The effect of buffer layers on structural quality of Si0.7Ge0.3 layers grown on Si(001) substrates by molecular beam epitaxy

1997 ◽  
Vol 117-118 ◽  
pp. 507-511
Author(s):  
T. Obata ◽  
K. Komeda ◽  
T. Nakao ◽  
H. Ueba ◽  
C. Tatsuyama
2002 ◽  
Vol 743 ◽  
Author(s):  
C. D. Lee ◽  
R. M. Feenstra ◽  
J. E. Northrup ◽  
L. Lymperakis ◽  
J. Neugebauer

ABSTRACTM-plane GaN(1100) is grown by plasma assisted molecular beam epitaxy on ZnO(1100) substrates. A low-temperature GaN buffer layer is found to be necessary to obtain good structural quality of the films. Well oriented (1100) GaN films are obtained, with a slate like surface morphology. On the GaN(1100) surfaces, reconstructions with symmetry of c(2×2) and approximate “4×5” are found under N- and Ga-rich conditions, respectively. We propose a model for Ga-rich conditions with the “4×5” structure consisting of ≥ 2 monolayers of Ga terminating the GaN surface.


Author(s):  
M. A. Sánchez-García ◽  
E. Calleja ◽  
E. Monroy ◽  
F. J. Sánchez ◽  
F. Calle ◽  
...  

High quality AlN layers with full widths at half maximum values of 10 arcmin and average surface roughness (rms) of 48Å were grown by molecular beam epitaxy on Si(111) substrates. A systematic study and optimization of the growth conditions was performed in order to use these AlN layers as buffers in the growth of GaN films. Atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques were employed to determine the surface and structural quality of the layers. Best AlN films were obtained at high substrate temperatures (Tsubs>900°C) and III/V ratios close to stoichiometry. Growth conditions with III/V ratios beyond stoichiometry (Al-rich) did not further improve the crystal quality. In these cases a higher substrate temperature is needed to prevent condensation of Al on the surface. GaN films with full width at half maximum of 10 arcmin and improved optical properties were grown on top of optimized AlN buffer layers.


1989 ◽  
Vol 7 (2) ◽  
pp. 517-522 ◽  
Author(s):  
R. J. Koestner ◽  
H.‐Y. Liu ◽  
H. F. Schaake ◽  
T. R. Hanlon

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.


2002 ◽  
Vol 743 ◽  
Author(s):  
Jun Suda ◽  
Kouhei Miura ◽  
Misako Honaga ◽  
Norio Onojima ◽  
Yusuke Nishi ◽  
...  

ABSTRACTThe effects of SiC surface treatment on the lattice relaxation of AlN buffer layers and the crystalline quality of GaN layers grown on the buffer layers were studied. AlN buffer layers and GaN main layers were grown by plasma-assisted molecular-beam epitaxy on on-axis 6H-SiC (0001)Si substrates. High-temperature HCl-gas etching resulted in an atomically flat SiC surface with (√3×√3)R30° surface reconstruction, while HCl-gas etching followed by HF chemical treatment resulted in an atomically flat surface with (1×1) structure. The AlN layer grown on the (1×1) surface showed slower lattice relaxation. GaN grown on the AlN buffer layer exhibited a (0002) X-ray rocking curve of 70 arcsec and 107 cm−2 of screw-type dislocation density, which was superior than that of GaN grown on (√3×√3)R30° surface.


1990 ◽  
Vol 216 ◽  
Author(s):  
W. Dobbelaere ◽  
J. De Boeck ◽  
W. De Raedt ◽  
J. Vanhellemont ◽  
G. Zou ◽  
...  

ABSTRACTInAs and InAs0.85Sb0.15p-“i”-n structures were grown on InAs, GaAs and Si substrates by Molecular Beam Epitaxy. The structural quality of the layers is discussed using Transmission Electron Microscopy and Rutherford Back Scattering. The influence of the material quality on the 77 K current-voltage measurements is explained. The spectral response of the devices was measured demonstrating peak responsivities of 2.1 A/W at 3.5μm wavelength for InAs0.85Sb0.15 detectors with a 4.3 μm cut-off wavelength.


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.


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