On the mechanism of cross-hatch pattern formation in heterostructures with a small lattice mismatch

2019 ◽  
Vol 479 ◽  
pp. 930-941
Author(s):  
V.A. Kovalskiy ◽  
V.G. Eremenko ◽  
P.S. Vergeles ◽  
O.A. Soltanovich ◽  
I.I. Khodos ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Lattice Mismatch ◽  
Small Lattice Mismatch ◽  
Small Lattice

Rectifying Property of the Heterojunction Composed of La0. 8Sr0.2MnO3 on Si with and without SrMnO3 Diffusion Barrier Layers

2011 ◽  
Vol 415-417 ◽  
pp. 756-759
Author(s):  
Tong Li ◽  
Yu Zhang ◽  
Xiao Chang Ni
Keyword(s):  
Barrier Layer ◽  
Diffusion Barrier ◽  
Lattice Mismatch ◽  
Rutherford Backscattering Spectrometry ◽  
Rf Magnetron Sputtering ◽  
Voltage Measurement ◽  
Small Diffusion ◽  
Barrier Layers ◽  
Small Lattice Mismatch ◽  
Small Lattice

La0.8Sr0.2MnO3 (LSMO) films with SrMnO3 (SMO) diffusion barrier layers were deposited on (100) Si substrates at 600oC by RF magnetron sputtering. From X-ray diffraction patterns (XRD), (110) peak of LSMO has been greatly enhanced in LSMO/SMO/Si, which may result from small lattice mismatch between SMO and LSMO Rutherford backscattering spectrometry spectra (RBS) measurements clearly show that there is a sharp interface between SMO and Si and small diffusion between LSMO and SMO after introducing SMO diffusion barrier layer. Small lattice mismatch is also considered to play an important role in deciding good interface quality. The current-voltage measurement shows a good rectifying property of LSMO/SMO/Si when the thickness of SMO is 50 nm. On further increasing SMO thickness, the junction currents are depressed at the same applied positive voltage. We attribute the results to the bigger junction resistance caused through introducing thicker barrier layer.

Morphological Stability of Semicoherent Solid-Solid Interfaces: a Simple Model

1991 ◽  
Vol 229 ◽  
Author(s):  
Craig Rottman
Keyword(s):  
Simple Model ◽  
Lattice Mismatch ◽  
Misfit Dislocations ◽  
Morphological Stability ◽  
Small Lattice Mismatch ◽  
Wide Range ◽  
Small Lattice ◽  
Interface Orientation ◽  
The Stability

AbstractThe stability of semicoherent interfaces between two solids with small lattice mismatch is examined. I consider the cases in which the rotation θ between the two solids is both zero and small. The interface orientation, characterized by a single angle φ, is arbitrary. The interfaces are composed of regularly spaced misfit dislocations, steps, and lattice dislocations. For a wide range of φ, many flat interfaces are unstable with respect to breaking up into two interfaces of distinct orientations, one of which contains only one of the two types of dislocations possible.

Theoretical investigation of zirconium carbide MXenes as prospective high capacity anode materials for Na-ion batteries

2018 ◽  
Vol 6 (28) ◽  
pp. 13652-13660 ◽  
Author(s):  
Qiangqiang Meng ◽  
Jiale Ma ◽  
Yonghui Zhang ◽  
Zhen Li ◽  
Alice Hu ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Theoretical Investigation ◽  
Anode Materials ◽  
Lattice Mismatch ◽  
High Capacity ◽  
Zirconium Carbide ◽  
Small Lattice Mismatch ◽  
Small Lattice ◽  
Large Charge

Large charge transfer and small lattice mismatch are beneficial for second layer Na atom adsorption.

