scholarly journals Growth of AlN crystals on AlN/SiC seeds by AlN powder sublimation in nitrogen atmosphere

2004 ◽  
Vol 9 ◽  
Author(s):  
V. Noveski ◽  
R. Schlesser ◽  
S. Mahajan ◽  
S. Beaudoin ◽  
Z. Sitar
Keyword(s):  
Chemical Vapor ◽  
Nitrogen Atmosphere ◽  
Growth Time ◽  
X Ray Diffraction ◽  
Temperature Growth ◽  
Step Flow ◽  
Surface Areas ◽  
Diffusion Controlled ◽  
Initial Nucleation ◽  
Step Flow Growth

AlN single crystals were grown on AlN/SiC seeds by sublimation of AlN powder in TaC crucibles in a nitrogen atmosphere. The seeds were produced by metallorganic chemical vapor deposition (MOCVD) of AlN on SiC crystals. The influence of growth temperature, growth time and source-to-seed distance on the crystallinity and the crystal growth rate were investigated. Crystals were grown in an RF heated sublimation reactor at growth temperatures ranging from 1800-2000°C, at a pressure of 600 Torr, nitrogen flow-rate of 100 sccm and source-to-seed distances of 10 and 35 mm. At 1870°C and a source-to-seed distance of 35 mm, isolated crystals were observed with few instances of coalescence. At 1930°C, a source-to-seed distance of 10 mm and longer growth times (~30 hrs), crystal coalescence was achieved. Above 1930°C, the decomposition of SiC was evidently affecting the growth morphology and resulted in growth of polycrystalline AlN. After an initial nucleation period, the observed growth rates (10-30 µm/hr) were in close agreement with predictions of a growth model that assumed gas-phase diffusion controlled growth. Optical and electron microscope observations revealed step-flow growth, while X-ray diffraction results showed the single crystal nature of the grown material. Single crystalline AlN was grown over surface areas of 200-300 mm2 and was transparent and essentially colorless.

scholarly journals Fabrication of Self-Assembling AlGaN Quantum Dot on AlGaN Surfaces Using Anti-Surfactant

1999 ◽  
Vol 4 (S1) ◽  
pp. 852-857 ◽  
Author(s):  
H. Hirayama ◽  
Y. Aoyagi ◽  
S. Tanaka
Keyword(s):  
Chemical Vapor ◽  
Organic Chemical ◽  
3 Dimensional ◽  
Step Flow ◽  
Self Assembling ◽  
Metal Organic ◽  
Dot Density ◽  
20 Nm ◽  
Step Flow Growth ◽  
Organic Chemical Vapor Deposition

We report on the first artificial fabrication of self-assembling AlGaN quantum dots (QDs) on AlGaN surfaces using metal organic chemical vapor deposition (MOCVD). The AlGaN QDs are fabricated using a growth mode change from 2-dimensional step-flow growth to 3-dimensional island formation by modifying the AlGaN surface energy with Si anti-surfactant. The average lateral size and the thickness of fabricated AlGaN QDs, as determined by AFM, are approximately 20 nm and 6nm, respectively. The dot density was found to be controlled from 5×1010 cm−2 down to 2×109 cm−2 by increasing the dose of Si anti-surfactant. We obtained the photoluminescence (PL) from AlGaN QDs embedded with Al0.38Ga0.62N capping layers. The Al incorporation in AlGaN QDs was controllable within the range of 1-5 %.

Step-flow growth of ZnO(0001) on GaN(0001) by metalorganic chemical vapor epitaxy

2008 ◽  
Vol 310 (15) ◽  
pp. 3407-3412 ◽  
Author(s):  
T. Ive ◽  
T. Ben-Yaacov ◽  
C.G. Van de Walle ◽  
U.K. Mishra ◽  
S.P. DenBaars ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Step Flow ◽  
Step Flow Growth ◽  
Metalorganic Chemical

The Study of High Temperature Annealing of a-SiC:H Films

2006 ◽  
Vol 514-516 ◽  
pp. 18-22
Author(s):  
Shibin Zhang ◽  
Z. Hu ◽  
Leandro Raniero ◽  
X. Liao ◽  
Isabel Ferreira ◽  
...  
Keyword(s):  
High Temperature ◽  
Chemical Vapor ◽  
Nitrogen Atmosphere ◽  
High Temperature Annealing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Induced Crystallization ◽  
Vapor Deposition Technique ◽  
Crystallization Effect ◽  
Induced Crystallization

A series of amorphous silicon carbide films were prepared by plasma enhanced chemical vapor deposition technique on (100) silicon wafers by using methane, silane, and hydrogen as reactive resources. A very thin (around 15 Å) gold film was evaporated on the half area of the a- SiC:H films to investigate the metal induced crystallization effect. Then the a-SiC:H films were annealed at 1100 0C for 1 hour in the nitrogen atmosphere. Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to analyze the microstructure, composition and surface morphology of the films. The influences of the high temperature annealing on the microstructure of a-SiC:H film and the metal induced metallization were investigated.

