Step Flow Surface Morphology in Plasma Assisted Molecular Beam Epitaxy Grown GaN

2000 ◽  
Vol 639 ◽  
Author(s):  
Kazuhide Kusakabe ◽  
Akihiko Kikuchi ◽  
Katsumi Kishino
Keyword(s):  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Driving Force ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Force Microscopy ◽  
Atomic Force ◽  
Flow Surface ◽  
Migration Enhanced Epitaxy ◽  
Surface Morphologies

ABSTRACTThe surface morphologies of homoepitaxial GaN films grown by molecular beam epitaxy (MBE) on metalorganic chemical vapor deposition (MOCVD) grown GaN template layers were investigated, using atomic force microscopy (AFM). Typical surface morphology of MBE-grown films on MOCVD-templates was dominated by spiral hillocks due to the high density of dislocations having a screw character and large driving force of MBE growth. Introduction of the AlN multiple interlayer (AlN -MIL) into MBE-GaN layers suppressed the formation of spiral hillocks. It was attributed to obstructing the dislocation propagation by AlN-MIL. Migration enhanced epitaxy (MEE) growth of GaN also reduced the density and tightness of spiral hillocks. This observation was attributed to that MEE growth technique decreased the driving force of growth.

Growth of Germanium on Porous Silicon (001)

1996 ◽  
Vol 452 ◽  
Author(s):  
W. H. Thompson ◽  
Z. Yamani ◽  
H. M. Nayfeh ◽  
M.-A. Hasan ◽  
J. E. Greene ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Porous Silicon ◽  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Porous Si ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nm Range

AbstractThe surface morphology of Ge grown on Si (001) and porous Si(001) by molecular beam epitaxy at 380 °C is examined using atomic force microscopy (AFM). For layer thicknesses of 30 nm, the surface shows islanding while still maintaining some of the underlying roughness of the surface of porous Si. For thicknesses in the 100 nm range, the surface roughness is not visible, but the islanding persists. Unlike the case of silicon where islands tend to merge and nearly disappear as the thickness of the deposited layer rises, we observe on the porous layer the persistence of the islands with no merging even for macroscopic thicknesses as large as 0.73 microns.

GaN Epitaxial Growth Process at High Growth Temperature by NH3 Source Molecular Beam Epitaxy

2003 ◽  
Vol 798 ◽  
Author(s):  
Naoki Ohshima ◽  
Akihiro Sugihara ◽  
Naoya Yoshida ◽  
Naohiko Okabe
Keyword(s):  
Molecular Beam Epitaxy ◽  
Epitaxial Layer ◽  
Growth Temperature ◽  
Molecular Beam ◽  
High Growth ◽  
High Energy ◽  
Force Microscopy ◽  
Gas Source ◽  
Atomic Force ◽  
Surface Morphologies

ABSTRACTWe have investigated in detail dependence of annealing GaN buffer layer and GaN growth processes on a sapphire substrate at a high temperature of 1000 degree C. The GaN layers are grown by NH3 gas source molecular beam epitaxy. The behavior of GaN buffer and epitaxial layer has been observed by in-situ reflection high-energy electron diffraction and the surface morphologies of as-grown and chemically etched GaN layers by atomic force microscopy. It is found that there is distinct difference in the surface morphology of epitaxial GaN layer between at growth temperatures of below 950 degree C and that of 1000 degree C. It has been considered that the growth kinetics of GaN epitaxial layer extremely depends on the growth temperature.

Films Grown on Vicinal GaAs(111) Substrates By Molecular Beam Epitaxy

1992 ◽  
Vol 263 ◽  
Author(s):  
K. Yang ◽  
L. J. Schowalter
Keyword(s):  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Atomic Force Microscope ◽  
Surface Reconstruction ◽  
Molecular Beam ◽  
Vicinal Surfaces ◽  
Atomic Force ◽  
Morphology Of Films ◽  
Surface Morphologies

ABSTRACTThe faceted surface morphology of films grown on on-axis GaAs(111) substrates in the reconstruction regime is studied with an atomic force microscope. It reveals that facets are vicinal surfaces. Surface morphologies of films grown on substrates tilted toward different directions have been compared. An explanation is given for all observed surface morphologies. Smooth films can only be obtained on substrates tilted toward [211] in the surface reconstruction regime.

Structural and Optical Properties of InAsSbBi Grown by Molecular Beam Epitaxy on Offcut GaSb Substrates

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 215
Author(s):  
Rajeev R. Kosireddy ◽  
Stephen T. Schaefer ◽  
Marko S. Milosavljevic ◽  
Shane R. Johnson
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Optical Quality ◽  
X Ray Diffraction ◽  
Interface Quality ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Lateral Variations

Three InAsSbBi samples are grown by molecular beam epitaxy at 400 °C on GaSb substrates with three different offcuts: (100) on-axis, (100) offcut 1° toward [011], and (100) offcut 4° toward [011]. The samples are investigated using X-ray diffraction, Nomarski optical microscopy, atomic force microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The InAsSbBi layers are 210 nm thick, coherently strained, and show no observable defects. The substrate offcut is not observed to influence the structural and interface quality of the samples. Each sample exhibits small lateral variations in the Bi mole fraction, with the largest variation observed in the on-axis growth. Bismuth rich surface droplet features are observed on all samples. The surface droplets are isotropic on the on-axis sample and elongated along the [011¯] step edges on the 1° and 4° offcut samples. No significant change in optical quality with offcut angle is observed.

