Temperature Dependent Quasi-Periodic Facetting of AlAs Grown by MBE on (100) GaAs Substrates

1993 ◽  
Vol 312 ◽  
Author(s):  
Richard Mirin ◽  
Mohan Krishnamurthy ◽  
James Ibbetson ◽  
Arthur Gossard ◽  
John English ◽  
...  
Keyword(s):  
Growth Conditions ◽  
High Energy ◽  
High Energy Electron ◽  
Temperature Dependent ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Atomic Force ◽  
Gaas Substrates ◽  
Transmission Electron ◽  
Facet Formation

AbstractHigh temperature (≥ 650°C) MBE growth of AlAs and AlAs/GaAs superlattices on (100) GaAs is shown to lead to quasi-periodic facetting. We demonstrate that the facetting is only due to the AlAs layers, and growth of GaAs on top of the facets replanarizes the surface. We show that the roughness between the AlAs and GaAs layers increases with increasing number of periods in the superlattice. The roughness increases to form distinct facets, which rapidly grow at the expense of the (100) surface. Within a few periods of the initial facet formation, the (100) surface has disappeared and only the facet planes are visible in cross-sectional transmission electron micrographs. At this point, the reflection high-energy electron diffraction pattern is spotty, and the specular spot is a distinct chevron. We also show that the facetting becomes more pronounced as the substrate temperature is increased from 620°C to 710°C. Atomic force micrographs show that the valleys enclosed by the facets can be several microns long, but they may also be only several nanometers long, depending on the growth conditions.

Epitaxial Growth of Silicon on CoSi2 (001)/Si (001)

1991 ◽  
Vol 220 ◽  
Author(s):  
Q. F. Xiao ◽  
J. R. Jimenez ◽  
L. J. Schowalter ◽  
L. Luo ◽  
T. E. Mitchell ◽  
...  
Keyword(s):  
Growth Conditions ◽  
High Energy ◽  
Thin Layers ◽  
Ex Situ ◽  
High Crystalline Quality ◽  
Cross Sectional ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Reconstructed Surface

ABSTRACTEpitaxial Si layers have been grown under a variety of growth conditions on CoSi2 (001) by molecular beam epitaxy (MBE). The structural properties of the Si overgrowth were studied by in-situ Reflection High Energy Electron Diffraction (RHEED), as well as ex-situ MeV4He+ ion channeling and High Resolution Transmission Electron Microscopy (HRTEM). Strong influences of the CoSi2 surface reconstruction on the Si overgrowth have been observed. RHEED studies show islanding growth of Si on the CoSi2 (001) (3/√2 × √2)R45 reconstructed surface, but smooth growth of Si on the CoSi2 (001) {√2 × √2)R45 reconstructed surface, under the same growth conditions. The growth of Si on thin layers of CoSi2 (2nm-6nm) with (√2 × √2)R45 reconstructed surface at 460°C results in high crystalline quality for the Si top layer, as indicated by good channeling minimum yield (Xmin < 6%), but cross-sectional TEM shows that the CoSi2 layers are discontinuous. We also report preliminary results on Si grown on a 2 × 2 reconstructed CoSi2 (001) surface.

Atomic Force Microscopy Study of GaN-Buffer Layers on SiC(0001) By MOCVD

1996 ◽  
Vol 423 ◽  
Author(s):  
Dongsup Lim ◽  
Dongjin Byun ◽  
Gyeungho Kim ◽  
Ok-Hyun Nam ◽  
In-Hoon Choi ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Microscopy Study ◽  
Growth Conditions ◽  
Interfacial Free Energy ◽  
Buffer Layers ◽  
Optimum Growth ◽  
Cross Sectional ◽  
Atomic Force ◽  
Transmission Electron ◽  
Gan Buffer Layer

AbstractBuffer layers promote lateral growth of films due to a decrease in interfacial free energy between the film and substrate, and large 2-dimensional nucleation. Smooth surfaces of thebuffer layers are desired. Optimum conditions for GaN-buffer growth on the vicinal surface of 6H-SiC(0001) were determined by atomic force microscope (AFM). AFM analysis of the GaN nucleation layers led to an optimum growth conditions of the GaN-buffer layer which was confirmed by cross-sectional transmission electron microscopy, Hall measurements and photoluminescence spectra. Optimum growth conditions for GaN-buffer layer on SiC(0001) was determined to be 1 minute growing at 550°C.

