Origin of Grown-in Dislocations in III-V Compound Semiconductor Epitaxial Layers

1985 ◽  
Vol 62 ◽  
Author(s):  
S. Nakahara ◽  
S. N. G. Chu
Keyword(s):  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Chemical Compositions ◽  
Misfit Dislocations ◽  
Quaternary Alloys ◽  
Transmission Electron ◽  
Half Loop ◽  
Micro Analysis ◽  
Inp Substrates ◽  
Lattice Matched

ABSTRACTA transmission electron microscope was used to study the origin of grown-in dislocations observed in quaternary InGaAsP layers grown by vapor phase epitaxy on (001) InP substrates. Many of the grown-in dislocations were found to exist as dislocation dipoles and were connected to particles formed at the lnGaAsP/lnP interface. X-ray micro-analysis has indicated that the particles are quaternary alloys having chemical compositions slightly richer in both Ga and P than that of the lattice-matched InGaAsP layer. In some cases, this compositional deviation led to a significant lattice mismatch. As the particle grows larger, a strain relaxation occurs by generating misfit dislocations around the particle in the form of a dislocation half loop. If these dislocation half loops do not develop into a complete loop by totally surrounding the particle, they leave two unclosed dislocation segments (a dislocation dipole), which are replicated by the quaternary overlayer along the substrate normal direction, i.e., [001]. These dislocations eventually become a source for grown-in dislocations.

Strain Relaxation in GaN/AlN Films Grown on Vicinal and On-Axis SiC Substrates

2006 ◽  
Vol 527-529 ◽  
pp. 1513-1516
Author(s):  
J. Bai ◽  
X. Huang ◽  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
B. Wagner ◽  
...  
Keyword(s):  
High Resolution ◽  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Crystalline Quality ◽  
Misfit Dislocations ◽  
Vicinal Surface ◽  
Burgers Vector ◽  
Surface Steps ◽  
Transmission Electron ◽  
Initial Stage

Strain relaxation in the GaN/AlN/6H-SiC epitaxial system grown by vicinal surface epitaxy (VSE) is investigated and compared with that in on-axis epitaxy. High resolution x-ray diffraction (HRXRD) measurements show that GaN films grown by VSE have improved crystalline quality. High resolution transmission electron microscope (HRTEM) studies reveal that there are two types of misfit dislocations (MDs) at AlN/6H-SiC interfaces: 60˚ complete dislocations along <1120 > directions with Burgers vector 1/3<1120 > and 60˚ Shockley partials along <10 10 > directions with Burgers vector 1/3<10 10 >. The latter are usually geometrical partial misfit dislocations (GPMDs) that are dominant in VSE to accommodate the lattice mismatch and stacking sequence mismatch simultaneously. In VSE, it is the high-density GPMDs formed at the vicinal surface steps that facilitate rapid strain relaxation at the initial stage of deposition and hence lead to superior crystalline quality of the subsequently grown GaN films.

Structural investigation of InAs/InGaAs/InP nanostructures: origin and stability of nanowires.

2004 ◽  
Vol 829 ◽  
Author(s):  
L. Nieto ◽  
H. R. Gutiérrez ◽  
J. R. R. Bortoleto ◽  
R. Magalhães-Paniago ◽  
M. A. Cotta
Keyword(s):  
Buffer Layer ◽  
Strain Relaxation ◽  
Additional Stress ◽  
Chemical Beam Epitaxy ◽  
Compositional Modulation ◽  
Transmission Electron ◽  
Inas Nanowires ◽  
Inp Substrates ◽  
Lattice Matched ◽  
Microscopy Images

ABSTRACTIn this letter we present results on the growth of InAs nanowires (NW's) on InGaAs lattice-matched to (100) InP substrates by Chemical Beam Epitaxy. We observed that the nanostructure stability depends on the thickness of the InGaAs layer. This effect may result from two different conditions: the nanostructure strain field depth and/or compositional modulation in the buffer layer. Our investigation shows that anisotropic strain relaxation for nanowires grown on InGaAs is faster than for those grown on InP but the elastic energy in the nanostructures is no different from the InAs/InP case. These results suggest that the InAs strain relaxation does not depend significantly on the InGaAs buffer layer thickness. Nevertheless, transmission electron microscopy images show an additional stress field superimposed on that usually observed for the InAs nanostructures, which is attributed to compositional modulation in the ternary layer.

