Effects of Growth Temperature on MOCVD-Grown GaAs-ON-Si

1989 ◽  
Vol 148 ◽  
Author(s):  
S. Nozaki ◽  
N. Noto ◽  
M. Okada ◽  
T. Egawa ◽  
T. Soga ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Growth Temperature ◽  
Lower Growth ◽  
Rocking Curve ◽  
X Ray ◽  
Gaas On Si ◽  
Good Surface ◽  
Step Growth ◽  
Higher Temperature ◽  
Lower Growth Temperature

ABSTRACTEffects of growth temperature on crystallinity and surface morphology of MOCVD-grown GaAs-on-Si were studied. The FWHM of the (400) x-ray peak in the rocking curve of GaAs-on-Si reduces from 340 to 230 arcs with increasing growth temperature from 650 to 700°C, but further increase of growth temperature does not significantly decrease the FWHM. The surface morphology of GaAs-on-Si grown at higher temperature is scaly and rough. Lower growth temperature is desirable to obtain GaAs-on-Si with good surface morphology. In order to eliminate the trade-off between crystallinity and surface morphology, the three-step growth process is proposed.

LPE Growth of Textured KNbO3 Film Using SrTiO3 Substrate and V2O5 Flux

2006 ◽  
Vol 11-12 ◽  
pp. 109-112
Author(s):  
T. Hibino ◽  
Kenichi Kakimoto ◽  
Hitoshi Ohsato
Keyword(s):  
Thin Films ◽  
Phase Diagram ◽  
Growth Rate ◽  
Liquid Phase ◽  
Surface Morphology ◽  
Liquid Phase Epitaxy ◽  
Growth Temperature ◽  
Film Growth ◽  
Lower Growth ◽  
Lower Growth Temperature

KNbO3 thin films were grown on (100) and (110) SrTiO3 substrates by liquid phase epitaxy (LPE) technique. The film orientation and surface morphology were characterized by XRD and AFM, respectively. The limited phase diagram of K2O-Nb2O5-V2O5 system was prepared by DTA measurement to investigate the effect of V2O5 flux on the LPE growth of KNbO3 film. The use of V2O5 flux enhanced a film growth rate at lower growth temperature.

Nucleation and Heterointerface Structure of InAs Epilayers Grown on InP Substrates

1992 ◽  
Vol 280 ◽  
Author(s):  
K. S. Chandra Sekhar ◽  
A. K. Ballal ◽  
L. Salamanca-Riba ◽  
D. L. Partin
Keyword(s):  
Surface Morphology ◽  
Electronic Properties ◽  
Growth Temperature ◽  
High Speed ◽  
Interface Roughness ◽  
Structural Defects ◽  
Lower Growth ◽  
Substrate Interface ◽  
Film Substrate ◽  
Inp Substrates

ABSTRACTHeteroepitaxial growth of indium arsenide films on indium phosphide substrates is being actively pursued since the electronic properties of these films make them promising materials for optoelectronic and other high speed devices. The various structural aspects of the film that affect their electronic properties are structural defects like dislocations, film-substrate interface roughness and chemical inhomogeneities. In InAs films, electrons accumulate at the film-air interface, making surface morphology an important factor that decides the electronic properties. The InAs films used in this study were grown on InP substrates by metal organic vapor deposition, at different temperatures. A higher growth temperature not only resulted in poor surface morphology of the film, but also created a rough film-substrate interface. However, at all deposition temperatures, the film-substrate interfaces are sharp. At lower growth temperature, the interfaces were flat. Films grown at lower temperatures had good surface morphology and a flat and shaip heterointerface.

A Comparative Study of GaN Films Grown on Different Faces of Sapphire by ECR-Assisted MBE

1992 ◽  
Vol 242 ◽  
Author(s):  
T. D. Moustakas ◽  
R. J. Molnar ◽  
T. Lei ◽  
G. Menon ◽  
C. R. Eddy
Keyword(s):  
Surface Morphology ◽  
Low Temperatures ◽  
Smooth Surface ◽  
Growth Process ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
X Ray ◽  
Sapphire Substrates ◽  
Growth Method ◽  
Step Growth

ABSTRACTGaN films were grown on c-plane (0001), a-plane (1120) and r-plane (1102) sapphire substrates by the ECR-assisted MBE method. The films were grown using a two-step growth process, in which a GaN buffer is grown first at relatively low temperatures and the rest of the film is grown at higher temperatures. RHEED studies indicate that this growth method promotes lateral growth and leads to films with smooth surface morphology. The epitaxial relationship to the substrate, the crystalline quality and the surface morphology were investigated by RHEED, X-ray diffraction and SEM studies.

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.