Interface structure and formation between gold and trimethylcyclohexane polycarbonate

1999 ◽  
Vol 14 (9) ◽  
pp. 3538-3543 ◽  
Author(s):  
C. v. Bechtolsheim ◽  
V. Zaporojtchenko ◽  
F. Faupel
Keyword(s):  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Cluster Formation ◽  
Systematic Investigation ◽  
Temperature Dependent ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Metal Diffusion ◽  
Atomic Force ◽  
Transmission Electron

This paper presents the results of a systematic investigation of structure and formation of the interface between gold and trimethylcyclohexane polycarbonate, particularly concerning interface evolvement during gold evaporation and the influence of evaporation rate, substrate temperature, and subsequent annealing. The means of investigation were cross-sectional transmission electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy. Extensive metal diffusion into the polymer and cluster formation near the interface were observed at deposition rates of the order of one monolayer per minute and below. The penetration depth is strongly temperature dependent. At high evaporation rates metal aggregation at the surface prevents cluster formation inside the polymer. No diffusion into the polymer was observed from metal films deposited at room temperature after extensive annealing at elevated temperatures.

A TEM study of low-temperature Ge growth on Ge(001)2×1

1993 ◽  
Vol 51 ◽  
pp. 804-805
Author(s):  
H.Z. Xiao ◽  
G. Xue ◽  
I.M. Robertson ◽  
H.K. Birnbaum ◽  
J.E. Greene
Keyword(s):  
Low Temperature ◽  
High Energy ◽  
Group Iv ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Group Iv Semiconductors ◽  
Transmission Electron ◽  
And Control ◽  
Post Deposition

One approach to a solution of the doping problem in the molecular beam epitaxy (MBE) growth of the group IV semiconductors, e.g., segregation, low incorporation, and control of the dopants, is to lower the growth temperatures. It has been found that the room temperature Si deposition becomes amorphous after growth of a limiting epitaxial thickness which increases rapidly with the growth temperature. However, the mechanism for this structural transition is not well understood. In the present paper, we report the preliminary results of a study on the mechanism of the low temperature MBE growth of Ge on Ge(001)2×1 over the temperature range of 20-100 °C at deposition rates R=0.05 and 0.1 nm s−1 in an MBE system which has a bass pressure of 5xl0−11 Torr which increases to about 2xl0−9 Torr during deposition. The structural transitions were investigated using a combination of in-situ reflection high-energy electron diffraction (RHEED) and post-deposition high resolution cross-sectional transmission electron microscopy (XTEM).

Manipulating InAs Dots with GaAs Patterns: Effect of GaAs Buffer Layer Growth and Pattern Profiles

1999 ◽  
Vol 571 ◽  
Author(s):  
Søren Jeppesen ◽  
Maria Gerling ◽  
Lars Samuelson ◽  
Mark S. Miller
Keyword(s):  
Buffer Layer ◽  
Photo Luminescence ◽  
Growth Conditions ◽  
High Energy ◽  
Layer Growth ◽  
Chemical Beam Epitaxy ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gaas Buffer Layer

ABSTRACTWe report on our efforts to selectively place chemical beam epitaxy grown Stranski-Krastanov InAs dots on GaAs patterns. The pattern profiles for placement depends on the growth conditions of a GaAs buffer layer grown on the lithographic patterns. Because we seek to suppress dot formation on (100)-oriented surfaces outside of the features, we investigated the effects buffer layer growth conditions have on dot nucleation using reflected high energy electron diffraction, atomic force microscopy and photo-luminescence. We conclude that buffer conditions favorable for patterns have negligible effect on the dots formed on the (100)- oriented surface, and that selective dot placement can be engineered by As pressure, InAs deposition and buffer growth conditions.

A Tem Study Of The Microstructural Evolution Of Mbe-Grown Gan

1997 ◽  
Vol 482 ◽  
Author(s):  
David M. Tricker ◽  
Paul D. Brown ◽  
Graeme Martin ◽  
J. Lu ◽  
D. I. Westwood ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Early Stage ◽  
Misfit Strain ◽  
High Energy ◽  
The Other ◽  
High Energy Electron ◽  
Zinc Blende ◽  
Gaas Substrates ◽  
Transmission Electron ◽  
Final Microstructure

AbstractThe evolution of the microstructure of GaN grown by molecular beam epitaxy on {001} and {111} oriented GaAs substrates has been followed using transmission electron microscopy and reflection high energy electron diffraction. A thin layer of GaN has been shown to form during the nitridation of the GaAs surface prior to growth. Growth of GaN then proceeds by an island mechanism. Faulting on the four {111} planes of the cubic zinc-blende phase which grows on the {001 } surface occurs at an early stage as a consequence of misfit strain. The distribution of the {111} microtwins is initially isotropic, but growth of one pair of {111} twins proceeds much faster than that of the other pair, leading to a final microstructure which has an anisotropic distribution of microtwins. Doping of GaN with Si hinders the growth of the zinc-blende phase, leading to a textured, columnar (0001) wurtzite microstructure. Evidence is presented to show that addition of Mg as a dopant may reduce the stacking fault energy of wurtzite GaN.

