å). The suggestion is put forward that the samples contain two types of fluctuator defects: 1) V atoms jumping between
the two nearest interstitial sites and 2) V atoms jumping between these interstitial sites near lattice defects.
Pis’ma Zh. Tekh. Fiz. 23, 58–65 (July 12, 1997) 相似文献
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5.
A. G. Banshchikov K. V. Koshmak A. V. Krupin N. S. Sokolov 《Technical Physics Letters》2012,38(9):809-811
Epitaxial NiF2 layers have been grown for the first time on CaF2(111)/Si(111) substrates by molecular beam epitaxy. By high-energy electron diffraction and X-ray diffractometry, it has been established that the layers crystallize in the metastable orthorhombic phase and the epitaxial relations at the NiF2/CaF2 heterointerface have been determined: $ (100)_{NiF_2 } ||(111)_{CaF_2 } ,[001]_{NiF_2 } ||[1\bar 10]_{CaF_2 } $ . 相似文献
6.
Hongmei Deng Jing Kong Pingxiong Yang 《Journal of Materials Science: Materials in Electronics》2009,20(11):1078-1082
The optical and structural characteristics of Sb-doped SnO2 films grown on Si (111) substrates by modified sol–gel technique have been investigated. The films are both polycrystalline
and retain the SnO2 peaks of the rutile phase corresponding to (110), (101), (211) and (310) without any other phases appearing. X-ray photoelectron
spectroscopy shows the peaks corresponding to the Sn 3d
5/2, the O 1s, and the Sb 3d
5/2 states. Refractive indices n, and extinction coefficients k, as functions of the incident photon energy were obtained for the films by spectroscopic ellipsometry measurement, and the
refractive indices were from 1.95 to 1.50 at 2.6 eV with increasing Sb content. The optical constants, n and k, of the films can be controlled by variable Sb content. These results are important for the applications in integrated optical
devices. 相似文献
7.
Gallium oxide (Ga2O3) films were deposited on MgO (100) substrates by metalorganic vapor phase epitaxy. Structure analyses showed that the films deposited at 550-700 °C were epitaxial β-Ga2O3 films with an out of plane relationship of β-Ga2O3(100)||MgO(100). The film deposited at 650 °C showed the best crystallinity and the microstructure of the film was investigated by high resolution transmission electron microscopy. A theoretical model of the growth mechanism was proposed and the in-plane epitaxial relationship was given to be β-Ga2O3[001]||MgO<011>. A four-domain structure inside the epitaxial film was clarified. The β-Ga2O3 film deposited at 650 °C showed an absolute average transmittance of 95.9% in the ultraviolet and visible range, which had an optical band gap of 4.87 eV. 相似文献
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10.
M. Godlewski J. P. Bergman B. Monemar U. Rossner R. Langer A. Barski 《Materials Science and Engineering: B》1997,50(1-3):113-116
We report the observation of bright photoluminescence (PL) emission from two types of GaN epilayers grown by molecular beam epitaxy (MBE). Wurtzite phase GaN/Si (111) epilayers are grown by gas source MBE process, whereas cubic phase GaN epilayers are grown on (001) Si covered by thin SiC film in the process of Si annealing in propane prior to the GaN growth. PL emissions are identified based on the results of detailed PL and time-resolved PL investigations. For the wurtzite phase GaN we observe an efficient up in the energy transfer from bound to free excitons. This process is explained by a large difference in the PL decay times for two types (free and bound (donor, acceptor)) of excitonic PL emissions. For cubic phase GaN we confirm recent suggestion that acceptors have smaller thermal ionization energies than those in the wurtzite phase GaN. 相似文献
11.
We report the structural and optical properties of InN films on Si(111) prepared by ion-beam-assisted filtered cathodic vacuum arc technique. X-ray diffraction and Raman spectroscopy measurements indicated that all the InN films were hexagonal crystalline InN. The InN films deposited at substrate temperature of 475 °C exhibited highly (0001) preferred orientation and texturing (cratered) surface morphology. The oxygen incorporated in the InN films was segregated in the form of amorphous indium oxide or oxynitride phases at the grain boundaries. Photoluminescence emission of ∼ 1.15 eV was observed at room temperature from the InN films. 相似文献
12.
V. N. Bessolov V. Yu. Davydov Yu. V. Zhilyaev E. V. Konenkova G. N. Mosina S. D. Raevskii S. N. Rodin Sh. Sharofidinov M. P. Shcheglov Hee Seok Park Masayoshi Koike 《Technical Physics Letters》2005,31(11):915-918
Oriented GaN layers with a thickness of about 10 μm have been grown by hydride-chloride vaporphase epitaxy (HVPE) on Si(111) substrates with AlN buffer layers. The best samples are characterized by a halfwidth (FWHM) of the X-ray rocking curve of ωθ = 3–4 mrad. The level of residual mechanical stresses in AlN buffer layers decreases with increasing temperature of epitaxial growth. The growth at 1080°C is accompanied by virtually complete relaxation of stresses caused by the lattice mismatch between AlN and Si. 相似文献
13.