Development of LPE process for fabrication of coated conductors

2000 ◽  
Vol 659 ◽  
Author(s):  
Teruo Izumi ◽  
Natsuro Hobara ◽  
Toru Izumi ◽  
Katsuya Hasegawa ◽  
Masahiko Kai ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Recent Progress ◽  
High Growth ◽  
High Growth Rate ◽  
Coated Conductors ◽  
The Other ◽  
Lower Growth ◽  
The Difference ◽  
Lower Growth Temperature ◽  
Selection Of

ABSTRACTRecent Progress of development for coated conductors by the LPE technique was reviewed. Double layered LPE films were applied to the growth on metal substrates. In both cases of MgO- and NiO- buffers, the constructions were succeeded to grow on Hastelloy and Ni tapes, respectively. In the case of the MgO-buffer, the problem, which is the melting back of the 1st LPE layer during dipping for the growth of the 2nd LPE layer, was found. The problem was solved by means of the selection of the materials for each LPE layer to introduce the difference in the growth temperature for the 1st and the 2nd layers. The lower growth temperature for the 1st LPE layer than that for 2nd one is effective to avoid the problem. On the other hand, the double layered LPE films on Ni tapes revealed Tc of 85K. Concerning the long tape processing, the high growth rate of 1≈ was confirmed even without rotation using the long tape apparatus.

Growth and Characterization of InSb films on Si (001)

2008 ◽  
Vol 1068 ◽  
Author(s):  
Lien Tran ◽  
Julia Dobbert ◽  
Fariba Hatami ◽  
W. Ted Masselink
Keyword(s):  
Substrate Temperature ◽  
Buffer Layer ◽  
Growth Temperature ◽  
Deep Level ◽  
Flux Ratio ◽  
Deep Levels ◽  
Structural Quality ◽  
Rocking Curve ◽  
X Ray ◽  
Native Oxides

ABSTRACTThe replacement of native oxides with deposited oxides in CMOS technology opens the door to replacing the Si with semiconductors without high-quality native oxides. For example, the use of InSb in logic applications could allow much lower operating voltages and power dissipation due to the InSb channels reaching saturation at significantly lower electric fields. Epitaxy of InSb onto Si could be done directly or using an intermediate layer such as GaP, GaAs, or InP. In the current work we describe the growth of InSb on Si (001) and discuss the structural and electrical properties of the resulting InSb films. The samples were characterized in terms of background electron concentration, mobility, deep level traps, Hall sensitivity, and x-ray rocking curve width.Samples were grown using molecular-beam epitaxy in a Riber-Compact 21T system. Antimony was supplied with a Veeco valved cracker cell. Vicinal Si(001) substrates offcut by 4º toward [110] were prepared by repeated oxidation and oxide-removal and then loaded into the MBE system. After the substrate temperature had been increased to about 820ºC, the surface shows a clear 24 reconstruction and appears to be free of oxide. This reconstruction remains until the substrate temperature reaches 1015ºC, at which temperature a 21 appears, indicating a dominance of double-height steps. After allowing the substrate to cool to the intended growth temperature for InSb, it is exposed to cracked Sb, resulting in the surface going from 21 to 11. This 11 reconstruction remains throughout the subsequent InSb deposition. InSb was deposited with a Sb/In flux ratio of about 5 and a growth rate of 0.2 nm/s. We have investigated growth temperatures between 300 and 420ºC for growth. To prevent the formation of the defects we introduced in some samples GaSb/AlSb supperlattice buffer layer. The best structural quality has been achieved at a growth temperature of 420ºC using GaSb/AlSb supperlattice buffer layer, resulting in our best electron mobility of 2.6104 cm2/Vs for a 2m film at room temperature. The samples grown at 420°C have the narrowest x-ray rocking curve width (FWHM of about 950 arcsec). Deep level noise spectra indicate the existence of the deep levels. The sample with the best crystal quality and highest mobility has the lowest traps. The deep levels have a temperature dependent behavior.

The Influence of Increasing Carbon Dioxide and Temperature on Competitive Interactions Between a C3 Crop, Rice (Oryza sativa) and a C4 Weed (Echinochloa glabrescens)

1996 ◽  
Vol 23 (6) ◽  
pp. 795 ◽  
Author(s):  
AMP Alberto ◽  
LH Ziska ◽  
CR Cervancia ◽  
PA Manalo
Keyword(s):  
Elevated Co2 ◽  
Growth Temperature ◽  
Competitive Ability ◽  
Relative Yield ◽  
Co2 Concentration ◽  
The Philippines ◽  
Replacement Series ◽  
Lower Growth ◽  
C4 Species ◽  
Lower Growth Temperature

