Mechanics of Elastic Dislocations in Strained Layer Structures

1988 ◽  
Vol 130 ◽  
Author(s):  
L. B. Freund ◽  
A. Bower ◽  
J. C. Ramirez
Keyword(s):  
Critical Thickness ◽  
Strain Relaxation ◽  
Continuum Theory ◽  
Growth Surface ◽  
Threading Dislocation ◽  
Strained Layer ◽  
Periodic Arrays ◽  
Layer Structures ◽  
Surface Irregularities ◽  
Generalized Driving Force

AbstractApplication of the elastic continuum theory of dislocations to modeling of phenomena associated with elastic strain relaxation in strained layer epitaxial heterostructures is discussed. The concept of critical thickness for onset of strain relaxation in a strained epitaxial layer is first reviewed, and some extensions to periodic arrays of dislocations and to multiple layers are described. Then, two issues are addressed that arise when the assumptions underlying the critical thickness concept are not met. One issue concerns the nucleation of dislocations at the growth surface of an epitaxial film, particularly the influence of surface irregularities on the activation energy for surface nucleation. A second issue concerns the kinetics of glide of a threading dislocation as it lays down an interface misfit dislocation when the layer thickness exceeds the critical thickness. A generalized driving force for the glide process is defined, and a relationship between this force and the glide speed is proposed.

The Stability of a Dislocation Threading a Strained Layer on a Substrate

1987 ◽  
Vol 54 (3) ◽  
pp. 553-557 ◽  
Author(s):  
L. B. Freund
Keyword(s):  
Optical Properties ◽  
Critical Thickness ◽  
Continuum Theory ◽  
Threading Dislocation ◽  
Critical Layer Thickness ◽  
Strained Layer ◽  
Mismatch Strain ◽  
The Stability ◽  
Work Done ◽  
The Continuum

The continuum theory of elastic dislocations is applied to estimate the critical thickness of a strained layer bonded to a substrate for a given mismatch strain. The formation of strained epitaxial layers is of interest due to their special electronic or optical properties, and critical thickness is understood to be the smallest thickness at which interface dislocations con form “spontaneously.” The criterion invoked here is based on the work done by the layer stress in driving a threading dislocation to lay down a misfit dislocation along the layer-substrate interface, and it is applied in a way that leads to a result that is independent of the deflected shape of the threading dislocation. The general form of the dependence of critical layer thickness on mismatch strain is similar to that based on equilibrium dislocation analysis.

Stability and Metastability in Semiconductor Strained-Layer Structures

1987 ◽  
Vol 103 ◽  
Author(s):  
Brian W. Dodson ◽  
I. J. Fritz ◽  
S. Thomas Picraux ◽  
Jeffrey Y. Tsao
Keyword(s):  
Experimental Data ◽  
Plastic Deformation ◽  
Structural Relaxation ◽  
Strain Relaxation ◽  
Dislocation Dynamics ◽  
Strained Layer ◽  
Stability Properties ◽  
Mismatch Strain ◽  
Layer Structures ◽  
Standard Models

ABSTRACTThe physics governing stability properties and relaxation of mismatch strain in semiconductor strained-layer structures is reviewed. Experimental data on stability and rates of strain relaxation are examined. We conclude that essentially all observations on structural relaxation of semiconductor strained-layer structures can be explained by standard models of plastic deformation adapted to the special conditions controlling dislocation dynamics in these structures.

Metastability in SiGe/Si Strained-Layer Structures

1988 ◽  
Vol 116 ◽  
Author(s):  
Brian W. Dodson
Keyword(s):  
Experimental Data ◽  
Plastic Deformation ◽  
Crystal Growth ◽  
Strain Relaxation ◽  
Dislocation Dynamics ◽  
Strained Layer ◽  
Layer Structures ◽  
Standard Models ◽  
Stability Limits

AbstractThe physics governing growth and stability properties in SiGe/Si strainedlayer structures is reviewed. The role of metastability in crystal growth is outlined. Experimental data on stability limits and rates of strain relaxation are examined. We conclude that essentially all observations on relaxation of semiconductor strained-layer structures can be explained by standard models of plastic deformation adapted to the special conditions controlling dislocation dynamics in these structures.

Mbe Growth of Strained-Layer InSb/InAlSb Structures

1990 ◽  
Vol 198 ◽  
Author(s):  
C.R. Whitehouse ◽  
C.F. Mcconville ◽  
G.M. Williams ◽  
A.G. Cullis ◽  
S.J. Barnett ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Critical Thickness ◽  
Multiple Quantum ◽  
Material System ◽  
X Ray Diffraction ◽  
Mbe Growth ◽  
X Ray ◽  
Strained Layer ◽  
Transmission Electron ◽  
Layer Structures

ABSTRACTThe MBE growth and related materials characterisation of InSb/InAlSb strained-layer structures is described. Band-gap considerations and critical thickness calculations are presented and indicate that this material system should offer considerable device potential. Detailed structural studies, performed using both transmission electron microscopy and X-ray diffraction, confirm the growth of high quality multiple quantum-wells, and 2K photoluminescence has shown corresponding energy upshifted transitions.

X-ray topography and EBIC studies of misfit dislocations in strained layer structures

1987 ◽  
Vol 102 ◽  
Author(s):  
N. Hamaguchi ◽  
T. P. Humphreys ◽  
C. A. Parker ◽  
S. M. Bedair ◽  
B-L. Jiang ◽  
...  
Keyword(s):  
Critical Thickness ◽  
Misfit Dislocations ◽  
X Ray ◽  
Strained Layer ◽  
Layer Structures ◽  
Lattice Matched

ABSTRACTX-ray topography(XRT) and EBIC have been used to study the generation of misfit dislocations in strained layer structures. Two structures studied were GaAs1−yPy(y=0.15) film and SLS consisting of InxGa1−xAs(x=0.08) and GaAs1−y Py(y=0.16) layers. XRT and EBIC techniques gave consistent results for the behavior of dislocations. The value of the critical thickness for generation of misfit dislocations in the former was found to be few times larger than that in the latter. EBIC image showed that a SLS lattice matched to the substrate is effective in reducing defects originating from the substrate.

Relaxation of Metastable Semiconductor Strained-Layer Structures by Plastic Flow

1987 ◽  
Vol 103 ◽  
Author(s):  
Brian W. Dodson ◽  
Jeffrey Y. Tsao
Keyword(s):  
Plastic Flow ◽  
Continuum Model ◽  
Critical Thickness ◽  
Misfit Strain ◽  
Relaxation Behavior ◽  
Strained Layer ◽  
Metastable Structures ◽  
Layer Structures ◽  
Bulk Diamond ◽  
Excess Stress

ABSTRACTThe relaxation of misfit strain in metastable structures by plastic flow is described using a continuum model based on Haasen's picture of plastic flow in bulk diamond-phase semiconductors and the concept of excess stress. This model provides a unified explanation of the equilibrium critical thickness, the relaxation behavior of metastable strained-layer structures, and the “metastable” critical thicknesses reported in many semiconductor strained-layer geometries.

Planar channeling in GaAs/InxGa1−xAs/GaAs strained‐layer structures

1989 ◽  
Vol 65 (4) ◽  
pp. 1510-1515 ◽  
Author(s):  
J. L. E. Stevens ◽  
B. J. Robinson ◽  
J. A. Davies ◽  
D. A. Thompson ◽  
T. E. Jackman
Keyword(s):  
Planar Channeling ◽  
Strained Layer ◽  
Layer Structures
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