Strain Relaxation Via Interface Nucleation of Misfit Dislocations in Intermixing Layers

1992 ◽  
Vol 263 ◽  
Author(s):  
Hyo-Hoon Park ◽  
Jung Kee Lee ◽  
El-Hang Lee ◽  
Jeong Yong Lee ◽  
Soon-Ku Hong
Keyword(s):  
Electron Microscopy ◽  
Homogeneous Nucleation ◽  
Critical Thickness ◽  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
Semiconductor Heterostructures ◽  
Misfit Dislocations ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Lattice Matched

ABSTRACTThe strain relaxation mechanism via the homogeneous nucleation of misfit dislocations from interface during interdiffusion in lattice-matched semiconductor heterostructures has been investigated. Transmission electron microscopy studies in intermixed GaInAsP/InP heterostructures revealed that the critical interdiffusion depth for the nucleation of 90° 1/6<112> partial dislocations from a tensile interface is much shallower than that of 60° 1/2<110> perfect dislocations from a compressive interface. A critical thickness model for the interface nucleation of these dislocations is developed as a modification of the classical surface nucleation'model.

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 Assessment of Different Mechanisms Contributing to Stress Relaxation in Strained InGaAs/InAlAs Systems

1992 ◽  
Vol 263 ◽  
Author(s):  
F. Peiro ◽  
A. Cornet ◽  
J.R. Morante ◽  
S. A. Clark ◽  
R.H. Williams
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stress Relaxation ◽  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Lattice Parameter ◽  
Growth Morphology ◽  
Transmission Electron ◽  
Inp Substrates

ABSTRACTA study by Transmission Electron microscopy (TEM) of strained InGaAs/InAlAs systems on InP substrates is presented. The influence of the lattice mismatch, epilayer thickness and modulation of the lattice parameter on the morphology of the system is analyzed. A discussion of the strain relaxation mechanisms occurring for each growth morphology is also presented.

Transmission electron microscopy of misfit dislocation and strain relaxation in lattice mismatched III-V heterostructures versus substrate surface treatment

2011 ◽  
Vol 1324 ◽  
Author(s):  
Y. Wang ◽  
P. Ruterana ◽  
L. Desplanque ◽  
S. El Kazzi ◽  
X. Wallart
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Treatment ◽  
Substrate Surface ◽  
Strain Relaxation ◽  
Dislocation Core ◽  
Misfit Dislocations ◽  
Heteroepitaxial Growth ◽  
Transmission Electron ◽  
Growth Initiation

ABSTRACTHigh resolution transmission electron microscopy in combination with geometric phase analysis is used to investigate the interface misfit dislocations, strain relaxation, and dislocation core behavior versus the surface treatment of the GaAs for the heteroepitaxial growth of GaSb. It is pointed out that Sb-rich growth initiation promotes the formation of a high quality network of Lomer misfit dislocations that are more efficient for strain relaxation.

Evaluation of the Interface Structure During Stranski-Krastanov Growth of GE(SI) on Si (001)

1991 ◽  
Vol 238 ◽  
Author(s):  
M. Albrecht ◽  
H. P. Strunk ◽  
P. O. Hansson ◽  
E. Bauser
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Interface Structure ◽  
Misfit Dislocations ◽  
Heteroepitaxial Growth ◽  
Dislocation Glide ◽  
Transmission Electron ◽  
Half Loop

ABSTRACTThe initial stages of heteroepitaxial growth of Ge0.85 Si0.15 on Si(001) grown from Bi solution (liquid phase epitaxy) are studid by transmission electron microscopy. Stranski-Krastanov growth is observed to take place. After growth of a pseudomorphic Ge0.85 Si0.15 layer of 4 monolayer thickness, islands form and grow pseudomorphically up to a thickness of 30 nm. Then first misfit dislocations form. The formation process of these dislocations is analyzed and discussed in terms of half loop nucleation at the surface and dislocation glide. Evidence for glide on (110) planes is put forward.

