Gallium Nitride Growth Using Diethylgallium Chloride as an Alternative Gallium Source

1998 ◽  
Vol 537 ◽  
Author(s):  
Ling Zhang ◽  
Rong Zhang ◽  
Marek P. Boleslawski ◽  
T.F. Kuech
Keyword(s):  
Growth Conditions ◽  
Rocking Curve ◽  
X Ray ◽  
Force Microscopy ◽  
Organic Vapor ◽  
Atomic Force ◽  
Curve Line ◽  
Metal Organic ◽  
Increasing Temperature ◽  
Trimethyl Gallium

AbstractMetal organic vapor phase epitaxy (MOVPE) of GaN has been carried out using diethyl gallium chloride (DEGaCI) and ammonia. The growth rate and efficiency of the DEGaCl-based growth decreases with increasing temperature when compared to trimethyl gallium (TMG)-based growth under similar conditions. Both low temperature buffer and the high temperature GaN layers were grown using the DEGaCI-NH3 precursor combination on the basal plane of sapphire and compared to similar structures grown using TMG and NH3. DEGaCl-based growth reveals an improved growth behavior under identical growth conditions to the conventional TMGa and ammonia growth. X-ray, Hall, and atomic force microscopy (AFM) measurements have been carried out on these samples providing a direct comparison of materials properties associated with these growth precursors. For the DEGaCl-based growth, the x-ray rocking curve line width, using the (0002) reflection, is as low as 300 arcsec on a 2.5-micron thick film. A RMS surface roughness of ∼0.5nm measured over a 10x10 micron area.

scholarly journals Gallium Nitride Growth Using Diethylgallium Chloride as an Alternative Gallium Source

1999 ◽  
Vol 4 (S1) ◽  
pp. 351-356
Author(s):  
Ling Zhang ◽  
Rong Zhang ◽  
Marek P. Boleslawski ◽  
T.F. Kuech
Keyword(s):  
Growth Conditions ◽  
Rocking Curve ◽  
X Ray ◽  
Force Microscopy ◽  
Organic Vapor ◽  
Atomic Force ◽  
Curve Line ◽  
Metal Organic ◽  
Increasing Temperature ◽  
Trimethyl Gallium

Metal organic vapor phase epitaxy (MOVPE) of GaN has been carried out using diethyl gallium chloride (DEGaCl) and ammonia. The growth rate and efficiency of the DEGaCl-based growth decreases with increasing temperature when compared to trimethyl gallium (TMG)-based growth under similar conditions. Both low temperature buffer and the high temperature GaN layers were grown using the DEGaCl-NH3 precursor combination on the basal plane of sapphire and compared to similar structures grown using TMG and NH3. DEGaCl-based growth reveals an improved growth behavior under identical growth conditions to the conventional TMGa and ammonia growth. X-ray, Hall, and atomic force microscopy (AFM) measurements have been carried out on these samples providing a direct comparison of materials properties associated with these growth precursors. For the DEGaCl-based growth, the x-ray rocking curve line width, using the (0002) reflection, is as low as 300 arcsec on a 2.5-micron thick film. A RMS surface roughness of ∼0.5nm measured over a 10×10 micron area.

InN Nanostructures: Strain and Morphology

2003 ◽  
Vol 798 ◽  
Author(s):  
Francois Demangeot ◽  
Jean Frandon ◽  
Claire Pinquier ◽  
Michel Caumont ◽  
Olivier Briot ◽  
...  
Keyword(s):  
Specific Growth ◽  
Careful Analysis ◽  
Growth Conditions ◽  
Force Microscopy ◽  
Organic Vapor ◽  
Atomic Force ◽  
Metal Organic ◽  
Raman Study ◽  
Gan Buffer Layer ◽  
Key Parameter

