Movpe Strip-Like Self-Organization of InAs Grown on InP Vicinal Surfaces

2000 ◽  
Vol 618 ◽  
Author(s):  
Laurent Auvray ◽  
Véronique Soulière ◽  
Hervé Dumont ◽  
Jacques Dazord ◽  
Yves Monteil ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Growth Parameters ◽  
Flux Ratio ◽  
Growth Conditions ◽  
Thin Layers ◽  
Vicinal Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nominal Thickness ◽  
Inp Substrates

ABSTRACTWe have investigated the influence of MOVPE growth parameters on the surface morphology of InAs nanostructures grown on 0.2° misoriented (001)InP substrates. Thin layers of nominal thickness of about 3 and 6 ML were deposited at 500°C with V/Ill flux ratios ranging from 50 to 240. The samples were cool down from 500 to 350°C during 6 minutes under either arsine or phophine atmosphere. The influence of this step has been found to greatly determine the surface morphology of the nanostructures observed by atomic force microscopy. Dots self-aligned along the steps and forming a non continuous strip, regularly spaced every 3-4 terraces have been obtained. The morphology of the strips can be varied with the growth conditions (V/III flux ratio). In this work, we will propose a mechanism for the formation of the strips observed during the cooling under phosphine atmosphere taking into account an As » P exchange.

scholarly journals Surface Morphology of MBE-grown GaN on GaAs(001) as Function of the N/Ga-ratio

1998 ◽  
Vol 3 ◽  
Author(s):  
O. Zsebök ◽  
J.V. Thordson ◽  
T.G. Andersson
Keyword(s):  
Surface Morphology ◽  
Surface Reconstruction ◽  
Defect Formation ◽  
Flux Ratio ◽  
Excitation Power ◽  
Rf Plasma ◽  
Molecular Beam Epitaxy Growth ◽  
Initial Growth ◽  
Force Microscopy ◽  
Atomic Force

Molecular beam epitaxy growth utilising an RF-plasma nitrogen source was used to study surface reconstruction and surface morphology of GaN on GaAs (001) at 580 °C. While both the nitrogen flow and plasma excitation power were constant, the grown layers were characterised as a function of Ga-flux. In the initial growth stage a (3×3) surface reconstruction was observed. This surface periodicity only lasted up to a maximum thickness of 2.5 ML, followed by a transition to the unreconstructed surface. Samples grown under N-rich, Ga-rich and stoichiometric conditions were characterised by high-resolution scanning electron microscopy and atomic force microscopy. We found that the smoothest surfaces were provided by the N/Ga-ratio giving the thickest layer at the (3×3)=>(1×1) transition. The defect formation at the GaN/GaAs interface also depended on the N/Ga-flux ratio.

Surface morphology of {100} faces ofL-arginine phosphate monohydrate single crystals investigated by atomic force microscopy

2005 ◽  
Vol 38 (4) ◽  
pp. 657-660 ◽  
Author(s):  
Y. L. Geng ◽  
D. Xu ◽  
X. Q. Wang ◽  
G. H. Zhang ◽  
G. W. Yu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Single Crystals ◽  
Liquid Flow ◽  
Growth Conditions ◽  
Mother Solution ◽  
Two Dimensional ◽  
Force Microscopy ◽  
Atomic Force

Surface morphology of {100} faces of LAP crystals was investigated by atomic force microscopy (AFM). Both the steps and the two-dimensional nuclei elongate along thebdirection, which is determined by the crystal structure. Fluctuations in the growth conditions could result in the formation of protuberances on the step fronts. Tree-like growth belts are initially observed on LAP crystals. It is assumed that the formation is caused by uneven liquid flow of the mother solution.

scholarly journals Diamond Films for Implantable Electrodes

10.14311/1638 ◽  
2012 ◽  
Vol 52 (5) ◽  
Author(s):  
Petra Henychová ◽  
Klára Hiřmanová ◽  
Martin Vraný
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Diamond Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Boron Doped ◽  
Implantable Electrodes ◽  
Average Size

Diamond is a promising material for implantable electrodes due to its unique properties. The aim of this work is to investigate the growth of boron-doped nanocrystalline diamond (B-NCD) films by plasma-enhanced microwave chemical vapor deposition at various temperatures, and to propose optimal diamond growth conditions for implantable electrodes. We have investigated the temperature dependence (450 °C–820 °C) of boron incorporation, surface morphology and growth rate on a polished quartz plate. Surface morphology and thickness were examined by atomic force microscopy (AFM).The quality of the films in terms of diamond and non-diamond phase of carbon was investigated by Raman spectroscopy. AFM imaging showed that the size of the grains was determined mainly by the thickness of the films, and varied from an average size of 40 nm in the lowest temperature sample to an average size of 150 nm in the sample prepared at the highest temperature. The surface roughness of the measured samples varied between 10 (495 °C) and 25 nm (800 °C). The growth rate of the sample increased with temperature. We found that the level of boron doping was strongly dependent on temperature during deposition. An optimal B-NCD sample was prepared at 595 °C.

