Edge-type misfit dislocations produced by thermal processing of pre-relaxed InxGa1−xAs/GaAs heterostructures

2000 ◽  
Vol 88 (10) ◽  
pp. 5975-5980 ◽  
Author(s):  
X. W. Liu ◽  
A. A. Hopgood ◽  
B. F. Usher ◽  
H. Wang ◽  
N. S. Braithwaite
Keyword(s):  
Thermal Processing ◽  
Misfit Dislocations ◽  
Edge Type

Growth Model of Epitaxial Pb(Zr0.52Ti0.48)O3 Nanoislands

2003 ◽  
Vol 784 ◽  
Author(s):  
Ming-Wen Chu ◽  
Izabela Szafraniak ◽  
Roland Scholz ◽  
Dietrich Hesse ◽  
Marin Alexe ◽  
...  
Keyword(s):  
Growth Model ◽  
Chemical Solution Deposition ◽  
Average Height ◽  
Misfit Dislocations ◽  
Chemical Solution ◽  
Cross Sectional ◽  
Solution Deposition ◽  
Edge Type ◽  
Niobium Doped ◽  
Truncated Pyramid

ABSTRACTSingle-crystalline, single-c-domain Pb(Zr0.52Ti0.48)O3 nanoislands (truncated-pyramid in shape) with an average height of ∼9 nm and a base length of ∼50 nm were grown on compressive niobium-doped SrTiO3(001) substrates using chemical solution deposition. Cross-sectional highresolution electron microscopy investigations allowed to propose a growth model of the islands, and they proved the existence of edge-type misfit dislocations at the interface.

scholarly journals Formation of misfit dislocations in strained-layer GaAs/In[sub x]Ga[sub 1−x]As/GaAs heterostructures during postfabrication thermal processing

2003 ◽  
Vol 94 (12) ◽  
pp. 7496 ◽  
Author(s):  
X. W. Liu ◽  
A. A. Hopgood ◽  
B. F. Usher ◽  
H. Wang ◽  
N. St. J. Braithwaite
Keyword(s):  
Thermal Processing ◽  
Misfit Dislocations ◽  
Strained Layer

Rapid Thermal Processing of Buried Sil−xGex Strained Layers; Photoluminescence Decay and Misfit Dislocation Generation.

1990 ◽  
Vol 198 ◽  
Author(s):  
D.C. Houghton ◽  
N.L. Rowell
Keyword(s):  
Quantum Wells ◽  
Misfit Dislocation ◽  
Thermal Processing ◽  
Internal Quantum Efficiency ◽  
Dislocation Nucleation ◽  
Multiple Quantum ◽  
Misfit Dislocations ◽  
Dislocation Generation ◽  
Strained Layers ◽  
Wide Range

ABSTRACTThe thermal constraints for device processing imposed by strain relaxation have been determined for a wide range of Si-Ge strained heterostructures. Misfit dislocation densities and glide velocities in uncapped Sil-xGex alloy layers, Sil-xGex single and multiple quantum wells have been measured using defect etching and TEM for a range of anneal temperatures (450°C-1000°C) and anneal times (5s-2000s). The decay of an intense photoluminescence peak (∼ 10% internal quantum efficiency ) from buried Si1-xGex strained layers has been correlated with the generation of misfit dislocations in adjacent Sil-xGex /Si interfaces. The misfit dislocation nucleation rate and glide velocity for all geometries and alloy compositions (0<x<0.25) were found to be thermally activated processes with activation energies of (2.5±0.2)eV and (2.3-0.65x)eV, respectively. The time-temperature regime available for thermal processing is mapped out as a function of dislocation density using a new kinetic model.

Dislocation Behaviour in GexSi1-x Epilayers on (001)Si

1989 ◽  
Vol 160 ◽  
Author(s):  
Eric P. Kvam ◽  
D.M. Maher ◽  
C.J. Humphreys
Keyword(s):  
Dislocation Density ◽  
Film Thickness ◽  
Critical Thickness ◽  
Three Dimensional ◽  
Critical Value ◽  
Misfit Dislocations ◽  
Island Growth ◽  
Edge Type ◽  
Dislocation Behaviour ◽  
Step Mechanism