ABSTRACTWe presented an experimental work on InN nanostructures grown on a GaN buffer layer deposited on sapphire (0001) by Metal Organic Vapor Phase Epitaxy. InN islands of controlled sizes were fabricated by using specific growth conditions and taking advantage of self-organization that results from Stranski-Krastanov growth mode. Then nanometric islands as small as 25 nm were characterized by using atomic force microscopy (AFM) and micro-Raman spectroscopy. AFM measurements revealed that the current shape of islands correspond to truncated hexagons. In-plane residual strain field was deduced from the E2 phonon frequency shift in micro-Raman spectra recorded on islands of various sizes. Careful analysis of these data made clear that the key parameter in determining the strain magnitude was the height of the islands: this was not surprising, keeping in mind that the shape was roughly independent of the size. Nevertheless, the dislocation density was believed to increase as function of the island thickness, leading to various degrees of strained relaxation, as probed by the present micro-Raman study. This conclusion was reinforced by the strain variation on the facets of single islands with respect to its value at the centre.

Investigation Of Nucleation And Initial Stage Of Gan Growth By Atomic Force Microscopy And X-Ray Diffraction

1997 ◽  
Vol 482 ◽  
Author(s):  
P. W. Yip ◽  
S.-Q. Wang ◽  
A. J. Drehman ◽  
L. D. Zhu ◽  
P. E. Norris
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Deposition Temperature ◽  
Yellow Luminescence ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Initial Stage

AbstractThe nucleation and initial stage of GaN growth on sapphire was investigated by atomic force microscopy, X-ray diffraction and photoluminescence. A 15 to 30 nm thick GaN buffer layer deposited at proper conditions was extremely smooth and nearly amorphous. Proper post deposition annealing resulted in the buffer crystallized. The buffer layer deposition temperature, thickness and annealing time and temperature must be coordinated. Low deposition temperature and/or insufficient annealing of the buffer results in a GaN wafer which has fine spiking surface morphology with an RMS of 3.4 nm for 1.4 μm wafer, strong yellow luminescence and wide xray rocking curve FWHM. High deposition temperature, longer crystallization time, and a low growth rate results in a wafer which exhibits strong band edge luminescence without noticeable yellow luminescence, and a narrow (002) diffraction rocking curve. However, the surface morphology exhibits well developed hexagonal feature with RMS roughness of 14.3 nm for a 570 nm thick layer. X-ray rocking curve analysis revealed buffer crystallization, domain coalescence and alignment process. The FWHM of the ω–scan of GaN (101) diffraction was 1700–2000 arc seconds for 200–1400 nm wafers which indicates that the twist of the domains is not changing much with the growth.

Comparison of the Microstructure of AlN Films Grown by MOCVD and by PLD on Sapphire Substrates

1996 ◽  
Vol 449 ◽  
Author(s):  
Yun-Xin Li ◽  
Lourdes Salamanca-Riba ◽  
V. Talyan ◽  
T. Venkatesan ◽  
C. Wongchigul ◽  
...  
Keyword(s):  
Low Density ◽  
Full Width ◽  
High Crystalline Quality ◽  
Rocking Curve ◽  
X Ray ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Film Substrate ◽  
Microscopy Images

ABSTRACT(0001) aluminium nitride thin films were grown epitaxially on (0001) Sapphire substrates by MOCVD at 1200° C and PLD at 800° C. Both films have the same epitaxial growth relationship: (0001)AlN//(0001)Sap, and the same in-plane relationship which shows a 30° rotation between A1N and Sapphire: [ 12 10]AlN//[0 110]Sap and [10 10]AlN //[ 2110]Sap. The full width at half maximum (FWHM) of x-ray rocking curve of the MOCVD A1N film was 0.16° and PLD A1N film was 0.2°. Films grown by both MOCVD and PLD showed high crystalline quality. HRTEM images showed that these films are single crystalline with very low density of defects.Dislocations in the film parallel to the film / substrate interface were observed in both A1N films. Atomic force microscopy images showed that the MOCVD films have flatter and larger terraces than the PLD films. The PLD technique for A1N growth needs to be improved further. But both films have a surface roughness of approximately 100nm.