Compliance at the GaSb/GaP Interface by Misfit Dislocations Array

2011 ◽  
Vol 324 ◽  
pp. 85-88
Author(s):  
Salim El Kazzi ◽  
Ludovic Desplanque ◽  
Christophe Coinon ◽  
Yi Wang ◽  
Pierrre Ruterana ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Energy ◽  
Misfit Dislocations ◽  
Initial Growth ◽  
Electron Diffraction Analysis ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

We study the initial growth of 10 monolayers (MLs) of GaSb on a (001) GaP substrate. Transmission electron microscopy and reflection high energy electron diffraction analysis show that an Sb-rich GaP surface promotes the formation of a 90° misfit dislocation array at the epi-substrate interface. Using atomic force microscopy, we investigate the influence of the growth temperature and the growth rate on the formation and the shape of GaSb islands.

The Heteronucleation of and Defect Generation in MBE-Grown InAs Layers

1988 ◽  
Vol 144 ◽  
Author(s):  
M. M. AI-Jassim ◽  
J. P. Goral ◽  
P. Sheldon ◽  
K. M. Jones
Keyword(s):  
Molecular Beam Epitaxy ◽  
Electron Diffraction ◽  
Molecular Beam ◽  
High Energy ◽  
Misfit Dislocations ◽  
High Energy Electron ◽  
Cross Sectional ◽  
Plan View ◽  
Gaas Substrates

ABSTRACTEpitaxial InAs layers were grown by molecular beam epitaxy (MBE) on GaAs substrates. The initial stages of nucleation were studied by in situ reflection high energy electron diffraction (RHEED). Cross-sectional TEM examination was used to investigate the morphology of the growing layer, while plan-view examination revealed the generation of misfit dislocations. The growth mode was found to depend mainly on the conditions used to nucleate the epitaxial layer. In most cases, Stranski-Krastanov type of growth was observed.

Mbe Growth and Characterization of (GaAs)l−x(Si2)x and (GaAs)1−x(Si2)x/GaAs Superlattices on GaAs Substrates

1995 ◽  
Vol 379 ◽  
Author(s):  
H.P. Lee ◽  
F.J. Szalkowski ◽  
X. Zeng ◽  
J. Wolfenstine ◽  
J. W. Ager
Keyword(s):  
Molecular Beam ◽  
Stacking Faults ◽  
Cross Sectional ◽  
Mbe Growth ◽  
X Ray ◽  
Gaas Substrates ◽  
Transmission Electron ◽  
Evaporation Source ◽  
Scattering Measurement

ABSTRACTLateral compositional graded (GaAs)1-x(Si2)x alloys were deposited on GaAs substrates in a III-V molecular beam epitaxy (MBE) chamber equipped with a electron-beam Si evaporation source. Single crystal GaAs-Si alloys were formed when the deposition temperature was 600°C or higher. The alloys were characterized by Energy Dispersive X-ray Spectroscopy (EDS), Raman scattering measurement and cross-sectional Transmission Electron Microscopy (XTEM). Dislocation-free (GaAs)1-x(Si2)x films of up to x = 0.07 were deposited. For alloys with x between 0.15 < < 0.25, the morphology deteriorates and a high density of stacking faults and micro-twins were observed.

Dynamical calculations for RHEED from MBE growing surfaces. I. Growth on a low-index surface

1991 ◽  
Vol 432 (1885) ◽  
pp. 195-213 ◽  
Keyword(s):  
Electron Diffraction ◽  
Molecular Beam ◽  
Diffraction Theory ◽  
Growth Conditions ◽  
High Energy ◽  
Layer Growth ◽  
High Energy Electron ◽  
Mbe Growth ◽  
Diffusive Growth ◽  
Almost All

Dynamical diffraction calculations have been made for reflection high-energy electron diffraction (RHEED) from molecular beam epitaxy (MBE) growing surfaces. Effects due to both the diffraction and growth conditions on the RHEED intensity oscillations during MBE growth have been investigated in detail for perfect layer growth, non-diffusive, diffusive growth, and distributed growth on a low-index surface. The results are compared with the kinematic diffraction theory, and are shown to be able to reproduce almost all features of measured RHEED intensity oscillations from low-index surfaces.

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