AbstractWe have observed that the nature of misfit dislocations introduced near the critical thickness in GexSi1-x alloys on (001)Si changes markedly in the region 0.4 ≤ x ≤ 0.5. At or below the lower end of this compositional range, the observed microstructure is comprised almost entirely of 60° type dislocations, while at the high end, the dislocation structure is almost entirely Lomer edge type. Concurrent with this change, the dislocation density at the top of the epilayer varies by a factor of about 60X. Similarly, several other observables (e.g. dislocation length and spacing) also change appreciably.Part of the reason for the morphological variation seems to be a change in the source for dislocation introduction, in conjunction with a change in glide behaviour of dislocations as a function of film thickness. Evidence will be presented that indicates strain, as well as thickness, has a critical value for some dislocation introduction mechanisms, and that these together determine the resulting microstructure.Furthermore, it appears unlikely that the edge-type Lomer dislocations which appear at about x = 0.5 are either introduced directly, by climb, or grown in, as in the three-dimensional island growth and coalescence which occurs when x approaches unity. Instead, a two-step mechanism involving glissile dislocations is proposed and discussed.

The Initial Stages of MBE Growth of InSb on GaAs(100) - A High Misfit Heterointerface

1989 ◽  
Vol 159 ◽  
Author(s):  
C.J. Kiely ◽  
A. Rockett ◽  
J-I. Chyi ◽  
H. Morkoc
Keyword(s):  
Three Dimensional ◽  
Misfit Strain ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Island Growth ◽  
Mbe Growth ◽  
Edge Type ◽  
Transmission Electron ◽  
Interfacial Defects ◽  
Square Array

ABSTRACTThe initial stages of heteroepitaxy of InSb on GaAs(100) grown by MBE have been studied by transmission electron microscopy. Three dimensional InSb island growth occurs in which the majority of the 14.6% misfit strain is accommodated by a square array of a/2<011= edge-type misfit dislocations. The implications of each island having a well defined defect array before coalescence into a continuous epilayer are discussed. Some 600-type a/2<101= interfacial defects and associated threading dislocations are also observed in coalesced films and possible reasons for their existence are explained. A strong asymmetrical distribution of planar defects in the InSb islands is observed and the origin of the asymmetry is discussed. Finally some evidence for local intermixing in the vicinity of the interface is presented.

The Nucleation and Propagation of Misfit Dislocations aear the Critical Thickness in Ge-Si Strained Epilayers

1987 ◽  
Vol 104 ◽  
Author(s):  
E. P. Kvam ◽  
D. J. Eaglesham ◽  
D. M. Maher ◽  
C. J. Humphreys ◽  
J. C. Bean ◽  
...  
Keyword(s):  
Lattice Parameter ◽  
Dislocation Segment ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
Parameter Mismatch ◽  
Growth Interface ◽  
Edge Type ◽  
X Ray ◽  
Transmission Electron ◽  
Dislocation Behavior

ABSTRACTThe nucleation and propagation of misfit dislocations in Ge-Si strained epilayers on (100) Si have been investigated using transmission electron microscopy and X-ray diffraction topography at low lattice parameter mismatch (˜ 0.8%). Misfit dislocations nucleate as half loops which are predominantly unfaulted (> 90%) at the advancing growth interface. Under the driving force of the epilayer strain, unfaulted half loops glide and expand on inclined { 111 }planes toward the heterointerface (i.e. substrate/epilayer interface). These unfaulted half loops consist of a 60°-dislocation segment which lies along < 011> in a plane parallel to the heterointerface (i.e. (100)) and this segment is connected to the growth interface by two screw dislocation segments which both lie on the same inclined {111} glide plane. As 60° dislocations reach the heterointerface on each of the four inclined {111} variants, they form an orthogonal array of misfit dislocations which lie along [011] and [011]. At higher lattice parameter mismatch (˜ 2%), there appear to be some important changes in the dislocation behavior and these changes result in orthogonal arrays of heterointerface dislocations which are predominantly edge type (i.e. 90°dislocations).

Role of the Surface Steps on the Growth of CrSi2 on {111} Silicon.