Transition From Inclined to In-Plane 60° Misfit Dislocations in a Diffuse Interface

1993 ◽  
Vol 319 ◽  
Author(s):  
X. J. Ning ◽  
P. Pirouz
Keyword(s):  
Strain Relaxation ◽  
Classical Model ◽  
Diffuse Interface ◽  
Misfit Dislocations ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Plan View ◽  
Transmission Electron ◽  
Mechanisms Of Formation ◽  
Film Substrate

AbstractDespite tremendous activity during the last few decades in the study of strain relaxation in thin films grown on substrates of a dissimilar material, there are still a number of problems which are unresolved. One of these is the nature of misfit dislocations forming at the film/substrate interface: depending on the misfit, the dislocations constituting the interfacial network have predominantly either in-plane or inclined Burgers vectors. While, the mechanisms of formation of misfit dislocations with inclined Burgers vectors are reasonably well understood, this is not the case for in-plane misfit dislocations whose formation mechanism is still controversial. In this paper, misfit dislocations generated to relax the strains caused by diffusion of boron into silicon have been investigated by plan-view and crosssectional transmission electron microscopy. The study of different stages of boron diffusion shows that, as in the classical model of Matthews, dislocation loops are initially generated at the epilayer surface. Subsequently the threading segments expand laterally and lay down a segment of misfit dislocation at the diffuse interface. The Burgers vector of the dislocation loop is inclined with respect to the interface and thus the initial misfit dislocations are not very efficient. However, as the diffusion proceeds, non-parallel dislocations interact and give rise to product segments that have parallel Burgers vectors. Based on the observations, a model is presented to elucidate the details of these interactions and the formation of more efficient misfit dislocations from the less-efficient inclined ones.

Defect Characterization of InAs Films Grown by Two-Step MOCVD on (100) InP Substrates

1992 ◽  
Vol 280 ◽  
Author(s):  
A. K. Ballal ◽  
L. Salamanca-Riba ◽  
D. L. Partin
Keyword(s):  
Electron Microscopy ◽  
Lattice Mismatch ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Plan View ◽  
Inp Substrates

ABSTRACTIn this paper we investigate the defect morphology and misfit strain in InAs films grown on (100) InP substrates using two-step metal organic chemical vapor deposition (MOCVD). High quality InAs films were obtained despite the 3.2% lattice-mismatch between the InAs film and the InP substrate. Cross-sectional and plan-view transmission electron microscopy has been used to characterize the ∼3μm thick InAs films. Almost all the lattice mismatch is accomodated by an orthogonal array of pure edge Lomer dislocations which are favored over the 60° type since they are more efficient in relieving misfit strain. In addition to misfit dislocations, threading dislocations were observed propagating through the film. Most of the threading dislocations were 60° type dislocations along the < 211 > and < 110 > directions on inclined {111} planes. The threading dislocations originate from island coalescence during film growth. High resolution electron microscopy shows the epitaxial relationship between the film and the substrate and reveals an abrupt and sharp interface with periodic dislocation cores.

Mechanisms of misfit strain relaxation in epitaxially grown BLT (Bi4-xLaxTi3O12, x = 0.75) thin films

2003 ◽  
Vol 779 ◽  
Author(s):  
Hyung Seok Kim ◽  
Sang Ho Oh ◽  
Ju Hyung Suh ◽  
Chan Gyung Park
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Strain Relaxation ◽  
Lattice Misfit ◽  
Misfit Strain ◽  
Misfit Dislocations ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
20 Nm

AbstractMechanisms of misfit strain relaxation in epitaxially grown Bi4-xLaxTi3O12 (BLT) thin films deposited on SrTiO3 (STO) and LaAlO3 (LAO) substrates have been investigated by means of transmission electron microscopy (TEM). The misfit strain of 20 nm thick BLT films grown on STO substrate was relaxed by forming misfit dislocations at the interface. However, cracks were observed in 100 nm thick BLT films grown on the same STO. It was confirmed that cracks were formed because of high misfit strain accumulated with increasing the thickness of BLT, that was not sufficiently relaxed by misfit dislocations. In the case of the BLT film grown on LAO substrate, the magnitude of lattice misfit between BLT and LAO was very small (~1/10) in comparison with the case of the BLT grown on STO. The relatively small misfit strain formed in layered structure of the BLT films on LAO, therefore, was easily relaxed by distorting the film, rather than forming misfit dislocations or cracks, resulting in misorientation regions in the BLT film.

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