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

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.

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

MRS Proceedings ◽

10.1557/proc-618-59 ◽

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.

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Surface Roughening and Composition Modulation of ZnSe-related II-VI epitaxial films

MRS Proceedings ◽

10.1557/proc-448-159 ◽

1996 ◽

Vol 448 ◽

Cited By ~ 2

Author(s):

Shigetaka Tomiya ◽

Hironori Tsukamoto ◽

Satoshi Itoh ◽

Kazushi Nakano ◽

Etsuo Morita ◽

...

Keyword(s):

Surface Morphology ◽

Surface Reconstruction ◽

Epitaxial Films ◽

Surface Roughening ◽

Force Microscopy ◽

Composition Modulation ◽

Atomic Force ◽

Transmission Electron ◽

Rich Condition ◽

Lattice Matched

AbstractWe have investigated ZnSSe and ZnMgSSe epitaxial layers lattice-matched to GaAs (001) substrates grown by molecular beam epitaxy using atomic force microscopy and transmission electron microscopy. Under II-rich conditions with c(2x2) surface reconstruction, surface morphology exhibited corrugation aligned in the [1ī0] direction and composition modulation was observed in the same [1ī0] direction. Under VI-rich condition with (2x1) surface reconstruction, the surface morphology becomes rounded grain-like and composition modulation was not observed. The formation of composition modulation is associated with the surface corrugated structures.

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Light Scattering Study of the Evolution of the Surface Morphology During Growth of Ingaas on GaAs

MRS Proceedings ◽

10.1557/proc-375-193 ◽

1994 ◽

Vol 375 ◽

Author(s):

C. Lavoie ◽

B. Haveman ◽

E. Nodwell ◽

T. Pinnington ◽

T. Tiedje ◽

...

Keyword(s):

Light Scattering ◽

Surface Morphology ◽

Ex Situ ◽

Molecular Beam Epitaxy Growth ◽

Elastic Light Scattering ◽

Force Microscopy ◽

Atomic Force ◽

Scattering Study ◽

Good Agreement

AbstractIn-situ elastic light scattering is used to measure the evolution of the surface morphology of InxGa1−xAs films during molecular beam epitaxy growth on GaAs substrates. The in-situ measurements are compared with ex-situ measurements of the surface morphology on quenched films by optical scatterometry and atomic force microscopy (AFM). The AFM results are in good agreement with the rms roughness obtained from light scattering and both techniques detect the onset of misfit dislocation formation in this system.

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Surface morphology and defect formation of the {100} face of ZnCd(SCN)4crystals investigated by AFM

Journal of Applied Crystallography ◽

10.1107/s0021889803022738 ◽

2003 ◽

Vol 36 (6) ◽

pp. 1448-1451 ◽

Cited By ~ 4

Author(s):

X. N. Jiang ◽

D. Xu

Keyword(s):

Surface Morphology ◽

Defect Formation ◽

Structural Features ◽

Crystal Defects ◽

Two Dimensional ◽

Force Microscopy ◽

Atomic Force ◽

The Face ◽

Direct Incorporation ◽

Different Parts

Surface morphology and defect formation of the prismatic {100} face of ZCTC crystals were investigated by atomic force microscopy (AFM). Both screw-dislocation-controlled growth and two-dimensional nucleation growth occur on the face at a supersaturation of 0.03. Steps advance with strong kinetic anisotropy along theb-axis direction, probably because different parts of the ZCTC molecules are exposed along different crystallographic directions. By comparing heights of elementary steps with the structure of the ZCTC crystal, it is deduced that the growth of ZCTC crystals occurs mostly by direct incorporation of monomers or dimers of ZCTC molecules into the crystal. Defects of hollow channels, negative crystals and cracks that are oriented preferentially along the direction of theborcaxis were observed. The formation of the defects is mainly related to the growth mechanism and structural features of the ZCTC crystal.

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Etching Treatment Effect on Surface Morphology of Dental Structures

Revista de Chimie ◽

10.37358/rc.17.11.5958 ◽

2017 ◽

Vol 68 (11) ◽

pp. 2700-2703 ◽

Cited By ~ 2

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.

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