3C-SiC Buffer Layers Converted from Si at a Low Temperature

1999 ◽  
Vol 572 ◽  
Author(s):  
H. M. Liaw ◽  
S. Q. Hong ◽  
P. Fejes ◽  
D. Werho ◽  
H. Tompkins ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Temperature ◽  
Single Crystal ◽  
Misfit Dislocation ◽  
Surface Region ◽  
Buffer Layers ◽  
Misfit Dislocations ◽  
Lattice Strains ◽  
High Resolution Tem ◽  
Sic Films

ABSTRACTWe have obtained single-crystal 3C-SiC films via conversion of the surface region of Si (111) and (100) wafers at 970 °C by reaction with C2H4 in an MBE reactor. The major defects in the films were clusters, voids, and misfit dislocations. Investigation by high resolution TEM images showed low lattice strains in the epitaxial layer due to the formation of 1 misfit dislocation for every 4 to 5 regular SiC planes that are bonded to Si at the interface. The clusters and voids often occurred in pairs. A model for forming the void-cluster pairs is suggested.

Misfit Dislocations in SiGe/Si Heterostructures: Nucleation - Propagation - Multiplication

2005 ◽  
Vol 108-109 ◽  
pp. 483-488 ◽  
Author(s):  
V.I. Vdovin ◽  
M.G. Mil'vidskii ◽  
M.M. Rzaev ◽  
Friedrich Schäffler
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Point Defects ◽  
Misfit Dislocation ◽  
Alloy Composition ◽  
Dislocation Nucleation ◽  
Buffer Layers ◽  
Misfit Dislocations ◽  
Intrinsic Point Defects

We present experimental data on the effect of low-temperature buffer layers on the dislocation structure formation in SiGe/Si strained-layer heterostructures under thermal annealing. Specific subjects include mechanisms of misfit dislocation nucleation, propagation and multiplication as well as the role of intrinsic point defects in these processes. Samples with lowtemperature Si (400°C) and SiGe (250°C) buffer layers were grown by MBE. In general, the processes of MD generation occur similarly in the heterostructures studied independently of the alloy composition (Ge content: 0.15, 0.30) and kind of buffer layer. Intrinsic point defects related to the low-temperature epitaxial growth influence mainly the rate of misfit dislocation nucleation.

scholarly journals HRTEM image-stitching for measurement of distances

2020 ◽  
Vol 5 (1) ◽  
pp. 13-17
Author(s):  
György Zoltán Radnóczi ◽  
Zoltán Herceg ◽  
Tamás Rafael Kiss
Keyword(s):  
Electron Beam ◽  
High Resolution ◽  
Single Crystal ◽  
Image Stitching ◽  
Hrtem Image ◽  
Lattice Image ◽  
High Resolution Tem ◽  
Better Than

AbstractVery accurate measurement of distances in the order of several µm is demonstrated on a single crystal Si sample by counting the lattice fringes on stitched high resolution TEM/STEM images. Stitching of TEM images commonly relies on correspondence points found in the image, however, the nearly perfect periodic nature of a lattice image renders such a procedure very unreliable. To overcome this difficulty artificial correspondence points are created on the sample using the electron beam. An accuracy better than 1% can be reached while measuring distances in the order of 1 µm. A detailed description of the process is provided, and its usability for accurately measuring large distances is discussed in detail.

High-resolution electron microscopy of epitaxial YBCO/Y2O3/YSZ on Si(001)

1993 ◽  
Vol 8 (9) ◽  
pp. 2112-2127 ◽  
Author(s):  
A. Bardal ◽  
O. Eibl ◽  
Th. Matthée ◽  
G. Friedl ◽  
J. Wecker
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Thick Layer ◽  
Atomic Layer ◽  
High Resolution Electron Microscopy ◽  
Stacking Fault ◽  
Buffer Layers ◽  
Misfit Dislocations ◽  
Resolution Electron ◽  
Unit Cells

The microstructures of YBa2Cu3O7−δ (YBCO) thin films grown on Si with Y-stabilized ZrO2 (YSZ) and Y2O3 buffer layers were characterized by means of high-resolution electron microscopy. At the Si–YSZ interface, a 2.5 nm thick layer of regrown amorphous SiOx is present. The layer is interrupted by crystalline regions, typically 5 to 10 nm wide and 10 to 50 nm apart. Close to the crystalline regions, {111} defects are present in the Si substrate. The typical defect observed is an extrinsic stacking fault plus a perfect dislocation close to the stacking fault which terminates extra {111} planes in the upper part of the Si. These defects are probably formed by condensation of Si self-interstitials created during oxide regrowth. Precipitates are present in the Si close to the Si–YSZ interface and indicate that in-diffusion of Zr has occurred. The YSZ–Y2O3 interface is atomically sharp and essentially planar and contains no second phases. Perfect misfit dislocations with Burgers vector 1/2〈110〉 are present at this interface along with unrelaxed elastic misfit stresses. The Y2O3–YBCO interface is atomically sharp and planar, but contains steps. (001) stacking faults are present in the YBCO above these steps; the faults are, however, healed a few unit cells away from the interface. By HREM analysis of ultrathin specimen areas, the atomic layer of the YBCO closest to the Y2O3 was found to be a barium-oxygen layer.

