Gallium Nitride Epitaxy on Silicon: Importance of Substrate Preparation

1995 ◽  
Vol 395 ◽  
Author(s):  
G. A. Martin ◽  
B. N. Sverdlov ◽  
A. Botchkarev ◽  
H. Morkoç ◽  
D. J. Smith ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Substrate Surface ◽  
Substrate Preparation ◽  
Rocking Curve ◽  
X Ray ◽  
Surface Steps ◽  
Threading Defects ◽  
Atomically Flat

ABSTRACTHexagonal GaN films grown on non-isomorphic substrates are usually characterized by numerous threading defects which are essentially boundaries between wurtzite GaN domains where the stacking sequences do not align. One origin of these defects is irregularities on the substrate surface such as surface steps. Using Si <111> substrates and a substrate preparation procedure that makes wide atomically flat terraces, we demonstrate that reduction of these irregularities greatly improves the crystalline and luminescent quality of GaN films grown by plasma-enhanced molecular beam epitaxy. X-ray rocking curve width decreases from over 1 degree to less than 20 minutes, while PL halfwidth decreases from over 15 meV to less than 10 meV.

Lattice Relaxation of AlN Buffer on Surface-Treated SiC in Molecular-Beam Epitaxy for Growth of High-Quality GaN

2002 ◽  
Vol 743 ◽  
Author(s):  
Jun Suda ◽  
Kouhei Miura ◽  
Misako Honaga ◽  
Norio Onojima ◽  
Yusuke Nishi ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Lattice Relaxation ◽  
Buffer Layers ◽  
Rocking Curve ◽  
X Ray ◽  
Hcl Gas ◽  
Aln Buffer ◽  
Atomically Flat

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.

Fabrication and characterization of ZnMgO nanowalls grown on 4H-SiC by molecular beam epitaxy

2019 ◽  
Vol 52 (1) ◽  
pp. 168-170
Author(s):  
Mieczyslaw A. Pietrzyk ◽  
Aleksandra Wierzbicka ◽  
Marcin Stachowicz ◽  
Dawid Jarosz ◽  
Adrian Kozanecki
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Optoelectronic Devices ◽  
Growth Conditions ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fabrication And Characterization

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.

High Resolution X-Ray Reflectometry and Diffraction of CaF2/Si(111) Structures Grown by Molecular Beam Epitaxy

1997 ◽  
Vol 484 ◽  
Author(s):  
E. Abramof ◽  
S. O. Ferreira ◽  
P. H. O Rappl ◽  
A. Y. Ueta ◽  
C. Boschetti ◽  
...  
Keyword(s):  
High Resolution ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Interface Roughness ◽  
X Ray Diffraction ◽  
Reflectivity Spectrum ◽  
X Ray ◽  
Interference Fringes ◽  
Reflectivity Spectra

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.

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 ◽  
...  
Keyword(s):  
Growth Rate ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Dilute Nitride ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Mbe Growth ◽  
X Ray ◽  
Related Defect

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.

Si and Mg Doped Gan Layers Grown by Gas Source Molecular Beam Epitaxy Using Ammonia

1997 ◽  
Vol 482 ◽  
Author(s):  
N. Grandjean ◽  
J. Massies ◽  
M. Leroux
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Light Emitting ◽  
X Ray ◽  
Sapphire Substrates ◽  
Gas Source ◽  
P Type ◽  
Mg Doped

AbstractThe growth of GaN layers was carried out on c-plane sapphire substrates by molecular beam epitaxy (MBE) using NH3. Undoped GaN layers were grown at 830°C with growth rates larger than 1 μm/h. Optical properties are characteristics of high quality GaN material and the linewidth of x-ray diffraction (0002) rocking curve is less than 350 arcsec. N- and p-type doping were achieved by using solid sources of Si and Mg. No post-growth annealing was needed to activate the Mg acceptors. As-grown GaN:Mg layers exhibit hole concentrations of 3×1017 cm−3and mobilities of 8 cm2/Vs at 300 K. Light emitting diodes (LEDs) based on GaN p-n homojunction have been processed. The turn on voltage is 3 V and the forward voltage is 3.7 V at 20 mA. The 300 K electroluminescence (EL) peaks at 390 nm.

