scholarly journals Comparative Growth of AlN on Singular and Off-Axis 6H and 4H-SiC by MOCVD

1999 ◽  
Vol 4 (S1) ◽  
pp. 344-350
Author(s):  
S. Wilson ◽  
C. S. Dickens ◽  
J. Griffin ◽  
M. G. Spencer
Keyword(s):  
High Energy ◽  
Two Dimensional ◽  
Comparison Study ◽  
High Energy Electron ◽  
High Quality ◽  
Force Microscopy ◽  
Step Flow ◽  
Atomic Force ◽  
Dimensional Growth ◽  
Atomically Flat

A comparison study of the growth of aluminum nitride (AlN) single crystal epitaxy on 6H-SiC and 4H-SiC substrates has been performed. The material has been characterized using atomic force microscopy (AFM) and reflective high energy electron diffraction (RHEED). AlN crystals were deposited on the following 6H-SiC substrates: singular with and without an initial SiC epilayer, and 3.5° off-axis with and without an initial SiC epilayer. AlN crystals were deposited on 8.0° off-axis 4H-SiC with and without initial SiC epilayers. AFM shows that the deposition of AlN on 6H-SiC and 4H-SiC with an initial SiC epilayer displays high quality quasi-two dimensional growth as atomically flat or step flow epitaxy.

Comparative Growth of AIN on Singular and Off-Axis 6H and 4H-SiC by MOCVD

1998 ◽  
Vol 537 ◽  
Author(s):  
S. Wilson ◽  
C. S. Dickens ◽  
J. Griffin ◽  
M. G. Spencer
Keyword(s):  
High Energy ◽  
Two Dimensional ◽  
Comparison Study ◽  
High Energy Electron ◽  
High Quality ◽  
Force Microscopy ◽  
Step Flow ◽  
Atomic Force ◽  
Dimensional Growth ◽  
Atomically Flat

AbstractA comparison study of the growth of aluminum nitride (AIN) single crystal epitaxy on 6H-SiC and 4H-SiC substrates has been performed. The material has been characterized using atomic force microscopy (AFM) and reflective high energy electron diffraction (RHEED). AIN crystals were deposited on the following 6H-SiC substrates: singular with and without an initial SiC epilayer, and 3.5° off-axis with and without an initial SIC epilayer. AIN crystals were deposited on 8.0° off-axis 4H-SiC with and without initial SIC epilayers. AFM shows that the deposition of AIN on 6H-SiC and 4H-SIC with an initial SiC epilayer displays high quality quasi-two dimensional growth as atomically flat or step flow epitaxy.

scholarly journals Dielectric Function of AlN Grown on Si (111) by MBE

1999 ◽  
Vol 572 ◽  
Author(s):  
Stefan Zollner ◽  
Atul Konkar ◽  
R. B. Gregory ◽  
S. R. Wilson ◽  
S. A. Nikishin ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Buffer Layers ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Growth Morphology ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dimensional Growth ◽  
Peak Widths

ABSTRACTWe measured the ellipsometric response from 0.7–5.4 eV of c-axis oriented AlN on Si (111) grown by molecular beam epitaxy. We determine the film thicknesses and find that for our AlN the refractive index is about 5–10% lower than in bulk AlN single crystals. Most likely, this discrepancy is due to a low film density (compared to bulk AlN), based on measurements using Rutherford backscattering. The films were also characterized using atomic force microscopy and x-ray diffraction to study the growth morphology. We find that AlN can be grown on Si (111) without buffer layers resulting in truely two-dimensional growth, low surface roughness, and relatively narrow x-ray peak widths.

Direct Measurement of Ion Beam Induced, Nanoscale Roughening of GaN

2005 ◽  
Vol 864 ◽  
Author(s):  
Bentao Cui ◽  
P. I. Cohen ◽  
A. M. Dabiran
Keyword(s):  
Ion Beam ◽  
High Energy ◽  
Surface Relaxation ◽  
Surface Roughening ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force ◽  
Continuum Equation ◽  
Argon Ions ◽  
Nanoscale Patterns

AbatractThe formation of ion induced nanoscale patterns such as ripple, dots or pores can be described by a linear continuum equation consisting of a surface roughening term due to curvature-dependent sputtering or asymmetric attachment of vacancies, and a surface smoothing term due to thermal or ion-induced diffusion. By studying ion-induced dimple volume change using atomic force microscopy, we show a method to measure the ion-roughening coefficient. Using this method, we found the roughening coefficient í was 45 nm2/sec at 730K for initial ion etchings with 300 eV Argon ions. Cathodoluminescence measurements indicated Ga-vacancy formation during ion bombardment. The activation energy for surface relaxation after ion etching was about 0.12 eV as measured by reflection high energy electron diffraction.

scholarly journals All chemical YBa2Cu3O7 superconducting multilayers: Critical role of CeO2 cap layer flatness

2009 ◽  
Vol 24 (4) ◽  
pp. 1446-1455 ◽  
Author(s):  
M. Coll ◽  
J. Gàzquez ◽  
R. Huhne ◽  
B. Holzapfel ◽  
Y. Morilla ◽  
...  
Keyword(s):  
Critical Role ◽  
High Energy ◽  
Buffer Layers ◽  
Solution Deposition ◽  
Ybco Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Densities ◽  
Atomically Flat

New advances toward microstructural improvement of epitaxial CeO2 films grown by chemical solution deposition and their use as buffer layers for YBa2Cu3O7 (YBCO) films are presented. We demonstrate that the degree of epitaxy and the fraction of (001) atomically flat surface area are controlled by the incorporation of tetravalent (Zr4+) or trivalent (Gd3+) cations into the ceria lattice. The degree of epitaxy has been investigated by means of Rutherford backscattering spectroscopy-channeling and reflection high-energy electron diffraction, and a new methodology is also presented to quantify the fraction of (001) atomically flat area from atomic force microscopy images. Results are further correlated with the superconducting properties, microstructure, and texture of YBCO films grown by the trifluoroacetate route. A comparison with pulsed laser deposition and YBCO films grown on the same ceria layers is also presented. This growth procedure has allowed us to obtain all chemical multilayer films with controlled microstructure and critical current densities above 4 MA cm−2 at 77 K.