Surface Morphology of Ingap in the Ai-Free Pump Ld

1996 ◽  
Vol 440 ◽  
Author(s):  
Ahn Goo Choo ◽  
Seong Heon Kim ◽  
Nam Heon Kim ◽  
Oleg Laboutine ◽  
Joon Sang Yu ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Growth Parameters ◽  
Peak Position ◽  
Full Width ◽  
Half Maximum ◽  
Peak Wavelength ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pl Spectrum ◽  
Reactor Pressure

AbstractWe have studied the effects of growth parameters and substrate orientations on InGaP quality using Normarski microscopy, photoluminescence (PL) spectrum and atomic force microscopy (AFM). The full width at half maximum (FWHNM) and peak position of PL spectrum were closely related with the surface morphology. The InGaP layers of narrower FWHM and shorter peak wavelength had smoother surface morphology. The InGaP layers grown on (100) substrates at the moderately low reactor pressure showed rougher surface than those on the tilted substrates. But the surface morphology was noticeably improved to be mirror-like at the lower reactor pressure. The surface morphology was inverted between the exact and tilted substrates in this reactor pressure. Furthermore, the samples grown on the tilted substrate exhibited rougher surface than the samples grown on the exact substrate. (111)B-misoriented growth surfaces had smoother than (111)A-misoriented surfaces.

scholarly journals Surface Morphology of Fe(III)-Porphyrin Thin Layers as Characterized by Atomic Force Microscopy

2018 ◽  
Vol 16 (3) ◽  
pp. 233
Author(s):  
Utari Utari ◽  
Kusumandari Kusumandari ◽  
Budi Purnama ◽  
Mudasir Mudasir ◽  
Kamsul Abraha
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Thin Layer ◽  
Indium Tin Oxide ◽  
Rotational Speed ◽  
Thin Layers ◽  
Atmospheric Conditions ◽  
Force Microscopy ◽  
Atomic Force ◽  
Coating Methods

Surface morphology of Fe(III)–porphyrin thin layers was studied using atomic force microscopy. The thin layer samples used in these experiments were deposited by spin coating methods on indium–tin-oxide substrates at room temperature under atmospheric conditions. Variations of thin layer of Fe(III)-porphyrin were done by modifying the rotational speed and the concentration of the solution. The experimental results demonstrated that the Fe(III)–porphyrin layers were observed as discrete nanomolecular islands. Both the number of nano-islands and thickness of the layer increased significantly with increasing concentration. A layer thickness of 15 nm was obtained for low concentrations of 0.00153 M and become 25 nm for dense concentrations of 0.153 M. Conversely, the higher number of islands were deposited on the surface of the substrate at a lower rotational speed.

Etching Treatment Effect on Surface Morphology of Dental Structures

2017 ◽  
Vol 68 (11) ◽  
pp. 2700-2703 ◽  
Author(s):  
Kamel Earar ◽  
Vasile Iulian Antoniac ◽  
Sorana Baciu ◽  
Simion Bran ◽  
Florin Onisor ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Phosphoric Acid ◽  
Human Teeth ◽  
Strong Bond ◽  
Force Microscopy ◽  
Atomic Force ◽  
Human Dentine ◽  
Dental Surface ◽  
Scanning Electron

This study examined and compared surface of human dentine after acidic etching with hydrogen peroxide, phosphoric acid liquid and gel. Surface demineralization of dentin is necessary for a strong bond of adhesive at dental surface. Split human teeth were used. After application of mentioned substances at dentin level measures of the contact angle and surface morphology were employed. Surface morphology was analyzed with the help of scanning electron microscopy and atomic force microscopy. Liquid phosphoric acid yielded highest demineralization showing better hydrophobicity than the rest, thus having more contact surface. Surface roughness are less evident and formed surface micropores of 4 �m remained open after wash and air dry providing better adhesive canalicular penetration and subsequent bond.

Surface morphology of As-deposited and laser-damaged dielectric mirror coatings studied in-situ by atomic force microscopy

1992 ◽  
Author(s):  
Mark R. Kozlowski ◽  
Michael C. Staggs ◽  
Mehdi Balooch ◽  
Robert J. Tench ◽  
Wigbert J. Siekhaus
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Force Microscopy ◽  
Dielectric Mirror ◽  
Atomic Force

Surface morphology studies on sublimation grown GaN by atomic force microscopy

1999 ◽  
Vol 200 (3-4) ◽  
pp. 348-352 ◽  
Author(s):  
R.S Qhalid Fareed ◽  
S Tottori ◽  
K Nishino ◽  
S Sakai
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Force Microscopy ◽  
Atomic Force
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