TEM study of Cosi2 formation via annealing of Co-Ti bilayers on Si

1995 ◽  
Vol 53 ◽  
pp. 464-465
Author(s):  
N. David Theodore ◽  
Andre Vantomme ◽  
Peter Crazier
Keyword(s):  
Thermal Instability ◽  
Lattice Mismatch ◽  
Field Effect Transistors ◽  
Contact Layer ◽  
Interface Roughness ◽  
Oxide Semiconductor ◽  
Surface Layers ◽  
Silicide Layer ◽  
Small Lattice ◽  
Buried Layers

Contact is typically made to source/drain regions of metal-oxide-semiconductor field-effect transistors (MOSFETs) by use of TiSi2 or CoSi2 layers followed by AI(Cu) metal lines. A silicide layer is used to reduce contact resistance. TiSi2 or CoSi2 are chosen for the contact layer because these silicides have low resistivities (~12-15 μΩ-cm for TiSi2 in the C54 phase, and ~10-15 μΩ-cm for CoSi2). CoSi2 has other desirable properties, such as being thermally stable up to >1000°C for surface layers and >1100°C for buried layers, and having a small lattice mismatch with silicon, -1.2% at room temperature. During CoSi2 growth, Co is the diffusing species. Electrode shorts and voids which can arise if Si is the diffusing species are therefore avoided. However, problems can arise due to silicide-Si interface roughness (leading to nonuniformity in film resistance) and thermal instability of the resistance upon further high temperature annealing. These problems can be avoided if the CoSi2 can be grown epitaxially on silicon.

Growth of a-plane ZnO Thin Films on r-plane Sapphire by Plasma-assisted MBE

2005 ◽  
Vol 891 ◽  
Author(s):  
Junqing Q. Xie ◽  
J. W. Dong ◽  
A. Osinsky ◽  
P. P. Chow ◽  
Y. W. Heo ◽  
...  
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Defect Density ◽  
Zno Thin Films ◽  
Rf Plasma ◽  
Misfit Dislocations ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Small Lattice

ABSTRACTZnO thin films have been epitaxially grown on r-plane sapphire by RF-plasma-assisted molecular beam epitaxy. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies indicate that the epitaxial relationship between ZnO and r-plane sapphire is (1120)ZnO // (1102)sapphire and [0001]ZnO // [1101]sapphire. Atomic force microscopy measurements reveal islands extended along the sapphire [1101] direction. XRD omega rocking curves for the ZnO (1120) reflection measured either parallel or perpendicular to the island direction suggest the defect density anisotropy along these directions. Due to the small lattice mismatch along the ZnO [0001] direction, few misfit dislocations were observed at the ZnO/Al2O3 interface in the high-resolution cross-sectional TEM image with the zone axis along the ZnO [1100] direction.

Characterization of Epitaxial Fe on GaAs(110) by Scanning Tunneling Microscopy

1989 ◽  
Vol 151 ◽  
Author(s):  
R. A. Dragoset ◽  
P. N. First ◽  
Joseph A. Stroscio ◽  
D. T. Pierce ◽  
R. J. Celotta
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Lattice Mismatch ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Small Lattice ◽  
Low Coverage ◽  
Substrate Temperatures ◽  
Stm Images ◽  
Interesting System

ABSTRACTIron on GaAs(110) comprises an interesting system not only due to small lattice mismatch, 1.4%, but also because of the magnetic properties of the overlayer. In the present work, scanning tunneling microscopy (STM) was used to investigate bcc Fe films in the 0.1 Å to 20 Å thickness range, grown at 300 K and 450 K substrate temperatures. STM images show Volmer-Weber growth with the formation of 3-D Fe islands 20–30 Å in diameter for 0.1–1 Å deposition at 300 K, increasing to 40–50 Å for thicker films. Iron island sizes at low coverage and thin film roughness at higher coverages both show significant dependence upon growth temperature.

Nucleation of misfit and threading dislocations in GaSb/GaAs(001) heterostructure

1996 ◽  
Vol 54 ◽  
pp. 946-947
Author(s):  
W. Qian ◽  
M. Skowronski ◽  
R. Kaspi ◽  
M. De Graef
Keyword(s):  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Extended Defects ◽  
Large Lattice ◽  
Threading Dislocation Density ◽  
Small Lattice ◽  
Large Lattice Mismatch

