Photo-Assisted Molecular Layer Epitaxy

1987 ◽  
Vol 101 ◽  
Author(s):  
Jun-Ichi Nishizava ◽  
Toru KurabayashI
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Surface Morphology ◽  
Epitaxial Film ◽  
Molecular Layer ◽  
Wavelength Dependence ◽  
Epitaxial Films ◽  
Time Duration ◽  
Induced Reaction

ABSTRACTPhotoexcitation effects of GaAs vapor phase epitaxy have been studied. The growth rate is enhanced by irradiating the substrate zone with an exciier laser irradiation at 2 4 9 n m wavelength, however, the growth rate is reduced by irradiating the source Ga zone with a 249 or 222m exciier laser at températures below 650*C. Because of sharp wavelength dependence and from the result of the theoretical estimations, these effects have been concluded to be caused not by a therma1 -induced reaction but, rather, by photoinduced reactions.Influence of photoexcitation of the film grown by molecular layer epitaxy has been also studied. Photoirradiation could be independently undertaken at different crystal growth steps, e.g. the irradiation duration could be synchronized with the time duration of each gases supply and exhaust. By this method “synchronized irradiation”, the quality of the epitaxial film and the surface morphology of epitaxial films grown by molecular layer epitaxy were improved.

Surface Morphology and Composition Characterization at the Initial Stages of AlN Crystal Growth

2000 ◽  
Vol 639 ◽  
Author(s):  
B. Liu ◽  
Y. Shi ◽  
L. Liu ◽  
J.H. Edgar ◽  
D.N. Braski
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Silicon Nitride ◽  
Chemical Composition ◽  
Surface Morphology ◽  
Stages Of Growth ◽  
Initial Stage ◽  
Bare Substrate

ABSTRACTThe morphology and composition of AlN crystals on 6H-SiC (0001) at the initial stage of crystal growth by sublimation re-condensation technique were investigated by SEM and SAM. Discontinuous AlN coverage occurred after 15 minutes growth. The AlN nuclei size, and growth rate increased as temperature increased or pressure decreased. The SiC substrate decomposed leaving hexagonal hillocks; simultaneously, the AlN nucleated on these SiC hillocks apparently rotated by 15° to 30°. The chemical composition of the substrate and different AlN crystal facets were characterized by SAM. The bare substrate area was stoichiometric SiC with insignificant conversion to silicon nitride, while Si and C preferentially incorporated in the AlN at the initial stages of growth on specific crystal planes.

HREM study of heteroepitaxial interfaces in the Ni.50Co.50O/Al2MgO4(100) system

1992 ◽  
Vol 50 (1) ◽  
pp. 374-375
Author(s):  
W. Cao ◽  
G. Thomas
Keyword(s):  
Electron Microscopy ◽  
Epitaxial Film ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Epitaxial Films ◽  
Critical Factors ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Film Substrate

Epitaxial CoO/NiO multilayers and alloys have been produced which show interesting structural and magnetic properties. Typically, epitaxial films are grown either by chemical vapor deposition or evaporation. However, sputtering can also yield high quality epitaxial films. The structure of the substrate and the interface of the film/substrate are critical factors to determine the quality of the epitaxial film. The CoO/NiO epitaxial films on the α-Al2O3 had been studied extensively in our previous work. In this paper, the heteroepitaxial interface in the Ni.50Co.50O/Al2MgO4 is studied by using high resolution electron microscopy. Transmission electron microscopy was performed using the JEOL-200CX and JEOL-ARM1000 microscopes at the National Center for Electron Microscopy, Berkeley.

Surface Morphology of Si1−x−y GexCy Epitaxial Films Deposited by Low Temperature UHV-CVD

1996 ◽  
Vol 440 ◽  
Author(s):  
S. John ◽  
E. J. Quinones ◽  
B. Ferguson ◽  
S. K. Ray ◽  
C. B. Mullins ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Carbon Concentration ◽  
Critical Thickness ◽  
High Vacuum ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Epitaxial Films ◽  
Ultra High Vacuum ◽  
Epitaxial Thin Films

AbstractSi1−x−y GexCy epitaxial films offer wider control of strain and bandgap. In such films the morphology is an important indication of the crystalline quality of the material. We report on the morphology of Si1−x−y GexCy epitaxial thin films deposited by Ultra High Vacuum Chemical Vapor Deposition at a temperature of 550° C and deposition pressures ranging from 1 to 10 mTorr. The precursors used were Si2H6, GeH4 and CH3SiH3. Germanium mole fractions ranging from 0% to 40% were studied with carbon concentrations varying from 2×1019 to 2×1021 atoms/cm3. AFM analysis of the surface indicates that the roughness is a function of both the carbon concentration and the film thickness. For high germanium concentrations with thickness beyond the critical thickness (of Si1−xGex), carbon is found to decrease the surface roughness of the film. Thus the surface morphology confirms the strain compensation provided by carbon which is also observed using XRD. For films below the critical thickness, as the carbon concentration is increased, three dimensional islanding is observed by RHEED and AFM, degrading the epitaxial quality of the material.