Epitaxial Films of High Tc Oxide Superconductors Y1Ba2Cu3O7 Grown on SrTiO3 by Molecular Beam Epitaxy

1987 ◽  
Vol 99 ◽  
Author(s):  
J. Kwo ◽  
T. C. Hsieh ◽  
M. Hong ◽  
R. M. Fleming ◽  
S. H. Liou ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Film Plane ◽  
Epitaxial Films ◽  
Superconducting Phase ◽  
Oxide Superconductors ◽  
High Tc ◽  
Rocking Curve ◽  
X Ray ◽  
High Degree

ABSTRACTOrientation ordered high-Tc oxide films of Y1Ba2Cu3O7 were prepared by molecular beam epitaxy on SrTiO3 substrates. A combination of effusion cells and e-beam evaporators was used with the addition of an oxygen jet. The superconducting phase is formed by further O2 anneal at temperatures ≥800° C. For SrTiO3 (100), the Y1Ba2Cu3O7 films grow in the orientation of either the c-axis or the a-axis perpendicular to the film plane. Films with predominant “c⊥” orientation exhibit a high degree of crystalline order with a rocking curve 0.3° wide. The Jc is about two times higher than those with the “a⊥” orientation of a comparable Tc (R=0). For a typical film of 9000Å thickness, a Tc (R=O) of 87K, and a Jc of 7 × 104 A/cm2 at 77K were reproducibly achieved. For SrTiO3 (110), X-ray showed twinning of (110) and (103) orientations in Y1Ba2Cu3O7, thus precluding the observation of anisotropy expected for the in-plane axes of [001] and [110].

Microstructure and optical properties of GaN films grown on porous SiC substrate by MBE

2002 ◽  
Vol 719 ◽  
Author(s):  
F. Yun ◽  
M. A. Reshchikov ◽  
L. He ◽  
T. King ◽  
D. Huang ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Optical Characterization ◽  
Skin Layer ◽  
Rocking Curve ◽  
Excitonic Transition ◽  
Porous Sic

AbstractGaN thin films were grown on porous SiC substrates using reactive molecular beam epitaxy with ammonia as the nitrogen source. Microstructure analysis and optical characterization were performed to assess the quality of the effect of pores on the growth and the quality of the GaN films. Results indicate that the GaN films on porous SiC are slightly less defective and more strain-relaxed (some completely relaxed) when grown on porous SiC substrate, as compared to growth on standard 6H-SiC substrates. Rocking curve FWHMs of 3.3 arcmin for (0002) diffraction and 13.7 arcmin for (1012) diffraction were obtained for sub-micron thick GaN films. Excitonic transition with FWHM as narrow as 9.5 meV was observed at 15K on the GaN layer grown on porous SiC without a skin layer.

The growth of gallium arsenide on Si(100) by molecular-beam epitaxy

1987 ◽  
Vol 65 (8) ◽  
pp. 904-908 ◽  
Author(s):  
W. T. Moore ◽  
R. L. S. Devine ◽  
P. Maigné ◽  
D. C. Houghton ◽  
J.-M. Baribeau ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Vacuum ◽  
Group Iv ◽  
Ultra High Vacuum ◽  
Buffer Layers ◽  
Threading Dislocations ◽  
X Ray Diffraction ◽  
X Ray

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.

Defect Microstructure of Thin Wurtzite GaN Films Grown by MBE

1995 ◽  
Vol 395 ◽  
Author(s):  
B.N. Sverdlov ◽  
A. Botchkarev ◽  
G.A. Martin ◽  
A. Salvador ◽  
H. MorkoÇ ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Buffer Layers ◽  
Full Width ◽  
Cross Sectional ◽  
Rocking Curve ◽  
X Ray ◽  
Transmission Electron ◽  
Threading Defects ◽  
Defect Densities ◽  
Defect Microstructure

ABSTRACTThin films of wurtzite GaN have been grown by molecular beam epitaxy on 6H SiC (basal plane), Si {111} and sapphire (c-plane) substrates with and without various buffer layers. The defect microstructure of the films and the substrate/buffer/GaN interfacial quality have been characterized by cross-sectional transmission electron microscopy. The morphology was dominated by threading defects that originated at the substrate/buffer and/or buffer/film interfaces. Typical defect densities dropped rapidly with distance from the substrate but remained ∼108–109/cm2, depending on the particular substrate, for film thicknesses approaching one micron or more. The best quality films were grown at 770°C on sapphire with A1N buffer layers, and had X-ray rocking curve full-width at half-maximum values of ∼ 55arc-sec.

Double-crystal x-ray rocking curve study of (Al,Ga)As:As grown by low temperature molecular beam epitaxy

1997 ◽  
Vol 71 (15) ◽  
pp. 2145-2147
Author(s):  
R. N. Sacks ◽  
J. A. Carlin ◽  
M. R. Melloch ◽  
J. C. P. Chang ◽  
K. S. Yap
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Molecular Beam ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray
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