Formation of Self-Assembled Nanometer-Scale InP Islands on Silicon Substrates

2000 ◽  
Vol 618 ◽  
Author(s):  
A.S. Bakin ◽  
D. Piester ◽  
H.-H. Wehmann ◽  
A.A. Ivanov ◽  
A. Schlachetzki ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Atomic Force Microscopy ◽  
Vapor Phase ◽  
Three Dimensional ◽  
Nanometer Scale ◽  
Silicon Substrates ◽  
Force Microscopy ◽  
Organic Vapor ◽  
Atomic Force ◽  
Metal Organic

ABSTRACTThree-dimensional islands of InP have been reproducibly grown in the Stranski-Krastanow growth mode on Si (001) and (111) by using metal-organic vapor phase epitaxy in order to obtain nanometer-scale quantum dots. Atomic-force microscopy was used to determine the morphology of the samples and to evaluate the dimensions of the islands. Formation of three-dimensional islands with densities as high as 2.5×1010 cm−2 and small sizes have been observed. The evolution of island morphology is explained in terms of strain-relaxing mechanisms at the first stages of InP/Si heteroepitaxy.

SURFACTANT EFFECT OF In ON THE MOVPE GROWTH OF Al- AND N-POLAR AlN

2016 ◽  
Vol 24 (06) ◽  
pp. 1750081
Author(s):  
QINQIN ZHUANG ◽  
JUNYONG KANG ◽  
SHUPING LI ◽  
WEI LIN
Keyword(s):  
Theoretical Calculations ◽  
Growth Conditions ◽  
X Ray ◽  
Force Microscopy ◽  
Surfactant Effect ◽  
Density Of Dislocations ◽  
Atomic Force ◽  
Surface Flatness ◽  
Movpe Growth

Al- and N-polar AlN have been grown by metalorganic vapor phase epitaxy (MOVPE) with the assistance of In dopant and characterized by in situ interferometry, ellipsometry, scanning electron microscopy, atomic force microscopy, and X-ray diffractometry. The growth of Al-polar AlN is faster with smoother surfaces than the N-polar ones, which is explained by theoretical calculations. The surfactant effect of In is confirmed by improving the growth rate and surface flatness without getting into the epilayer. Additionally, In is also favorable for reducing the density of dislocations and improving the crystalline quality, especially that of Al-polar AlN. The results suggest that using In surfactant to grow the Al-polar AlN epilayer leads to a better crystal quality under proper pre-growth treatments, low- and high-temperature AlN growth conditions.

Drastic Change in the Gan Film Quality by In-Situ Controlling Surface Reconstructions In Gsmbe

1997 ◽  
Vol 482 ◽  
Author(s):  
X. Q. Shen ◽  
S. Tanaka ◽  
S. Iwai ◽  
Y. Aoyagi
Keyword(s):  
Growth Conditions ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Gas Source ◽  
Atomic Force ◽  
Surface Reconstructions ◽  
Gan Film

AbstractGaN growth was performed on 6H-SiC (0001) substrates by gas-source molecular beam epitaxy (GSMBE), using ammonia (NH3) as a nitrogen source. Two kinds of reflection high-energy electron diffraction (RHEED) patterns, named (1×1) and (2×2), were observed during the GaN growth depending on the growth conditions. By careful RHEED study, it was verified that the (1×1) pattern was corresponded to a H2-related nitrogen-rich surface, while (2×2) pattern was resulted from a Ga-rich surface. By x-ray diffraction (XRD), photoluminescence (PL) and atomic force microscopy (AFM) characterizations, it was found that the GaN quality changed drastically grown under different RHEED patterns. GaN film grown under the (1×1) RHEED pattern showed much better qualities than that grown under the (2×2) one.

