Defects and Surfactant Action of Antimony on GaAs and GaAs1-xNx on GaAs [100] by Molecular Beam Epitaxy

2003 ◽  
Vol 799 ◽  
Author(s):  
W. K. Cheah ◽  
W. J. Fan ◽  
S. F. Yoon ◽  
S. Wicaksono ◽  
R. Liu ◽  
...  

ABSTRACTLow temperature (4.5K) photoluminescence (PL) measurements of GaAs(N):Sb on GaAs grown by solid source molecular beam epitaxy (MBE) show a Sb-related defect peak at ∼1017nm (1.22eV). The magnitude of the Sb-related impurity PL peak corresponds in intensity with the prominence of the additional two-dimensional [115] high-resolution x-ray diffraction (HRXRD) defect peaks. The elimination of these defects can be a measure of the improvement in crystal quality of GaAsN:Sb and a Sb flux ≥ 1.3×10−8 Torr is needed to invoke the surfactant behavior in III-V dilute nitride MBE growth for a growth rate of 1μm/hr.

2019 ◽  
Vol 52 (1) ◽  
pp. 168-170
Author(s):  
Mieczyslaw A. Pietrzyk ◽  
Aleksandra Wierzbicka ◽  
Marcin Stachowicz ◽  
Dawid Jarosz ◽  
Adrian Kozanecki

Control of nanostructure growth is a prerequisite for the development of electronic and optoelectronic devices. This paper reports the growth conditions and structural properties of ZnMgO nanowalls grown on the Si face of 4H-SiC substrates by molecular beam epitaxy without catalysts and buffer layers. Images from scanning electron microscopy revealed that the ZnMgO nanowalls are arranged in parallel rows following the stripe morphology of the SiC surface, and their thickness is around 15 nm. The crystal quality of the structures was evaluated by X-ray diffraction measurements.


1997 ◽  
Vol 484 ◽  
Author(s):  
E. Abramof ◽  
S. O. Ferreira ◽  
P. H. O Rappl ◽  
A. Y. Ueta ◽  
C. Boschetti ◽  
...  

AbstractCaF2 layers were grown by molecular beam epitaxy on differently prepared Si(111) substrates. X-ray reflectivity spectra were measured and fitted. From the fitting process, the thickness of the CaF2 layer was precisely (within 1 Å) determined and the CaF2/Si interface roughness was also obtained. This roughness was used as an evaluation parameter for the quality of the layers. The CaF2/Si sample from which the intentional oxide was desorpted at 800°C inside the growth chamber exhibited the most clear x-ray reflectivity spectrum with very well resolved interference fringes. The epitaxial relations of the CaF2/Si samples grown at temperatures between 250 and 700°C were determined from x-ray diffraction analysis.


SPIN ◽  
2014 ◽  
Vol 04 (04) ◽  
pp. 1440025 ◽  
Author(s):  
GAVIN R. BELL ◽  
CHRISTOPHER W. BURROWS ◽  
THOMAS P. A. HASE ◽  
MARK J. ASHWIN ◽  
SEAN R. C. MCMITCHELL ◽  
...  

The cubic polymorph of the binary transition metal pnictide (TMP) MnSb , c- MnSb , has been predicted to be a robust half-metallic ferromagnetic (HMF) material with minority spin gap ≳1 eV. Here, MnSb epilayers are grown by molecular beam epitaxy (MBE) on GaAs and In 0.5 Ga 0.5 As (111) substrates and analyzed using synchrotron radiation X-ray diffraction. We find polymorphic growth of MnSb on both substrates, where c- MnSb co-exists with the ordinary niccolite n- MnSb polymorph. The grain size of the c- MnSb is of the order of tens of nanometer on both substrates and its appearance during MBE growth is independent of the very different epitaxial strain from the GaAs (3.1%) and In 0.5 Ga 0.5 As (0.31%) substrates.


2002 ◽  
Vol 743 ◽  
Author(s):  
E. Monroy ◽  
N. Gogneau ◽  
E. Bellet-Amalnc ◽  
F. Enjalbert ◽  
J. Barjon ◽  
...  

ABSTRACTIn this paper, we study the surfactant capability of In for the growth of AlGaN/GaN heterostructures by plasma-assisted molecular beam epitaxy. Growth conditions were determined to have a self-regulated 1×1 In adlayer on AlxGa1-xN (0001). The presence of this In film favors two dimensional growth of AlGaN under stoichiometric conditions, and inhibits the formation of metal droplets on the surface. The quality of these layers was assessed by high resolution X-ray diffraction, atomic force microscopy and photoluminescence.


1987 ◽  
Vol 65 (8) ◽  
pp. 904-908 ◽  
Author(s):  
W. T. Moore ◽  
R. L. S. Devine ◽  
P. Maigné ◽  
D. C. Houghton ◽  
J.-M. Baribeau ◽  
...  