Verification of the elastic constants for α-Al2O3using high-resolution neutron diffraction

2010 ◽  
Vol 44 (1) ◽  
pp. 216-218 ◽  
Author(s):  
Erich H. Kisi ◽  
Christopher J. Howard ◽  
Jianfeng Zhang
Keyword(s):  
High Resolution ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Elastic Constants ◽  
Diffraction Method ◽  
Polycrystalline Sample ◽  
Lattice Strains ◽  
Recent Suggestion

Precise lattice strains measured using high-resolution neutron diffraction from a solid polycrystalline sample are used to explore the single-crystal elastic constants of α-Al2O3(corundum). The analysis confirms a recent suggestion that, contrary to the long-accepted view, the sign ofs14should be negative. It also indicates that the magnitude ofs13should be adjusted from −0.38 × 10−12to −0.47 × 10−12 Pa−1. It is found that, micromechanically, the polycrystal responds to stress in a manner very close to the Reuss limit. The results confirm the applicability of the diffraction method, which could prove useful when other techniques give ambiguous results.

Growth And High Resolution Tem Characterization of GexSi1−x/Si Hetero-Structures by Remote Plasma-Enhanced Chemical Vapor Deposition

1991 ◽  
Vol 235 ◽  
Author(s):  
R. Qian ◽  
I. Chung ◽  
D. Kinosky ◽  
T. Hsu ◽  
J. Irby ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
High Resolution ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Misfit Dislocations ◽  
Remote Plasma ◽  
Tem Analysis ◽  
Plan View ◽  
Lattice Constants ◽  
High Resolution Tem

ABSTRACTRemote Plasma-enhanced Chemical Vapor Deposition (RPCVD) has been used to grow GexSi1−x/Si heteroepitaxial thin films at low temperatures (∼450°C). In situ RHEED has been used to confirm that smooth, single crystal heteroepitaxial films can be grown by RPCVD. Plan-view and cross-sectional TEM have been employed to study the microstructure of the heteroepitaxial films. Lattice imaging high resolution TEM (HRTEM) has shown perfect epitaxial lattice alignment at the heterojunction interfaces. GexSi1−x/Si films which exceed their CLT's appreciably show dense Moiré fringes under plan-view TEM. The spacings between the fringes have been used to estimate the relaxed lattice constants. In addition to the inhomogeneous strain observed in-XTEM, Selected Area electron Diffraction (SAD) analysis of the interfaces displays two split patterns. The spacings between the diffraction spots have been used to calculate the lattice constants in the epitaxial films in different crystal directions, which agree very well with the prediction by Vegard's law as well as the estimate from plan-view TEM analysis. HRTEM analysis also reveals the crystallographic nature of the interfacial misfit dislocations in the relaxed films.

Epitaxial La0.67(Sr,Ca)0.33MnO3 Films on Si for IR Bolometer Applications

2004 ◽  
Vol 811 ◽  
Author(s):  
A.M. Grishin ◽  
S.I. Khartsev ◽  
J.-H. Kim ◽  
Jun Lu
Keyword(s):  
Colossal Magnetoresistance ◽  
Buffer Layers ◽  
Maximum Temperature ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
High Resolution Tem ◽  
Noise Equivalent Temperature Difference ◽  
Sharp Interfaces ◽  
Heteroepitaxial Layers

ABSTRACTWe report on processing and properties of La0.67(Sr,Ca)0.33MnO3(LSCMO) films grown by pulsed laser deposition technique on Si(001) substrates buffered with Bi4Ti3O12/CeO2/YSZ heteroepitaxial layers. X-ray diffraction shows cube-on-cube growth of epitaxial Bi4Ti3O12/CeO2/YSZ/Si heterostructure whereas the LSCMO layer grows in the “diagonal-on-side” manner onto the Bi4Ti3O12 (BTO) template. High resolution TEM images demonstrate sharp interfaces between the buffer layers and LSCMO film as well as rare misfit dislocations on the CeO2/YSZ interface. LSCMO film processing conditions have been optimized to get maximum temperature coefficient of resistivity TCR = 4.4%K-1 and colossal magnetoresistance(CMR) ‘Delta;ρ/ρ ∼ 2.9%kOe-1 @ 294K. Almost ultimate CMR performance at room temperature has been achieved due to successive improvement of c-axisorientation of layers: full widths at half-maximum (FWHM) 0.65, 0.58, 0.65, 1.13 and 0.18 degrees in LSCMO/BTO/CeO2/YSZ/Si stack, respectively. Characterization of electrical noise in CMR film yields noise equivalent temperature difference (NETD) as low as 1.2 ‘mu;K/√Hz @ 30Hz and 294K.