GaSb thin film grown on GaAs is a promising substrate for fabrication of electronic and optical devices such as infrared photodetectors. However, these two materials exhibit a 7.8% lattice constant mismatch which raises concerns about the amount of extended defects introduced during strain relaxation. It was found that, unlike small lattice mismatched systems such as InxGa1-xAs/GaAs or GexSi1-x/Si(100), the GaSb/GaAs interface consists of a quasi-periodic array of 90° misfit dislocations, and the threading dislocation density is low despite its large lattice mismatch. This paper reports on the initial stages of GaSb growth on GaAs(001) substrates by molecular beam epitaxy (MBE). In particular, we discuss the possible formation mechanism of misfit dislocations at the GaSb/GaAs(001) interface and the origin of threading dislocations in the GaSb epilayer.GaSb thin films with nominal thicknesses of 5 to 100 nm were grown on GaAs(001) by MBE at a growth rate of about 0.8 monolayers per second.

Three-Dimensional Carrier Confinement in Strain-Induced Self-Assembled Quantum Dots

MRS Bulletin ◽  
1996 ◽  
Vol 21 (4) ◽  
pp. 50-54 ◽  
Author(s):  
P.M. Petroff ◽  
G. Medeiros-Ribeiro
Keyword(s):  
Degrees Of Freedom ◽  
Lattice Mismatch ◽  
Energy Levels ◽  
Three Dimensional ◽  
Quantum Structures ◽  
Semiconductor Film ◽  
Confining Potential ◽  
Semiconductor Electronic ◽  
Carrier Energy ◽  
Small Lattice

Recent technological and materials advances in semiconductors have brought about the possibility of producing heterostructures within which carriers are confined to an ultrasmall region of space (a few thousand atoms) by a potential barrier. When the dimensions of the confining potential are smaller than the electron wavelength (a few tens of nanometers), the semiconductor electronic and optical properties are drastically altered. In these so-called quantum structures, carrier energy levels are quantized and their energy depends on the confining-potential dimensions and magnitude.Some of these quantum structures have already found technological applications. For example the quantum-well (QW) semiconductor laser is part of every CD player. It is also widely used as the light source for intercontinental optical communications. The carrier confining potential in this case is provided by two wider bandgap semiconductor layers sandwiching a thin (3–20 nm) smaller bandgap semiconductor film. The carriers have two degrees of freedom within the QW. The QWs are grown by epitaxial deposition on a crystalline substrate. The substrate may or may not be lattice-matched with the epitaxial film. In some instances, a small lattice mismatch may be required to obtain the desired band-gap value for the QW material. These are the so-called pseudomorphically strained QW structures and devices.

Trend in crystal structure of layered ternary T-Al-C carbides (T = Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, W, and Ta)

2007 ◽  
Vol 22 (10) ◽  
pp. 2685-2690 ◽  
Author(s):  
Jingyang Wang ◽  
Yanchun Zhou ◽  
Ting Liao ◽  
Zhijun Lin
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Strain Energy ◽  
Lattice Mismatch ◽  
Layered Compounds ◽  
Structural Units ◽  
Early Transition Metal ◽  
Small Lattice ◽  
Ternary Carbides ◽  
Atomic Radii

Layered ternary T-Al-C ceramics containing early transition metal Sc, Zr, and Hf, crystallize with the TnAl3Cn+2 formula, while others containing neighbor elements Ti, V, Cr, Nb, Mo, W, and Ta yield the Tn+1AlCn formula. Ternary TnAl3Cn+2 ceramics are structurally characterized by NaCl-type TC slabs being separated by Al4C3-type AlC layers. In the present study, we suggest that the ability of forming the TnAl3Cn+2 carbide could be traced back to the structure mismatches between the TC, Al4C3 and TnAl3Cn+2 compounds. Ternary carbides following the TnAl3Cn+2 formula experience small lattice mismatches and strain energies. Moreover, the discrepancy between crystal structures of TnAl3Cn+2 and Tn+1AlCn is interpreted by lattice mismatch and the produced strain energy for the ternary T-Al-C ceramics. We also present close relationships between the atomic radii of transition metal and lattice mismatch, as well as the strain energy. The proposed method is not only helpful to explain the trend in crystal structure of T-Al-C based ceramics, but may be also general to predict the crystal structure of layered compounds constructed by alternatively stacked structural units.

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