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.

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.

Equilibrium Analysis of Lattice-Mismatched Nanowire Heterostructures

2002 ◽  
Vol 737 ◽  
Author(s):  
E. Ertekin ◽  
P.A. Greaney ◽  
T. D. Sands ◽  
D. C. Chrzan
Keyword(s):  
Simple Model ◽  
Misfit Dislocation ◽  
Critical Thickness ◽  
Lattice Mismatch ◽  
Equilibrium Analysis ◽  
Misfit Dislocations ◽  
Model Based ◽  
Large Lattice ◽  
Large Lattice Mismatch

ABSTRACTThe quality of lattice-mismatched semiconductor heterojunctions is often limited by the presence of misfit dislocations. Nanowire geometries offer the promise of creating highly mismatched, yet dislocation free heterojunctions. A simple model, based upon the critical thickness model of Matthews and Blakeslee for misfit dislocation formation in planar heterostructures, illustrates that there exists a critical nanowire radius for which a coherent heterostructured nanowire system is unstable with respect to the formation of misfit dislocations. The model indicates that within the nanowire geometry, it should be possible to create perfect heterojunctions with large lattice-mismatch.

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.

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.

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.

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

Atomistic Calculation of Stability and Metastability of Coherently Strained Silicon-Like Structures

1986 ◽  
Vol 77 ◽  
Author(s):  
Brian W. Dodson ◽  
Paul A. Taylor
Keyword(s):  
Lattice Mismatch ◽  
Continuum Theory ◽  
Stability Limit ◽  
Test System ◽  
Misfit Dislocations ◽  
Strained Layers ◽  
Empirical Potentials ◽  
The Stability ◽  
Three Body ◽  
Microscopic Techniques

ABSTRACTMonte Carlo based microscopic techniques were used to study the stability and metastability of thin coherently strained layers of mismatched siliconlike semiconductor material grown on the (111) silicon surface. The structural energy was calculated using three-body empirical potentials. For layers greater than about 20 Å thickness, the critical layer thickness associated with thermodynamic stability agrees quantitatively with continuum theory. For thinner layers, however, considerable variations from the continuum theory are found. For a strained layer six monolayers thick, the test system is found to be metastable against the nucleation of misfit dislocations to a lattice mismatch of about 11%, compared to the 4% equilibrium stability limit.

Anisotropy of Strain Relaxation in III-V Semiconductor Heterostructures

2004 ◽  
Vol 230-232 ◽  
pp. 93-100 ◽  
Author(s):  
O. Yastrubchak ◽  
T. Wosiński ◽  
J.Z. Domagała ◽  
E. Łusakowska
Keyword(s):  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Growth Conditions ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Misfit Stress ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Small Lattice

Partially relaxed III–V heterostructures: GaAs/InGaAs and InP/InAlAs/InGaAs, with a small lattice mismatch, grown using molecular beam epitaxy under compressive or tensile misfit stress at the (001) interface, have been investigated by means of high-resolution X-ray diffractometry, atomic force microscopy and generalized ellipsometry. Additionally, transmission electron microscopy and electron-beam induced current in a scanning electron microscope have been employed to reveal misfit dislocations at the heterostructure interface. Chemical etching was used to determine polarity of the crystals and threading dislocation densities in the epitaxial layers. Our findings are interpreted in terms of the dependent on growth conditions, material’s composition and doping glide velocities of two types of misfit dislocations: α and β, differing in their core structure and lying along two orthogonal 〈110〉 crystallographic directions at the (001) interface.

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.

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