Synchrotron radiation was used to study the texture of polycrystalline CoSi2 films that were formed by a solid-state reaction between a 30 nm Co film and Si(111), (110) and (001) substrates. All films were strongly textured, and several texture components were identified. We discuss the simultaneous occurrence of axiotaxy (i.e. alignment of lattice planes across the interface) and several different types of epitaxy in each of the films. Comparison of the different texture components observed on the three substrate orientations suggests a strong preference for the alignment of CoSi2{110} planes in the film with Si{110} planes in the substrate, and twinning around Si[111] directions. 相似文献
14.
The growth structure of MgF2 and NdF3 films grown on polished CaF2(111) substrates deposited by molecular beam deposition has been investigated using transmission electron microscopy (TEM) of microfractographical and surface replications as well as cross-sectional TEM, atomic force microscopy, packing density, and absorption measurements. It has been shown that by taking advantage of ultrahigh vacuum environments and a special stratification property of MgF2 and NdF3 films, the preparation of nanocrystalline films of high packing density and low optical absorption is possible at a substrate temperature of 425 K. 相似文献
15.
B. P. Falcão J. P. Leitão J. C. González M. R. Correia K. G. Zayas-Bazán F. M. Matinaga M. B. Moreira C. F. Leite A. G. de Oliveira 《Journal of Materials Science》2013,48(4):1794-1798
Mg-doped GaAs nanowires have been grown by molecular beam epitaxy on a partially Au-coated Si(111) substrate by the vapor–liquid–solid mechanism. Outside the coated areas, a thin film of GaAs was grown epitaxially at the same time. The optical properties in both parts of the sample were investigated by photoluminescence spectroscopy, as a function of temperature. A structured emission in the range ~1.25–1.55 eV was observed at 10 K and the resemblances in both cases were identified. The radiative transitions are discussed with relevance to known defect centers in the GaAs thin films and to their possible relation with the zinc-blende and wurtzite phases in the nanowires. The presence of both crystalline phases in the nanowires was confirmed by μ-Raman spectroscopy. 相似文献
16.
A. N. Georgobiani A. N. Gruzintsev V. I. Kozlovskii Z. I. Makovei A. N. Red’kin Ya. K. Skasyrskii 《Inorganic Materials》2006,42(7):750-755
ZnO nanorods have been grown on (111) Si substrates by chemical vapor deposition in a horizontal reactor, with no catalyst. The nanorods grown far from the outlet end of the reactor are larger in size, have a higher structural perfection, and exhibit more efficient room-temperature edge luminescence in comparison with the nanorods grown at the outlet end. The low-temperature cathodoluminescence spectrum of the nanorods also depends on their position in the reactor during growth, which is interpreted in terms of the density of native defects. The nanorods exhibit room-temperature stimulated emission in the excitonic spectral region. 相似文献
17.
《Materials Letters》2006,60(9-10):1229-1232
Radial-aligned GaN nanorods were synthesized by ammoniating Ga2O3 films on Mg layer deposited on Si(111) substrates. The products were characterized by X-Ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transformed infrared spectra (FTIR) and high-resolution transmission electron microscopy (HRTEM). The SEM images indicated that the products consisted of radial-aligned GaN nanorods. The XRD and the selective area electron diffraction (SAED) patterns showed that nanorods were hexagonal GaN single crystals. 相似文献
18.
《Materials Letters》2007,61(19-20):4103-4106
Needle-shaped GaN nanowires have been synthesized on Si (111) substrate through ammoniating Ga2O3/MgO films under flowing ammonia atmosphere at the temperature of 950 °C. The as-synthesized GaN nanowires were characterized by X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM). The results demonstrate that these nanowires are hexagonal GaN and possess a smooth surface with an average diameter about 200 nm and a length ranging from 5 μm to 15 μm. In addition, the diameters of these nanowires diminish gradually. The growth mechanism of crystalline GaN nanowires is discussed briefly. 相似文献
19.
LaSrCoO3 thin films were spin-coated onto SrTiO3(100) substrates by the dipping-pyrolysis process. X-ray diffraction -2 scans and X-ray diffraction scans were used to determine the crystallinity and in-plane alignment behavior of the films. The X-ray diffraction pattern shows the film obtained by annealing at 800°C was highly oriented. The X-ray diffraction pole-figure analysis and reciprocal-space mapping (-2 scans) of the resulting film showed that the film comprising the pseudocubic phase had an epitaxial relationship with the SrTiO3 substrate. 相似文献
20.
Structure and microstructure of yttria thin films grown by electron beam physical vapour deposition on a stationary Si (111) substrate at room temperature (RT), 500° and 700 °C, were investigated by the grazing-incidence X-ray diffraction and scanning electron microscopy, respectively. X-ray photoelectron spectroscopy provided information on the surface contamination from the atmosphere and the Y oxidation state. A strong effect of the deposition temperature and the vapour flux incidence angle was found. The film deposited at RT is polycrystalline with very fine grains of the body-centered cubic (bcc) crystallographic symmetry. An increase of deposition temperature results in a rapid growth of bcc grains with an improved crystalline structure. Moreover, the based-centered monoclinic phase appears for the deposition temperature of 700 °C. Preferred grain orientation (texture) with two main components, (400) and (622), was observed in the films deposited at 500 °C whereas no texture was found for 700 °C. The microstructure exhibits the columnar feather-like structure of different degrees of perfection which can be explained by the shadowing effects caused by an oblique vapour flux incidence angle. Surface morphology of the films is governed by a combination of the triangular and four-sided (square) columns. All films were found to be dense with a little porosity between the columns. 相似文献