Synthesis of ZnO Nanorod Arrays Structure on Si Substrate

2015 ◽  
Vol 1131 ◽  
pp. 53-59
Author(s):  
Suttinart Noothongkaew ◽  
Supakorn Pukird ◽  
Worasak Sukkabot ◽  
Ki Seok An
Keyword(s):  
Zno Nanorods ◽  
Chemical Vapor ◽  
Yellow Emission ◽  
Growth Time ◽  
Zno Nanorod ◽  
Nanorod Arrays ◽  
Zno Nanorod Arrays ◽  
X Ray Diffraction ◽  
Vapor Deposition Technique ◽  
Condensation Growth

ZnO nanorod arrays were synthesized with simple chemical vapor deposition technique with template without using catalyst by controlling the growth time and condensation growth. The surface morphology of nanostructure were characterized by using field emission scanning electron microscopy (FE-SEM), we found that the ZnO nanorod arrays were uniformly covered on substrate. The extremely strong ZnO (0002) peaks were observed by using X-ray diffraction (XRD), shown the preferred (0001) orientation and high crystalline quality of the ZnO nanostructures. The optical properties were investigated by using photoluminescence (PL). These results showed the contribution of green-yellow emission attributed to the strong inner reflection and scattering. Our results indicating that the uniform ZnO nanorods arrays can be synthesized by using a simplified method. Furthermore, they will be implemented as application for nanodevice fabrication or for gas sensors and solar cells.

Fabrication of Self-Assembling AlGaN Quantum Dot on AlGaN Surfaces Using Anti-Surfactant

1998 ◽  
Vol 537 ◽  
Author(s):  
H. Hirayama ◽  
Y Aoyagi ◽  
S. Tanaka
Keyword(s):  
Chemical Vapor ◽  
Organic Chemical ◽  
3 Dimensional ◽  
Step Flow ◽  
Self Assembling ◽  
Metal Organic ◽  
Dot Density ◽  
20 Nm ◽  
Step Flow Growth ◽  
Organic Chemical Vapor Deposition

AbstractWe report on the first artificial fabrication of self-assembling AlGaN quantum dots (QDs) on AIGaN surfaces using metal organic chemical vapor deposition (MOCVD). The AlGaN QDs are fabricated using a growth mode change from 2-dimensional step-flow growth to 3-dimensional island formation by modifying the AlGaN surface energy with Si anti-surfactant. The average lateral size and the thickness of fabricated AlGaN QDs, as determined by AFM, are approximately 20 nm and 6nm, respectively. The dot density was found to be controlled from 5×1010cm-2 down to 2×109 cm-2 by increasing the dose of Si anti-surfactant. We obtained the photoluminescence (PL) from AlGaN QDs embedded with Al0.38Ga0.62N capping layers. The Al incorporation in AlGaN QDs was controllable within the range of 1-5 %.

AFM Observations on the Growth Mechanisms of Epitaxial Perovskite Oxide SrRuO3 Thin Films

1997 ◽  
Vol 474 ◽  
Author(s):  
R. A. Rao ◽  
Q. Gan ◽  
C. B. Eom
Keyword(s):  
Thin Films ◽  
Growth Mechanism ◽  
Three Dimensional ◽  
Plane Domain ◽  
Perovskite Oxide ◽  
X Ray Diffraction ◽  
Island Growth ◽  
Step Flow ◽  
Atomic Force ◽  
Step Flow Growth

ABSTRACTThe growth mechanism and surface morphology of epitaxial SrRuO3 thin films deposited on exact and vicinal (001) SrTiO3 and exact (001) LaAlO3 substrates has been studied. Vicinal substrates with miscut angle, a, up to 4° toward [010] direction were used. Atomic force microscope images show that the films grown on exact (001) SrTiO3 substrate had a growth mechanism involving two dimensional nucleation. In contrast, characteristic step patterns were observed on the films deposited on vicinal substrates, suggesting that these films had a step flow growth mode. The films deposited on exact (001) LaAlO3 substrates had a three dimensional island growth, due to the incoherence between the film and substrate lattice. These results were found to be consistent with the results of x-ray diffraction analysis of the in-plane domain structure.

HVPE and MOVPE GaN Growth on Slightly Misoriented Sapphire Substrates

1999 ◽  
Vol 595 ◽  
Author(s):  
Olivier Parillaud ◽  
Volker Wagner ◽  
Hans-Jörg Bühlmann ◽  
François Lelarge ◽  
Marc Ilegems
Keyword(s):  
Substrate Surface ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Step Flow ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Step Flow Growth ◽  
Gan Buffer Layer

AbstractWe present preliminary results on gallium nitride growth by HVPE on C-plane sapphire with 2, 4 and 6 degrees misorientation towards M and A directions. A nucleation GaN buffer layer is deposited prior the growth by MOVPE. Surface morphology and growth rates are compared with those obtained on exact C-plane oriented sapphire, for various growth conditions. As expected, the steps already present on the substrate surface help to initiate a directed step-flow growth mode. The large hillocks, which are typical for HVPE GaN layers on (0001) sapphire planes, are replaced by more or less parallel macro-steps. The width and height of these steps, due to step bunching effect, depend directly on the angle of misorientation and on the growth conditions, and are clearly visible by optical or scanning electron microscopy. Atomic force microscopy and X-ray diffraction measurements have been carried out to quantify the surface roughness and crystal quality.

STUDY OF EPITAXIAL GROWTH OF DIAMOND FILM ON HETERO-MATERIAL SUBSTRATE

2005 ◽  
Vol 19 (22) ◽  
pp. 1087-1093
Author(s):  
YUAN LIAO ◽  
QINGXUAN YU ◽  
GUANZHONG WANG ◽  
RONGCHUAN FANG
Keyword(s):  
Epitaxial Growth ◽  
Diamond Film ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Crystals ◽  
Initial Nucleation ◽  
Hot Filament

We study the epitaxial growth mechanism of diamond films using various hetero-materials as substrates in a hot-filament chemical vapor deposition (HFCVD) chamber. The same parameters were maintained in the nucleation and growth processes of diamond films on these substrates. The experimental results showed that the dominant orientation of diamond crystals has a relation with that of substrates identified by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The preference of diamond films on non-diamond substrates is explained as heteroepitaxial growth. We think that the initial nucleation process is the key to the heteroepitaxial growth of diamond film.

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