The growth of GaAs on Si(100) directly and with Ge buffer layers has been carried out sequentially under ultra high vacuum conditions in a double-ended III–V and group IV molecular beam epitaxy system. These heterostructures were examined by cross-section transverse emission microscopy, Rutherford backscattering, X-ray diffraction, and photoluminescence spectroscopy.Dislocation densities were observed to be high [Formula: see text] near both the GaAs–Si and the Ge–Si interfaces and to decrease to ~5 × 108 cm−2 a few micrometres from these interfaces. No dislocations were observed to originate at the GaAs–Ge interface, but the threading dislocations existing in the Ge buffer layer were found to propagate across this interface without significant deviation. The crystalline quality of the GaAs grown on Ge buffer layers was comparable with that grown on Si directly. However, GaAs has not yet been grown on the highest quality Ge buffer layers obtainable.


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.


2001 ◽  
Vol 696 ◽  
Author(s):  
Gu Hyun Kim ◽  
Jung Bum Choi ◽  
Joo In Lee ◽  
Se-Kyung Kang ◽  
Seung Il Ban ◽  
...  

AbstractWe have studied infrared photoluminescence (PL) and x-ray diffraction (XRD) of 400 nm and 1500 nm thick InAs epilayers on GaAs, and 4 nm thick InAs on graded InGaAs layer with total thickness of 300 nm grown by molecular beam epitaxy. The PL peak positions of 400 nm, 1500 nm and 4 nm InAs epilayer measured at 10 K are blue-shifted from that of InAs bulk by 6.5, 4.5, and 6 meV, respectively, which can be largely explained by the residual strain in the epilayer. The residual strain caused by the lattice mismatch between InAs and GaAs or graded InGaAs/GaAs was observed from XRD measurements. While the PL peak position of 400 nm thick InAs layer is linearly shifted toward higher energy with increase in excitation intensity ranging from 10 to 140 mW, those of 4 nm InAs epilayer on InGaAs and 1500 nm InAs layer on GaAs is gradually blue-shifted and then, saturated above a power of 75 mW. These results suggest that adopting a graded InGaAs layer between InAs and GaAs can efficiently reduce the strain due to lattice mismatch in the structure of InAs/GaAs.


1989 ◽  
Vol 151 ◽  
Author(s):  
W. R. Bennett ◽  
R. F. C. Farrow ◽  
S. S. P. Parkin ◽  
E. E. Marinero

ABSTRACTWe report on the new epitaxial system LaF3/Er/Dy/Er/LaF3/GaAs (111) grown by molecular beam epitaxy. X-ray diffraction studies have been used to determine the epitaxial relationships between the rare earths, the LaF3 and the substrate. Further studies of symmetric and asymmetric reflections yielded the in-plane and perpendicular strain components of the rare earth layers. Such systems may be used to probe the effects of magnetoelastic interactions and dimensionality on magnetic ordering in rare earth metal films and multilayers.


2000 ◽  
Vol 639 ◽  
Author(s):  
Ryuhei Kimura ◽  
Kiyoshi Takahashi ◽  
H. T. Grahn

ABSTRACTAn investigation of the growth mechanism for RF-plasma assisted molecular beam epitaxy of cubic GaN films using a nitrided AlGaAs buffer layer was carried out by in-situ reflection high energy electron diffraction (RHEED) and high resolution X-ray diffraction (HRXRD). It was found that hexagonal GaN nuclei grow on (1, 1, 1) facets during nitridation of the AlGaAs buffer layer, but a highly pure, cubic-phase GaN epilayer was grown on the nitrided AlGaAs buffer layer.


1998 ◽  
Vol 537 ◽  
Author(s):  
Nicolas Grandjean ◽  
Jean Massies ◽  
Mathieu Leroux ◽  
Marguerite Latigt ◽  
Pierre Lefebvre ◽  
...  

AbstractAIGaN/GaN quantum well (QWs) were grown on (0001) sapphire substrates by molecular beam epitaxy (MBE) using ammonia as nitrogen precursor. The Al composition in the barriers was varied between 8 and 27 % and the well thickness from 4 to 17 monolayers (MLs, 1ML = 2.59Å). X-ray diffraction (XRD) experiments are used to investigate the strain state of both the well and the barriers. The QW transition energy are measured by low temperature photoluminescence (PL). A large quantum confined Stark effect is observed leading to QW luminescence much lower than the emission line of the GaN buffer layer for well width above a certain critical thickness. The built-in electric field responsible for such a phenomenon is deduced from fit of the PL data. Its magnitude is of several hundred kV/cm and increases linearly with the Al composition.


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