A Model for Lattice-Mismatched Epitaxy: A Continuum View

1992 ◽  
Vol 280 ◽  
Author(s):  
B. G. Orr ◽  
C. W. Snyder
Keyword(s):  
Surface Diffusion ◽  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
High Energy ◽  
Growth Mode ◽  
Scanning Tunneling ◽  
Physical Factors ◽  
Diffusion Kinetics ◽  
Tunneling Microscopy ◽  
Lattice Mismatched Epitaxy

To date, primarily only idealized equilibrium models for the growth mode and strain relaxation of elastically strained overlayers have been proposed. Here we present a general continuum model for lattice-mismatched epitaxy. As molecular beam epitaxy is inherently a nonequilibrium growth process, surface diffusion kinetics is incorporated in the model. Additionally, a new strain relaxation mechanism in a dislocation-free film is considered. Experimental support for our view is obtained from measurements made by reflection high energy electron diffraction, scanning tunneling microscopy, and transmission electron microscopy on the growth of InGaAs on GaAs(100). These results demonstrate the strong effects which strain, surface diffusion kinetics, and surface energy have on growth mode. From analytical and numerical analysis in 1 + 1 dimensions, the interrelationship of such physical factors is revealed. Our improved understanding enables control over the growth behavior of strained-layer superlattices and heterostructures.

Evolution of Stress and Relaxation of Strain of Ge and SiGe Alloy Films on Si(001)

2001 ◽  
Vol 696 ◽  
Author(s):  
R. Koch ◽  
J. J. Schulz ◽  
B. Wassermann ◽  
G. Wedler
Keyword(s):  
Strain Relaxation ◽  
Misfit Strain ◽  
Growth Mode ◽  
Ex Situ ◽  
Scanning Tunneling ◽  
Misfit Dislocations ◽  
Tunneling Microscopy ◽  
Structural Investigations ◽  
Alloy Films ◽  
Sige Alloy

AbstractWe report on real time stress measurements by a sensitive cantilever beam technique of Ge and SiGe Alloy Films on Si(001) in combination with structural investigations by in situ STM (scanning tunneling microscopy) and ex situ AFM (atomic force microscopy). Characteristic features in the stress curves provide detailed insight into the development and relief of the misfit strain as well as the respective growth mode. For the Stranski-Krastanow system Ge/Si(001) the strain relaxation proceeds mainly in two steps: (i) by the formation of 3D islands on top of the Ge wetting layer and (ii) via misfit dislocations in larger 3D islands and upon their percolation. Co-deposition of Si influences the stress behavior drastically. The growth mode changes from Stranski-Krastanow to a kinetic 3D island mode at Si concentrations of about 20% leading to the so far smallest quantum dots of the Ge/Si system.

Growth of Si on Ge(001)2×l by gas-source molecular beam epitaxy

1993 ◽  
Vol 51 ◽  
pp. 806-807
Author(s):  
H.Z. Xiao ◽  
R. Tsu ◽  
I.M. Robertson ◽  
H.K. Birnbaum ◽  
J.E. Greene
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Strain Relaxation ◽  
Misfit Strain ◽  
High Energy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Gas Source ◽  
High Quality Result ◽  
Strained Layer Superlattices

The growth of SiGe strained-layer superlattices (SLS) has been received considerable attention due to the electronic and optoelectronic properties of these layers. In addition, these structures offer tantalizing possibilities for "band gap engineering" through the use of strain and chemically ordered alloys. The remaining barriers to grow the SiGe SLS structures with high quality result from the generation of large densities of defects, such as dislocations, twins, stacking faults, etc., at the heterointerfaces arising from the misfit strain relaxation. Other problems associated with the growth of the SiGe SLS structures are segregation and low incorporation of the dopants and inter-diffusion of Si and Ge. In the present study, the inter-mixing of Si and Ge and the generation of the defects in Si epilayers grown on Ge(001)2×1 at 550 °C by gas-source molecular beam epitaxy (MBE) from Si2H6 were studied using transmission electron microscopy (TEM), in-situ reflection high-energy electron diffraction (RHEED), scanning tunneling microscopy (STM) and electron energy-loss spectroscopy (EELS).

COMBINED HRLEED AND STM INVESTIGATIONS ON THE INITIAL STAGES OF Cu HETEROEPITAXY Ru(0001)

1997 ◽  
Vol 04 (06) ◽  
pp. 1167-1171 ◽  
Author(s):  
CH. AMMER ◽  
K. MEINEL ◽  
H. WOLTER ◽  
A. BECKMANN ◽  
H. NEDDERMEYER
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Strain Relaxation ◽  
Local Scale ◽  
Low Energy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Low Energy Electron Diffraction ◽  
Layer Structures ◽  
Low Energy Electron

Recent scanning tunneling microscopy (STM) observations revealed different layer structures in the heteroepitaxial Cu/Ru(0001) system with increasing film thickness attributed to various stages of strain relaxation. High-resolution low-energy electron diffraction (HRLEED) analysis permits one to derive more exactly both lattice periodicities and lattice rotations. Furthermore, the representative character of local STM results can be proved. However, STM measurements are needed to identify and to assign the satellite spots to coexistent different superstructures which are superposed incoherently in the diffraction pattern. Generally, the integral LEED results confirm the crystallographic data obtained by STM in a local scale.

Scanning-tunneling-microscopy study of the surface diffusion of sulfur on Re(0001)

1993 ◽  
Vol 47 (4) ◽  
pp. 2320-2328 ◽  
Author(s):  
J. C. Dunphy ◽  
P. Sautet ◽  
D. F. Ogletree ◽  
O. Dabbousi ◽  
M. B. Salmeron
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Surface Diffusion ◽  
Microscopy Study ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Scanning Tunneling Microscopy Study

Growth mode of 2-mercaptobenzoxazole on Cu(100) studied by scanning tunneling microscopy

2000 ◽  
Vol 470 (1-2) ◽  
pp. L7-L12 ◽  
Author(s):  
G. Contini ◽  
V.Di Castro ◽  
A. Angelaccio ◽  
N. Motta ◽  
A. Sgarlata
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Growth Mode ◽  
Scanning Tunneling ◽  
Tunneling Microscopy
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