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

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.

2011 ◽  
Vol 1295 ◽  
Author(s):  
Costel Constantin ◽  
Abhijit Chinchore ◽  
Arthur R. Smith

ABSTRACTThe combination of the molecular beam epitaxy growth method with the in-situ reflection high energy electron diffraction measurements currently offers unprecedented control of crystalline growth materials. We present here a stoichiometric study of MnxSc(1-x) [x = 0, 0.03, 0.05, 0.15, 0.25, 0.35, and 0.50] thin films grown on MgO(001) substrates with this growth method. Reflection high energy electron diffraction and atomic force microscopy measurements reveal alloy behavior for all of our samples. In addition, we found that samples Mn0.10Sc0.90 and Mn0.50Sc0.50 display surface self-assembled nanowires with a length/width ratio of ~ 800 – 2000.


2002 ◽  
Vol 743 ◽  
Author(s):  
N. Onojima ◽  
J. Suda ◽  
H. Matsunami

ABSTRACTAluminum nitride (AlN) has been grown on 6H-silicon carbide (SiC) substrates with the non-polar (1120) face using rf plasma-assisted molecular-beam epitaxy (rf-MBE). Reflection high-energy electron diffraction (RHEED) revealed that AlN and 6H-SiC (1120) had an exact epitaxial relationship, i.e., [1120]AlN|[1120]SiC and [0001]AlN∥[0001]SiC. From the result of microscopic Raman scattering spectroscopy, the stacking structure of the AlN epitaxial layer was suggested to be a 2H structure, not a 6H structure. A directly grown AlN layer and layer with AlN low-temperature (LT) buffer layer were investigated based on atomic force microscopy (AFM) and X-ray diffraction (XRD).


1995 ◽  
Vol 401 ◽  
Author(s):  
Y. Gao ◽  
S. A. Chambers

AbstractEpitaxial films of NbxTi1−xO2 rutile were grown on TiO2 (110) and (100) at 600 °C by oxygen-plasma-assisted molecular beam epitaxy using elemental Ti and Nb sources. The epitaxial films were characterized by means of reflection high-energy and low-energy electron diffraction (RHEED/LEED), x-ray photoelectron spectroscopy and diffraction (XPS/XPD), ultraviolet photoemission spectroscopy (UPS) and atomic force microscopy (AFM). The epitaxial films grow in a layer-by-layer fashion and have excellent short- and long-range structure order at x≤0.3 on TiO2(110) and at x≤0.15 on TiO2(100). However, the epitaxial films become rough and disorder at higher doping levels. Nb substitutionally incorporates at cation lattice sites, leading to NbxTi1−xO2 solid solutions. In addition, the oxidation state of Nb in the NbxTi1−xO2 films has been determined to be +4.


2000 ◽  
Vol 639 ◽  
Author(s):  
Kazuhide Kusakabe ◽  
Akihiko Kikuchi ◽  
Katsumi Kishino

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.


2000 ◽  
Vol 639 ◽  
Author(s):  
M. J. Lukitsch ◽  
G. W. Auner ◽  
R. Naik ◽  
V. M. Naik

ABSTRACTEpitaxial Al1−xInxN films (thickness ∼150 nm) with 0 ≤ × ≤ 1 have been grown by Plasma Source Molecular Beam Epitaxy on Sapphire (0001) at a low substrate temperature of 375°C and were characterized by reflection high energy electron diffraction (RHEED), x-ray diffraction (XRD), and atomic force microscopy (AFM). Both RHEED and XRD measurements confirm the c-plane growth of Al1-xInxN films on sapphire (0001) with the following epitaxial relations: Nitride [0001] ∥ Sapphire [0001] and Nitride < 0110 > ∥ Sapphire <2110>. The films do not show any alloy segregation. However, the degree of crystalline mosaicity and the compositional fluctuation increases with increasing In concentration. Further, AFM measurements show an increased surface roughness with increasing In concentration in the alloy films.


1995 ◽  
Vol 399 ◽  
Author(s):  
Yoshitaka Okada ◽  
James S. Harris ◽  
Atsushi Sutoh ◽  
Mitsuo Kawabe

ABSTRACTThe purpose of this work is to achieve a high-quality epitaxy of GaAs-on-Ge system at low growth temperatures of 300 ∼ 400°C, by atomic hydrogen-assisted molecular beam epitaxy (H-MBE), in attempt to reduce Ge segregation to a minimum and to realize a layer-by-layer two-dimensional (2D) growth mode from the initial stages of the growth. A high-quality heteroepitaxy is expected in H-MBE technique as atomic H is known to act as an effective surfactant modifying the kinetics and energetics of the growth, which are practically difficult to control on atomic-scale unless a third element like a surfactant is introduced into the growth system. It is shown with the support of reflection high-energy electron diffraction (RHEED), secondary ion mass spectroscopy (SIMS), and atomic force microscopy (AFM) characterization that an enhanced layer-by-layer 2D growth can actually be realized and (2×4) GaAs(001) surface can be achieved in low-temperature heteroepitaxy on vicinal Ge(001) substrates at 400 °C by H-MBE.


Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 215
Author(s):  
Rajeev R. Kosireddy ◽  
Stephen T. Schaefer ◽  
Marko S. Milosavljevic ◽  
Shane R. Johnson

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.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 823
Author(s):  
Shizheng Yang ◽  
Hongliang Lv ◽  
Likun Ai ◽  
Fangkun Tian ◽  
Silu Yan ◽  
...  

InP layers grown on Si (001) were achieved by the two-step growth method using gas source molecular beam epitaxy. The effects of growth temperature of nucleation layer on InP/Si epitaxial growth were investigated systematically. Cross-section morphology, surface morphology and crystal quality were characterized by scanning electron microscope images, atomic force microscopy images, high-resolution X-ray diffraction (XRD), rocking curves and reciprocal space maps. The InP/Si interface and surface became smoother and the XRD peak intensity was stronger with the nucleation layer grown at 350 °C. The Results show that the growth temperature of InP nucleation layer can significantly affect the growth process of InP film, and the optimal temperature of InP nucleation layer is required to realize a high-quality wafer-level InP layers on Si (001).


1998 ◽  
Vol 512 ◽  
Author(s):  
N. Grandjean ◽  
M. Leroux ◽  
J. Massies ◽  
M. Mesrine ◽  
P. Lorenzini

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.


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