The Initial Stages of Growth of Ordered GaInP and GaInAs Grown by Metal Organic Vapor Phase Epitaxy

1999 ◽  
Vol 583 ◽  
Author(s):  
M. C. Hanna ◽  
A. Mascarenhas ◽  
Hyeonsik M. Cheong
Keyword(s):  
Raman Spectroscopy ◽  
Atomic Force Microscopy ◽  
Direct Evidence ◽  
Force Microscopy ◽  
Step Flow ◽  
Organic Vapor ◽  
Stages Of Growth ◽  
Atomic Force ◽  
Metal Organic ◽  
Step Flow Growth

AbstractWe have used atomic force microscopy (AFM) and Raman spectroscopy to investigate the development of the surface morphology of (001) direct and vicinal GaInP and GaInAs grown under conditions to produce strong CUPtB ordering. Raman spectroscopy provided direct evidence of CuPtB ordering in layers as thin as 10 nm for GaInP and 5 nm for GaInAs. We find that the morphology of GaInP and GaInAs on (001)6B substrates consists of ridges, which are aligned predominately along the [110] direction (A-direction). These ridges are well developed even at layer thicknesses of 2 nm, and their sides consist of step-bunches and near (001) terraces. On (001) direct substrates, the GaInP morphology is similar to that obtained on 6B substrates, although the step bunches have no preferential orientation, while GaInAs (001) growth proceeds by a combination of 2D-island and step flow growth. We discuss possible reasons for the differences in the morphology of ordered GaInP and GaInAs. The results of this work suggest it may be difficult to produce abrupt heterointerfaces in structures containing ordered GalnP and GaInAs alloys.

Multivariable study on homoepitaxial diamond growth using isotopically enriched carbon-13 gas mixtures

2009 ◽  
Vol 24 (2) ◽  
pp. 493-498 ◽  
Author(s):  
Gopi K. Samudrala ◽  
Yogesh K. Vohra
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Nitrogen Vacancy ◽  
Diamond Growth ◽  
Plasma Chemical ◽  
Rocking Curve ◽  
X Ray ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Atomic Force

We report our observations on the homoepitaxial diamond growth by microwave plasma chemical vapor deposition (MPCVD) experiments on Type Ib diamond substrates conducted by varying three independent variables. In a feed gas mixture of H2, N2, O2, and 13CH4, the amount of nitrogen was varied in the range of 0 to 4000 ppm, the amount of methane was varied from 2% CH4/H2 to 6% CH4/H2, and the substrate temperature was varied in the range of 850 to 1200 °C. We used isotopically enriched carbon-13 methane gas as the source of carbon in the plasma to clearly distinguish the grown diamond layer from the underlying substrate using Raman spectroscopy. The x-ray rocking curve measurements confirmed the homoepitaxial nature of the deposited layers with a slight increase in the full width at half-maximum for sample grown with the highest nitrogen content in the plasma. Optical and atomic force microscopy revealed dramatic changes in surface morphology with variation in each parameter. The nitrogen incorporation in carbon-13 diamond layers was monitored through photoluminescence spectroscopy of nitrogen–vacancy complexes. A twentyfold increase in diamond growth rate was clearly achieved in this multivariable study.

Epitaxial Batio3 and Knbo3 Thin Films On Various Substrates for Optical Waveguide Applications

1996 ◽  
Vol 441 ◽  
Author(s):  
L. Beckers ◽  
W. Zander ◽  
J. Schubert ◽  
P. Leinenbach ◽  
Ch. Buchal ◽  
...  
Keyword(s):  
Optical Materials ◽  
Rutherford Backscattering Spectrometry ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
Rocking Curve ◽  
X Ray ◽  
Flat Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Yield Values

AbstractTechnologically interesting optical materials such as BaTiO3 and KnbO3 are difficult to grow as single crystals of large dimensions. Thin film techniques can overcome this problem by synthesizing these materials on commercially available substrates. We demonstrate the deposition of single crystalline BaTiO3 and KnbO3 on MgO, SrTiO3 and buffered MgO substrates by Pulsed Laser Deposition (PLD). The samples are characterized by Rutherford Backscattering Spectrometry / Channeling (RBS/C), X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). We found excellent crystalline quality, confirmed by RBS/C minimum yield values of 2 % and a FWHM of 0.36° of the BaTiO3(002) rocking curve. Even films of a few microns thickness have been grown without loss of crystalline perfection, and all films show very flat surfaces. The RMS roughness of a 950 nm BaTiO3 film was found to be 1.1 nm.

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