Growth and High Resolution Tem Characterization of GexSi1−x/Si Hetero-Structures by Remote Plasma-Enhanced Chemical Vapor Deposition

1991 ◽  
Vol 236 ◽  
Author(s):  
R. Qian ◽  
I. Chung ◽  
D. Kinosky ◽  
T. Hsu ◽  
J. Irby ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
High Resolution ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Misfit Dislocations ◽  
Remote Plasma ◽  
Tem Analysis ◽  
Plan View ◽  
Lattice Constants ◽  
High Resolution Tem

AbstractRemote Plasma-enhanced Chemical Vapor Deposition (RPCVD) has been used to grow GexSi1−x/Si heteroepitaxial thin films at low temperatures (∼450°C). In situ RHEED has been used to confirm that smooth, single crystal heteroepitaxial films can be grown by RPCVD. Plan-view and cross-sectional TEM have been employed to study the microstructure of the heteroepitaxial films. Lattice imaging high resolution TEM (HRTEM) has shown perfect epitaxial lattice alignment at the heterojunction interfaces. GexSi1−x/Si films which exceed their CLT's appreciably show dense Moiré fringes under plan-view TEM. The spacings between the fringes have been used to estimate the relaxed lattice constants. In addition to the inhomogeneous strain observed in XTEM, Selected Area electron Diffraction (SAD) analysis of the interfaces displays two split patterns. The spacings between the diffraction spots have been used to calculate the lattice constants in the epitaxial films in different crystal directions, which agree very well with the prediction by Vegard's law as well as the estimate from planview TEM analysis. HRTEM analysis also reveals the crystallographic nature of the interfacial misfit dislocations in the relaxed films.

Investigation of InN layers grown by MOCVD using analytical and high resolution TEM: The structure, band gap, role of the buffer layers

2006 ◽  
Vol 203 (1) ◽  
pp. 158-161 ◽  
Author(s):  
P. Ruterana ◽  
M. Abouzaid ◽  
F. Gloux ◽  
W. Maciej ◽  
J. L. Doualan ◽  
...  
Keyword(s):  
High Resolution ◽  
Band Gap ◽  
Buffer Layers ◽  
High Resolution Tem

TWO-DIMENSIONAL STRUCTURAL MODULATION IN Bi–O SURFACE LAYER OF CLEAVED Bi2Sr2CaCu2O8+δ SINGLE CRYSTAL REVEALED BY STM AT SUPERCONDUCTING STATE

1993 ◽  
Vol 07 (20) ◽  
pp. 1313-1320 ◽  
Author(s):  
H. J. TAO ◽  
B. YIN ◽  
Q. S. YANG ◽  
Z. X. ZHAO ◽  
F. GAO ◽  
...  
Keyword(s):  
Surface Layer ◽  
High Resolution ◽  
Low Temperature ◽  
Single Crystal ◽  
Two Dimensional ◽  
Tetragonal Lattice ◽  
Atomic Chains ◽  
Structural Modulation ◽  
High Resolution Images ◽  
First Time

The Bi–O planes of Bi 2 Sr 2 CaCu 2 O 8+δ single crystal have been investigated with low-temperature STM at 77 K. High-resolution images have been obtained, which show tetragonal lattice in a-b plane with very small in-plane modulations along both directions of Bi atomic chains. In some images, a two-dimensional structural modulation that mainly results from corrugations in the c-direction has been observed for the first time.

Effect of Various Crucibles for High Quality AIN Crystal Growth on SiC Seed by PVT Method

2015 ◽  
Vol 821-823 ◽  
pp. 1007-1010
Author(s):  
Hee Jun Lee ◽  
Hee Tae Lee ◽  
Hee Won Shin ◽  
Mi Seon Park ◽  
Yeon Suk Jang ◽  
...  
Keyword(s):  
Crystal Growth ◽  
High Resolution ◽  
Single Crystal ◽  
Interface Structure ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Bulk Crystals ◽  
High Quality ◽  
Xrd Pattern ◽  
High Resolution Tem

Aluminum nitride (AlN) bulk crystals, approximately 50.8mm in diameter and up to 5mm thickness, were grown by a physical vapor transport (PVT) method in a tantalum crucible. To investigate the effect of crucible materials, various crucible materials, a graphite and TaC-coated graphite and tantalum crucible were used for the AlN growth. XRD pattern of AlN crystal grown on SiC seed in the Ta-crucible exhibited only (00l) peaks, indicating that AlN single crystal was successfully grown on SiC seed. The interface structure between AlN and SiC crystals was observed by a high resolution TEM.

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