Study on TlBr Single Crystal Growth Using Improved Electro Dynamic Gradient Method

2011 ◽  
Vol 415-417 ◽  
pp. 1979-1982
Author(s):  
Zhi Ping Zheng ◽  
Jing Wang ◽  
Lin Quan ◽  
Shu Ping Gong ◽  
Dong Xiang Zhou
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Electrical Properties ◽  
Temperature Gradient ◽  
Growth Conditions ◽  
Single Crystal Growth ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
X Ray

Electro Dynamic Gradient (EDG) method was utilized for TlBr crystal growth in this paper. The influence of crystal growth conditions such as temperature gradient and growth rate on optical and electrical properties of grown TlBr crystals was investigated. The quality of TlBr crystals was characterized by infrared (IR) transmittance spectrum, X-ray diffraction, and I-V measurements.

scholarly journals Lateral Growth of InN on GaN/Sapphire

2001 ◽  
Vol 693 ◽  
Author(s):  
Fuh-Hsiang Yang ◽  
Jih-Hsien Hwang ◽  
Kuei-Hsien Chen ◽  
Ying-Jay Yang
Keyword(s):  
Raman Spectrum ◽  
Surface Morphology ◽  
Growth Conditions ◽  
Epitaxial Films ◽  
Lateral Growth ◽  
High Quality ◽  
Stripe Pattern ◽  
Rocking Curve ◽  
X Ray

AbstractThe lateral growth of high quality InN on the stripe-pattern GaN/sapphire substrate with an OMVPE system was studied. The surface morphology and structural properties were investigated. Epitaxial films were achieved due to the greatly reduced strain by lateral growth. Two kinds of growth mode were observed due to different growth conditions of V/III ratios. X-ray rocking curve with FWHM of 700 arcsec shows the good quality of the film and E2 mode of Raman spectrum with FWHM of 3.5 cm-1 is among the best results ever reported in the literature.

Effects of the Growth Rate on the Quality of 4H Silicon Carbide Films for MOSFET Applications

2014 ◽  
Vol 778-780 ◽  
pp. 95-98 ◽  
Author(s):  
Massimo Camarda ◽  
Stefania Privitera ◽  
Ruggero Anzalone ◽  
Nicolò Piluso ◽  
Patrick Fiorenza ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Roughness ◽  
Silicon Carbide ◽  
Surface Morphology ◽  
Growth Rates ◽  
Stacking Faults ◽  
High Growth ◽  
Mos Devices

In this paper we investigate the role of the growth rate (varied by changing the Si/H2ratio and using TCS to avoid Si droplet formation) on the surface roughness (Rq), the density of single Shockley stacking faults (SSSF) and 3C-inclusions (i.e. epi-stacking faults, ESF). We find that optimized processes with higher growth rates allow to improve the films inallthe considered aspects. This result, together with the reduced cost of growth processes, indicates that high growth rates should always be used to improve the overall quality of 4H-SiC homoepitaxial growths. Furthermore we analyze the connection between surface morphology and density of traps (Dit) at the SiO2/SiC interface in fabricated MOS devices finding consistent indications that higher surface roughness (step-bunched surfaces) can improve the quality of the interface by reducing theDitvalue.

Growth of Crystalline Superlattices of Aluminum Nitride/Zirconium Nitride on SI(111): Roughness and Layer Interruptions

1991 ◽  
Vol 237 ◽  
Author(s):  
W. J. Meng ◽  
J. Heremans
Keyword(s):  
Growth Rate ◽  
Surface Roughness ◽  
Surface Morphology ◽  
Aluminum Nitride ◽  
Substrate Temperature ◽  
Buffer Layer ◽  
Zirconium Nitride ◽  
Layer Surface ◽  
Substrate Interface

ABSTRACTWe report on growth of crystalline superlattices of aluminum nitride/zirconium nitride on aluminum nitride buffered Si(111) substrates. We observed increased buffer layer surface roughness as compared with the buffer/Substrate interface. This roughness in turn influences the quality of the superlattice. We report results of surface morphology examination as a function of growth rate and substrate temperature.

TEMPERATURE DEPENDENCE OF THE CRYSTAL GROWTH RATE IN POLAR GLACIERS

1987 ◽  
Vol 48 (C1) ◽  
pp. C1-661-C1-662 ◽  
Author(s):  
J. R. PETIT ◽  
P. DUVAL ◽  
C. LORIUS
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Temperature Dependence ◽  
Crystal Growth Rate
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