Role of the Step Density in Reflection High-Energy Electron Diffraction: Questioning the Step Density Model

1997 ◽  
Vol 78 (12) ◽  
pp. 2381-2384 ◽  
Author(s):  
U. Korte ◽  
P. A. Maksym
Keyword(s):  
Electron Diffraction ◽  
High Energy ◽  
Energy Electron ◽  
Density Model ◽  
High Energy Electron ◽  
Step Density

Step-density variations and reflection high-energy electron-diffraction intensity oscillations during epitaxial growth on vicinal GaAs(001)

1992 ◽  
Vol 46 (11) ◽  
pp. 6815-6824 ◽  
Author(s):  
T. Shitara ◽  
D. D. Vvedensky ◽  
M. R. Wilby ◽  
J. Zhang ◽  
J. H. Neave ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Epitaxial Growth ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Diffraction Intensity ◽  
Step Density

Migration Enhanced Epitaxy of GaAs Studied by Reflection High Energy Electron Diffraction and Scanning Tunneling Microscopy

1993 ◽  
Vol 312 ◽  
Author(s):  
Jianming Fu ◽  
D. L. Miller ◽  
J. Kim ◽  
M. C. Gallagher ◽  
R. F. Willis
Keyword(s):  
Electron Diffraction ◽  
Scanning Tunneling Microscopy ◽  
High Energy ◽  
Energy Electron ◽  
Ex Situ ◽  
Scanning Tunneling ◽  
High Energy Electron ◽  
Tunneling Microscopy ◽  
Migration Enhanced Epitaxy ◽  
Step Density

AbstractMigration enhanced epitaxy (MEE) of GaAs on (001) GaAs substrates was studied by reflection high energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). In MEE, Ga and As species are alternately deposited on the growing surface. Ga adatom migration can be enhanced by the low arsenic pressure environment. The STM study was performed ex-situ by the arsenic capping and decapping procedure. We have demonstrated the correlation between the peak RHEED specular intensity during MEE growth and the variation of the lateral step density on the surface, even though the surface stoichiometry changes repetitively during MEE. The peak RHEED intensity during MEE is inversely dependent on the surface step density. The MEE surface exhibited a lower step density than the MBE surface, as shown by both RHEED and STM. However, the MEE surface still exhibited a much higher step density than a well-annealed surface. Consequently we believe that to achieve an atomically flat interface, annealing at high temperature in an arsenic flux is still necessary even if MEE is employed.

Surface Of Li-Doped ZnSe Grown On Misoriented GaAs(001) Substrates

1996 ◽  
Vol 442 ◽  
Author(s):  
Minoru Yoneta ◽  
Masakazu Ohishi ◽  
Hiroshi Saito ◽  
Mitsuhiro Ohura ◽  
Katsumoto Fujii ◽  
...  
Keyword(s):  
Growth Rate ◽  
Molecular Beam Epitaxy ◽  
Electron Diffraction ◽  
Molecular Beam ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Photoluminescence Spectra ◽  
Step Density

AbstractThe surface of Li-doped ZnSe grown on misoriented GaAs(001) substrates by molecular beam epitaxy is studied by means of reflection high energy electron diffraction. Sharp and curved streaky RHEED patterns are observed for all the layers grown on the misoriented substrate towards [110], irrespective of off-angles. No curved pattern, however, is observed on ZnSe layers grown on misoriented GaAs(001) towards [110] with off-angle larger than 5°. We confirmed that the Li-array is surely formed along [110], and that the length of the Li-array is longer than 32Å to be observable as curved streaks. It is also confirmed that the growth rate of Li-doped ZnSe is proportional to the step density, and that the growth rate on the misoriented substrate towards [110] is higher than that on the misoriented substrate towards [110]. The photoluminescence spectra of Li-doped ZnSe layers grown on misoriented GaAs are reported.

Kinematic Approximations in TED and RHEED Analysis of Reconstructed Surfaces

1990 ◽  
Vol 48 (2) ◽  
pp. 396-397
Author(s):  
L. -M. Peng ◽  
M. J. Whelan
Keyword(s):  
Electron Diffraction ◽  
Kinematic Analysis ◽  
Incident Beam ◽  
High Energy ◽  
Energy Electron ◽  
Great Success ◽  
High Energy Electron ◽  
Kinematic Approximation ◽  
Reconstructed Surfaces

In recent years there has been a trend in the structure determination of reconstructed surfaces to use high energy electron diffraction techniques, and to employ a kinematic approximation in analyzing the intensities of surface superlattice reflections. Experimentally this is motivated by the great success of the determination of the dimer adatom stacking fault (DAS) structure of the Si(111) 7 × 7 reconstructed surface.While in the case of transmission electron diffraction (TED) the validity of the kinematic approximation has been examined by using multislice calculations for Si and certain incident beam directions, far less has been done in the reflection high energy electron diffraction (RHEED) case. In this paper we aim to provide a thorough Bloch wave analysis of the various diffraction processes involved, and to set criteria on the validity for the kinematic analysis of the intensities of the surface superlattice reflections.The validity of the kinematic analysis, being common to both the TED and RHEED case, relies primarily on two underlying observations, namely (l)the surface superlattice scattering in the selvedge is kinematically dominating, and (2)the superlattice diffracted beams are uncoupled from the fundamental diffracted beams within the bulk.

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