Effect of V/III Ratio on the Properties of GaN Layers Grown by Molecular Beam Epitaxy Using NH3

1998 ◽  
Vol 512 ◽  
Author(s):  
N. Grandjean ◽  
M. Leroux ◽  
J. Massies ◽  
M. Mesrine ◽  
P. Lorenzini
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Flux Ratio ◽  
Buffer Layers ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Piezoelectric Field ◽  
Secondary Ion

ABSTRACTAmmonia as nitrogen precursor has been used to grow III-V nitrides by molecular beam epitaxy (MBE) on c-plane sapphire substrates. The efficiency of NH3 has been evaluated allowing the determination of the actual V/III flux ratio used during the GaN growth. The effects of the V/III ratio variation on the GaN layer properties have been investigated by photoluminescence (PL), Hall measurements, atomic force microscopy (AFM), and secondary ion mass spectroscopy (SIMS). It is found that a high V/III ratio leads to the best material quality. Optimized GaN thick buffer layers have been used to grow GaN/AlGaN quantum well (QW) heterostructures. Their PL spectra exhibit well resolved emission peaks for QW thicknesses varying from 3 to 15 monolayers. From the variation of the QW energies as a function of well width, a piezoelectric field of 450 kV/cm is deduced.

scholarly journals Hexagonal Boron Nitride Tunnel Barriers Grown on Graphite by High Temperature Molecular Beam Epitaxy

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yong-Jin Cho ◽  
Alex Summerfield ◽  
Andrew Davies ◽  
Tin S. Cheng ◽  
Emily F. Smith ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Temperature ◽  
Molecular Beam Epitaxy ◽  
Boron Nitride ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
Hexagonal Boron Nitride ◽  
Graphite Substrate ◽  
Force Microscopy ◽  
Atomic Force

Abstract We demonstrate direct epitaxial growth of high-quality hexagonal boron nitride (hBN) layers on graphite using high-temperature plasma-assisted molecular beam epitaxy. Atomic force microscopy reveals mono- and few-layer island growth, while conducting atomic force microscopy shows that the grown hBN has a resistance which increases exponentially with the number of layers, and has electrical properties comparable to exfoliated hBN. X-ray photoelectron spectroscopy, Raman microscopy and spectroscopic ellipsometry measurements on hBN confirm the formation of sp2-bonded hBN and a band gap of 5.9 ± 0.1 eV with no chemical intermixing with graphite. We also observe hexagonal moiré patterns with a period of 15 nm, consistent with the alignment of the hBN lattice and the graphite substrate.

Molecular Beam Epitaxy of AlN Layers on Si (111)

2008 ◽  
Vol 1068 ◽  
Author(s):  
Jean-Christophe Moreno ◽  
Eric Frayssinet ◽  
Fabrice Semond ◽  
Jean Massies
Keyword(s):  
Molecular Beam Epitaxy ◽  
Acoustic Wave ◽  
Wave Speed ◽  
Molecular Beam ◽  
Bulk Acoustic Wave ◽  
X Ray Diffraction ◽  
High Crystalline Quality ◽  
Force Microscopy ◽  
Atomic Force ◽  
Film Bulk

ABSTRACTIn this work, we present a study of epitaxial Aluminium Nitride (AlN) for thin film bulk acoustic wave (BAW) applications. Molecular beam epitaxy (MBE) was used to perform high crystalline quality AlN thin films growth on different silicon substrate preparations. A morphological study was performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM), while structural properties and acoustic wave speed were respectively assessed by X-ray diffraction and acoustic picoseconds.

Epitaxial Growth and Characterization of the Ordered Vacancy Compound CuIn3Se5 on GaAs (100) Fabricated by Molecular Beam Epitaxy

1994 ◽  
Vol 340 ◽  
Author(s):  
Art J. Nelson ◽  
M. Bode ◽  
G. Horner ◽  
K. Sinha ◽  
John Moreland
Keyword(s):  
Molecular Beam Epitaxy ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
Symmetric Vibration ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

ABSTRACTEpitaxial growth of the ordered vacancy compound (OVC) CuIn3Se5 has been achieved on GaAs (100) by molecular beam epitaxy (MBE) from Cu2Se and In2Se3 sources. Electron probe microanalysis and X-ray diffraction have confirmed the composition for the 1-3-5 OVC phase and that the film is single crystal Culn3Se5 (100). Transmission electron microscopy (TEM) characterization of the material also showed it to be single crystalline. Structural defects in the layer consisted mainly of stacking faults. Photoluminescence (PL) measurements performed at 7.5 K indicate that the bandgap is 1.28 eV. Raman spectra reveal a strong polarized peak at 152 cm−1, which is believed to arise from the totally symmetric vibration of the Se atoms in the lattice. Atomic force microscopy reveals faceting in a preferred (100) orientation.

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