Many of the most troublesome weeds in agricultural systems are C4 plants. As atmospheric CO2 increases it is conceivable that competitive ability of these weeds could be reduced relative to C3 crops such as rice. At the International Rice Research Institute (IRRI) in the Philippines, rice (IR72) and one of its associated C4 weeds, Echinochloa glabrescens, were grown from seeding to maturity using replacement series mixtures (100:0, 75:25, 50:50, 25:75, and 0:100, % rice:%weed) at two different CO2 concentrations (393 and 594 μL L-1) in naturally sunlit glasshouses. Since increasing CO2 may also result in elevated growth temperatures, the response of rice to each CO2 concentration was also examined at daylnight temperatures of 27/21 and 37/29�C. At 27/21�C, increasing the CO2 concentration resulted in a significant increase in above ground biomass (+47%) and seed yield (+55%) of rice when averaged over all mixtures. For E. glabrescens, the C4 species, no significant effect of CO2 concentration on biomass or yield was observed. When grown in mixture, the proportion of rice biomass increased significantly relative to that of the C4 weed at all mixtures at elevated CO2. Evaluation of changes in competitiveness (by calculation of plant relative yield (PRY) and replacement series diagrams) of the two species demonstrated that, at elevated CO2, the competitiveness of rice was increased relative to that of E. glabrescens. However, at the higher growth temperature (37/29�C), growth and reproductive stimulation of rice by elevated CO2 was reduced compared to the lower growth temperature. This resulted in a reduction in the proportion of rice:weed biomass present in all mixtures relative to 27/21�C and a greater reduction in PRY in rice relative to E. glabrescens. Data from this experiment suggest that competitiveness could be enhanced in a C3 crop (rice) relative to a C4 weed (E. glabrescens) with elevated CO2 alone, but that simultaneous increases in CO2 and temperature could still favour a C4 species.

Effect of O2/Ni ratio on structure and surface morphology of atmospheric pressure MOCVD grown NiO thin films

2013 ◽  
Vol 1577 ◽  
Author(s):  
Teuku M. Roffi ◽  
Motohiko Nakamura ◽  
Kazuo Uchida ◽  
Shinji Nozaki
Keyword(s):  
Surface Morphology ◽  
Atmospheric Pressure ◽  
Incident Angle ◽  
Chemical Vapor ◽  
Angle Measurement ◽  
Molar Ratio ◽  
Organic Chemical ◽  
Rocking Curve ◽  
X Ray ◽  
Nio Films

ABSTRACTEffect of oxygen to nickel molar ratio (O2/Ni) on the crystallinity of atmospheric pressure metal organic chemical vapor deposition (APMOCVD) grown NiO at 500°C is reported. X-ray diffraction (XRD) analysis including grazing incident angle θ of 0.6°, θ-2θ, ɸ and rocking curve scan are employed for crystallographic characterization. Furthermore, surface roughness is studied by atomic force microscopy (AFM). No evidence of diffraction peaks in X-ray grazing incident angle measurement confirms that all the grown NiO films are well oriented along a certain direction. θ-2θ scan results further indicate that the samples are highly oriented only along [111] direction on (0001) sapphire substrates. The analysis of full width at half maximum (FWHM) of rocking curve scan of (111) plane shows that higher O2/Ni ratio results in better crystallinity. The best crystallinity is achieved with FWHM as low as 0.106° at (111) rocking curve scan corresponding to 82.57nm grain size. AFM measurement shows that NiO films grown with higher O2/Ni ratio have smoother surface morphology.

scholarly journals Strain relaxation in GaN layers grown on porous GaN sublayers

1999 ◽  
Vol 4 (1) ◽  
Author(s):  
M. Mynbaeva ◽  
A. Titkov ◽  
A. Kryzhanovski ◽  
I. Kotousova ◽  
A.S. Zubrilov ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Strain Relaxation ◽  
Vapour Phase ◽  
Crystalline Quality ◽  
Epitaxial Layers ◽  
High Quality ◽  
High Crystalline Quality ◽  
Vapour Phase Epitaxy ◽  
X Ray ◽  
Good Surface

We have studied epitaxial GaN layers grown by hydride vapour phase epitaxy (HVPE) on porous GaN sublayers formed on SiC substrates. It was shown that these layers can be grown with good surface morphology and high crystalline quality. X-ray, Raman and photoluminescent (PL) measurements showed that the stress in the layers grown on porous GaN was reduced to 0.1-0.2 GPa, while the stress in the layers grown directly on 6H-SiC substrates remains at its usual level of about 1 GPa. Thus, we have shown that growth on porous GaN sublayer is a promising method for fabrication of high quality epitaxial layers of GaN with low strain values.

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