Reflection High Energy Electron Diffraction and Atomic Force Microscopy Studies of MnxSc(1-x) Alloys Grown on MgO(001) Substrates by Molecular Beam Epitaxy

2011 ◽  
Vol 1295 ◽  
Author(s):  
Costel Constantin ◽  
Abhijit Chinchore ◽  
Arthur R. Smith
Keyword(s):  
Atomic Force Microscopy ◽  
Molecular Beam Epitaxy ◽  
Electron Diffraction ◽  
Molecular Beam ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force ◽  
Growth Method

ABSTRACTThe combination of the molecular beam epitaxy growth method with the in-situ reflection high energy electron diffraction measurements currently offers unprecedented control of crystalline growth materials. We present here a stoichiometric study of MnxSc(1-x) [x = 0, 0.03, 0.05, 0.15, 0.25, 0.35, and 0.50] thin films grown on MgO(001) substrates with this growth method. Reflection high energy electron diffraction and atomic force microscopy measurements reveal alloy behavior for all of our samples. In addition, we found that samples Mn0.10Sc0.90 and Mn0.50Sc0.50 display surface self-assembled nanowires with a length/width ratio of ~ 800 – 2000.

Epitaxy of Al films on GaN studied by reflection high-energy electron diffraction and atomic force microscopy

1997 ◽  
Vol 70 (8) ◽  
pp. 990-992 ◽  
Author(s):  
Q. Z. Liu ◽  
L. Shen ◽  
K. V. Smith ◽  
C. W. Tu ◽  
E. T. Yu ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Electron Diffraction ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force

Wet Etching Methods for Perovskite Substrates

1999 ◽  
Vol 587 ◽  
Author(s):  
Victor Leca ◽  
Guus Rijnders ◽  
Gertjan Koster ◽  
Dave H. A. Blank ◽  
Horst Rogalla
Keyword(s):  
Ph Value ◽  
Substrate Surface ◽  
High Energy ◽  
Etching Time ◽  
Epitaxial Thin Films ◽  
Etch Pits ◽  
High Quality ◽  
Oxide Electronics ◽  
Force Microscopy ◽  
Atomically Flat

AbstractIn oxide electronics substrates with atomically flat terraces are a request for growing high-quality epitaxial thin films. In this paper results on chemical etching of some substrates with perovskite, ABO3, structure (e.g., SrTiO3, LSAT - the (LaAlO3)0.3(Sr2AlTaO6)0.35 solid solution, and NdGaO3) are presented. In order to obtain high quality substrates, different etchants (NH4F + HF, HCl + NH4Cl, and HCl + HNO3) with various pH values have been studied. From Atomic Force Microscopy (AFM), in air, we conclude that, irrespective of the etchant that has been used, a substrate surface with a BOx terminated layer and atomically flat terraces without etch pits could be obtained. The pH-value and temperature of the etchant and the etching time, however, influence significantly the surface quality. Reflection high energy electron diffraction (RHEED) patterns confirmed the AFM results.

Deposition of GaN Films on Freestanding CVD Thick Diamond Films

2010 ◽  
Vol 654-656 ◽  
pp. 1740-1743 ◽  
Author(s):  
Dong Zhang ◽  
Yi Zhen Bai ◽  
Fu Wen Qin ◽  
Ji Ming Bian
Keyword(s):  
Electron Cyclotron Resonance ◽  
Diamond Films ◽  
Chemical Vapor ◽  
High Energy ◽  
Organic Chemical ◽  
High Quality ◽  
Small Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Metal Organic

High quality GaN films are deposited on freestanding thick diamond films by electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition (ECR-PEMOCVD). The characteristics of GaN films were investigated by x-ray diffraction analysis (XRD), reflection high energy electron diffraction (RHEED) and atomic force microscopy (AFM). The high quality GaN films with small surface roughness of 8.3 nm and high c-orientation are successfully achieved at the optimized nitriding time with the diamond substrate. These properties of GaN films with small surface smoothness and high c-orientation are well used as piezoelectric films for surface acoustic wave (SAW) devices.

High Quality Homoepitaxial Diamond Films Grown in End-Launch Type Reactors

1995 ◽  
Vol 416 ◽  
Author(s):  
Kazushi Hayashi ◽  
Sadanori Yamanaka ◽  
Hideyo Okushi ◽  
Koji Kajimura
Keyword(s):  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Schottky Contacts ◽  
High Quality ◽  
Chemical Vapor Deposition Reactor ◽  
Step Flow ◽  
Atomic Force ◽  
Microscope Images ◽  
Atomically Flat

ABSTRACTHigh quality diamond films have been successfully grown, by step-flow, on (001) diamond substrates using an end-launch type chemical vapor deposition reactor. Electrical properties of as-deposited diamond films as well as the surface morphology and the film crystallinity were investigated. Optical and atomic-force microscope images indicated that diamond films consisted of atomically flat terraces and macroscopic steps running parallel to [110×l and 1×2 double-domain structure. The currentvoltage characteristics of Al-Schottky contacts to these step-flow grown diamond films showed excellent rectification properties, indicating the potential of this material for electronic applications.

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