1995 ◽  
Vol 402 ◽  
Author(s):  
André M. Rocher ◽  
André Oustry ◽  
Marie José David ◽  
Michel Caumont
Keyword(s):  
Elastic Energy ◽  
Solid Phase ◽  
Misfit Dislocations ◽  
Solid Phase Epitaxy ◽  
Step Width ◽  
Orientation Relationships ◽  
Edge Type ◽  
Burgers Vector ◽  
Surface Steps

AbstractCrSi2 layers grown by solid phase epitaxy on a nominal (111) Si surface exhibit in the same proportion two different orientation relationships, named A and B. When CrSi2 is deposited on a 8° vicinal (111) Si surface, B-type orientation is favoured with respect to the A type. This result can be explained by the fact that both the step width introduced by the miscut and the planar coincidence between {1100}Crsi2 and {111}Si are nearly equal to 23Å. Edge type misfit dislocations are observed at the interface with the same spacing. Their Burgers vector component along [111] is almost compensated by the atomic steps along the <110> directions. The role of the steps is discussed in term of elastic energy. Steps introduce misfit dislocations which make possible coherent growth of the B type orientation.

Nanopattern Formation by Periodic Array of Interfacial Misfit Dislocations in Bi(111)/Si(001) Heteroepitaxy

2007 ◽  
Vol 1059 ◽  
Author(s):  
Giriraj Jnawali ◽  
H. Hattab ◽  
C. Bobisch ◽  
A. Bernhart ◽  
E. Zubkov ◽  
...  
Keyword(s):  
Elasticity Theory ◽  
Lattice Mismatch ◽  
Compressive Strain ◽  
Periodic Array ◽  
Misfit Dislocations ◽  
Strain Fields ◽  
Edge Type ◽  
Large Lattice ◽  
Large Lattice Mismatch

ABSTRACTDespite their large lattice mismatch of 18 %, the lattices of Bi(111) and Si(001) fit surprisingly well. A remaining compressive strain in the Bi film of 2.3 % along the direction is accommodated by the formation of a periodic array of edge-type misfit dislocations confined to the interface. The strain fields surrounding each dislocation interact with each other, producing a quasi-periodic nanopattern of grating-like periodic height undulations on the surface. The separation and the amplitude of the height undulations have been derived by spot profile analyzing LEED and STM surface height profiles. The observed undulations agree well with elasticity theory.

Space Distribution of Deep Levels in SiGe/Si Heterostructure

1993 ◽  
Vol 325 ◽  
Author(s):  
Zhang Rong ◽  
Yang Kai ◽  
Gu Shulin ◽  
Shi Yi ◽  
Huang Hongbin ◽  
...  
Keyword(s):  
Thermal Processing ◽  
Deep Level ◽  
Deep Levels ◽  
Defect Complex ◽  
Space Distribution ◽  
Misfit Dislocations ◽  
Defect States ◽  
Before And After ◽  
Related Defect ◽  
Measure Distribution

AbstractThe small-pulse DLTS had been developed to measure distribution of deep levels in CVD grown SiGe/Si heterostructure before and after thermal processing at 800°C. Changes of defect states was found and after processing the original single deep level 0.62eV under the condition band split into two separated traps. A new weak deeper trap signal was found only in the just relaxed region. It could be Ge-related defect complex with misfit dislocations.

Nucleation and Growth of Cosi2 on (001) and (111) Si

1987 ◽  
Vol 102 ◽  
Author(s):  
C.W.T. Bulle-Lieuwma ◽  
A.H. Van Ommen ◽  
J. Hornstra
Keyword(s):  
Electron Microscopy ◽  
Defect Structure ◽  
Nucleation And Growth ◽  
Thermal Reaction ◽  
Nucleation Mechanism ◽  
Misfit Dislocations ◽  
Lattice Match ◽  
Edge Type ◽  
Burgers Vector ◽  
Transmission Electron

ABSTRACTNucleation and growth of epitaxial CoSi2 on Si by the thermal reaction of vapour deposited Co on (001) and (111) Si have been studied by transmission electron microscopy (TEM). On (001)-Si the layer consists of CoSi2 grains. Apart from an aligned (a)-orientation, CoSi2 occurs in a number of orientations, including a (110) preferential (b)-orientation. On (111) Si, single-crystalline layers are obtained, predominantly in the B-type orientation, which is rotated through 180° relative to the aligned (111)-orientation (A-type). The interfacial defect structure consists of misfit dislocations of edge-type with Burgers vector b=a/6<112>, running in <110> directions. The observations for both (001) and (111) Si are related to geometrical lattice match between CoSi2 and Si. In addition to the experimental results, a computer program has been made which calculates the matching between various orientations of CoSi2 and Si. The nucleation of B-type CoSi2 for (111) Si and the different oriented grains for (001) Si are discussed in terms of a nucleation mechanism at steps at the interface in combination with a relatively large mismatch.

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